Gut Microbiome Composition and Metabolic Capacity Differ by FUT2 Secretor Status in Exclusively Breastfed Infants

Area of Science:

• Microbiome research
• Human genetics
• Infant nutrition

Background:

• The fucosyltransferase2 (FUT2) gene polymorphism affects gut disease risk.
• Secretor individuals have fucosylated mucosa, supporting gut bacteria.
• Maternal secretor status influences milk oligosaccharides, but infant impact was unknown.

Purpose of the Study:

• To investigate the impact of maternal and infant secretor status on the early infant fecal microbiome.
• To determine if infant FUT2 genotype or phenotype is more influential on the infant microbiome.

Main Methods:

• Analysis of fecal microbiome samples from 59 exclusively breastfed 2-month-old infants.
• Measurement of maternal and infant secretor status via FUT2 genotype and phenotype.
• Comparison of microbiome alpha diversity, enterotypes, and metabolic pathways based on secretor status.

Main Results:

• Infant secretor status, not maternal, strongly associated with infant microbiome composition.
• Higher alpha diversity observed in full-secretor infants compared to low- or non-secretors.
• Distinct microbial enterotypes linked to infant secretor phenotype, including Bifidobacterium dominance.

Conclusions:

• Infant secretor status is a key determinant of early gut microbial colonization and metabolic capacity in breastfed infants.
• FUT2 genotype and phenotype in infants play a crucial role in shaping their developing microbiome.
• Maternal secretor status has a lesser impact on the infant microbiome compared to infant's own status.