Oligofructose in infant formula, gut bacteria, stools and hydration over 8 weeks
What it found
Adding oligofructose to infant formula raised helpful gut bacteria and softened stools in babies over 8 weeks.
Hydration stayed normal across all groups.
What they found
Studies in people
Gut bacteria changes
Babies getting oligofructose had a bigger rise in bifidobacteria over 8 weeks than those on plain formula. Their increase matched what was seen in the breastfed babies.
Softer stools
At week 8, babies fed the oligofructose formula passed softer stools than those on plain formula. Their stool softness fell between the plain formula group and the breastfed group, without any change in how often they went.
Hydration stayed normal
Doctors checked weight, skin, mouth moisture and wet diapers at several points. Every baby in every group had normal hydration throughout the 8 weeks.
Other gut bacteria unchanged
Levels of other gut bacteria, including Bacteroides and clostridia, changed by about the same amount in both formula groups over the study.
Tummy troubles and dropouts
Stomach issues like spitting up happened equally in both formula groups. However, more babies left the oligofructose group because of these common tummy troubles, though none were serious.
What the authors conclude
- They conclude that adding 3.0 g/L of oligofructose to formula boosted helpful gut bacteria to levels similar to breastfed babies.
- They note that the added fiber softened stools without changing how often babies went or upsetting their water balance.
- The authors suggest future work should look at specific bacterial types and check whether these benefits last after babies stop taking the formula.
How it was done
Human milk contains natural fibers that feed gut bacteria and soften stools, but these are missing from standard formula. Manufacturers add plant fibers like oligofructose to copy this effect, though some worry extra fiber might upset a baby's water balance.
Ninety-five formula-fed babies were randomly given either a standard formula or the same formula with 3.0 g/L of oligofructose for 8 weeks. Fifty breastfed babies were also followed as a comparison group. Babies were between 5 and 14 days old when they started.
What it can’t tell you
- This trial only lasted 8 weeks, so it cannot show whether the effects on gut bacteria or stools continue long term.
- It also tested just one dose of oligofructose, so scientists do not yet know if different amounts would produce the same results.
Who paid
- Conflicts
- Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Susan Wernimont, Robert Northington, Manjiang Yao, and Jodi Bettler are employees of Nestlé Nutrition. Martin Kullen was an employee of Wyeth Nutrition at the time of the study and is currently employed by DuPont Nutrition & Health, Wilmington, Delaware.
The paper
- Title
- Effect of an α-lactalbumin-enriched infant formula supplemented with oligofructose on fecal microbiota, stool characteristics, and hydration status: a randomized, double-blind, controlled trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wernimont S, Northington R, Kullen MJ, Yao M, Bettler J (2015). Effect of an α-lactalbumin-enriched infant formula supplemented with oligofructose on fecal microbiota, stool characteristics, and hydration status: a randomized, double-blind, controlled trial. Clinical pediatrics. doi:10.1177/0009922814553433Free full textPubMed 25297064DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error