The Role of the Gut Microbiome Dysbiosis in Metabolic Dysfunction: A Mini Review

Highlights: What are the main findings? In addition to its role in regulating glucose metabolism, it also has an emerging potential to modulate the gut microbiome beneficially; accordingly, Metformin may indirectly support improved brain health. What are the implications of the main findings? Metformin has a promising therapeutic role in promoting cognitive and neurological well-being. This review provides a comprehensive overview of the complex and dynamic bacterial composition of the human gastrointestinal (GI) microbiota and explores its integral role in the microbiome–gut–brain axis. It discusses the physiological and molecular pathways through which the gut microbiota communicates with the central nervous system, highlighting key barriers that can impede effective signaling along this axis. The review also delves into the influence of microbiota on brain health, including cognitive function, mood regulation, and neuroinflammation. It considers how disruptions in this system—known as dysbiosis—can contribute to metabolic and neurological dysfunction. The central focus of the article is the role of the commonly prescribed antidiabetic drug metformin, not only in regulating glucose metabolism but also in its emerging potential to beneficially modulate the gut microbiome. By doing so, metformin may indirectly support improved brain health. Ultimately, the article seeks to inform both healthcare practitioners and patients about the promising therapeutic implications of microbiome-targeted strategies, particularly metformin, in promoting cognitive and neurological well-being.