A second brain?

Your gut holds trillions of microbes. Together they are called the microbiome. They help digest food and work with your immune system.

Your gut also has its own network of nerves. It talks to your brain in both directions. Scientists call this link the gut-brain axis.

What the research shows

Research on the gut, mood and skin is still early. The links are promising, but no one can yet say that one causes the other.

Diet and the microbiome are clearer. In one large citizen-science study, researchers counted the plants people ate. Those eating 30 or more different plants a week had more diverse gut microbes than those eating 10 or fewer.

Foods that help

In a Stanford trial, 36 healthy adults followed a diet high in fermented foods for ten weeks. Their gut microbes became more diverse, and 19 markers of inflammation fell. The foods included yoghurt, kefir, kimchi and kombucha.

A high-fibre diet in the same trial had a different effect. Both are worth eating. Variety is the easiest rule to follow.

Small steps

Count plants, not calories. Fruit, vegetables, whole grains, beans, nuts, seeds and herbs all count.

Add a fermented food you enjoy, and build up slowly. If you have ongoing gut symptoms, see your doctor first.

FAQs

References

1. Stanford Medicine. Fermented-food diet increases microbiome diversity and decreases inflammation, July 2021.
2. Wastyk HC et al. Gut-microbiota-targeted diets modulate human immune status. Cell, 2021.
3. McDonald D et al. American Gut: an open platform for citizen science microbiome research. mSystems, 2018.

This article is for information. It is not medical advice. Speak to your doctor about your own health.