Monday, May 20, 2013


Do bacteria play a role in controlling body weight in humans? On the face of it this theory may be far fetched but tentative studies indirectly do indicate that these tiny creatures living in different parts of human body help to maintain good health and disturbing their equilibrium can possibly lead to  undesirable consequences such as lower immunity and bloated bodies.  Over weight and obesity can be quite debilitating, as such morbid conditions invariably contribute many diseases like CVD, Hypertension, Kidney disorders etc and there is a global concern that if not given adequate attention to this potentially dangerous situation, this world will be full of morbid people making every body's life miserable.

There are many dietary regimes proposed for weight control and different diets help different people to varying extent. Who does not know about Atkins Diet or South Beach Diet which were once a craze with weight watchers but all of them eventually faded from the scene because of the uncertainties associated with such restrictive diets. If BMI is used as a criterion, those having values beyond 30 need to watch out for complications arising out of overweight and beyond a BMI value of 35 it can be obese becoming morbid obesity if it still goes higher. Those who are desperate do go on strict diet control for a stipulated time, do lose significant weight but promptly regains the weight once diet restriction is removed. In the case of diabetics, efficient blood glucose control can make a difference between normal life and dangerous flirting with even death. The HbA1C values recorded quarterly beyond 7 is considered unhealthy. As restrictions on sugar become more and more acute, the cravings for sweet foods also become more and more irresistible!

Surgical intervention like Bariatric surgery, intestinal stapling etc become imperative under extreme conditions of obesity to prevent development of morbidity but these are all considered unnatural becoming an option only under extreme conditions.  There is even a stomach pump available that can evacuate the stomach contents within 20-30 minutes of consuming the food!  What kind of life these unfortunate victims will have after such surgical interventions? Out of millions of people, hardly a couple hundred thousands opt for surgery to get relief from the sufferings associated with overweight and obesity. Thus there is a genuine need to evolve a much more simpler technique which can bring relief to these people vulnerable to putting on weight or resistance to shedding weight through natural process of dietary control. Of course the theory that overweight is net game between calorie intake and calorie expenditure through physical activity still holds good but most consumers find it extremely difficult to "manage" their daily calorie intake by controlling the food intake and an active exercise regimen.

Here comes the role of microorganisms which have become omnipotent in every walk of life to day. The importance of prebiotic and probiotic foods in maintaining good gut health is already well known in qualitative terms but knowledge about which microorganisms do what is still somewhat hazy. Thousands of processed foods containing such microbes in active form are offered by the industry and an active cell count of 4 billion live cells is considered desirable for getting the benefits of these health foods. Here again opinion varies regarding what species are more effective and what is the most desirable proportion some of these microbes must be present in the food. It is also not clear whether the type of diet consumed has any bearing on the efficacy of function of these microbes and what should be desirable consumption levels in daily diets. Thus the picture that is presented to the consumer lacks clarity and raise many unanswered questions.

It is a fact that in human beings microbial cells outnumber human ones, and many new studies have brought out the crucial role played by trillions of bacteria and other microorganisms that live in their own ecosystem in the gut. Recent discovery that Clostridium difficile bacteria can infect people through exposure to hospitals, nursing homes and such community centers and most antibiotics known to man are ineffective in controlling the infection, was quite baffling for some time. Antibiotics, which are used nowadays routinely to treat even a mild cold,  were found to wipe out many natural microorganisms present in the guts which would have normally kept C. difficile in check. It is scary to imagine that severe cases of  such infection can be life-threatening and after running out of all options the medical profession is gradually coming to accept the somewhat startling idea that the best therapy that works involves a fecal transplant from a healthy person to the one who is sick. This is to rehabilitate the population of beneficial microorganisms that were present in the guts before administration of antibiotics.

The focus has now turned on a new thinking which correlates the efficiency of  gastric bypass surgery to changes in  microbiological profile brought about by the surgery. Some studies had shown that the microbial profile of the intestine in an obese person changed significantly after the surgery, becoming more like that of someone who was thin. But was the change due to surgery itself, or from the weight loss that followed the operation? And did the microbial change have any effects of its own? True such studies would be difficult and time-consuming in humans and researcher had to use laboratory mice, which were fattened up with a rich diet. One group had gastric bypass operations, and two other groups had "sham" operations in which the animals' intestines were severed and sewn back together. The point was to find out whether just being cut open, without having the bypass, would have an effect on weight or gut bacteria. One sham group was kept on the rich food, while the other was put on a weight-loss diet. In the bypass mice, the microbial populations quickly changed, and the mice lost weight.  How the altered intestinal bacteria might cause weight loss is not clearly understood though it appeared that the microbes have caused increased metabolic rate burning more energy.

According to some most recent studies a particular species of bacteria Akkermansia mucilophilia which inhabits human gut and constitutes about 3-5% of the microbial mass in normal humans helps reduce body weight by slowing down of absorption of calorie rich foods across the intestinal membrane. Quantitatively the levels of this bacteria in obese people are much below the normal levels encountered in healthy persons and probably this finding confirms the earlier guess attributing a weight reduction role to intestinal bacteria.A.mucilophilia appears to be able to modify the mucal surface of the intestine so that transport of calorie rich food components is regulated efficiently. There is also a nagging suspicion that even though they are residing in the intestine, they might be playing more critical role in regulating body metabolism in some way which needs to be elucidated. Though the findings were based on laboratory studies using mice, there is a strong likelihood that such a relation exists in humans also. Surprisingly this bacteria also reduced insulin resistance giving hope that one day, not too distant a future, a more affordable and easy to manage bacterial therapy may emerge to attack obesity and diabetes without the trauma associated with highly restrictive diet regime and surgical intervention.

Now that the role of bacteria in body weight control has been technically demonstrated there is need to expand the scope of studies to bring to surface whether there are others also involved in weight reduction and if so their precise role. Establishing the ability of bacteria to control calorie intake by the body may be just one part of the eventual treatment regime that may become a reality soon but any therapy can be good only if there is discipline while eating. A combination of mild diet control and bacterial therapy can be a win-win situation as and when more information emerges on these friendly bugs, aptly called the "gut soldiers".

(After composing the above article some time in April by this author, New York Times published an extremely informative and incisive article on May 15, 2013 regarding the overwhelming influence of microorganisms on human life written by the internationally acknowledges Guru of food technology Prof Michael Pollan. This Blogger recommends this article for reading by every one on this planet to appreciate the role of these tiny creatures which are sought to be destroyed indiscriminately by the modern man in the name hygiene and sanitation using many bactericides including broad spectrum antibiotics! Access the article through the following


1 comment:

diabeteshealthcare said...

In this evil disease the balance of blood sugar level is the most important factor and really it damages the blood cells and vessels too.

Diets for diabetics