Research on the characteristics of gut microbiota in overweight patients with early-onset type 2 diabetes mellitus.

Background: Early-onset type 2 diabetes mellitus (EOD), defined as a metabolic disorder diagnosed before the age of 40, with higher risks of complications, vascular events, and mortality, poses a significant threat to public health. Its prevalence has risen markedly in overweight populations in recent years, yet the underlying mechanisms remain elusive. Emerging evidence highlights a close association between gut microbiota (GM) and metabolic disorders, suggesting that modulating gut microbial dysbiosis may serve as a potential strategy for preventing and managing overweight EOD.

Methods: In this study, we enrolled 30 overweight EOD patients and 30 healthy controls, analyzing their GM profiles and correlations using physicochemical clinical parameters and fecal metabolites.

Results: The results demonstrated significant differences in GM composition between overweight EOD patients and healthy controls. EOD patients exhibited increased the ratio of Firmicutes/Bacteroidetes at the phylum level. At the genus level, Bilophila, Serratia, Lachnospira, and Parabacteroides were enriched in EOD patients, while taxa, such as Faecalibacterium, Ruminococcaceae, and Clostridia_UCG-014, showed significant depletion. Correlation analyses revealed that Clostridia_UCG-014 abundance was negatively associated with body mass index (BMI) (P < 0.05), waist-to-height ratio (WHtR) (P < 0.05), fasting plasma glucose (FPG) (P < 0.05), low-density lipoprotein cholesterol (LDL-C) (P < 0.05), and triglycerides (TG) (P < 0.05), but positively correlated with high-density lipoprotein cholesterol (HDL-C) (P < 0.05). Conversely, Bilophila abundance displayed positive correlations with BMI (P < 0.05), WHtR (P < 0.05), FPG (P < 0.05), LDL-C (P < 0.05), and TG (P < 0.05). Meanwhile, biofilm formation (Escherichia coli), nitrogen metabolism, arginine and proline metabolism, beta-lactam resistance, drug metabolism (other enzymes), glycerolipid metabolism and sucrose metabolism showed decreases in overweight EOD patients, respectively (P < 0.05).

Conclusions: These results indicate that Bilophila and Clostridia_UCG-014 may serve as microbial biomarkers for the identification of obesity-related EOD.