Probiotics and mental disorders

Neurodegenerative and neuropsychiatric disorders continue to pose significant public health challenges due to their progressive course, high prevalence, and substantial socioeconomic impact. Conventional therapies are often limited by pharmacoresistance, side effects, and suboptimal efficacy, emphasizing the need for complementary and integrative approaches. Emerging research underscores the pivotal role of the gut–brain axis (GBA) in neurological health, highlighting psychobiotics and specific probiotic strains with potential mental health benefits as promising adjunctive interventions. This review synthesizes current evidence on the GBA’s involvement in conditions such as Alzheimer’s disease, Parkinson’s disease, depression, and anxiety. We explore how psychobiotics may influence neuroinflammation, oxidative stress, and neurotransmitter signaling, thereby supporting cognitive function and emotional regulation. Findings from both preclinical and clinical studies are examined, including quality-of-life measures and neuropsychiatric comorbidities. Additionally, we discuss recent innovations, including precision psychobiotics, microbiota–drug interactions, and their implications for overlapping metabolic and neurodegenerative disorders.