Thursday, July 18, 2013


In spite of enormous strides made by medical science, there are still a few diseases which defy standard treatment protocols. Use of antibiotics which are widely available with different efficiency can control most of the infectious diseases caused by different pathogens though its over use is reported to be causing the so called antibiotic resistance among people leaving fewer options to the physicians to treat them. Added to this problem is the tendency of the meat industry to use some of the antibiotics in the feeds to facilitate the growth of food animals which practice indirectly increases the exposure of consumers to these life saving wonder drugs. Infection by Clostridium difficile can be serious for many and most strains are not amenable to antibiotic therapy and development of an unusual treatment regime, reported recently involves fecal transplant from healthy persons to the one suffering from infection by this pathogenic bug. 

C.difficile is gram positive bacteria which has been found to cause difficult to cure intestinal disease. It is not yet known where these bugs flourish though hospitals and nursing homes are the usual places from where infection is transmitted.  Interestingly fecal matter of some individuals are reported to contain this microbe in significant numbers and therefore any surface coming in contact with fecal matter can be vulnerable to C.difficile infection. Only few persons harbor the bacteria in their guts along with others, most of them beneficial. As this is a spore forming bacteria, it is resistant to most bactericidal techniques and stay put for long time with the capacity to regenerate under favorable conditions. For example those who get exposed to C.difficile, ingest the spores which go through the acidic condition of the stomach unaffected to become active once they gain entry into the intestine. The million dollar question is why only some people are vulnerable to C.difficile rampage while a large majority are safe from this dreadful disease?

Even though C.difficile present in some people does not exert any ill effect probably due to the overwhelming numbers of other bacterial species present in the intestine which do not allow this pathogen to grow in sufficient numbers to produce the toxins that produce the typical disease symptoms. C.difficile infection when become evident causes bloated stomach and severe diarrhea, leading to "toxic megacolon" and can be fatal in many cases. In the US alone over 14000 people die because of this disease. One of the observations of some significance is that C.difficile infection assumes serious health problem mostly in persons who are administered repeated antibiotic doses which destroy the natural flora in the GI tract allowing C.difficile to assume critical population density necessary for the manifestation of the typical symptoms. The age old practice of replenishing the natural bacterial population after antibiotic treatment by good physicians is based on this perception that there is such a need to protect the gut health adversely affected by the antibiotic administration.  

Metronedazole, Vancomycin and Fedaxomycin are last line of defense to control the rampage of this pathogen though all the infected patients do not respond to them equally. C.difficile, because of its spore forming capacity can pass through the highly acidic environment of the stomach without any damage to it and once it reaches the intestine where conditions are favorable for "sprouting' of the spores into vegetative phase of growth the deadly toxins are produced with the attendant consequences. While debating about the ability of C.difficile to gain entry into human digestive tract, it is believed that lack of personal hygiene and poor sanitation practices are primarily responsible for introducing them into the environment like that exists in some hospitals and nursing homes where they can stay for long time in their spore form, waiting to be transferred to all and sundry who come in contact with surfaces so contaminated. Food industry is vulnerable to C.difficile contamination as most detergents and sanitizers are not effective in killing them. Chlorine is one of the few bactericidal agents found to be able to control the C.difficile population in food processing facilities.    

According to some recent studies transplanting feces from a healthy person into the gut of one who is sick can quickly cure severe intestinal infections caused by C.difficile. Such transplants appear to have cured almost 95% of the patients studied so far who had recurring infections with C. difficile bacteria. In contrast antibiotics could cure only less than 25% of the infected patients  The treatment appears to work by restoring the gut's normal balance of bacteria, which fight off C. difficile. Fecal transplants have been used sporadically for years as a last resort to fight this stubborn and debilitating infection. Worldwide, about 500 people with the C.difficile infection have had fecal transplantation. It involves diluting stool with a liquid, like salt water, and then pumping it into the intestinal tract via an enema, a colonoscope or a tube run through the nose into the stomach or small intestine. Stool can contain hundreds or even thousands of types of bacteria, and researchers do not yet know which ones have the curative powers. Therefore as of know feces must be used intact for transplanting.

Unlike organ transplants, fecal transplant does not suffer from any rejection problem and therefore needs no life time consumption of anti-rejection drugs. Imagine the relief the affected patients will get from such a transplant who other wise suffer from severe diarrhea, vomiting and fever. Interestingly this treatment regime has been worked out based on trial and error with no supporting scientific data. Human GI tract contains more than 700 species of microorganisms and man's knowledge about them is still incomplete. If recent reports are to be believed human microbiome study is more or less complete and the puzzle involving fecal transplant may soon be resolved once this study is completed. If and when scientists are able to identify the specific bacteria, singly or in combination, present in the feces of healthy adults, responsible for the beneficial effect of fecal transplant, the treatment may see a dramatic change with isolated and laboratory cultured bacteria being used in stead of the feces.   


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