Antibiotics, social status and fat

In the New York Times yesterday, Pagan Kennedy reminds us of the link between antibiotics and weight gain:

IF you walk into a farm-supply store today, you’re likely to find a bag of antibiotic powder that claims to boost the growth of poultry and livestock. That’s because decades of agricultural research has shown that antibiotics seem to flip a switch in young animals’ bodies, helping them pack on pounds. Manufacturers brag about the miraculous effects of feeding antibiotics to chicks and nursing calves. Dusty agricultural journals attest to the ways in which the drugs can act like a kind of superfood to produce cheap meat.

But what if that meat is us?

Researchers also tried this out in a study of Navy recruits…The Navy men who took a dose of antibiotics every morning for seven weeks gained more weight, on average, than the control group.

A study in mice last year found the same thing: when fed a stream of antibiotics, they slowly fattened up:

The antibiotics altered the composition of bacteria in the guts of the mice and also changed how the bacteria broke down nutrients. The bacteria in treated mice activated more genes that turn carbohydrates into short-chain fatty acids, and they turned on genes related to lipid conversion in the liver. Presumably, these shifts in molecular pathway enable fat build-up. Just as farm animals get fat, the antibiotic-fed mice put on weight.

Given that high-status individuals (well, baboons) have been shown to have enriched immune-related genes compared to low-status individuals, I wonder if social status can regulate weight gain (etc) through the composition of bacterial flora? Just a thought, and not something I know a lot about…