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Sunday, August 3, 2014

Are Fecal Transplants the New Probiotcs?

Despite the marvels of modern medicine, nature is sometimes still the best cure. One good example is fecal microbiota transplant or FMT, which involves the transfer of stool from a healthy person to a sick person. This ancient technique, which dates back to fourth-century China, is making a comeback because it can cure an infection that is too often incurable: Clostridium difficile, also known as C. diff. 

This bacterium can be found inside healthy people who never become sick, but most of the time it causes symptoms that range in severity from mild diarrhea and abdominal cramping to bloody stools, dangerous inflammation of the colon, organ failure, and death. When complications develop, even mild cases of C. diff infection can quickly progress to a fatal disease without prompt treatment.

C. diff bacteria produce toxins which attack the lining of the intestines and an unusually aggressive strain of C. diff has emerged since the year 2000. It produces far more toxins than other strains and it's more resistant to medications. Previously, C. diff infection was most common in people taking antibiotics or medications used to reduce the production of stomach acid and in individuals staying in health care facilities like hospitals and nursing homes, where C. diff spores can live for months on contaminated surfaces because they're immune to alcohol-based antiseptics and hand sanitizers. The new strain is turning up in people who don't have these risk factors.  

According to the CDC, the incidence of C. diff infection is on the rise. Severe cases are being seen more frequently, patients are having more complications, and relapse is becoming more common. C. diff infection has grown into a global epidemic. Now more than ever, doctors and patients alike are seeking alternative treatments.

Probiotics are a supplement form of the healthy bacteria that naturally protect us from harmful bacteria like C. diff. Sometimes they're used as an adjunctive or alternative treatment for C. diff infection, but they have limitations. Our gut microbiota, the collection of microbes inside our intestines, contains trillions of bacteria that make up at least a thousand different species. Probiotics contain only billions of bacteria composing just a few or, at most, dozens of different species. They’re very sensitive to heat and require cool temperatures to remain viable, so these products can quickly lose potency. And in many cases, quality is questionable. A 2008 study found that only 1 of 14 probiotic supplements contained what was listed on the label.

Scientists are still learning about the complex interactions between our bodies and our microbiota, but we already know that they do far more than protect us against disease-causing bacteria. They also help digest food, break down environmental toxins, make essential nutrients like vitamins and short chain fatty acids, modulate the immune system, help regulate inflammation, influence the production of neurotransmitters like serotonin, and play an important role in appetite, satiety, energy usage, and fat accumulation. Some scientists even refer to gut microbiota as a metabolic organ

Like other organs, when it becomes diseased, a transplant can be curative. Because bacteria make up more than half our stool, FMT from a healthy donor is a much more potent dose of probiotics than a supplement could ever supply. Not only does it deliver a much larger volume of bacteria; it provides a much greater diversity of microbes, all in the exact right proportions.  

FMT has already been shown to be the most effective treatment for recurrent and antibiotic-resistant C. diff infection. One study found a 94% cure rate in patients with recurrent C. diff infections treated with FMT while only 31% of patients treated with antibiotics were cured. 

Studies using FMT to treat other diseases are already underway and so far results have been promising for conditions affecting the gastrointestinal tract like irritable bowel syndrome (IBS), Crohn’s disease, and ulcerative colitis. There is also interest in using FMT to treat metabolic diseases like diabetes and obesity, and immune-related illnesses like allergies, autoimmune diseases, and even cancer.

During FMT, stool is collected from a healthy donor who has been screened for infectious diseases like hepatitis, syphilis, and HIV. The stool sample is tested for C. diff and parasites. If all tests are negative, it is mixed with saline, strained, and introduced into one end of the patient's digestive tract or the other, and sometimes both. 

Capsules taken by mouth have been utilized but more common methods employ a nasogastric tube, nasoduodenal tube, nasojejunal tube, endoscopy, sigmoidoscopy, colonoscopy, or enema. Because enemas can only treat the lower part of the large intestine, they usually require more treatments than procedures that reach the full length of the colon.

Launched last year, non-profit organization OpenBiome, based at the Massachusetts Institute of Technology, provides filtered, frozen feces from screened donors and connects patients interested in FMT to doctors who perform the treatment. 

Because access to clinical FMT procedures is still limited, some people opt to recruit a healthy family member or friend to donate stool, then they prepare and perform the enema themselves. They report that it's easy, inexpensive, and highly effective.

Some experts say that biological mothers are the ideal donors and other biological relatives are the next best choice. Other experts recommend household members, whether they are biologically related or not, because they share the same microbial environment. Yet others recommend donors with the same blood type, which has also been shown to affect the kinds of microbes that populate the gut. 

Ultimately, it’s most important that donors have not taken antibiotics within the past six months (or, ideally, never taken them at all), that they have been maintaining a healthy weight, and that they’re free of gastrointestinal, metabolic, autoimmune, and neurological conditions.

Done properly, FMT doesn't have any serious side effects, but it could be risky for individuals with compromised immunity. This includes people taking immunosuppressive medications, those undergoing cancer treatments, and anyone with advanced HIV or AIDS. Pathogenic fecal bacteria present in small amounts may not cause problems for a healthy donor but they could trigger serious disease in people who can’t mount an adequate immune defense.

For more information about FMT, visit the website of The Fecal Transplant Foundation. You’ll find the latest news updates, a list of providers, information about clinical trials, and answers to frequently asked questions.

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