Modulation of Gut Microbiota and Gut-Brain Axis as a Therapeutic approach in Traumatic brain injury: Implications for Neurological Outcomes

ObjectiveThis systematic review aimed to evaluate the impact of gut microbiota modulation including probiotics, dietary interventions, and enteral nutrition strategies on neurological recovery, functional outcomes, morbidity, and mortality in patients with traumatic brain injury (TBI). MethodsThe review was conducted according to PRISMA 2020 guidelines and registered in PROSPERO. A comprehensive search was performed across PubMed, Embase, Web of Science, Scopus, and Cochrane Library up to September 2025. Inclusion criteria comprised original clinical studies in human TBI patients that investigated microbiota related interventions and reported neurological, gastrointestinal, or microbiome outcomes. Risk of bias was assessed using the Joanna Briggs Institute (JBI) tools. ResultsAmong five eligible studies (four RCTs and one cohort; n = 725), early or individualized enteral nutrition and probiotic supplementation were generally associated with better metabolic and inflamatory profiles, fewer gastrointestinal complications, and a non significant trend toward improved neurological scores (GCS, GOS). However, effect sizes weres mall and certainty low due to limited sample sizes and methodological heterogeneity. ConclusionModulation of the gut brain axis, particularly through early and tailored enteral nutrition, appears to improve clinical outcomes and mitigate complications in TBI patients. Probiotics demonstrate safety and potential benefit, though evidence remains preliminary. Larger, multicenter randomized controlled trials are warranted to confirm efficacy, define optimal timing and formulations, and assess longterm neurological recovery.