Generally, We are Overweight.
In America, more than a third of adults (34.9 percent) are obese (1). The widely known causes: high calorie diet, not enough exercise, and of course, unlucky genes from parents. However, researchers have found one more reason hidden in our guts: a huge amount of gut bacteria.
Low Diversity of Gut Microbiome Could Be a Cause of Obesity
The role of the gut microbiome (bacteria called collectively) in obese and lean individuals showed that the microbiome of lean people has more diversity than that of obese people (2).
Researchers transplanted fecal microbiome from pairs of female twins to germ-free mice that were fed low-fat meals. Amazingly, mice that received bacteria from an obese twin grew heavier and showed more body fat than mice with bacteria from a lean twin (3). The fat mice also contained a less diverse gut microbiome.
This means that the bacterial population could be the cause of obesity, not the result of obesity. And it also means it could be possible to prevent the development of obesity.
- Ogden, Cynthia L., et al. "Prevalence of childhood and adult obesity in the United States, 2011-2012." Jama 311.8 (2014): 806-814.
- Turnbaugh, Peter J., et al. "A core gut microbiome in obese and lean twins."nature 457.7228 (2009): 480-484.
- Ridaura, Vanessa K., et al. "Gut microbiota from twins discordant for obesity modulate metabolism in mice." Science 341.6150 (2013): 1241214.