Bacteria within you — which outnumber your own cells about 100 times — may be affecting both your cravings and moods to get you to eat what they want, and may be driving you toward obesity. That’s the conclusion of an article published this week in the journal BioEssays by researchers from UC San Francisco, Arizona State University and University of New Mexico from a review of the recent scientific literature.
How your gut microbiome may control you
- The diverse community of microbes, collectively known as the gut microbiome, influence human eating behavior and dietary choices to favor consumption of the particular nutrients they grow best on, rather than simply passively living off whatever nutrients we choose to send their way.
- Some bacterial species prefer fat, and others sugar, for instance. They vie with each other for food and to retain a niche within their ecosystem — your digestive tract — and they also often have different aims than you do when it comes to your own actions.
- Bacteria may influence your decisions by releasing signaling molecules into your gut. Because the gut is linked to the immune system, the endocrine system, and the nervous system, those signals could influence your physiologic and behavioral responses — and health.
- Bacteria may be acting through the vagus nerve, which connects 100 million nerve cells from the digestive tract to the base of the brain, changing taste receptors, producing toxins to make you feel bad, and releasing chemical rewards to make you feel good.
- Certain strains of bacteria increase anxious behavior (in mice).
- Some strains of bacteria cause stomach cancer and perhaps other cancers.