Guest guest Posted June 25, 2007 Report Share Posted June 25, 2007 Yeast May Help Fight Infection ~ May 2004 No.182 ~ There is a growing concern in the health sector that we are using too many antibiotics. The concern is a rise in infections and diarrhea caused by antibiotic resistant bacteria. Infection by Clostridium difficile, a bacteria that can survive as spores for many months, has become the most common cause of infectious diarrhea in hospitalized patients. In many hospitals it has become a major problem, as people develop serious infections while staying in hospitals for other health problems. Hands of staff, as well as a various sites within institutions have been found to be contaminated with Clostridium difficile. Contaminated toilets, bathing tubs, and electronic thermometers have been implicated as sources of Clostridium difficile. A recent report in a Canadian medical journal reported that 89 deaths in hospitals in two Canadian cities could be attributed to infections by Clostridium difficile. A second report indicated that one hospital in Quebec may have had 100 patients die due to the same bacterial infection in the last 18 months. There is a growing concern in the health sector that we are using too many antibiotics. The advent of antibiotics saw a major reduction in many infectious diseases. However, over time bacteria, particularly pathogenic (harmful) bacteria, are able to mutate and find ways to overcome the lethal effects of antibiotics. The solution to this has been to use more , and different antibiotics. Antibiotics do kill harmful bacteria, but they also kill helpful bacteria at the same time. The term probiotics was coined to describe microorganisms (bacteria and yeasts) which are beneficial to health and disease resistance. It is believed, that by consuming probiotic bacteria and yeasts, a proper balance on the population of microflora that inhabit our gastrointestinal systems can be achieved, leading to good health. How exactly probiotic yeasts and bacteria work in the body is still not clear. There is experimental data (in animals) to show that probiotic bacteria can stimulate our immune system and this could in turn result in improved disease resistance. It is also known that some microorganisms, as a defense mechanism, produce metabolites called bacteriocins that are toxic to other microorganisms. A third possibility is more. It may be that probiotic bacteria are able to stick to the walls of the intestine and prevent pathogenic bacteria from finding a niche where they can grow and produce their toxic effects. Consuming probiotics may be a new and better way to fight pathogenic bacteria. A small number of studies have been published which show the yeast Saccharomyces boulardii, when consumed in high numbers, reduce the recurrence of Clostridium difficile disease (CDD), also known as antibiotic associated diarrhea (AAD). It is still not known how the yeast is able to kill the pathogenic bacteria or reduce its toxic effects, but large doses (1 gram per day containing 1010-1012 yeasts) are required to produce an effect. Since no foods contain this large number of yeasts, the patients were given capsules each day. It may well be that in the future, doctors will advise their patients to start taking Saccharomyces boulardiias a week or two before going into the hospital - a more natural way to combat disease and infection Reference McFarland LV, Surawicz CM, Greenberg RN, Fekety R, Elmer GW, Moyer KA, Melcher SA, Bowen KE, Cox JL, Noorani Z, et al.A randomized placebo-controlled trial of Saccharomyces boulardii in combination with standard antibiotics for Clostridium difficile disease. JAMA. 1994 Jun 22-29;271(24):1913-81 Clostridium difficile (C. difficile): Questions and Answers2 Other articles on probiotics § http://www.medicinalfoodnews.com/vol08/issue2/yeast ---------- Probiotics - Bacteria that are Good for Your Health ~ February 1997 No.2 ~ Microbiologists have studied the large number of bacteria in the intestine of humans for some time. Their first task was to count and identify the many different bacteria. This has proven to be such a big job that it is still going on. As various bacteria were identified, people started asking what these bacteria were doing in the intestine. It soon became evident that the bacteria residing in the intestines could be affected by their host and vice versa. Quickly the findings of the microbiologists started to interest others concerned about nutrition, metabolism, health. It was British scientist, Roy Fuller who first popularized the definition of a probiotic. Fuller credits another scientists D. Lilly and R. Stillwell for actually coining the word. According to Fuller a probiotic is ‘a live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance’. Fuller’s definition applied to his work with animals, but it was quickly modified and extended to include humans. The number of foods that are considered to be probiotics is not large but probiotic foods are probably more familiar to the consumer in terms of being good for your health. yogurt, kefir, and koumis are fermented milk products that have long histories. All three are considered probiotics. There are other, less well known, probiotics on the market now. Food manufacturers are researching other products that contain bacteria that could soon be on the market as probiotics. An even faster growing trend is the sale of foods that are prebiotics. Prebiotics are foods that contain nutrients that are required by bacteria for growth and metabolism. The bacteria that live in the intestines of humans survive on the supply of partially digested food that is passing down the gastrointestinal tract. Certain bacteria require specific nutrients to grow. If the diet of the human contains those nutrients the bacteria will survive and grow; if the nutrients are not in the diet, the bacteria cannot grow. Adding or increasing specific foods or food ingredients to the diet, changes the numbers and types of bacteria in the intestines. The largest group of prebiotics on the market right now are oligosaccharides. These complex sugars are required by certain intestinal bacteria. By including oligosaccharides in the diet, the growth of specific bacteria populations can be altered. Comments 1 KTKC99 - Wed, 15 Aug 2001 21:55:10 I was just wondering, I take a probiotic supplement but it does not contain any FOS or prebiotics. what kinds of foods could i include in my diet that would help my friendly bacteria to grow better, without using an actual supplement? 