Gut Bacteria and Diet Affect Weight Gain
Gut bacteria from lean people can reduce weight gain in obese mice, but only if the animals are eating a healthy diet, finds a study published in Science that adds to the understanding of how microbes play a role in obesity.
People – and animals – are teeming with a community of gut microbes that play a role in good health. Previous research has suggested a person’s microbes also affect weight gain and obesity. This team of scientists found that lean and obese twins have differences in gut microbes.
For this study, the scientists used microbes from two sets of twins, one lean and the other obese. The twins’ microbes were transplanted into microbe-free mice that had been raised under sterile conditions. All the mice were fed the same chow. After several weeks, the animals that had received a transplant from the obese twin sibling were relatively more obese compared to the mice that had the transplanted microbes from the lean twins. The differences were not associated with how much the mice ate.
In another test the scientists investigated the affect of two types of Americans’ diet on the microbe-carrying animals. The researchers made two types of diets, based on the highest and lowest categories from government survey dietary data. Some mice were fed a diet high in fruits and vegetables and low in saturated fats; another group ate a high saturated fat diet low in fruits and vegetables.
The mice consuming the healthier diet were able to have the lean-twins microbes colonize in their guts and, as before, these mice were protected from weight gain.
But in the animals consuming the unhealthy diet, the lean microbes were not able to colonize the obese mice guts and the mice gained weight.
The findings show that diet can play a key factor in microbe-associated body composition, note the authors, and provide a starting point for future research.
V. K. Ridaura, J. J. Faith, F. E. Rey, J. Cheng, A. E. Duncan, A. L. Kau, N. W. Griffin, V. Lombard, B. Henrissat, J. R. Bain, M. J. Muehlbauer, O. Ilkayeva, C. F. Semenkovich, K. Funai, D. K. Hayashi, B. J. Lyle, M. C. Martini, L. K. Ursell, J. C. Clemente, W. Van Treuren, W. A. Walters, R. Knight, C. B. Newgard, A. C. Heath, J. I. Gordon. Gut Microbiota from Twins Discordant for Obesity Modulate Metabolism in Mice. Science. 2013; 341 (6150).