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Randomized, placebo-controlled trial reveals the impact of dose and timing of Bifidobacterium infantis probiotic supplementation on breastfed infants’ gut microbiome

C. O'Brien, Steven A. Frese, Karina Cernioglo, K. Damián-Medina, Ryan D. Mitchell, G. Casaburi, R. A. Melnyk, B. Henrick et al.

Msphere, 2025

40 participants · 6 citations

Abstract

ABSTRACT A dysfunctional gut microbiome has become increasingly common in infants born in high-income countries as Bifidobacterium strains no longer dominate the gut microbiome. Probiotics containing Bifidobacterium infantis have been used in breastfed newborns to successfully restore the gut microbiome; however, no studies to date have demonstrated this effect in older breastfed infants whose gut microbiomes are transitioning toward stability and maturity. This is a 9-week randomized controlled trial wherein 2–4 months old exclusively breastfed infants (n = 40) received 0 CFU/day B. infantis EVC001 (placebo), 4.0 × 109 CFU/day B. infantis EVC001 (low), 8.0 × 109 CFU/day B. infantis EVC001 (medium), or 1.8 × 1010 CFU/day B. infantis EVC001 (high) in equal allocation for 28 consecutive days beginning on day 8. Stool samples were collected on study days 7, 10, 14, 21, 28, 35, 42, and 63. Fecal B. infantis levels were significantly higher in all supplement groups compared with placebo on day 28 and day 63. On day 28, fecal B. infantis levels were significantly higher in infants who received any (low, medium, and high) dose compared with baseline. The abundance of fecal Bifidobacteriaceae significantly increased nearly 2-fold in response to B. infantis EVC001 supplementation. No matter the dose, probiotic supplementation with B. infantis in 2- to 4-month-old exclusively breastfed infants resulted in colonization until at least 1 month post-supplementation. IMPORTANCE This study…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 40 participants or records.

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