2 Mike - Thur, 16 Aug 2001 15:51:09 You can create a healthy bacterial balance (or flora) within your gut by eating lots of prebiotic foods, including nearly all fruits and vegetables, but especially artichokes, onions, leeks, oats, salsify, chicory, wheat, wholemeal bread, porridge and bananas http://www.medicinalfoodnews.com/vol01/issue1/pro011 ------ Bifido Bacteria – The Friendly Bacteria ~ by The Editor - June 1997 No.10 ~ The principle behind any probiotic product is that the food contains live bacteria, and that when the food is consumed the bacteria pass down the digestive tract and reside long enough in the intestines to provide some beneficial effect to the consumer. The critical question is always “which bacteria should be used in a href= " /dictnary/probioti.htm " rel= " help " >probiotic preparations”. There are thousands of different bacteria, many with strange sounding names. Those who eat yogurt are probably most familiar with Lactobacillus bulgaricus and Streptococcus thermophilus. It is these two bacteria that are used primarily to change milk to yogurt, and so when you eat yogurt you are also eating at the same time large numbers of live L. bulgaricus and S. thermophilus. How many bacteria is a large number? A good yogurt will contain 107 or more of each bacteria per gram. That‘s 10 million! But bifido bacteria are quickly gaining a reputation around the world as a bacteria that is beneficial to health. In fact, many refer to bifido bacteria as the “friendly bacteria”, because of the growing evidence that points to bifido bacteria as being good for health. Some yogurts now contain bifido bacteria in addition to Lactobacillus bulgaricus and Streptococcus thermophilus. Bifido bacteria are found in highest quantities in the intestines of breast fed newborns. As the baby ages and its diet changes, the numbers of Bifido bacteria declines and other bacteria, some associated with disease, increase in numbers. In studies carried out in primarily in Japan, it was shown that adding Bifido bacteria back into the diet improved diarrhea, and constipation. Various strains of Bifido bacteria have been shown to be able to synthesize vitamins that may be available to the host. There have also been reports of the infection preventing ability of Bifido bacteria and their antitumor effect, How these bacteria exert their beneficial effects is not well understood. The bacteria use the food passing down through the intestine to live, grow and reproduce. It may be that some substances produced by the bacteria lower the acidity or pH of the intestinal contents. The bacteria also produce volatile fatty acids or VFA’s. Several VFA’s have been shown to inhibit the growth of certain cancer cells. A third possibility is that the bacteria contain or produce enzymes that detoxify potential carcinogens as they pass through the intestine. Table 1 BIFIDO FACTS Common Strains: B. breve, B. infantis, B. longum, B. adolescentis Location of B. Bacteria in the Body : large intestine Sugars used by Bifido Bacteria: short chain fructooligosaccharides, lactulose, lactitol Foods Containing Bifido Bacteria : some yogurts Other articles on bifido bacteria § http://www.medicinalfoodnews.com/vol01/issue3/bifido -------- Synbiotics for Good Gut Health ~ May 2006 No.205 ~ First it was probiotics. Then it was prebiotics. Now the two are being combined to produce synbiotics. The principal behind probiotics is that our gastrointestinal system is populated by a large number and variety of different bacteria. In very general terms, some of the bacteria contribute to our good health, but others are responsible for disease and infections. By consuming foods that contain probiotic bacteria, it is believed that the population of beneficial bacteria can be increased – perhaps only temporarily – and good metabolism, and heath will be achieved. However, finding bacteria that have probiotic properties has not been easy. In addition, since the probiotic bacteria that are consumed do not normally reside in the digestive system, they are soon washed out of the intestines if consumption of the probiotic product is stopped. CRC press1 The concept of prebiotics was developed to overcome the technical problems associated with probiotics. Bacteria that live in our GI tract, survive and grow using the partially digested food that passes down from the small intestine to the large intestine. Detailed research has shown that some bacteria (bifido bacteria in particular) have very specific nutrient needs, and therefore by selecting specific foods or food ingredients, it is possible to increase the numbers of target bacteria. This has the advantage that no external bacteria are being given, but rather the numbers of resident bacteria are increased. During the period of consumption of the prebiotic, the numbers of specific bacteria have been shown to increase by up to 100 fold, but similar to the situation with probiotics, when the consumption of the prebiotic stops, the gut bacteria numbers quickly return to their original values. Some products, called synbiotics, are now being sold that contain both probiotic bacteria and prebiotic sugars. Such products take advantage of both the addition of beneficial bacteria and the encouragement of the growth of resident beneficial bacteria. Fructo-oligosaccharides are the most common prebiotic sugar used in such products to-day but, in the future, other sugars will be used to target other bacteria besides bifidobacteria. Definition of Probiotic Bacteria Live microorganisms when administered in adequate amounts that confer a health benefit on the host. Note that foods that contain probiotic bacteria are also often referred to as probiotics (e.g. yogurt). Definition of Prebiotic A nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and / or activity of a limited number of bacteria in the colon. Examples of Prebiotic Sugars Fructo-oligosaccharides (inulin, FOS etc) Soy oligosaccharides Galacto-oligoaccharides Lactulose Raffinose Reference Farnworth ER. (2001) Probiotics and prebiotics2 In Handbook of Nutraceuticals and Functional Foods, CRC Press, pp. 407-422. http://www.medicinalfoodnews.com/vol10/2006/synbiotics --------- 100 Trillion Bacteria in Your Gut: Learn How to Keep the Good Kind There By Dr. Joseph Mercola with Rachael Droege You probably don't think about your gut very often but this may make you start--the bacteria in your bowels outnumber the cells in your body by a factor of 10 to one. This gut flora has incredible power over your immune system, which, of course, is your body's natural defense system that keeps you healthy. In other words, the health of your body is largely tied into the health of your gut, and it's hard to have one be healthy if the other is not. One of the reasons why your gut has so much power has to do with the 100 trillion bacteria--about three pounds worth--that line your intestinal tract. This is an extremely complex living system that aggressively protects your body from outside offenders. However, if you are eating as many sugars as the typical American (about 175 pounds per year) then you are feeding the " bad " bacteria, which are more likely to cause disease than promote health, rather than promoting the " good " bacteria that help protect you from disease. Exposure to chemicals will also contribute to this disruption in your gut microflora, and over time the imbalance will lead to illness. A large part of the influence of the " bad " bacteria is on the intestinal lining (mucousal barrier) that is over 300 square meters, or about the size of a tennis court. Beneficial bacteria in your gut can help to boost the immune system, prevent allergic inflammation and food