Showing posts with label fecal transplant. Show all posts
Showing posts with label fecal transplant. Show all posts

Sunday, October 13, 2013

GUT BACTERIA-WILL THEY HELP ATTACK OBESITY EPIDEMIC?

How desperate people can be when all measures to control body weight come to naught and drastic approaches like bariatric surgery become the most practical step. However such strategies cannot be a standard solution to the problems of millions of people who are confronted by the weight gain syndrome. It is true that the basic scientific foundation for explaining body weight gain is the excess intake of calories through carbohydrates and fats in the diet that become fat deposits in different parts of the body causing weight gain. Balancing of the diet with regard to calories is a prerequisite for avoiding weight gain.

The million dollar question is how to balance the diet vis-a-vis calories? Unless one is aware of the calorie expenditure through physical activity it is next to impossible to decide what and how much to eat. Though a 2000 calories diet is recommended for a healthy normal human, it can be insufficient if the physical activity is too high as encountered by athletes and others doing heavy work. On the other hand a sedentary person with minimum physical activity does not need that much calories through the daily diet. While obesity is an ugly disease with the person suffering from it presenting a grotesque picture and bloated body cynosure of all eyes in public places! While physical appearance is one undesirable feature of obesity, much more crucial is the vulnerability of these unfortunate victims to serious diseases like heart attack, stroke, diabetes, kidney disorders etc.

The Body Mass Index (BMI) is supposed to tell whether one is obese or not and generally any figure beyond 30 is considered dangerous while BMI in the range 20-25 is desirable. There can be many contradictions in putting obesity on a BMI scale with some persons having normal health even when BMI exceeds 25 while some low BMI individuals do suffer from many diseases like diabetes and heart ailments, obviously due to reasons other than high body weight. Though there is a general belief that food intake and exercise can minimize the chances of obesity there can be other reasons for individuals to get high BMI in spite of low calorie diet and regular exercise. Unfortunately the current understanding of this area of human science is not complete and with each passing day new information is emerging regarding the various factors that play different roles in causing obesity.

It was quite recently that scientists discovered about the role of gut bacteria in human health and hundreds of studies have brought about the fact that bacteria in general and intestinal bacteria in particular play an important role in maintaining good health. The fact that new born babies with practically a sterile intestine acquire rapidly a host of bacteria through mother's milk indicating that even different bacteria residing in different parts of the body of a human being play decisive roles in protecting the person as a natural defense and use of chemicals and other antibacterial materials used liberally for keeping away disease causing pathogens can be, in reality, a foolish thing to do in the long run! No one knows precisely how much damage such sanitizing agents can cause to disturb the equilibrium that exists among different species of bacteria that colonize human body.

"Fecal transplant" which has become a standard treatment regime for patients suffering from incurable diseases like Crohn's diseas, Irritable bowel syndrome and others is a telling commentary on the usefulness of bacteria in providing relief to human beings from serious diseases. Though it may sound repulsive to think about transferring feces from one person to another one,  the success of this approach has been so dramatic that thousands of people are becoming candidates for fecal transplant every year all over the world. What is not clearly understood is the identity of the particular species or combinations of them that is providing the relief to the recipients and how long it will take to come out with an answer is any body's guess. But dramatic break through can be expected in the foreseeable future in this critical area.                      

Recent studies focusing on the likely role of gut bacteria on development of obesity are no less dramatic in unfolding another dimension to the beneficiary role played by bugs. in what is considered a solid evidence researchers used pairs of human twins in which one was obese and the other lean. On transfer of gut bacteria from these twins into mice revealed some startling facts which may have long term implications on obesity research. The mice with bacteria from fat twins grew fat while those that received bacteria from lean twins stayed lean! (those that got bacteria from lean twins stayed lean). It is just an empirical observation which needs to be interpreted carefully without drawing any definitive conclusion. With these studies it does not become logical for obese people to become right candidates for fecal transplant. Unless scientists are able to isolate most important bacterial species present in the feces which are responsible for the effect, the scientific theory behind such treatments cannot be unraveled.

What is not to be forgotten is that human biology is so complex it is difficult to pin point what all factors contribute to the phenomenon of obesity. These include genetics, diets and living styles followed by different people. Interestingly it has been shown that with the right diet it should be possible to  change the bacteria in a fat person's gut so that they promote leanness rather than obesity. Further in the presence of a low-fat diet, bacteria from a lean twin can take over the gut of a mouse that already had bacteria from a fat twin causing significant weight loss in the latter but the opposite does not happen and no matter what the diet, bacteria from a fat mouse do not take over in a mouse that is thin. It really adds up to a quiet riddle which needs some unraveling by the scientific community.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

Thursday, July 18, 2013

UNUSUAL TREATMENT FOR UNUSUALY STUBBORN DISEASES-FECAL TRANSPLANT

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.   

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com