Chemicals produced by gut microbiota may be driving the development of amyloid plaques in the brain of people with Alzheimer’s disease (AD), a new study found. Amyloid plaques are clumps of proteins, such as beta-amyloid 42, that accumulate around nerve cells, disrupting their function. Amyloid plaques are commonly found in patients with neurodegenerative diseases, like AD, but the key factors driving the formation of these plaques have remained elusive. Previous studies have established correlations between the presence of certain gut bacterial strains and AD, but the potential mechanisms involved have not been elucidated. In this new study, researchers worked with 89 patients with different degrees of cognitive performance, analysing different aspects of their health and measuring multiple biomarkers. Their results pointed to lipopolysaccharides and the short-chain fatty acids acetate and valerate, both produced by gut bacteria, as two key candidates influencing the formation of amyloid plaques.