Impactos de diferentes partes da beterraba (Beta vulgaris L.) sobre a microbiota intestinal de indivíduos com hipertensão arterial

Abstract

Beet (Beta vulgaris L.) is one of the most widely produced foods in Brazil and is rich in nutrients and bioactive compounds, particularly nitrate and betalain, which makes it a potential food with functional claims. These characteristics have increased interest in the vegetable due to the potential benefit to cardiovascular health from the endogenous production of nitric oxide in the intestine, inducing a reduction in blood pressure. Arterial hypertension (AH) is one of the most prevalent diseases worldwide due to its complex multifactorial etiology. The aim of this study was to evaluate the impact of different parts of beet on the intestinal microbiota of individuals diagnosed with AH using an in vitro colonic fermentation system. The study was carried out in different stages, starting with the freeze-drying of the beet root (FDBR), the stalks and leaves (FDBSL) and the whole vegetable (root, stalks and leaves) (FDWB). The freeze-dried materials were subjected to physicochemical characterization, followed by in vitro gastrointestinal digestion and colonic fermentation (48 h) with faecal inoculum from individuals with AH, determination of bacterial composition (metagenomics), metabolite formation (nuclear magnetic resonance) and antioxidant capacity (ABTS•+, DPPH•

, and FRAP). The results showed that FDBR, FDBSL and FDWB influenced bacterial composition, microbial metabolic activity and antioxidant capacity during fermentation. FDBR, FDBSL and FDWB increased the relative abundance of several bacterial populations after 48 h of fermentation, including Proteobacteria (FDBR 3.19 - 72.0%, FDBSL 2.6 - 76, 5%, FDWB 2.1 - 77.9%) and Bacteroidetes (FDBSL 1.2 - 12.0%, FDWB 1.8 - 6.9%) and a reduction in the Firmicutes population (FDBR 85.9 - 16.6%, FDBSL 88.7 - 8.9%, FDWB 85.2 - 9.3%). The increase in metabolic activity was evidenced by the reduction in pH (FDBR 6.73 ± 0.15 - 5.09 ± 0.81, FDBSL 6.74 ± 0.22 - 6.03 ± 0.33, FDWB 6.68 ± 0.18 - 5.50 ± 0.76) and consumption of sugars (cellobiose, erythritol, glucose, maltose and glucose uridine diphosphate) in the fermentation medium, with an increase in short-chain fatty acids (acetate, butyrate and propionate) and maintenance of antioxidant capacity. The different parts of the beet had a positive impact on the intestinal microbiota of hypertensive patients, highlighting the functional diversity of the substrates from the formation of metabolites to control the disease, but the FDBR sample had the highest production of Bifidobacterium, a genus that could be exploited in the prevention and control of AH through the restoration of balance to the intestinal microbiota from a dietary strategy.