allergy, clear up eczema in children and heal the intestines from a variety of ailments. Fortunately, you can influence the composition of the good and bad bacteria in your gut by optimizing your diet and supplementing it with a high-quality probiotic, or good bacteria. As written in a report in the October 2003 American Journal of Clinical Nutrition, " probiotics can act as partners of the defense system of the intestine. " The typical American diet is so full of sugar and grains that--although I don’t often recommend supplements--nearly everyone can benefit from probiotics. You should look for a high potency, multi-strain variety, which can be found in most health food stores. Since the best type of probiotic to use can become highly specific, you may want to discuss the varieties with an experienced health food store employee. I recommend probiotics to nearly all of our new patients, as it is a helpful start for their health recovery. This is not a lifetime recommendation, however. Once you are eating the right foods it is generally possible to maintain a healthy bacterial balance in your gut without the use of probiotics. On a side note, probiotics are especially helpful when you are traveling in the event you get an infectious diarrhea. Typically, large doses of a high-quality probiotic--about one-half to one full bottle in one day--are quite useful for a rapid resolution of the diarrhea. Related Articles: Beneficial Bacteria (Probiotics) May Halt Allergies In Babies Beneficial Bacteria Helps Heal Intestines One Third of Probiotics, " Good Bacteria " Products Like Acidophilus, Found to be Worthless Beneficial Bacteria (Probiotics) During Pregnancy & Breastfeeding Helps Protect Against Eczema 'Good' Bacteria Help Kids with Diarrhea Good Bacteria Fights the Flu http://www.mercola.com/2003/oct/18/bacteria_gut.htm ----------------- Source: Washington University School Of Medicine November 6, 2002 More on: Bacteria, Microbiology, Mice, Microbes and More, Extreme Survival, Gastrointestinal Problems Teamwork In The Intestine: Gut Bacteria Interact With Intestine To Regulate Blood Supply Science Daily — St. Louis, Nov. 4, 2002 -- Bacteria aren't always bad. In fact, they can be extremely helpful partners. According to research at Washington University School of Medicine in St. Louis, microbes found naturally in the mouse and human gut interact with intestinal cells, called Paneth cells, to promote the development of blood vessels in the intestinal lining. " This study provides insights into the mutually beneficial partnerships forged between mammals and their native microbes, " says principal investigator Jeffrey I. Gordon, M.D., the Dr. Robert J. Glaser Distinguished University Professor and head of the Department of Molecular Biology and Pharmacology. " These symbiotic relationships probably are most important in the gut, which contains the largest and most complex collection of bacteria. " Gordon's team found that a key developmental program orchestrating formation of blood vessels in the gut following birth is a responsibility shared by intestinal bacteria and their host. The study appears in the November 5 issue of the Proceedings of the National Academy of Sciences; Thaddeus S. Stappenbeck, M.D., Ph.D., instructor of molecular biology and pharmacology, is first author and Lora Hooper, Ph.D., instructor of molecular biology and pharmacology, is co-author. The team examined three groups of six-week-old male mice. One group of animals was reared with normal bacteria; another group was reared without any intestinal bacteria; a third group began bacteria-free but then were colonized with microbes taken from intestines of normal mice. An imaging technique called confocal microscopy provided three-dimensional images of sections of intestinal tissue taken from each group of animals. The images offer a clear view of cells and blood vessels in tissue samples, and allow investigators to measure the density of capillaries, small blood vessels in the wall of the intestine. In mice lacking intestinal bacteria, blood vessel formation stopped early during postnatal development. Remarkably, this developmental program restarted and was completed just 10 days after implanting microbes into bacteria-free mice. Moreover, colonization by one particular type of bacteria commonly found in normal mouse and human intestine, called Bacteroides thetaiotaomicron, or B. thetaiotaomicron, stimulated blood vessel development as efficiently as implantation of a whole microbial society. The researchers also examined the pathway by which bacteria influence blood vessel formation. They engineered mice lacking Paneth cells, normal components of the intestinal lining that help defend the body against attacks by harmful bacteria. Without Paneth cells, blood vessels could not completely develop, even when microbes such as B. thetaiotaomicron were introduced. The team concluded that B. thetaiotaomicron and Paneth cells work together to stimulate postnatal blood vessel formation. " Our findings illustrate the importance of co-evolution of animals and their microbial partners, " says Gordon. " Bacteria that live in the intestine appear to provide mammals with several necessary services for healthy development. Unraveling the molecular foundations of these relationships may provide new ways of preventing or treating a variety of diseases. " ### Reference: Stappenbeck TS, Hooper LV, Gordon JI. Developmental regulation of intestinal angiogenesis by indigenous microbes via Paneth cells. Proceedings of the National Academy of Sciences, November 5, 2002. Funding from the National Institutes of Health, AstraZeneca and the Burroughs-Wellcome Foundation supported this research. The full-time and volunteer faculty of Washington University School of Medicine are the physicians and surgeons of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare. Note: This story has been adapted from a news release issued by Washington University School Of Medicine. http://www.sciencedaily.com/releases/2002/11/021106075408.htm Related Science Stories Search And Destroy: Newly Identified Gut Protein Kills Bacteria Friendly Microbes Control Intestinal Genes, Study Finds Researchers Identify Molecular Basis Of Inflammatory Bowel Disease Researchers Identify Antibiotic Protein That Defends The Intestine Against Microbial Invaders Gaps In Intestinal Barrier Could Cause Crohn's Disease ------------ Source: Sahlgrenska Academy at Göteborg University June 20, 2007 More on: Bacteria, Microbes and More, Extreme Survival, Microbiology, Infectious Diseases, Dentistry Resistant Gut Bacteria Will Not Go Away By Themselves Science Daily — E. coli bacteria that have developed resistance to antibiotics will probably still be around even if we stop using antibiotics, as these strains have the same good chance as other bacteria of continuing to colonise the gut, according to a thesis at the Sahlgrenska Academy. E. coli bacteria are found naturally in large quantities in our intestines. These bacteria do not normally cause disease, but there are several strains that can result in diarrhoea. In serious