The microbiota-mitochondria axis: linking metabolic dysfunction to neurodegeneration.

The interplay between gut microbiota and mitochondria represents a dynamic relationship that profoundly impacts host physiology, ranging from maintaining intestinal homeostasis to regulating systemic metabolic and neurological functions. Microbial metabolites such as short-chain-fatty-acids, bile acids, and amino acid derivatives serve as pivotal modulators of mitochondrial bioenergetics, oxidative stress management, and fission-fusion processes. These interactions are vital for preserving epithelial integrity, supporting energy metabolism, shaping immune responses, and managing inflammatory signaling pathways. Disruptions within this microbiota-mitochondria axis are associated with various pathologies, including non-alcoholic fatty liver disease, obesity, type 2 diabetes, and chronic inflammatory conditions like inflammatory bowel disease. Additionally, growing evidence connects gut dysbiosis and mitochondrial dysfunction to neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease, highlighting the importance of this bidirectional relationship in maintaining neuronal health. On a mechanistic level, pathways involving AMPK, sirtuins, and PGC-1α govern mitochondrial biogenesis and adaptive responses to microbial signals. Dysregulation of these pathways can heighten oxidative stress, hinder mitophagy, and contribute to systemic inflammation. Emerging therapeutic strategies aim to target this axis through dietary modifications, probiotics and engineered microbes, FMT, and mitochondria-specific pharmacological treatments. These interventions focus on restoring metabolic stability, enhance resilience against oxidative damage, and slowing disease progression. By integrating insights from fields such as metabolism, immunology, and neuroscience, this review positions the microbiota-mitochondria axis as a critical area of focus in biomedical research. A deeper understanding of this communication network offers promising opportunities for precision therapies aimed at addressing metabolic, inflammatory, and neurodegenerative diseases.