RESUMEN
BACKGROUND: In recent years, an increasing number of studies have indicated a bidirectional relationship between gut microbiota and the kidneys (the gut-kidney axis). Currently, the potential causal relationship between gut microbiota and diabetic nephropathy remains unclear. This study explores the causal effects of gut microbiota on diabetic nephropathy through Mendelian randomization. METHODS: We carried out a comprehensive Mendelian Randomization (MR) analysis, drawing on the Genome-wide Association Study (GWAS) data for 196 varieties of gut microbiota and diabetic nephropathy. The primary analytical approach employed was the inverse-variance weighted, supplemented by the MR-Egger, weighted median, simple mode, and weighted mode. We rigorously assessed heterogeneity with Cochran's Q test and examined pleiotropy via MREgger intercept and MR-PRESSO tests. To ensure the reliability of our findings, we conducted funnel plots and leave-one-out analysis. RESULTS: Our study indicates a causal relationship between the increased risk of diabetic nephropathy and specific gut microbiota, including the Bacteroidia (P=0.01892; OR=1.593; 95%CI, 1.080-2.350), Bacteroidales (P=0.01892; OR=1.593; 95%CI, 1.080-2.350), and LachnospiraceaeUCG008 (P=0.01350; OR=1.452; 95%CI, 1.080-1.953). Conversely, potential protective factors include the Proteobacteria (P=0.00397; OR=0.528; 95%CI, 0.342-0.815), Gammaproteobacteria (P=0.00965; OR=0.474; 95%CI, 0.270-0.834), Lentisphaeria (P=0.04417; OR=0.756; 95%CI, 0.576-0.993), Victivallales (P=0.04417; OR=0.756; 95%CI, 0.576-0.993), and Dialister (P=0.00118; OR=0.513; 95%CI, 0.343-0.768). CONCLUSION: This study confirms the causal effects of gut microbiota on diabetic nephropathy. Identifying the risk and protective factors within the gut microbiota for diabetic nephropathy offers fresh insights and novel approaches for preventing and treating this condition.
RESUMEN
Gut microbiota imbalance could lead to various diseases, making it important to optimize the structure of the gut flora in adults. Lactobacillus paracasei ZFM54 is a bacteriocin- and folic acid-producing Lactobacillus strain. Herein, L. paracasei ZFM54 was used as the potentially probiotic bacterium to ferment milk together with a yogurt starter. We optimized the fermentation conditions, and the obtained yogurts were then subjected to volatile and nonvolatile metabolome analysis, showing that L. paracasei ZFM54 can not only improve the acidity, water holding capacity and live lactic acid bacteria counts, but also improve many volatile acid contents and increase some beneficial nonvolatile metabolites, such as N-ethyl glycine and l-lysine, endowing the yogurt with more flavor and better function. The regulatory effects of the co-fermented yogurt on the intestinal microecology of volunteers were investigated by 16S rRNA sequencing and short-chain fatty acid (SCFA) analysis after consuming the yogurt for a 2-wk period, showing a better effect to increase the relative abundance of beneficial bacteria such as Ruminococcus and Alistipes, decrease harmful bacteria (Escherichia-Shigella and Enterobacter), and enhance the production of SCFA (acetate, propionate, and butyric acid) compared with the control yogurt. We found that L. paracasei ZFM54 can significantly improve the health benefits of yogurt, laying the foundation for its commercial application in improving gut microbiota.