FIGURE 2.

Gut microbiota activated inflammasome signaling leads to phenotypes specific to depression. Sterile inflammatory responses involving inflammasome signaling is a key mechanism of stress-induced depression and the gut microbiota has been shown to impact inflammasome signaling at several levels. Symbionts, or beneficial bacteria, have been shown to promote gut barrier integrity, and guide T-cell regulation toward an anti-inflammatory phenotype (green). Pathobionts, or bacteria with a negative effect, have the opposite effect, compromising the gut barrier integrity, activating immune response through the release of pathogen associated molecular patterns (PAMPs) and pushing T cell development toward a proinflammatory state (red). Overall, these effects lead to inflammasome activation in the periphery and the microglia that ultimately promote the development of depression.