Fecal Dysosmobacter spp. concentration is linked to plasma lipidome in insulin-resistant individuals with overweight, obesity and metabolic syndrome

Background Obesity is reaching epidemic proportions worldwide. This excessive increase of adipose tissue is a risk factor for the development of multiple diseases and premature death. Amongst associated diseases, metabolic syndrome is one of the main comorbidities of obesity. In this context, the gut microbiota has been recognized as both shaping and responding to host energy metabolism. Recently metabolomics has emerged as a powerful tool to capture a snapshot of the metabolites present in a specific tissue, offering new insights into host-microbiota interactions. Integrating metabolomics with gut microbiota studies could help us better understand how specific species impact on host metabolomic profile. Dysosmobacter welbionis has been identified as a promising next generation beneficial bacteria with potential effects on fat mass and glucose metabolism in mice, and fecal Dysosmobacter spp concentration was inversely correlated to body mass index fasting glucose and plasmatic HbA1c in humans. Methods Concentration of Dysosmobacter spp was quantified by qPCR in the stools of insulin resistant overweight/obese participants with a metabolic syndrome and plasma metabolites were analyzed using untargeted metabolomics. Correlations between Dysosmobacter spp fecal abundance and the 1169 identified plasma metabolites were uncovered using Spearman correlations followed by a false discovery rate correction. Results Interestingly, among the detected metabolites, Dysosmobacter spp was exclusively associated with lipid molecules, primarily structural lipids involved in membrane formation. This finding aligns with previous in vivo studies highlighting lipid profile alterations in multiple tissues of mice treated with this bacterium. Conclusion These results suggest that Dysosmobacter spp plays a specific role in host lipid metabolism. Further studies are needed to elucidate the underlying mechanisms and assess its potential therapeutic applications.