Prebióticos melhoram comportamentos indicadores associados à ansiedade em modelo animal

Abstract

Anxiety is a common mental disorder, with high prevalence rates and relevant social and personal costs, which demand new therapies for their treatment. These behavioral changes can reshape the composition of the intestinal microbiota by means of stress hormones, inflammation and autonomic changes, as well as promoting the consumption of highly palatable foods, influencing which intestinal bacteria thrive. In turn, intestinal bacteria can release metabolites, toxins and neurohormones that alter eating behavior and mood. Supplementation of functional foods has been shown to beneficially modify the composition of the intestinal microbiota, as the microbiota that receives prebiotics provides beneficial microorganisms with a competitive advantage over other bacteria in the colonic ecosystem, in addition, the microbiota that receives prebiotics ferment this functional food, which elevates the supply of energy to the host in the form of short-chain fatty acids, in addition to reducing levels of corticosterone and raising the gamma amino butyric acid. These resulting products are released into the bloodstream, affecting the GI tract, as well as other distant organs such as the central nervous system. We conducted a narrative review in order to describe the effects of prebiotics on anxiety indicators in an animal model, providing information on bioactive carbohydrates, with an emphasis on their prebiotic properties in murines. In addition to this, we have structured a systematic review with meta-analysis to answer the question: Do prebiotics improve anxiety-indicating behaviors? The data and articles used in the systematic review and meta-analysis were obtained during the month of July 2018, and the research strategy was repeated in July 2019. The open field test (OF), serum corticosterone level and the changing the profile of the microbiota were considered as the primary parameters of interest in this investigation. The calculations of the meta-analyzes were performed using the RevMan 5.3 software. We found 411 complete articles, abstracts, review articles or book chapters that included the keywords used in the bibliographic research, of these, at the end of the screening and evaluation, six experimental studies met the inclusion criteria in the meta-analysis. The results of the systematic review and meta-analyzes indicate that the use of prebiotics has beneficial effects, which directly or indirectly reduce behaviors that indicate anxiety in murines, and these benefits are related to the reduction of corticosterone levels and to an increase in the population beneficial bacteria, in particular Lactobacillus spp. and Bifidobacterium spp..This work also suggests starting new studies using prebiotics as a therapeutic alternative or complementary therapy to the conventional treatment of anxious behaviors in humans, considering that the beneficial microbiota and its connection with brain regions recognized as modulators of emotions and neuroendocrine response to stress may be underlying the pathophysiology of anxiety.