Intestinal fungal dysbiosis in gestational diabetes mellitus is associated with adverse pregnancy outcomes.

BACKGROUND

Our study aims to compare the differences in gut fungal community structure between pregnant women with gestational diabetes mellitus (GDM) and healthy pregnant women at 24-28 weeks of gestation, and to explore the correlation between differential fungi, clinical indicators and adverse pregnancy outcomes.

METHODS

We selected 96 pregnant women with GDM and 92 healthy pregnant women, all of whom had established prenatal care records at Hangzhou Women's Hospital, and assigned them to the case group and the control group respectively. Fecal samples were collected from all participants at 24-28 weeks of gestation and sequenced using ITS rRNA gene sequencing. We then compared the fungal community characteristics between the two groups, screened for differential fungi between the groups, analyzed their association with clinical indicators, and further explored influencing factors for adverse pregnancy outcomes.

RESULTS

There were significant differences in gut fungal characteristics and clinical indicators between pregnant women with GDM and the healthy group. Compared with the healthy group, the α-diversity (including the Shannon, Simpson index, etc.) of gut fungi in pregnant women with GDM was decreased (P < 0.01). There were differential changes in the community structure. At the genus level, Candida contributed to the clustering analysis of pregnant women with GDM and was positively correlated with glucose metabolism indicators, whereas eight genera including Saccharomycopsis, Aspergillus, Penicillium and Pichia were more enriched in the gut of healthy pregnant women. To accurately identify the key fungi in the two groups, a random forest algorithm was used in the study for ranking. In addition, Spearman's correlation analysis revealed a significant correlation between the differential fungi and clinical indicators. Additionally, logistic multivariate regression analysis revealed that intestinal Saccharomyces acted as an independent protective factor against adverse pregnancy outcomes in pregnant women with GDM (OR = 0.206, 95CI%: 0.046-0.916, P = 0.038).

CONCLUSIONS

Pregnant women with GDM in the second trimester of pregnancy exhibit intestinal fungal dysbiosis. This dysbiotic state is associated with abnormal pregnancy-related clinical indicators and is also closely correlated with a significant increase in the risk of adverse pregnancy outcomes.