Gestational diabetes-combined excess weight gain exacerbates gut microbiota dysbiosis in newborns, associated with reduced abundance of Clostridium, Coriobacteriaceae, and Collinsella

Abstract

Background: Existing literature indicates that Gestational diabetes mellitus (GDM) and maternal obesity disrupt the normal colonization of the neonatal gut microbiota alone. Still, the combined impact of GDM and excessive gestational weight gain (EGWG) on this process remains under explored. The association between gestational weight gain before/after GDM diagnosis and neonatal gut microbiota characteristics is also unclear.The purpose of this study is to conduct investigation and analysis on the above-mentioned issues, providing a basis for optimizing clinical management plans.

Methods: This study involved 98 mother-infant pairs categorized into GDM and non-GDM groups. The GDM group was further subdivided based on gestational weight gain (GWG) into normal (GDM+NGWG) and excessive (GDM+EGWG) weight gain groups. Neonatal stool samples were collected within 24 hours post-delivery for gut microbiota profiling through 16S rRNA gene sequencing. Statistical analyses explored correlations between total GWG/BMI gain and those before/after GDM diagnosis (t-GWG/GBG; b-GWG/GBG; a-GWG/GBG) with key bacterial taxa.

Results: Notable genus-level changes included enrichment of Escherichia and Klebsiella, and depletion of Bacteroides, Bifidobacterium, Coprococcus, Ruminococcus among GDM-Total and GDM+EGWG groups compared to non-GDM. Further,LEfSe analysis identified 30 differential bacteria taxa between GDM-Total and healthy control groups, which increased to 38 between GDM+EGWG and non-GDM groups, highlighting more pronounced microbial shifts associated with EGWG. Clostridium was negatively correlated with t-GWG and newborn birth weight; The Coriobacteriaceae showed a negative correlation with t-GWG, t-GBG, and a-GBG. Additionally,Collinsella exhibited negative correlations with t-GBG and a-GBG.

Conclusion: This study has identified that the presence of EGWG in GDM mothers further exacerbated neonatal gut microbial perturbations. Total GWG/GBG and those after the diagnosis of GDM were negatively correlated with the abundance of neonatal gut Clostridium, Coriobacteriaceae, and Collinsella. These findings provide new insights for precise prevention and management of GDM.

Keywords: 16S rRNA; excessive gestational weight gain; gestational diabetes mellitus; gut microbiota; newborns.

Figure 1

The workflow of study design.

Figure 2

Alpha and beta diversity of gut microbiota in offspring. (A) Comparisons of Chao, ACE, Shannon, Simpson, and Coverage diversity indices among offspring born to mothers with non-GDM, GDM-Total, and GDM+EGWGgroups, with PERMANOVA results indicating beta diversity differences between groups; (B, C) Principal Coordination Analysis (PCoA) based on unweighted UniFrac distances, illustrating microbial community structures in offspring born to mothers in the non-GDM group compared to those in the GDM-Total (B) and GDM+EGWG (C) groups.

Figure 3

Gut Microbiota Analysis in Offspring from GDM+NGWG and GDM+EGWG Groups. (A) Alpha diversity indices (Chao1, ACE, Shannon, Simpson, and Coverage) and beta diversity (PERMANOVA) comparing microbiota diversity between GDM-NGWG and GDM-EGWG groups, with P-values indicating significance.; (B) Principal Coordinate Analysis (PCoA) based on unweighted UniFrac distances, showing microbial community differences between the groups; (C, D) Relative abundances of microbial phyla (C) and genera (D) in offspring from the GDM+NGWG and GDM+EGWG groups; (E) LEfSe analysis, with a cladogram (left) showing differentially abundant taxa and an LDA score plot (right) displaying the effect size of these taxa, with purple indicating enrichment in the GDM+NGWG group and blue in the GDM+EGWG group.

Figure 4

Differential Bacteria in GDM-Total and GDM+EGWG groups compared to non-GDM. (A-B) Relative proportions of abundant microbes at the phylum (A) and genus (B) levels in offspring born to mothers in the non-GDM, GDM-Total, and GDM+EGWG groups; (C, D) LEfSe analysis of gut microbiota in offspring born to mothers in the GDM-Total versus non-GDM groups (C) and the GDM+EGWG versus non-GDM groups (D). The left side of each panel displays a cladogram (branch diagram) that illustrates the taxonomic hierarchy of bacterial taxa with significant differences in abundance between groups, colored according to the group in which they are enriched. The right side shows a corresponding histogram (LDA score plot) where the length of each bar represents the LDA score, indicating the effect size of each differentially abundant taxon, with colors denoting enrichment in the respective group (orange for GDM-Total, blue for GDM+EGWG, and gray for non-GDM).

Figure 5

Ecological association networks in the GDM-Total and GDM-EGWG groups. Nodes represent the top 20 genera by abundance, with edges illustrating the predicted ecological interactions between these genera. The size of each node corresponds to the strength of interaction, with larger nodes indicating more central or influential genera within the network. Different color blocks highlight distinct modularity classes, indicating clusters of genera that are more closely associated with each other within each group’s microbial community network.

Figure 6

Associations of Pregnancy weight gain with altered gut bacteria. (A) Heatmap showing the Spearman’s rank correlation coefficients between six pregnancy weight gain indices (t-GWG, t-GBG, b-GWG, b-GBG, a-GWG, a-GBG, NBW) and 21 gut bacterial taxa. Positive correlations are indicated in orange, and negative correlations in blue, with color intensity reflecting the strength of the correlation (P < 0.05). (B) Scatter plots illustrating significant correlations between key bacterial taxa (Coriobacteriia, Collinsella, Clostridium) and various pregnancy weight gain indices, highlighting relationships with specific time points (before OGTT, after OGTT, total pregnancy); (C) Line graphs summarizing the correlations of Collinsella, Clostridium, and Coriobacteriia with clinical indicators at different pregnancy stages. Colors represent the timing of weight gain: brown for pre-pregnancy to OGTT, blue for OGTT to pre-delivery, and orange for pre-pregnancy to pre-delivery. Shapes indicate the specific weight gain indices: circles for GBG and triangles for GWG. The gray line represents the 0.002 significance threshold.