Efeitos da ß-glucana de levedura isolada e em combinação com Lactobacillus acidophilus-la5 na microbiota colônica de pacientes diabéticos tipo II

Abstract

Yeast β-glucans (BGL) are polysaccharides recognized for their physiological functionality as prebiotics. Type 2 Diabetes Mellitus (T2DM) is a public health concern with a high prevalence worldwide. The use of dietary components with functional properties, such as prebiotics and probiotics, has proven to be a promising strategy for T2DM prevention and management. This study evaluated the effects of BGL derived from discarded brewery yeast, alone and in combination with the probiotic Lactobacillus acidophilus LA-5 (LA5), on the composition and metabolism of the gut microbiota of type 2 diabetic patients. BGL, obtained from discarded brewery yeast cream, was characterized by nuclear magnetic resonance. Treatments with BGL (7.5 g), LA5 (10⁶ CFU/g), and LA5-BGL [LA5 (10⁶ CFU/g) + BGL (7.5 g)] were administered once daily for seven days. A dynamic colonic fermentation model using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) was applied, and the gut microbiota was assessed across treatments in terms of composition and diversity using 16S rRNA gene sequencing. Ammonia ions and short-chain fatty acid levels were also measured. BGL, alone or combined with the probiotic strain LA5, contributed to balancing the gut microbiota of diabetic individuals. A significant increase in microbial richness was observed in the treated groups compared to the control (T2DM gut microbiota without treatment), with Chao1 indices of 61.75 for BGL, 40.00 for LA5, 55.50 for LA5-BGL, and 10.5 for the control (p=0.028). BGL, LA5, and their combination increased the relative abundance of Bacteroides, Alistipes, Lactobacillus, Subdoligranulum, and Acidaminococcus, as well as the levels of short-chain fatty acids (propionate, butyrate, and acetate). BGL and LA5 enhanced the secretion of the proinflammatory cytokine IL-6 (p<0.05), with the highest concentrations observed in the LA5 group, followed by BGL and LA5-BGL. All treatments increased the anti-inflammatory cytokine IL-10 (p<0.05), with the highest IL-10 levels found in the BGL and LA5-BGL treatments. These findings indicate potential beneficial effects of BGL, alone or in combination with LA5, on the gut microbiota and metabolic markers of adults with T2DM, suggesting its potential use as an adjuvant in the treatment of this condition via gut microbiota modulation. The results of this study open promising avenues for future research, including large-scale clinical trials to confirm the observed benefits on gut microbiota modulation and metabolic markers in T2DM patients. Furthermore, they highlight the potential for developing sustainable functional products by utilizing industrial by-products.