BIOCHEMISTRY OF THE GUT–BRAIN AXIS: THE MODULATORY ROLE OF MICROBIOTA METABOLITES IN NEUROTRANSMISSION AND NEUROINFLAMMATION

The gut–brain axis represents a complex bidirectional communication system linking the gastrointestinal tract and the central nervous system. Recent advances in microbiome research have revealed that gut microbiota plays a crucial role in regulating neurological functions through the production of bioactive metabolites. These microbial metabolites, including short-chain fatty acids, tryptophan derivatives, and neuroactive compounds, act as important biochemical mediators influencing neurotransmission and neuroinflammatory processes. The present study analyzes the biochemical mechanisms through which microbiota-derived metabolites modulate neuronal signaling pathways and immune responses in the brain. A literature-based analytical approach was used to review scientific studies related to microbial metabolism and gut–brain communication. The findings indicate that microbial metabolites significantly influence neurotransmitter systems such as serotonin, dopamine, and gamma-aminobutyric acid (GABA). Furthermore, these metabolites regulate neuroinflammatory responses by modulating microglial activation and cytokine production. Short-chain fatty acids, particularly butyrate, demonstrate anti-inflammatory and neuroprotective properties. Overall, the results highlight the critical role of gut microbiota metabolites in maintaining neurological homeostasis and suggest potential therapeutic strategies targeting the gut microbiome for the prevention and treatment of neurological disorders.