Feeding infants blueberries as one of their first solid foods could help strengthen their immune systems and support long-term gut health, according to new research from the University of Colorado Anschutz.
The clinical trial—published in the journal Nutrients and Frontiers in Nutrition—is the first to rigorously test the effects of a specific food on infant health using a double-blind, randomized, placebo-controlled design.
Blueberries, often considered a "superfood" for adults, have never before been studied in infants at this level.
"For parents beginning to wean their infants, it's incredibly difficult to find solid, research-backed advice on what foods to introduce," paper author and pediatrics researcher professor Minghua Tang said in a statement.
"This study is a critical first step in filling that gap by offering real data on how a specific food like blueberries can improve your infant's health."
The study tracked 61 infants in the Denver area, each aged between five and 12 months old. Each day, babies consumed either a freeze-dried blueberry powder or a placebo powder with no blueberries, while parents maintained their children's regular diets.
Every two months, researchers collected stool and blood samples to monitor gut bacteria, immune system markers and allergy-related outcomes. They also tracked growth and overall dietary habits.
The team found that babies and toddlers consuming blueberry powder showed improved allergy symptoms (symptoms were pre-existing and not caused by the blueberries).
Signs of reduced inflammation and a stronger immune response also appeared in this group, while gut microbiota shifted in ways considered beneficial for immune health.
To avoid choking hazards, the researchers recommend pureeing blueberries for younger infants and mashing or cutting them into small pieces for older babies and toddlers.
"This research supports the idea that blueberries are not only safe for infants but also offer meaningful health benefits," Tang said.
"Just a few blueberries a day could make a difference in supporting long-term health. We view infancy as a critical window of opportunity and what we introduce during this time can have lasting effects as children grow."
The team notes that more studies are needed to understand how other early foods may shape gut bacteria and immunity. With stronger guidance, parents could have clearer evidence about which first foods may best support their children's development.
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Reference
Glime, G. N. E., Matzeller, K. L., Frank, D. N., Kotter, C., Kofonow, J. M., Robertson, C. E., Venter, C., Campbell, W. W., Krebs, N. F., & Tang, M. (2025). 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. Frontiers in Nutrition, 12. https://doi.org/10.3389/fnut.2025.1623521