Suplementação de probióticos e efeitos na função cognitiva: do declínio leve a doença de Alzheimer

Abstract

Introduction: Aging can lead to cognitive decline and be related to the progression of Alzheimer's disease, which is common in older adults. The use of probiotics to modulate the microbiota and reduce cognitive impairment has been a strategy under investigation. The objective of the study was to review the effect of probiotic supplementation on cognitive function, gut microbiota, and inflammatory parameters in individuals without cognitive impairment, mild cognitive decline, or Alzheimer's disease. Method: A review of randomized clinical trials published in the last ten years was conducted in the PubMed, Web of Science, and Scopus databases using specific descriptors. Results: Twelve articles were included in the review that indicated improvement with probiotic supplementation in cognitive function and gut microbiota, both in healthy individuals (n=2) and those with mild cognitive impairment (n=4). On the other hand, among the six studies with individuals with AD, only two reported improvement in cognitive function after supplementation. Probiotic supplementation also increased the neurotrophic factor (n=3), reduced oxidative stress (n=2) and gastrointestinal symptoms (n=2), and increased quality of life (n=2). Conclusion: Healthy individuals and those with impaired cognitive function may benefit from the use of probiotics, possibly through the reduction of inflammatory and oxidative factors, in addition to the modulation of the intestinal microbiota. However, further studies are recommended to elucidate the mechanisms of action of probiotics, determine the correct dose, identify the most effective strains, and establish a more standardized and safe approach to the prevention of cognitive decline and AD-related symptoms.