Figure 1.

Communication pathways and mechanistic links between gut microbiota and brain plasticity. The microbiota–gut–brain axis comprises a complex bidirectional communication system mediated by neural (central nervous system, enteric nervous system (ENS), and branches of the sympathetic and parasympathetic systems), immune, endocrine, and humoral pathways. BDNF: brain-derived neurotrophic factor; CREB: cAMP-response element binding protein; HPA: hypothalamic–pituitary–adrenal; NMDA: N-methyl-D-aspartate; SCFAs: short-chain fatty acids. Created with BioRender.com (accessed on 25 July 2021).