Do These Gut Microbes Make Me Look Fat?
Microbes are getting plenty of attention lately for their impact on human health and wellness. (Mostly) friendly bacteria of many different species live in and on our bodies. In a very real sense, they’re an integral part of us. In the gut, they’re responsible for aiding digestion; generating important vitamins, and making amino acids available, among other things.
It’s the “other things” that intrigue scientists. For instance, what effect do gut bacteria have on whether someone will become fat? Surely obesity is the result of eating too many calories and burning too few. Right? Well, maybe not.
Fascinating research using a mouse model of human obesity suggests that leanness is a function of one’s gut “microbiota;” the mix of different bacterial species living in the intestines. If this proves true for humans, it may have profound implications for the war on obesity.
Scientists from Washington University School of Medicine obtained stool samples from identical human twins with the rare trait that one twin was obese while the other was lean. The use of twins allowed the scientists to rule out genetic differences that might influence body weight.
Germ-free mice were infected with stool from either lean or fat twins. All test mice were then fed the same diet. Remarkably, mice “infected” with normal gut bacteria from a lean person grew up lean. Mice “infected” with bacteria from the fat twin grew fat. Fat mice that were eventually “infected” with “lean” bacteria became slim, furthering the evidence that the make-up of one’s gut bacteria has a huge influence on one’s body weight.
Best of all? A diet rich in fruits and vegetables encourages the growth of the “lean” gut microbiota profile.
Ridaura VK, Faith JJ, Rey FE, Cheng J, Duncan AE, Kau AL, et al. Gut microbiota from twins discordant for obesity modulate metabolism in mice. Science. 2013 Sep 6;341(6150):1241214. doi: 10.1126/science.1241214.