Gut microbiota changes linked to gestational diabetes risk

Gut microbiota changes linked to gestational diabetes risk | Image Credit: © sdecoret - © sdecoret - stock.adobe.com.

Certain gut microbiota signatures have been linked to gestational diabetes mellitus (GDM) incidence, according to a recent study published in Microbiology Spectrum.¹

Gut microbiota signatures linked to gestational diabetes

The data highlighted significant differences in gut microbiota composition among patients with gestational diabetes vs those with healthy pregnancies. According to investigators, this information may be used to inform the prevention and management of gestational diabetes.

“These findings suggest that microbiota-based tools could enable early, non-invasive detection of gestational diabetes mellitus, offering new opportunities for prevention and personalized management,” wrote investigators.

Data and sample collection

The trial was conducted to compare gut microbiota composition among pregnant women with GDM vs healthy pregnancy.² Pregnant women aged 18 to 40 years and at 11- to 13-weeks’ gestation during recruitment were recruited and classified based on GDM status.

Patients with type 1 or 2 diabetes, Functional gastrointestinal disorders, in vitro fertilization use, multiple pregnancies, or hormonal treatments or antibiotic use in the past 3 months were excluded.

Electronic medical records were assessed for clinical data such as GDM diagnoses. Medical records were also assessed for demographic, clinical, and obstetric data. Height, weight, fecal samples, and other relevant baseline data were obtained at recruitment.

The control group included women with no complications that would influence gut microbiota composition during pregnancy, while the GDM group included those with a GDM diagnosis during pregnancy. The diagnosis was based on World Health Organization recommendations.

Fecal sample processing and DNA sequencing

Tubes with nucleic acid preservation buffer were used by participants at home for fecal sample collection. These samples were transferred to the laboratory within 24 hours and stored at −80°C.

The Fecal Genomic DNA Extraction Kit (AU46111-96, BioTeke, China) was used to extract fecal DNA for sequencing. Cutadapt and FLASH software were used to process raw sequencing data. Low-quality reads, sequences shorter than 100 bp, and those with over 5% ambiguous bases were filtered.

Key microbial findings in healthy pregnancies

There were 61 healthy women aged 18 to 40 years included in the final analysis. These patients provided fecal samples at 11- to 13-weeks’ gestation and blood samples at 24- to 28-weeks’ gestation.

At 11- to 13-weeks’ gestation, Firmicutes, Bacteroidota, Proteobacteria, Actinobacteriota, and Verrucomicrobiota were identified as the predominant components of gut microbiota. Of these, Verrucomicrobiota may have unique effects of pregnancy through maintaining mucosal integrity and immune modulation.

Porphyromonas, Escherichia-Shigella, Akkermansia, Lactobacillus, Prevotella, and Bifidobacterium were identified at a genus level. Akkermansia has been indicated as vital for maintaining gut mucosal barrier integrity, which may be pivotal for a healthy pregnancy. Pregnancy-associated infections may also be prevented through lactic acid production by Lactobacillus.

Microbiota differences between GDM and control groups

When comparing GDM cases with controls, both groups had Firmicutes with the most relative abundance, followed by Proteobacteria and Bacteroidota. However, the GDM group had lower Firmicutes and higher Proteobacteria, highlighting a potential link between GDM and dysbiosis.

GDM patients also showed a more diverse microbial composition at the genus level. This included an increased relative abundance of pathogenic genera such as Escherichia-Shigella and Klebsiella, while beneficial genera such as Bifidobacterium, Faecalibacterium, and Akkermansia were reduced.

The GDM and control groups shared 19 microbial phyla at 11- to 13-weeks’ gestation, which comprised 73.08% of all identified phyla. However, 11.54% of detected phyla were found only in the GDM group, and 15.38% only in the control group.

Implications for early prediction

Proteobacteria and Actinobacteriota were found as the dominant phyla in GDM patients. This highlighted a potential increase in chronic low-grade inflammatory risk, potentially contributing to GDM pathogenesis. Overall, the data showed significant differences in gut microbiotas of GDM patients vs healthy controls.

“These results provide a foundation for new strategies in GDM early warning and intervention and lay the groundwork for developing gut microbiota-based diagnostic tools and therapeutic approaches,” wrote investigators.

References

1. Gut microbiota analysis can help catch gestational diabetes. American Society for Microbiology. July 1, 2025. Accessed July 14, 2025. https://www.eurekalert.org/news-releases/1089420.
2. Yao W, Wen R, Huang Z, et al. Gut microbiota composition in early pregnancy as a diagnostic tool for gestational diabetes mellitus. Microbiology Spectrum. 2025. doi:10.1128/spectrum.03390-24