Introducing blueberry powder as one of the first complementary foods changes the gut microbiota composition and diversity in U.S. human milk-fed infants: a double-blind, randomized controlled trial.

Introduction: Complementary feeding is a critical period marked by rapid changes in the infant's diet, nutrient needs, and gut microbiota. However, the effects of specific foods introduced during complementary feeding, such as blueberries, on the developing infant gut microbiota remain unclear. Our primary aim was to evaluate the effect of daily consumption of freeze-dried blueberry powder during complementary feeding on gut microbiota development in U. S. human-milk-fed infants. Methods: In a double-blind, randomized, placebo-controlled feeding trial, infants from the Denver metro area (Colorado, United States) were randomly assigned to consume up to 10 g of freeze-dried blueberry powder or an isocaloric placebo powder, combined with liquid or semi-liquid and served as a puree, daily from 5 to 12 months of age. Stool samples were collected bimonthly to assess gut microbial diversity and composition. Novel taxa were identified through parsimony insertion into the SILVA reference phylogenetic tree. Infant length, weight and dietary intakes were also assessed. Results: Seventy-six caregiver-infant pairs consented and enrolled in the study and 61 completed the study (blueberry group Conclusion: Introducing blueberries as one of the first complementary foods, in the form of freeze-dried powder served as a puree, exerts potential benefits in gut microbiota development and maturation in this cohort of human-milk-fed infants. Systematic review registration: https://clinicaltrials.gov/study/NCT05006989.