Association of Gut Microbiome Shifts With Metabolic Alterations in Prediabetes: A Cross-Sectional Study

Background Early identification and intervention are essential to prevent the progression of prediabetes to type 2 diabetes mellitus (T2DM). The gut microbiota plays a key role in host metabolism, and its dysbiosis may contribute to metabolic disorders. This study aimed to compare gut microbiota profiles between individuals with prediabetes and healthy adults and to explore their potential metabolic associations. Materials and methods  A total of 117 adults aged 18-65 years were recruited, including 57 patients with prediabetes and 60 healthy controls. Demographic data and stool samples were collected. Gut microbiota composition was analyzed using 16S rRNA gene sequencing targeting the V3-V4 region. To minimize batch effects, raw sequencing data from both cohorts were processed using a unified bioinformatics pipeline. Results  Individuals with prediabetes exhibited significantly lower gut microbial diversity (Simpson index, p < 0.001) and distinct microbial composition (Permutational Multivariate Analysis of Variance (PERMANOVA), p = 0.001) compared with healthy controls. Additionally, several bacterial genera differed significantly between groups, with 11 genera enriched and four genera depleted in the prediabetes group, indicating a shift in gut microbiota structure associated with prediabetes. Conclusion  The gut microbiota of individuals with prediabetes differed significantly from that of healthy adults, showing reduced diversity and altered bacterial composition. These findings indicate that gut microbiota dysbiosis is associated with prediabetes-related metabolic alterations, although causal relationships cannot be inferred due to the cross-sectional design.