Gut Bacteria, Intestinal Problems and Fecal Transplants
The Importance of Gut Bacteria
The human body contains at least ten times more bacterial cells than human cells. Most of these bacteria live in our gut and are very helpful. They are so important in our lives that without their presence we may experience disease. Doctors have discovered that a sample of feces containing the gut bacteria of a healthy person can be used to treat some intestinal diseases. The feces (or stool) is delivered to the patient as a fecal transplant.
As unpleasant as fecal transplants may sound, they have been a wonderful boon for some people. The transplants have been most helpful for people suffering from serious Clostridium difficile infections. It's possible that fecal transplants will become even more useful as researchers learn more about the composition and function of our microbe community.
The microorganisms in the small and large intestine are known as gut flora or intestinal flora in addition to gut bacteria. A community of microbes on or in the human body is called a microbiome.
The gastrointestinal tract, digestive tract or gut consists of the following parts (in order): mouth, esophagus, stomach, small intestine (duodenum, jejunum and ileum), large intestine (colon and rectum) and anus. The small intestine is folded and the large intestine loops upwards so that part of it lies under the stomach.
The Intestinal Microbiome
Most of our gut bacteria live in our large intestine, where they are accompanied by a smaller number of yeasts and other microscopic organisms. Many live in the colon, the longest part of the large intestine. Some bacteria live in the small intestine, however, especially in the ileum, which is the last section of the small intestine.
It's thought that between 500 and 1000 different kinds of bacteria and trillions of individual bacteria normally live in the large intestine. Most of the microorganisms in the intestine are helpful, but some are harmful. A healthy gut has far more beneficial microbes than harmful ones.
It may seem strange that we contain more bacterial cells than our own cells. This is possible because bacteria have smaller cells than humans and because the bacteria often colonize cavities in our bodies.
Benefits of the Intestinal Microbiome
The relationship between us and the helpful microbes in our gut is mutually beneficial. Gut bacteria feed on nutrients that enter the large intestine from the small intestine. The intestine also provides a warm and moist habitat for the bacteria. The bacteria help us by producing nutrients that we absorb, such as vitamin K and biotin.
Another benefit of gut bacteria is that some ferment the soluble fibre that we eat into short-chain fatty acids. These acids have many helpful effects, including enhancing the activity of the immune system, improving the structure and function of the intestinal lining, lowering the blood cholesterol level and helping to regulate the blood glucose level.
Good bacteria also help to prevent the growth of pathogens (disease-causing microbes) in the large intestine. In addition, they break down material that we are unable to digest. They may also reduce inflammation.
The Importance of the Human Microbiome
The Human Microbiome Project
There’s still a lot to be learned about the inhabitants of the large intestine and the roles that they play in our bodies. Scientists know that the human body contains a huge collection of microbes but have many questions about the identity of the microbes, how the microbes help us and the effects – either beneficial or detrimental – of the microbes on disease.
In 2008, the National Institutes of Health in the United States launched the Human Microbiome Project (HMP). In this project researchers want to identify and catalogue the microorganisms found on the skin and in the body’s cavities and to discover the functions of these microbes in health and disease.
The aim of the HMP is to characterize microbial communities found at multiple human body sites and to look for correlations between changes in the microbiome and human health.— NIH Human Microbiome Project
Intestinal Problems That Have Been Treated With Fecal Transplants
At the moment, most fecal transplants are performed to treat gut disorders caused or suspected to be caused by gut dysbiosis (an abnormal community of bacteria in the gut).
Some patients with Crohn’s disease, ulcerative colitis or a Clostridium difficile infection have responded well to fecal transplantation. Crohn’s disease and ulcerative colitis are forms of inflammatory bowel disease. (Bowel is another name for intestine.) Researchers have recently discovered evidence suggesting that people with inflammatory bowel disease have an abnormal community of gut bacteria and that this community is determined by a person's genetic makeup. Clostridium difficile is an infectious bacterium and is one of the superbugs.
Fecal transplants have about a 90% success rate in people with a persistent and serious Clostridium difficile infection. In addition, the improvement in the patient's condition may occur as soon as one to three days after treatment. Fecal transplants have about a 45% success rate for people with inflammatory bowel disease (IBD). The success rate is higher in some subgroups with IBD and lower in others. The lower success rate for IBD than for a Clostridium difficile infection may reflect the fact that IBD seems to involve more than just a gut bacteria problem.
What is Crohn's Disease?
Crohn's disease is a disorder involving inflammation of the gastrointestinal tract. Any section of the GI tract may be inflamed, from the mouth to the anus. The lower part of the small intestine and the first part of the large intestine are the most common sites affected, however. Patches of inflamed tissue appear on the intestinal lining and may be deep.
