Targeting the microbiota-gut-brain axis in Alzheimer’s and Parkinson´s disease: recent therapeutic approaches

INTRODUCTION: Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative disorders with limited disease-modifying treatment options. Evidence suggests that the microbiota-gut-brain axis (MGBA) plays a role in these diseases by facilitating communication between the gut and the central nervous system. Associations have been found between altered gut microbiota composition and function, impaired barrier integrity, dysregulated metabolite production, and immune activation to neuroinflammation and progressive neurodegeneration. AREAS COVERED: This review summarizes and critically assesses recent studies from the past year to provide an updated overview of therapeutic strategies targeting the MGBA in both diseases. We discuss dietary interventions, probiotics, postbiotics, microbial metabolites, and approaches targeting gut barrier function. We also highlight strategies such as fecal transplantation, photobiomodulation, and PD-targeted metabolism therapies using butyrate and resistant starch. EXPERT OPINION: While these interventions have shown promising results in preclinical and early clinical trials, their clinical application is limited by methodological heterogeneity, interindividual variability and a lack of standardized protocols. Successful implementation requires carefully designed clinical trials, particularly longitudinal studies of presymptomatic cohorts, standardized microbiome analyses, and integrated multi-omics approaches to elucidate causal relations and facilitate personalized treatment strategies.