cases, they can also cause peritonitis and septicaemia. The faeces of 128 Swedish infants were analysed in the studies underlying the thesis. The results show that 21% of E. coli strains in these infants’ gut flora were resistant to at least one type of antibiotic. Even children who had never been given antibiotics had resistant bacterial strains in their intestines. “This is a growing problem, and it’s serious even when ordinary harmless bacteria develop resistance, as these genes can be transferred to more harmful bacteria,” says microbiologist Nahid Karami. Many had thought that resistant bacteria would disappear if the use of antibiotics were to be reduced, but the thesis shows that E. coli strains carrying resistance genes are just as good at colonising the gut for long periods as sensitive strains. ”Our research suggests that there’s little cost to the bacteria from carrying a resistance gene, and this presumably means that this resistance will be retained for a long time by the bacteria in our gut flora even if we stop using antibiotics,” says Karami. Bacteria have a natural ability to absorb and transfer resistance genes to other bacteria. The study discovered two cases of such transfers between E. coli strains found simultaneously in a child’s intestines. The first was in an infant who was treated with penicillin, and the second in an infant who was not treated with antibiotics. “Our results suggest that the transfer of resistance genes in the gut flora may be very common, which makes the resistance issue much more serious, as genes can easily be transferred from bacteria in the normal flora to more harmful bacteria,” says Karami. Note: This story has been adapted from a news release issued by Sahlgrenska Academy at Göteborg University. http://www.sciencedaily.com/releases/2007/06/070619165543.htm Related Science Stories Permanent Resistance To Antibiotics Cannot Be Prevented, According To Dutch Research Over-use Of Antibiotics In Fish-for-food Industry Encourages Bacterial Resistance And Disease Insect Antibiotics -- Resistance Is Futile! Cecropin A Bypasses Outer Defenses To Kill Bacteria From The Inside Treating Acne With Antibiotics Leads To Resistance Report Examines Use Of Antibiotics In Agriculture ------------ Study: Gut Bacteria Determine Fat or Thin Rossella Lorenzi, Discovery News June 19, 2006 — A microbe that converts waste into methane for daily flatulence could make the difference between fat people and thin people, according to a new study that looks into the menagerie of microorganisms living in our colon. Called Methanobrevibacter smithii (M. smithii), the bacterium is key to how well we process calories, reports Jeffrey Gordon, director of the Center for Genome Sciences at Washington University School of Medicine in St. Louis, Missouri, and and his graduate student Buck Samuel. The bacteria are essentially the body’s waste-removal workhorses. They mop up hydrogen and byproducts released by the gut bacteria, helping them digest complex sugars. In this way, the stored calories are liberated and absorbed. " We are superorganisms containing a mixture of not just human cells but also bacterial cells and cells of another microscopic domain of life known as archaea, " Gordon said in a statement. " The genes present in this community of 10-100 trillion bugs vastly outnumber our own genes and are a key part of our genetic landscape, providing us with attributes we have not had to evolve on our own. " One such attribute is the ability to break down non-digestible complex carbohydrates known as polysaccharides. Gut bacteria such as Bacteroides thetaiotaomicronchop these complex sugars into short-chain fatty acids that account for up to 10 percent of a person's daily calorie intake. Gordon and Samuel tested whether M. smithii, which was recently recognized as the most common archaeon in human intestines, could speed up digestion within a group of germ-free mice. The researchers colonized one group of these mice with the polysaccharide-digesting bacterium B. thetaiotaomicron. Another group was colonized with M. smithii, while a third group received both B. thetaiotaomicron and M. smithii. Mice from a control group were colonized with the sulfate-reducing bacterium Desulfovibrio piger, which is the most abundant species in healthy adults. All the mice then received the same amount of food – a standard rodent chow rich in plant polysaccharides. Mice colonized with both B. thetaiotaomicron and M. smithii had significantly more fat than animals colonized with either microbe alone or with the other bacteria. The researchers concluded that M. smithii collaborate with B. thetaiotaomicron to increase calorie intake from food. " M. smithii acts as a ‘power broker’ in the distal gut community, " they wrote in the Proceedings of the National Academy of Sciences, where the study was published.. Indeed, without M. smithii’s activity and synergy with B. thetaiotaomicron, accumulation of byproducts would slow sugar digestion, basically inhibiting the absorption of calories. The finding would explain why different people gain different amounts of calories from identical foods. " Further studies are needed to understand how to manipulate the representation of M. smithii and or other archaeons in our gut microbiota: the results could lead to a novel means for preventing obesity in the overfed or increasing caloric harvest in the underfed, " wrote the researchers. According to microbiologist Martin Blaser of New York University, the study is very important. " It begins to describe the complex interactions between the microbes adapted to the intestinal tract and the metabolism of the host animal, " Blaser told Discovery News. " Although the study was done in mice, it is a model system for human biology. " http://dsc.discovery.com/news/2006/06/19/gutbacteria_hea.html?category=health & gu\ id=20060619092011 --------------- How gut bacteria escape detection Bacteria living in the human intestine escape detection by the immune system by disguising themselves as gut cells, researchers say. A US team examined bacteria from the genus Bacteroides - the most commonly found bacteria in the human gut. They found the bacteria wrap themselves in a sugar substance derived from molecules taken from the surface of cells in the gut. Details of the Harvard Medical School research are in the journal Science. It is extremely important that the resident bacteria in our intestine do not generate a deleterious immune response Dr Laurie Comstock This form of molecular mimicry may help to explain how humans tolerate the presence of billions of bacteria in the gut without launching an immune system attack. The Harvard team found that Bacteroides bacteria coat themselves with a form of fucose, a molecule which is abundant on the surface of intestinal epithelial cells. Previous research has shown that Bacteroides can stimulate intestinal epithelial cells to produce molecules such as fucose. It now seems that the bacteria are then able to incorporate this molecule in a slightly modified form directly into their own cells. Digestive role Bacteroides play