The bacteria in your intestines may influence brain functioning and can even promote neurodegeneration.

In a study of 89 people, high blood levels of lipopolysaccharides (LPSs) and the short chain fatty acids (SCFAs) acetate and valerate were associated with large amyloid deposits in the brain. LPSs and SCFAs are markers of inflammation and proteins produced by intestinal bacteria.

High levels of butyrate — an SCFA produced when gut bacteria ferment fibre — were associated with less amyloid.

The study represents a continuation of prior research by the team, which found that the gut microbiota in people with Alzheimer’s disease differs from those without the condition; in those with Alzheimer’s, microbial diversity is reduced, with certain bacteria being overrepresented and other microbes decreased.

Optimizing your gut flora is a key strategy to preventing Alzheimer’s and a host of other chronic diseases.