GUT X``MICROBIOME–BRAIN AXIS: MICROBIOTA-DERIVED BIOMARKERS IN DEPRESSION, ANXIETY, AND NEURODEGENERATION

Abstract

The gut microbiome profoundly influences brain function via the gut–brain axis, affecting mental health and neurodegenerative processes [1–5]. Microbiota-derived metabolites—including short-chain fatty acids (SCFAs), tryptophan metabolites, trimethylamine N-oxide (TMAO), and bile acids—have emerged as potential biomarkers for depression, anxiety, and neurodegeneration [1–5]. Human and animal studies suggest that alterations in these metabolites correlate with disease severity, progression, and treatment response [1–7]. Integration of microbiome analysis with metabolomics, neuroimaging, and genomics may enhance early diagnosis, risk stratification, and personalized therapy [2,4,8,9]. Future research should focus on standardization, longitudinal validation, and translational applications of microbiota-derived biomarkers in clinical practice [3–5].