Probiotic Modulation of Maternal Gut and Milk Microbiota and Potential Implications for Infant Microbial Development in the Perinatal Period

KIAN DENG TYE¹XiaoYi Liu²Chan Huang¹Chen Li¹ChaoLi Wu¹JunLue Lin¹YongJin Yu¹XinZi Lin^1*

• ¹Obstetrics Department, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
• ²The First Affiliated Hospital of Jinan University, Guangzhou, China

Background: Probiotics are live microorganisms that may enhance or restore gut microbiota. They are often recommended during pregnancy and infancy for potential benefits, but evidence is inconclusive. This study aimed to investigate probiotic supplementation's effects on maternal and infant gut and milk microbiota and its link to nutrient intake during pregnancy. Method: A total of 23 pregnant women were enrolled and divided into a probiotic group (n = 11) and a non-probiotic control group (n=12). Probiotic effects were evaluated through fecal and milk microbiota analysis via 16S rRNA gene sequencing. Nutrient intake data were collected to assess differences linked to probiotics. Key microbiota diversity and richness were analyzed using linear discriminant analysis effect size (LEfSe) and weighted gene co-expression network analysis (WGCNA) to explore associations with diet and sample characteristics. Predictive microbial pathway characteristics were identified using time series analysis, random forest algorithms, and logistic regression models. Results: Nutrient intake did not significantly differ between groups, and overall microbial diversity and richness were stable. However, LEfSe revealed distinct genera in both maternal gut and milk microbiota linked to probiotic intake. WGCNA identified microbial modules correlated with specific nutrient patterns and sampling conditions. Predictive genus clusters associated with probiotics demonstrated robust classification performance, suggesting functional shifts in microbial communities with potential implications for immune programming in early life. Conclusion: Probiotic supplementation during pregnancy may modulate key microbial taxa in maternal gut and milk, potentially influencing microbial recognition and immune signaling in the maternal–infant dyad. These findings highlight complex diet–microbiota– immune interactions within reproductive and lactational systems, offering insights into strategies for enhancing maternal and neonatal health resilience.