Feeding Type Shapes Infant Gut Microbiota and Metabolite Profiles in a Simulated Colonic Model

Area of Science:

• Infant nutrition and gut microbiome research.
• Microbial ecology and metabolomics.

Background:

• Infant gut microbiota establishment is influenced by feeding type.
• Human milk (HM) and infant formula (IF) induce distinct microbial profiles.

Purpose of the Study:

• To compare the effects of raw HM, pasteurized HM (Past-HM), and infant formula (IF) on infant gut microbial composition and metabolite production.
• To investigate the impact of feeding type on microbial diversity and short-chain fatty acid (SCFA) profiles in an in vitro infant gut model.

Main Methods:

• Utilized a 4-stage in vitro infant gut model inoculated with infant fecal samples.
• Employed quantitative polymerase chain reaction (qPCR) and 16S rRNA gene sequencing for microbial profiling.
• Analyzed short-chain fatty acid (SCFA) profiles using gas chromatography.

Main Results:

• Feeding type was the dominant factor influencing microbiota and metabolite profiles.
• Past-HM and goat milk-based IF (GIF) promoted Bifidobacterium dominance and higher total SCFAs, particularly acetic acid, compared to raw HM.
• Specific correlations were observed between Bifidobacterium and acetic acid, and Escherichia-Shigella and propionic acid.

Conclusions:

• Early feeding choices critically direct infant gut microbial colonization and metabolic activity.
• Pasteurization of human milk may alter its impact on the developing infant gut microbiome compared to raw human milk.