The cause of Crohn's disease isn't known. It is known that the patient's immune system behaves abnormally, which results in damage to the GI tract. The immune system may be responding to the presence of certain bacteria in the gut and may stay active even when these bacteria are destroyed. There seems to be a genetic tendency to develop the disease when the right environmental trigger appears.
Patients with Crohn’s disease may have mild symptoms or may have severe symptoms that make life very difficult and unpleasant. Gastrointestinal tract problems often include bloody diarrhea and abdominal pain. Symptoms may extend beyond the GI tract. The patient may suffer from loss of appetite, weight loss, fatigue, joint pain, fever, nausea, vomiting, skin problems and eye inflammation.
People with Crohn's disease generally experience flare-ups, or periods when their symptoms are severe, alternating with periods of remission when their symptoms are weaker or absent.
What is Ulcerative Colitis?
Ulcerative colitis produces similar symptoms to those caused by Crohn’s disease, but the intestinal effects are slightly different. The inflamed tissue in the intestine generally appears only in the colon (the longest section of the large intestine) and the rectum (the chamber at the the end of the large intestine that stores the feces before it's eliminated). In addition, only the surface layer of the intestinal lining is affected in ulcerative colitis, while in people with Crohn's disease the damage goes deeper into the lining.
As in Crohn's disease, the immune system is behaving abnormally in a person with ulcerative colitis. Also as in Crohn's disease, the cause of the disorder isn't known for certain. It may be due to either the presence of harmful bacteria or an inappropriate immune response to healthy ones.
People with ulcerative colitis experience flare-ups and remissions. They are more like to experience an absence of symptoms during remissions than people with Crohn's disease.
Clostrifium difficile, or C. Diff
Clostridium difficile is a bacterium that infects the large intestine, causing colitis (inflammation of the colon), severe diarrhea, nausea, vomiting, abdominal pain, dehydration and a fever. Infection by Clostridium difficile, also known as C. difficile or C. diff., may occasionally be fatal.
C. diff is classified as a superbug. Infections tend to develop in hospitals and other medical facilities, although they appear in the general community as well. Like other superbugs, the bacterium is resistant to many antibiotics and is difficult to kill. In fact, the infection often appears in patients who have been taking antibiotics for a different infection. The antibiotics kill other bad bacteria and good bacteria as well, but don't affect C. diff. Without good bacteria to keep C. diff under control, the Clostridium difficile population increases and causes unpleasant effects.
Fecal Microbiota Transplantation and Stool Preparation
Fecal transplantation is an attempt to correct a health problem by improving the composition of the gut flora. The goal is to insert beneficial microoganisms into the large intestine. The transplanted microbes will hopefully reproduce, fighting or crowding out dangerous bacteria. Fecal transplantation is also known as fecal bacteriotherapy and human probiotic infusion.
Fecal transplantation is not a new technique. It's been performed since the 1950s. The process has only recently begun to be seriously investigated by researchers, however.
Dr. Thomas Borody, an Australian gastroenterologist, is a leading practitioner of fecal transplants. He is not only treating gut disorders with fecal transplants but is also investigating whether other disorders such as multiple sclerosis, chronic fatigue syndrome and Parkinson's disease can be improved by fecal transplants. Other doctors are trying to find out if transplantation of beneficial bacteria from the stool of lean people into overweight people can treat obesity.
The transplanted stool is inserted into the colon or occasionally through a tube inserted in the nose or mouth. The recipient doesn't smell or taste the stool that is administered by the second method.
A Fecal Transplant and a C. difficile Infection
Safe Fecal Transplants
Fecal transplants are simple to perform and often have rapid benefits. However, the transplantation must be done by a doctor or under a doctor’s guidance. Safety is extremely important. The sample of feces must be prepared properly. In addition, donors and their feces need to be screened for known parasites so that the recipient doesn't develop a serious or even deadly infection as a result of the transplant.
It's very important that donated feces is checked for the presence of dangerous bacteria and other parasites before any type of fecal transplant is performed.
The Acceptibility of Fecal Transplantation
At the moment, fecal transplantation is usually considered to be a “last resort” treatment for patients suffering from debilitating or very dangerous intestinal problems who have tried all other treatments without success. This is because there hasn’t been much scientific research concerning fecal transplantation (although this situation is changing now) and also because of the difficulty in ensuring that the donated feces is prepared properly and is free of pathogens.
As the effectiveness of the treatment is being demonstrated - especially in the case of serious C. diff infections - more and more patients are clamouring for a fecal transplant. The procedure may sound repulsive to a healthy person. For someone who is experiencing debilitating intestinal symptoms, however, the procedure often sounds like a godsend. Hopefully researchers will discover ways to make fecal transplants effective for even more people and diseases.
More About Gut Bacteria and Fecal Transplants
© 2011 Linda Crampton
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