a crucial role in the digestive process, helping to break down food products and supplying some vitamins and other nutrients that we cannot make ourselves. Researcher Dr Laurie Comstock told the BBC News website: " Compared to the wealth of knowledge regarding mechanisms used by bacterial pathogens to cause disease, relatively little is known about how the trillions of bacteria in the mammalian intestine establish and maintain beneficial relationships with the host. " It is extremely important that the resident bacteria in our intestine do not generate a deleterious immune response. " Bacteroides are able to degrade a great variety of plant polysaccharides so that the host is able to use them for energy. " Many of these plant polysaccharides could not be used by the host without the aid of the bacteria. " Dr Alastair Forbes, a consultant gastroenterologist at St Mark's Hospital, London, said the findings were interesting. He said it was possible they could be used in the long-term to develop new forms of probiotic treatment for gastrointestinal disorders. Probiotics, preparations containing beneficial bacteria, have already been used to treat conditions such as ulcerative colitis and pouchitis. " The use of probiotics has had some success, but their use is made difficult by the fact that the bugs tend not to persist in the gut, and treatments have to be given week after week, " Dr Forbes said. " If there was some way of modifying bacteria so they could continue to infect the gut, but remain safe, that would be useful. " Dr Forbes said scientists were also working on prebiotic treatments, which provide nutrients to encourage the growth of certain bacteria. However, he said knowledge about the bacteria which live in the gut was still relatively limited. It is estimated that only about 20-30% of the bacteria that inhibit the gut have been identified. Story from BBC NEWS: http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/4358285.stm Published: 2005/03/21 00:30:35 GMT © BBC MMVII Should we top up our friendly bacteria? 01 Nov 04 | Health Gut teems with different viruses 20 Oct 03 | Health --------------- Gut bacteria may provide insight into weight loss Laura Geggel Issue date: 12/9/05 Section: News When a grocery shopper glances at the nutritional information on a box of Cheerios, the number of calories is 110 calories for a serving size of one cup. But depending on the type of bacteria living in the shopper's gut, the full 110 calories may not be fully absorbed. The number of calories denotes " the absolute amount of energy in that serving, and shoppers with different [types] of bacteria in their gut may harvest and store different amounts of energy from that same serving, " said Jeffrey Gordon, the director of the Center for Genome Sciences at the School of Medicine, and the Dr. Robert J. Glaser Distinguished University Professor. Over 800 species of microbes live in the human gut. Consequently, research on bacteria may be able to offer insights about how energy and weight are stored in the human body. Gut bacteria also may be the key to drug therapies that could treat a variety of digestive or weight loss processes. Gordon, along with Ruth Ley, an instructor in molecular biology and pharmacology, recently received approval from the National Institutes of Health to sequence 100 microbial genomes. " We think of this as the next logical step in the human genome project because the micro-biome is an integral part of our genetic landscape, " said Gordon. " We can begin to understand the different types of properties these organisms bring to us. " " Most people think of bacteria as being adversaries, pathogens, [but] we think that most of our encounters with microbes are friendly and mutually beneficial, " he continued. Although the microbes that reside in human guts are foreign entities, often introduced at the time of birth, from mothers and from the environment, they are essential to digestion and fat storage. " We've done experiments in [bacteria] free mice that show that when you add bacteria in a very short period of time, the mice acquire a market increase of 60 percent in the amount of fat cells, " Gordon said. He added that, " The way that works is that the microbes help break down these indigestible components of the diet and liberate the calories, but they also help the host by allowing the energy that is liberated to be stored in fat cells. They do so by manipulating a series of genes in the host. " " You can think of this symbiosis in a very elegant way, in that microbes not only help break down components of the diet and liberate calories that would otherwise be lost, but also to ensure that those calories are stored, " said Gordon. Gut bacteria, for instance, can break down polysaccharides, a carbohydrate found in plants that are integrated into everything from bread to pasta. Gut bacteria, also believed to influence metabolism, may eventually allow scientists to form drugs specific to people with certain species of bacteria living in their gut. " Armed with that knowledge of what the metabolic potential of these microbes are, I think that we will begin to see clinical trials within the next five years. For example, the nature of nutritional advice is predicated on the knowledge of what the microbes in an individual's gut can do, so [individuals could have] more of a personalized nutrition of what they should consume, " said Gordon. The microbes, which interact with genes in the storage of fat, could potentially help overweight individuals drop pounds. " This gene product, which actually operates to limit the amount of fat stored, could become more of a potential therapeutic agent, " he said. Despite the crucial role gut bacteria play in digestion and energy storage, the microbes' genomes have only recently been addressed within the scientific community. While the first comprehensive description of microbes in the human gut was published in June 2005, Gordon explained that the study only included three adult humans. " There was quite a large differences in types of bacteria present, " he said. " We don't know if the membership to the community vary or operate differently. It may be that there's a lot of redundancy among the types of bacteria even though they're called different organisms, they may perform similar functions. " Gordon and Ley hope to sequence gut bacteria first in mice and then compare and contrast microbes in people living in different regions of the planet, " both to understand how humans vary in respect to one another and how environment influences differences in genes, " said Gordon. http://media.www.studlife.com/media/storage/paper337/news/2005/12/09/News/Gut-Ba\ cteria.May.Provide.Insight.Into.Weight.Loss-1126368.shtml ----------- Hospital Stress Turns Friendly Gut Bacteria Nasty, Killing 40% Of PatientsMain Category: GastroIntestinal / Gastroentorology News Article 10 Mar 2007 - 0:00 PDT Researchers have discovered that our friendly gut bacteria, vital partners in fermenting and processing our everyday food, turn on us in times of stress such as major surgery, cancer chemotherapy or