Karen Harris

Karen Harris is a professional writer and editor with more than two decades of experience in research-driven nonfiction writing. With a background in journalism and a Master's degree in English, she brings a meticulous approach to fact-finding, source evaluation, and clear communication of complex topics. Her work spans health, lifestyle, and consumer education, always with a focus on accuracy and readability.

Context

Human milk oligosaccharides (HMOs) are among the most abundant components of breast milk and are known to shape the infant gut microbiome. Standard cow's milk-based infant formulas historically contain very low levels of oligosaccharides that do not match those found in human milk. This trial investigated whether adding two specific HMOs to infant formula could shift gut microbiota composition closer to that of breastfed infants and whether those microbiota changes were associated with later infection-related health outcomes.

Study Overview

Design: Randomized, double-blind, controlled, multicenter clinical trial with microbiota sub-analysis


Population: 175 healthy, full-term formula-fed infants (0–14 days at enrollment); 35 breastfed infants as reference group


Follow-up: 12 months


Funding: Fully funded by Société des Produits Nestlé SA; most authors are Nestlé employees


Evidence Certainty (GRADE): Not formally GRADE-rated; exploratory/secondary analysis of a safety trial


Comparison:

  • Test group: Infant formula + 2 HMOs (2′-fucosyllactose [2′FL] + lacto-N-neotetraose [LNnT]) from 0–6 months
  • Control group: Same formula without HMOs, 0–6 months
  • Reference group: Exclusively breastfed infants (non-randomized)
  • Both formula groups received the same HMO-free follow-up formula from 6–12 months

Key Findings

  • At 3 months, the gut microbiota of HMO-supplemented infants was significantly closer to that of breastfed infants in terms of diversity and bacterial composition, compared to the control formula group.
  • HMO supplementation increased the proportion of infants with a high-Bifidobacterium gut community type (FCT BiH) - the type predominant in breastfed infants - at the expense of a lower-Bifidobacterium type (FCT Bi) more common in control formula-fed infants.
  • The effect was especially pronounced in infants born by Caesarean section.
  • Infants with FCT BiH at 3 months were significantly less likely to require antibiotics in the first year of life (OR 0.4; 95% CI 0.17–0.93; p = 0.033) compared to those with FCT Bi.
  • At 12 months (6 months after stopping HMO supplementation), microbiota differences between formula groups were no longer statistically significant.
  • No significant differences in antibiotic or antipyretic use reached statistical significance at the overall group level (ITT analysis).

Limitations

  • This microbiota analysis was a secondary, exploratory objective of a trial powered for safety - not for microbiota or clinical outcomes.
  • Only two stool sampling time points (3 and 12 months); no intermediate data.
  • Significant dropout reduced the per-protocol population, potentially affecting statistical power.
  • The breastfed group was non-randomized and enrolled separately, limiting direct comparisons.
  • Timing of solid food introduction and daycare attendance - both major infection risk factors - were not recorded.
  • Entirely industry-funded; the majority of authors are employed by Nestlé.

Neutral Interpretation

This study provides exploratory evidence that supplementing infant formula with two HMOs (2′FL and LNnT) can shift the gut microbiota of formula-fed infants toward a composition more similar to breastfed infants during the intervention period. The association between a high-Bifidobacterium gut community type and reduced antibiotic use is biologically plausible but hypothesis-generating rather than confirmatory, given the exploratory design, full industry funding, and absence of effect at 12 months. Independent replication in larger, independently funded trials is needed before clinical conclusions can be drawn.

Full Citation

Berger B, Porta N, Foata F, et al. Linking Human Milk Oligosaccharides, Infant Fecal Community Types, and Later Risk To Require Antibiotics. mBio. 2020;11(2):e03linking. 

PMID: 32184252. 

Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC7078481/

Disclosure

This summary is based on the published study. It is provided for informational purposes only and does not constitute medical advice.