Abstract
Introduction: Critical patients, both due to brain injury and neurodegenerative diseases, have an increased risk of developing nutritional malnutrition due to complex problems and deleterious effects of diseases on protein and energy metabolism, resulting in metabolic dysregulation, hypercatabolic state and depletion of energy reserves energy. Objective: It was to carry out a systematic review to externalize and discuss the main findings on the effects of enteral nutritional therapy, as well as on the action of the gut microbiota in patients with brain injuries or neurodegenerative diseases. Methods: The PRISMA Platform systematic review rules were followed. The search was carried out from March to May 2025 in the Web of Science, Scopus, Embase, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 108 articles were found, and 20 articles were evaluated in full, and 08 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 30 studies with a high risk of bias and 24 studies that did not meet GRADE and AMSTAR-2. Most studies showed homogeneity in their results, with X2=88.9%>50%. Enteral nutrition supplemented with probiotics effectively decreases the risk of mortality, gastrointestinal complications, and infection, and shortens the length of stay in the intensive care unit, therefore, it should be widely adopted for the management of these patients. Nasal inspiratory pressure during a sniff at baseline is an early indicator of disease progression and therefore the need for enteral nutrition in amyotrophic lateral sclerosis. Furthermore, problems with tolerance, diarrhea, and abdominal distension decreased between the 3 and 6-month visits in patients who received home enteral nutrition.