bowel disease and seize the opportunity to create havoc and kill our other probiotic bacteria. Swimmer's Ear, infections from wearing contact lenses, and puncture wounds in children's feet which turn septic are all caused by the common bacteria Pseudomonas aeruginosa, which is widely found in soil, water and sewage. While only 3% of people normally harbour this organism in their intestines, during hospitalization for critical illness, more than 50% of patients end up with this bacteria. Most of the time Pseudomonas aeruginosa lives within our guts in peaceful co-existence when we have plenty of food and good health. But in times of stress such as during hospital stays they rapidly turn on us and become concerned only for their own survival. Patients infected with Pseudomonas aeruginosa have a high fatality rate approaching 40%. " Since most hospital acquired infections develop from bacteria we already have in our guts, working out how to shield them from the stress molecules we produce may be a more effective treatment than trying to use antibiotics to kill them " , says medical researcher Professor Olga Zaborina from the University of Chicago, USA. The scientists have discovered for the first time that these bacteria have a highly sophisticated sensing apparatus which recognises and intercepts chemical compounds we produce during stress such as endorphin hormones, immune system molecules such as interferon, and signals produced by damaged and oxygen starved tissues like adenosine. " This means that the bacteria have evolved a way of taking advantage of any opportunity through their highly refined 'sense and respond circuits' which can identify the very molecules we humans use to respond to stress or illness " , says Professor Zaborina. " This virulence circuitry is so clever that P. aeruginosa can recognise our weakness, communicate this information to other bacteria, and simultaneously release compounds which kill our normal probiotic gut bacteria " , giving them home field advantage right off the bat. Currently over-using antibiotics in hospitals is causing major problems with the spread of antibiotic resistance amongst bacteria. Even ordinary environmental bacteria have evolved a highly sophisticated mechanism to become resistant to antibiotics, enabling them to kill badly stressed and weak patients. Intestinal bacteria such as P. aeruginosa are a particular problem because they form a protective slime, called a biofilm, which stops antibiotics from killing them. Even within the slime they can still sense and respond to a host's stress chemicals, causing infections. The only treatments available until now have been a 'take no prisoners' approach using antibiotics which kill several types of bacteria including the normal, protective, probiotic bacteria in our guts, further weakening the patient. " If we do not find a strategy to contain intestinal bacteria rather than eliminating them, which helps spread resistance, we will soon run out of effective antibiotics " , says Professor Zaborina. " We know of many diseases caused or complicated by intestinal bacteria such as Inflammatory Bowel Disease, infectious diarrhoea, or cancer treatments such as chemotherapy and bone marrow transplants " . " Yet in all these cases specific bacterial strains responsible for the problem cannot always be identified, because the species are difficult to culture " , says Professor Zaborina. In addition it is not just the mere presence of the strains in the intestine that may be threatening, but rather the state of their virulence, which is not routinely examined clinically. " Exposing the Dr Jekyll and Mr Hyde nature of intestinal bacteria is a key to understanding how they behave. We cannot afford to ignore their will to survive during stress " . The scientists suggest that in future paying better attention to the needs of our gut bacteria, especially when someone is sick, dehydrated, starved or stressed, could help to reduce the need for antibiotics and lead to a lower hospital acquired infection rate. About the SOCIETY FOR GENERAL MICROBIOLOGY The SGM has been established for over 50 years, promoting and supporting the art, science and significance of microbiology and associated subjects worldwide. SOCIETY FOR GENERAL MICROBIOLOGY Marlborough House Basingstoke Road, Spencers Wood Reading RG7 1AG http://www.socgenmicrobiol.org.uk http://www.medicalnewstoday.com/medicalnews.php?newsid=64924 --- Evolution Of Symbiotic Bacteria In The Distal Human IntestineMain Category: Biology / Biochemistry News Article 19 Jun 2007 - 1:00 PDT The total number of microbes that colonize the surfaces of our adult bodies is thought to be ten times greater than the total number of our human cells. Our microbial partners provide us with certain features that we have not had to evolve on our own. In this sense, we should consider ourselves to be a supraorganism whose genetic landscape includes both our own genome as well as the genomes of our resident microbes, and whose physiologic features are an amalgamation of human and microbial metabolic traits. The largest collection of microbes resides in our gut, which harbors trillions of bacteria, representing hundreds of species, most falling into two groups: the Bacteroidetes and the Firmicutes. The researchers have sequenced the genomes of two human gut-dwelling Bacteroidetes, and compared their genomes to the genomes of other bacteria that live both inside and outside of our bodies. The results illustrate that adaptation to the gut habitat is a dynamic process that includes acquisition of genes from other microorganisms. These findings emphasize the importance of including the evolution of " our " microbial genomes when considering the evolution of humans. Citation: Xu J, Mahowald MA, Ley RE, Lozupone CA, Hamady M, et al. (2007) Evolution of symbiotic bacteria in the distal human intestine. PLoS Biol 5(7): e156. doi:10.1371/journal.pbio.0050156. Please Public Library of Science 185 Berry Street, Suite 3100 San Francisco, CA 94107 USA http://www.plos.org http://www.medicalnewstoday.com/medicalnews.php?newsid=74221 --- Your Gut Bacteria Makes You Fat, Diabetic, Fatty Livered and Full of Bad Cholesterol - Bacteria from our intestines, more important for our health than thought By: Stefan Anitei, Science Editor Bacteria in your guts are not just simple guests eating on your leftovers. Beside digestive conditions, these bugs induce more severe problems, like obesity and now they were found to influence how fat is digested and deposited in the liver. An imbalanced gut flora can affect this metabolic path and trigger diseases. Our gut has up to 100 trillion bacteria, about 10% of the number of the human body's cells. In 2006, one team revealed that obese people carry a somewhat different bacterial species load than normal weighed people. Other approaches showed that gut microbes can induce insulin resistance, determining type 2 diabetes and fatty liver disease, a severe condition. To see how microbes impair metabolism, a team at the Nestlé Research Center in Lausanne, Switzerland, led by biochemist Jeremy Nicholson of Imperial College London studied the health of seven mice whose gut flora was substituted with that of a 3-week old human infant. These results were compared with those achieved from mice with normal gut flora. After four weeks, the team determined levels of 12 bile acids in each mouse's urine, blood, liver and small intestine. The liver synthesizes about 6 types of bile acids, which are released into the small intestine to help digest fats. From the gut, the bile acids reach again the liver and control cholesterol metabolism and other endocrine processes. " But different gut microbes can modify the structure of bile acids in different ways, adding or snipping off various parts of the molecules, which would presumably alter their fat-dissolving abilities, " said Nicholson. 