Microbes seem to influence how well tea plants absorb nutrients.

Artur Szymczyk/Alamy

Changing the community of microorganisms found on the roots of tea plants can make your favorite brew more delicious.

Just as the bacteria living in our gut can affect our health, the microbes living in and around plant roots play a role in how plants absorb nutrients from the soil. But little is known about their effects on the flavor and nutritional content of tea. Xinbiao Yang at the University of California, Riverside.

To learn more, Yang and his colleagues collected and analyzed tea plants.Camellia sinensis) is grown in Fujian Province, China. They found that certain soil microbes adapted to high nitrogen concentrations, which increased the production of a chemical called theanine in plant roots, and therefore levels in leaves, especially in a variety called Rogi.

Theanine adds a rich, umami flavor to the blend, and its amount is considered a key marker of tea quality. It also has antioxidant and anti-inflammatory properties and can counteract the stimulant effect of caffeine, says Yang.

For the next phase of their study, the researchers extracted 21 of the most theanine-beneficial microbes from the soil to create a bespoke microbial community, whose composition was exactly the same as that found naturally around Rogoi. It was similar.

Applying this mixture to the roots of other tea plant species increases theanine levels, even in nitrogen-deficient soils. “Not only are there more health benefits, but it also enhances the sweet and savory taste of the tea,” says Yang.

The team hopes to use specific microbial communities to improve the quality of tea and improve the nutrition of other plants such as rice in the future.

“Improving nitrogen assimilation efficiency could also reduce our dependence on fertilizers, which could have huge implications for the future of agriculture,” says Yang.