Breastfeeding, early-life feeding practices and adolescent gut microbiota: Long-term associations in a birth cohort

Resumo

Background & aims
Breastfeeding plays a critical role in shaping the infant gut microbiome by promoting the growth of beneficial bacteria essential for intestinal health. However, its long-term impact remains poorly elucidated. This study investigates the association between breastfeeding practices and gut microbiota diversity and composition in adolescence.
Methods
We analyzed data from 362 participants in the birth cohort, with breastfeeding history at three months as the primary exposure. Additional exposures included breastfeeding duration, and timing and type of complementary food introduction. Gut microbiota was assessed at 12 years through 16S rRNA gene sequencing (V3–V4 region) of DNA from fecal samples. Alpha (Chao1, Simpson, Shannon) and beta diversity (weighted and unweighted UniFrac) metrics, alongside relative taxonomic abundances, were evaluated as primary outcomes.
Results
No significant differences were observed in microbial diversity between exclusive breastfed (EBF), mixed feeding and non-breastfed groups at three months. However, relative abundance analyses suggested associations between breastfeeding patterns at three months and specific bacterial taxa. Non-breastfed children exhibited a higher relative abundance of Ruminococcus (β = 0.44; 95% CI: 0.11–0.74) compared to EBF, while those who had mixed breastfeeding showed an association with a higher probability of Alloprevotella detection at age 12 (OR = 2.82; CI 95% 1.14; 6.95). These associations did not remain significant after multiple testing correction. Early introduction of liquids (<6 months) was associated with lower Ruminococcus abundance (β = −0.40; 95% CI: 0.72–0.07), whereas early introduction of semi-solid foods was linked to lower odds of Alloprevotella presence (OR = 0.35; 95% CI: 0.15–0.82).
Conclusions
Although breastfeeding and early dietary practices may exert lasting effects on adolescent gut microbiota composition, these associations appear modest. Further research with larger cohorts and multi-omics approaches is needed to clarify the underlying mechanisms and clinical implications.