Figure 2.

A common link between metabolic dysregulation and AD is dysbiosis of the human intestinal tract or “gut”—commonly defined as a disturbance of or change in the density and/or composition of gut microbiota. Bacterial metabolites (purple box), may influence metabolism to directly or indirectly impact neuronal function. Overall, the gut–brain axis (the brain affects the gut through neuronal and hormonal signals, and the gut microbiome affects the brain) is an important integrative system that modulates metabolic balance and, hence, is a potential target for managing AD.