fig1

Figure 1. A schematic summarizing the pathways of gut–brain bidirectional communication with the emphasis on the immune system, the vagus nerve, and the endocrine system. The importance of the gut bacterial metabolites in this communication as well as lifestyle changes that affect microglia functioning in normal physiology and during neurological diseases with neuroinflammatory component are indicated. LPS: lipopolysaccharide; SCFAs: short-chain fatty acids