Abstract
Objective
To clarify the impact of maternal nutrition and breastfeeding on infant gut microbiota development.
Methods
In a cohort of 67 mother-infant dyads, maternal diet and milk composition were analyzed alongside longitudinal infant fecal 16S rRNA profiling at 42 days, 6 months, and 12 months.
Results
The infant gut microbiota underwent marked shifts over the first year, with increases in
Firmicutes
and
Bacteroidota
, decreases in
Actinobacteriota
and
Proteobacteria
, and increasing alpha diversity. Feeding mode was the strongest predictor of infant gut microbiota. Feeding mode, delivery mode, maternal dietary deficiency, complementary feeding timing, and breast-milk density were each associated with distinct microbial taxa, with 14 genus-/phylum-level associations identified.
Conclusion
Significant phylum-level shifts occurred over the first year, specifically increases in
Firmicutes
and
Bacteroidota
. Feeding mode was the dominant predictor of microbiota composition at 12 months, with additional associations for delivery mode, complementary feeding timing, maternal dietary deficiency, and breast-milk density.