07/31/2025
Besides the ENS, how else does the gut microbiome communicate with the brain?
The gut microbiome communicates with the brain through several interconnected pathways beyond the enteric nervous system (ENS). These include:
Brain, Gut, and Microbiome: Understanding the Connection
Vagus Nerve: This major nerve directly connects the gut and the brain, acting as a crucial communication highway. The vagus nerve senses the environment of the gut, including chemical signals from the microbiota and releases from enteroendocrine cells, and relays this information to the brain. In turn, the brain can send signals back to the gut via the vagus nerve, affecting functions like digestion and the immune response.
Immune System: The gut houses a significant portion of the body's immune cells. The gut microbiota interacts with these immune cells, influencing both the innate and adaptive immune responses. These immune cells and their signaling molecules, such as cytokines, can travel through the bloodstream and influence brain function, including neuroinflammation and behavior.
Endocrine System and Metabolites: Gut microbes produce various metabolites, such as short-chain fatty acids (SCFAs), tryptophan metabolites, and neurotransmitters like serotonin and γ-aminobutyric acid (GABA). These can enter the bloodstream and act on the brain or interact with the ENS and vagus nerve to influence brain function. The gut microbiome also interacts with the hypothalamic-pituitary-adrenal (HPA) axis, which is the body's central stress response system.
In essence, the gut microbiome communicates with the brain via a complex network involving direct nerve connections, immune system activation, and the production of chemical messengers that circulate throughout the body.