17 variants of bile acid were detected in the gut, assigned into two chemical classes. The mice with the human bacterial flora had more of one class of bile acid and less of the other, translated into significantly different metabolites levels in the urine, blood and liver compared to mice type bacterial flora. " The results are the first to provide a detailed analysis how gut bugs shift the balance of metabolites present, " said medical microbiologist David Relman of Stanford University. " They also mean that altering gut microflora has far-reaching physiological consequences for the host animal. " Mice with the human bacteria also presented more LDL (bad cholesterol), in the liver and less glutathione, a natural antioxidant that impedes tissue damage. " Major changes to gut flora like this could predispose the body toward disease. " said Nicholson. http://news.softpedia.com/news/Your-Gut-Bacteria-Makes-You-Fat-Diabetic-Fatty-Li\ vered-and-Full-of-Bad-Cholesterol-55592.shtml ----------- Hacking Your Body's Bacteria for Better Health Brandon Keim 04.26.07 | 2:00 AM Modern humans are bacteria-killing machines. We assassinate microbes with hand soap, mouthwash and bathroom cleaners. It feels clean and right. But some scientists say we're overdoing it. All this killing may actually cause diseases like eczema, irritable bowel syndrome and even diabetes. The answer, they say, is counterintuitive: Feed patients bacteria. " Probiotics (pills containing bacteria) have resulted in complete elimination of eczema in 80 percent of the people we've treated, " says Dr. Joseph E. Pizzorno Jr., a practicing physician and former member of the White House Commission on Complementary and Alternative Medicine Policy. Pizzorno says he's used probiotics to treat irritable bowel disease, acne and even premenstrual syndrome. " It's unusual for me to see a patient with a chronic disease that doesn't respond to probiotics. " Clinical trial data on probiotics is incomplete, but there are many indications that hacking the body's bacteria is beneficial. In sheer numbers, bacterial cells in the body outnumber our own by a factor of 10, with 50 trillion bacteria living in the digestive system alone, where they've remained largely unstudied until the last decade. As scientists learn more about them, they're beginning to chart the complex symbiosis between the tiny bugs and our health. " The microbes that live in the human body are quite ancient, " says NYU Medical Center microbiologist Dr. Martin Blaser, a pioneer in gut microbe research. " They've been selected (through evolution) because they help us. " And it now appears that our daily antibacterial regimens are disrupting a balance that once protected humans from health problems, especially allergies and malfunctioning immune responses. " After the Second World War, when our lifestyles changed dramatically, allergies increased. Autoimmune diseases like diabetes and inflammatory bowel disease are increasing, " says Kaarina Kukkonen, a University of Helsinki allergy expert. " The theory behind (what causes) the diseases is the same: Lacking bacterial stimulation in our environments may cause this increase. I think this is the tip of the iceberg. " In a recent study, Kukkonen and her colleagues gave a probiotic containing four strains of gut bacteria to 461 infants labeled as high risk for developing allergic disorders. After two years, the children were 25 percent less likely than those given a placebo to develop eczema, a type of allergic skin inflammation. The study was published in the January issue of Journal of Allergy and Clinical Immunology. Microbial exposures early in life, scientists believe, cause mild inflammation that calibrates the body's responses to other pathogens and contaminants later in life. Without exposure as infants, researchers say, people can end up with unbalanced immune systems. " Many of the most difficult problems in medicine today are chronic inflammatory diseases, " says Blaser. " These include rheumatoid arthritis, lupus, atherosclerosis, eczema and multiple sclerosis. One possibility is that they're autoimmune or genetic diseases. The other possibility is that they are physiological responses to changes in microbiota. " Blaser's specialty is Helicobacter pylori, a strain once common in every human stomach but now rare in the West. Its disappearance may have benefits: H. pylori-related inflammation is associated with peptic ulcers and some stomach cancers. However, H. pylori also reduces acid reflux, which in turn is associated with asthma and esophageal cancers. H. pylori's decline, says Blaser, correlates with a rapid rise in those afflictions. H. pylori deficiency may also contribute to obesity, he says, because the bacteria help regulate production of two hormones, ghrelin and leptin, that affect metabolism and appetite. Low levels of Bacteroidetes have also been linked to obesity. Studies indicate that bacterial imbalances are associated with irritable bowel syndrome, post-surgical infections and type 1 diabetes. The health-food movement has moved ahead with probiotics without regard for clinical trial results. Women commonly use supplements like acidophilus to treat yeast infections. Other probiotics are making their way into products such as Kashi Vive cereal " to help you care for your digestive system " and Dannon's Activia yogurt, which in its first year boasted more than $100 million in sales. But scientists say over-the-counter probiotics are of inconsistent quality. Pizzorno, for example, buys his probiotics from companies that sell directly to doctors. Consumer probiotics don't always contain medically recognized bacterial strains, he said, and often the bacteria they contain are dead. " Most of the companies don't have any research ongoing at all, " says Stig Bengmark, a University of London hepatologist. " They buy cheap bacteria from yogurt companies and say it's good, but it's never proven. " To more precisely hack the gut bacteria, Blaser calls for a Gut Genome Project, modeled after the Human Genome Project. It's a daunting task: The human genome, mapped to great fanfare but still dimly understood, contains a tenth of the genes believed to be in our gut bacteria. But though difficult, such research could prove vital. " The world is very aware of the concept of global warming, which