Gut Bacteria and Weight

Gut bacteria partly responsible for obesity

Many trillions (millions of millions!) of microbes all over us and in us. Specially in our guts.

Gut Bacteria Can Cause Overweight or Obesity  

An Entire Eco-System in Our Intestines

Gut bacteria probably have a lot to do with the obesity epidemic.

There is a whole world of bacteria living inside us. 100 trillion (that´s a one followed by 14 noughts!) or so microbes resident in our guts. About 3,500 species, weighing together about 3 pounds ( 1,4 kilos)  –  the size of a football.  The microbial cells in our innards outnumber our own cells by a factor of 10 to 1.  This dark microbial world is separate from us, yet an integral part. It helps us digest the food and drink we consume and it is also important for producing vitamins, excreting toxins and regulating hormones. It also helps to heal wounds, look after our immune systems and it affects our entire metabolism. A lot of the bacteria down there is essential for our good health and most of the rest is benign. Certainly, our microbial world deserves much better than the shudder it usually provokes.

But there is some bacteria that can apparently cause life-threatening overweight and obesity problems.

Does Bacteria in the Gut Really Help Cause Obesity?

Doctors have known for a long time that there is a connection of some kind between the microbes in our intestines and obesity. The cause of this connection was never clear. Much evidence has now accumulated that our intestinal flora is, in fact, frequently responsible, or partly so,  for overweight and obesity.  There have been many studies around the world, all leading to similar conclusions.

Washington University Experiments:   The New York Times carried an interesting report on 5th September, 2,013.  In 2013, Washington University (St. Louis)   published the results of a study, led by Dr. Jeffrey I. Gordon. This experiment involved sets of twins and mice. In each case, one twin was obese and the other thin. Bacteria from the gut of each twin was transferred into mice. The results were surprising. The mice that received bacteria from obese twins started getting fatter, while those that received bacteria from thin twins stayed lean. This seemed like a very strong indication of a connection between get bacteria and weight. But mice and humans are different, so it was a clue, but not definitive.

Perhaps even more surprising was something else that arose from this study. This was that it was possible, with the right diet, to get bacteria from a lean mouse to take over the gut of a mouse that had received bacteria from a fat twin. The fat mouse would then start to lose weight.