Mixed

In pregnant women, higher fecal abundance of Bifidobacterium and Bacteroides is associated with normal pre-pregnancy BMI and normal gestational weight gain, whereas higher abundance of Staphylococcus, Enterobacteriaceae, and Escherichia coli is associated with overweight status and excessive weight gain.

This observational study suggests that maintaining a healthy weight during pregnancy is associated with a gut microbiome rich in Bifidobacterium and Bacteroides, and lower in E. coli and Staphylococcus. While this paper does not prescribe a specific probiotic regimen, it highlights the importance of dietary patterns (like fiber intake, which was slightly higher in normal-weight women) that support these beneficial bacterial populations. Pregnant women should focus on a balanced diet to support a healthy microbiome, as aberrant microbiota may be transferred to the newborn.