Figure 1.

The gut microbiota–brain axis and neurodegenerative disorders. The gut microbiota–brain axis encompasses neuronal, immune, and metabolism pathways that mediate gut-to-brain communication. The gut microbiota may act as an intermediate factor between the host and the environment to mediate disease onset and neuropathology. ENS, enteric nervous system; DC, dendritic cell. (The images were purchased and adapted from Servier Medical Art by Servier, licensed under a Creative Commons Attribution 3.0 Unported License.)