{"id":3304,"date":"2025-12-15T09:00:00","date_gmt":"2025-12-15T08:00:00","guid":{"rendered":"https:\/\/www.tgd.care\/?p=3304"},"modified":"2025-12-12T14:59:33","modified_gmt":"2025-12-12T13:59:33","slug":"microbiota-gut-brain-axis","status":"publish","type":"post","link":"https:\/\/www.tgd.care\/en\/articles\/microbiota-gut-brain-axis\/","title":{"rendered":"The Microbiota\u2013Gut\u2013Brain Axis: The Complete Updated Overview"},"content":{"rendered":"\r\n

The microbiota \u2013 gut \u2013 brain axis<\/strong> represents one of the most fascinating and promising fields in contemporary biomedical research. It is a bidirectional communication system that connects the gut microbiota<\/a><\/strong>, the enteric nervous system, and the central nervous system. This complex network plays a crucial role in maintaining physiological balance and modulating numerous processes, from immunity to mood regulation.<\/p>\r\n

In recent years, attention has focused especially on alterations in the microbiota associated with inflammation, cognitive dysfunction, and neurological disorders<\/strong>. Although many mechanisms are not yet fully understood, it is now evident that gut microorganisms communicate with the brain through multiple integrated pathways, influencing complex functions such as emotions, sleep, memory, pain perception, and energy metabolism.<\/p>\r\n

In this article you can find an overview of the main systems through which the gut ecosystem interacts with the brain.<\/p>\r\n

\"Microbiota<\/p>\r\n\r\n\r\n\r\n

Communication pathways of the microbiota\u2013gut\u2013brain axis<\/h2>\r\n\r\n\r\n\r\n

The vagus nerve<\/h3>\r\n

The vagus nerve<\/strong> is one of the main communication routes between the gut and the brain. Its afferent fibers can detect metabolic and immune signals<\/strong> such as microbial neurotransmitters, short-chain fatty acids, and cytokines. Physiological or potentially harmful metabolites present in the gut can activate these pathways or cross the intestinal and blood\u2013brain barriers. This affects stress perception, pain, mood regulation, and inflammatory responses.<\/p>\r\n

The immune system<\/h3>\r\n

The microbiota profoundly regulates immune activity<\/strong>. Its metabolites and microbial fragments modulate cytokine production. When this communication is altered, as in dysbiosis, systemic inflammation or neuroinflammation can occur, contributing to neurological and psychiatric disorders.<\/p>\r\n

The hypothalamic\u2013pituitary\u2013adrenal (HPA) axis<\/h3>\r\n

The HPA axis is the central regulator of the stress response. Its dysregulation is implicated in mood disorders and is often associated with increased cortisol and inflammatory mediators. Neural structures such as the amygdala play a key role in emotional processing. Bacteria can influence its anatomy and physiology, helping explain many emotional and stress-related aspects linked to the microbiome.<\/p>\r\n

Alterations in communication pathways between the microbiota and the brain may trigger inflammatory responses.<\/strong> Certain pathogenic microorganisms produce metabolites that stimulate cytokine production and promote inflammation in the central nervous system, contributing to neurological disorders. Cognitive and emotional dysfunctions may therefore accompany intestinal dysbiosis.<\/p>\r\n\r\n\r\n\r\n

Neuroactive microbial metabolites in the microbiota\u2013gut\u2013brain axis<\/h2>\r\n\r\n\r\n\r\n

The balance of the gut microbiota also affects nervous system well-being through the production or modulation of key neurotransmitters\u2014one of the most extensively studied mechanisms.<\/p>\r\n

Serotonin<\/h3>\r\n

Serotonin is essential for the regulation of emotions, sleep, appetite, and pain perception. Its precursor, tryptophan<\/strong>, depends partly on the state of the microbiota. About 90% of total serotonin is found in the gastrointestinal tract<\/strong>, and only 10% in the brain.<\/p>\r\n

SCFAs (short-chain fatty acids)<\/h3>\r\n\r\n\r\n\r\n

Acetate, propionate, and butyrate<\/strong> are produced by fiber fermentation. They can cross the intestinal and blood\u2013brain barriers, influence neurotransmitter release, and modulate immune function. Butyrate, in particular, is associated with:<\/p>\r\n\r\n\r\n\r\n