A Pilot Study Exploring the Relationship Between Milk Composition and Microbial Capacity in Breastfed Infants

Area of Science:

• Microbiome research
• Human milk oligosaccharides (HMOs)
• Infant gut microbiome

Background:

• Maternal obesity is linked to childhood obesity, potentially via infant gut microbiome alterations.
• Human milk oligosaccharides (HMOs) are key modulators of the infant gut microbiome.
• Maternal diet and BMI may influence HMO profiles and infant gut microbial colonization.

Purpose of the Study:

• To characterize HMO profiles in normal-weight versus overweight/obese mothers.
• To quantitatively link HMO concentrations to infant gut microbiome composition and function.
• To investigate the impact of maternal BMI on milk HMOs and infant gut microbial ecology.

Main Methods:

• Cross-sectional pilot study of 9 normal-weight and 11 overweight/obese breastfeeding mothers and their infants.
• Collection of human milk and infant rectal swabs 7-9 weeks postpartum.
• Analysis of HMOs (HPLC), microbiome composition (16S rRNA sequencing), and microbial functions (metagenomic sequencing).

Main Results:

• No significant differences in HMO profiles or infant microbiome composition based on maternal BMI.
• Infant gut microbiota dominated by Bifidobacterium and other typical lineages.
• Positive correlations found between specific HMOs (LNnT, LNH) and the bacterial genus Prevotella.
• Identified HMO-degradative capacity within Bifidobacterium and Prevotella genera.

Conclusions:

• Maternal BMI status does not appear to influence human milk HMO profiles.
• Specific HMOs correlate with infant gut bacterial taxa, impacting microbiome composition.
• Human milk composition plays a role in shaping the infant gut microbiome's taxonomic and functional potential.