Sunday, October 13, 2013


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.


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