is a macro-ecological change, " Blaser says. " I postulate that there are similar micro-ecological changes going on inside us. " See Also: Wired Science Blog: Biology The Bacteria Whisperer Life, Reinvented West Recruits Bacteria Assassins http://www.wired.com/medtech/health/news/2007/04/bacteriahacking ---------------- Gut Bacteria May Determine Dieting Efficiency By Neil Osterweil, Senior Associate Editor, MedPage Today Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco December 21, 2006 ST. LOUIS, Dec. 21 -- Bacteria in the gut may be arbiters of weight loss or gain, according to a revolutionary theory proposed by researchers here. The way it works, said Jeffrey I. Gordon, M.D., of Washington University, and colleagues, is that when an overweight person goes on a diet, one group of efficient bacteria moves out of the gut and another less-efficient group moves in to fill the void. This finding suggested that manipulation of intestinal microbes might some day be used to treat obesity, they reported in the Dec. 21 issue of Nature. When the investigators conducted a census of intestinal flora in obese people as they lost weight, they found that the proportion of Bacteriodetes and Firmicutes bacteria changed in tandem with the drop in excess poundage. Whether the change in bacteria drives the weight loss, or the weight loss puts pressure on the bacterial composition of the gut, is unclear, the authors acknowledged, but the findings raise intriguing questions about the nature of obesity. In studies with mice, the authors also found that bacteria in obese animals helped the body be more efficient at extracting energy from food, and that the trait could be transmitted from fat mice to thin. When germ-free mice were populated with the type of gut bacteria typical in obese animals, they put on significantly more fat than germ-free mice colonized with " lean " bacteria, the investigators wrote. " This is a potentially revolutionary idea that could change our views of what causes obesity and how we depend on the bacteria that inhabit our gut, " wrote Randy J. Seeley, Ph.D., and Matej Bajzer of the Obesity Center at the University of Cincinnati, in an accompanying editorial. " But a great deal remains poorly understood. Most notably, it is not clear whether such small changes in caloric extraction can actually contribute to meaningful differences in body weight. " Dr. Gordon agreed that energy intake and expenditure -- diet and exercise -- are the major contributors to body weight, but noted that gut bacteria may also play a part. " The amount of calories you consume by eating, and the amount of calories you expend by exercising are key determinants of your tendency to be obese or lean, " said Dr. Gordon, director of the Center for Genome Sciences at Washington University. " Our studies imply that differences in our gut microbial ecology may determine how many calories we are able to extract and absorb from our diet and deposit in our fat cells. " The bugs in question are bacteria in the phyla Bacteriotedes and Firmicutes, species of which comprise more than 90% of intestinal microbes in both humans and mice. In an earlier study, the investigators had shown that genetically obese mice had 50% fewer Bacteroidetes and proportionately more Firmicutes in their guts than lean littermates, and that the differences in proportion held true across different species within the respective phyla. In one of two studies published in Nature, the authors, led by Ruth Ley, Ph.D., a microbial ecologist in Dr. Gordon's group, reported follow-up results on microbial studies of 12 obese patients followed at a weight-loss clinic over a year. Half of the patients were on a calorie-restricted low-fat diet, and the other half were on a calorie-restricted low carbohydrate diet. The authors monitored the gut flora in the patients by sequencing 16S ribosomal RNA genes from stool samples. At baseline the patients had the same relative proportions of gut microflora as the obese mice: short on Bacteriodetes species and long on Firmicutes. But as they lost weight, the proportions began to shift, as Bacteriodetes species enjoyed a population boom, and Firmicutes species dwindled in number. The changes occurred equally in patients on both diets. In addition, just as they had seen in mice, the authors observed that Bacteriodetes species as a group increased, not just one or two species. In the second study, led by Peter Turnbaugh, a Ph.D., student in Dr. Gordon's lab, the investigators conducted metagenomic studies in obese and lean mice using massively parallel DNA sequencing, and found that the microbiome in the obese mice had a greater capacity for digesting polysaccharides, indicating an enhanced ability to process food. And when they transferred the microflora from obese or lean mice into germ-free animals, they found that the newly colonized animals who had received bugs from the cecum of obese mice laid in significantly more fat without an increase in caloric intake. In contrast, the once germ-free mice who got bacteria from their lean brethren put on some fat, but not nearly as much. " Are some adults predisposed to obesity because they 'start out' with fewer Bacteroidetes and more Firmicutes in their guts? " Dr. Gordon asked. " Can features of a reduced Bacteroidetes-Firmicutes enriched microbial community become part of our definition of an obese state or a diagnostic marker for an increased risk for obesity? And can we intentionally manipulate our gut microbial communities in safe and beneficial ways to regulate energy balance? " In their editorial, Dr. Seeley and Bajzer noted that the mechanism whereby differences in body weight translate in changes in intestinal bacteria are unknown. " Given that acquiring food from the environment can be both calorically expensive and potentially dangerous, it would seem to be most adaptive to extract as many calories from every bite of food as possible, " they wrote. " Moreover, if caloric extraction does become more efficient, the regulatory system would dictate that the organism responds by reducing its caloric intake, " they continued. " If a host organism had the ability to change its microbiota so as to increase caloric extraction, it would seem most adaptive to do so when facing famine conditions and losing weight. However, the data indicate just the opposite -- the microbiota seems to be more efficient in obese humans who already have the most stored energy, and shifts to being less efficient as the subjects lose weight. " Neither the authors nor the editorialists declared any financial conflicts. Additional Obesity Coverage Primary source: Nature Source reference: Ley RE et al. " Human gut microbes associated with obesity. " Nature 444;7122:1022-23. Additional source: Nature Source reference: Bajzer M and Seeley RJ. " Obesity and gut flora. " Nature 444;7122:1009-10. http://www.medpagetoday.com/Pediatrics/Obesity/tb/4750 --- Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Games. Quote Link to comment Share on other sites More sharing options...
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