Association of culture-detected vaginal microbiota and body composition parameters with gestational diabetes outcomes

Objective To evaluate associations between culture-detected vaginal microbial colonization, body composition parameters, and lifestyle factors in women with gestational diabetes (GD). Design Cross-sectional observational study. Setting Tertiary university hospital, Department of Obstetrics and Perinatology, Lublin, Poland. Population One hundred pregnant women, including 47 with GD and 53 healthy controls. Methods Anthropometric measurements, bioelectrical impedance analysis (BIA), and vaginal culture-based microbiological assessment were performed. Dietary habits, lifestyle behaviours, and supplement use were evaluated using a validated questionnaire. BIA assessed hydration status and body composition, including total body water, extracellular and intracellular water, lean tissue mass, and body cell mass. Main outcome measures Prevalence of selected vaginal microorganisms ( Candida albicans , Streptococcus agalactiae ), body composition indices, and lifestyle factors. Results Women with GD had significantly higher BMI during pregnancy, greater lean tissue mass and body cell mass, and increased total and extracellular water compared with controls (all p < 0.05). Vaginal swabs showed a higher prevalence of Candida albicans (27.7% vs. 5.7%) and Streptococcus agalactiae (23.4% vs. 0%) in the GD group. Women with GD more frequently reported alcohol and coffee consumption before pregnancy and were less likely to use folic acid or probiotic supplements. Due to multiple comparisons, some findings may reflect type I error and should be interpreted cautiously. Conclusions GD was associated with a higher prevalence of selected culture-detected vaginal microorganisms, as well as differences in body composition and health-related behaviours. These findings highlight potential interactions between metabolic status, microbial colonization, and lifestyle factors in pregnancy. Given the cross-sectional design, causality cannot be inferred, and comprehensive microbiome studies are needed to confirm broader ecological changes.