Related differences in fecal bacteria of Chinese northern pregnant women of different ages: associations with maternal clinical indicators and neonatal outcomes

Abstract

The gut microbiota, a vital "microbial organ," influences digestion, immunity, and metabolism. Aging alters gut microbiota of pregnant women through metabolic and hormonal pathways, thereby impacting neonatal health. In this study conducted in northern China, we compared two groups: advanced maternal age (AMA, ≥35 years) and younger maternal age (YMA, 20-34 years), analyzing fecal bacteria and maternal metabolism via biomarker measurements and microbial sequencing. Results showed AMA had significantly higher serum levels of alkaline phosphatase (AKP), 25-hydroxyvitamin D [25(OH)D], and creatinine, while YMA exhibited higher Cu but lower Fe concentrations. Although the fecal bacteria of AMA participants showed greater diversity, the YMA group displayed a more stable bacterial composition, characterized by a higher abundance of beneficial bacteria (e.g., Bifidobacterium) and a lower prevalence of potential pathogens (e.g., Streptococcus). Metabolically, the fecal bacterial network in YMA participants was more integrated, whereas the AMA group showed a "high-complexity, low-efficiency" pattern with disrupted metabolic pathways, which may contribute to adverse pregnancy outcomes. This study highlights age-related dysbiosis of the fecal bacteria in pregnant women and its impact on maternal and neonatal health, advocating for personalized prenatal care strategies for women with AMA.

Keywords: age; clinical indicators; fecal bacteria; microbiota dysbiosis; pregnant women.

Figure 1

The linear regression scatter plots of height, weight and Apgar score of AMA (A) and YMA (B).

Figure 2

Analysis of diversity index differences in fecal bacterial communities between AMA and YMA groups. (A) Shannon’s diversity index. (B) Chao 1 index. (C) Observed species. (D) Inter-group differential OTUs.

Figure 3

PCA score plot (A) and PCoA score plot (B) for fecal bacterial communities of AMA and YMA groups.

Figure 4

Accumulation maps of fecal bacterial community composition and dominant species maps for AMA and YMA groups at the phylum level (A,B), genus level (C,D), and species level (E,F).

Figure 5

Top 10 differences in relative abundance of species among AMA and YAM (A, phylum level, B, genus level, C, species level).

Figure 6

Co-occurrence of microorganisms in AMA (A) and YMA (B).

Figure 7

Correlation analysis of physiological indicators and neonatal indices for the AMA (A) and YMA (B) groups.

Figure 8

Mantel test of physicochemical indicators and bacterial communities for the AMA (A) and YMA (B) groups. Linear regression analysis of AKP and Hb in the blood of the AMA (C) and YMA (D) groups.

Figure 9

Correlation analysis between serum indices and major bacterial genera for the AMA (A) and YMA (B) groups.