Fermented foods

Fermented foods — yoghurt, kefir, sauerkraut, kimchi, kombucha and others — are made or transformed by live microorganisms, and many are eaten with those cultures still present.

They matter because a randomised Stanford trial found that a diet high in fermented foods over ten weeks increased gut-microbiome diversity and lowered several markers of inflammation — a promising signal, though from one short study.

In practice, regularly including fermented foods with live cultures is a low-risk way to add microbial variety and diet quality; note that pasteurised, shelf-stable versions may no longer contain live cultures.

Sources

• Wastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell 2021 (fermented-foods arm: increased microbiome diversity, lower inflammatory markers)