RESOURCES

With age, a diet lacking in the essential amino acid tryptophan — which has a key role in our mood, energy level, and immune response — makes the gut microbiome less protective and increases inflammation body-wide, investigators report.

In a normally reciprocal relationship that appears to go awry with age, sufficient tryptophan, which we consume in foods like milk, turkey, chicken, and oats, helps keep our microbiota healthy.