This Thanksgiving, as you savor your turkey and stuffing, here's something else to give thanks for: the army of microbes that help you digest the feast. Because when you eat, you're feeding them too—and triggering an enormous bloom of gut bacteria. In fact, as many as a billion new E. coli bacteria may come into being during one of those feeding frenzies. But twenty minutes after that population explosion begins, the bacteria reach critical mass, and put on the brakes. And when they enter that 'resting state,' they start pumping out a particular suite of proteins.

Researchers harvested those postprandial proteins from E. coli and added them to the colons of rats. And the proteins appeared to interact with endocrine cells in the gut, flipping on the production of hormones that tell the brain "Hey, stop eating. We're full." Meanwhile, mice injected with the E. coli proteins over the course of a week ate less at each meal (though they compensated by eating more often.) All of which suggests that the proteins put out by bacteria can influence—and even interfere with—our sense of feeling stuffed. The study is in the journal Cell Metabolism. [Jonathan Breton et al, Gut Commensal E. coli Proteins Activate Host Satiety Pathways following Nutrient-Induced Bacterial Growth]

As far as overeating goes—the researchers say we probably won't inject people with bacterial appetite suppressants anytime soon. But it might be worth paying closer attention to the health and composition of our gut bacteria, since they do appear to play a role in regulating our urge to eat. So as you’re stuffing yourself with stuffing on Thursday, you might ask yourself: what would my gut bacteria want?

—Christopher Intagliata

[The above text is a transcript of this podcast.]