Human milk oligosaccharides (HMOs) are the third most abundant solid component in human milk after lactose and lipids. Preclinical research has demonstrated that HMOs and specifically 2′-fucosyllactose (2′-FL) are more than a prebiotic and have multiple functions, including immune, gut, and cognition benefits. Previously, human milk has been the only source for significant levels of HMOs. The most abundant HMO in most mothers’ breast milk is 2′-FL. Recently, 2′-FL has been synthesized and shown to be structurally identical to the 2′-FL found in human milk. 2′-FL HMO is now available in some commercial infant formulas. The purpose of this narrative review was to summarize the clinical experiences of feeding infant formula supplemented with the HMO, 2′-FL. Most of these studies investigated standard intact milk protein-based infant formulas containing 2′-FL, and one evaluated a partially hydrolyzed whey-based formula. Collectively, these clinical experiences demonstrated that 2′-FL being added to infant formula was safe, well-tolerated, and absorbed and excreted with similar efficiency to 2′-FL in human milk. Further, infants that were fed formula with 2′-FL had immune benefits, fewer parent-reported respiratory infections, and improved symptoms of formula intolerance. Ultimately, infant formula with 2′-FL supports immune and gut health and is closer compositionally and functionally to human milk.

Partially hydrolyzed formulas (pHF) represent a significant percentage of the infant formula market. A new whey-based, palm olein oil (PO)-free pHF was developed and a masked, randomized, parallel growth study was conducted in infants fed this formula or a commercially available whey-based pHF with PO. Infants between 0 and 8 days were to be enrolled and studied to 119 days of age. Growth and tolerance of infants were evaluated. Mean weight gain from 14 to 119 days of age was similar between groups. There were no significant differences between groups in weight, length, head circumference (HC), or length or HC gains. Infants fed the new PO-free pHF had significantly softer stools than those fed the PO-containing formula except at 119 days of age. This study demonstrates that whereas growth of infants fed different formulas during the first 4 months of life may be similar, infants may tolerate individual formulas differently.

ObjectiveHuman milk oligosaccharides (HMOs) are the third largest solid component in mature human milk. The objective of this study was to evaluate gastrointestinal tolerance of infants fed infant formula supplemented with short‐chain fructooligosaccharides (scFOS) and 2‐fucosyllactose (2′FL).MethodsWe conducted a prospective, randomized, multi‐center, double‐blinded, controlled 3‐arm tolerance study in full term, singleton infants (birth weight ≥ 2490g) enrolled between 0 and 8 days of age. At enrollment, formula‐fed infants were randomized to one of two experimental milk‐based infant formulas with a caloric density of 643 kcal/L. Experimental Formula 1 (EF1) did not contain oligosaccharides (n=42) and Experimental Formula 2 (EF2) contained 2g/L scFOS and 0.2g/L 2′FL (n=46). The 2 formula groups were compared with a human milk‐fed (HM) reference group (n=43). Infants were exclusively fed formula or human milk from enrollment until 35 days of age. Data related to intake, stool patterns, anthropometrics and parental questionnaires were collected. The primary outcome was average mean rank stool consistency (MRSC) from Study Day 1 to Visit 3. MRSC was calculated from stool records (1=watery, 2=loose/mushy, 3=soft, 4=formed, 5=hard).ResultsThirty‐six (86%) subjects in the EF1 group, 41 (89%) in the EF2 group and 42 (98%) in the HM group completed the study. There were no differences among groups for gender, ethnicity, race, gestational age, birth weight or age at enrollment. Reported results are from the protocol evaluable analysis. From Study Day 1 to Visit 3, there were no differences in MRSC among the three feeding groups. MRSC was 2.37 ± 0.10, 2.15 ± 0.10 and 2.06 ± 0.08 for the EF1, EF2 and HM groups respectively. There were also no differences among groups for predominant stool consistency from Study Day 1 to Visit 3. The average number of stools per day for the HM group was significantly greater than EF1 (p<0.0001) and EF2 (p<0.0001) from Study Day 1 to Visit 3. At Visit 3, there were no differences between groups for average volume of study formula intake, number of study formula feedings per day, anthropometric data or percent feedings with spit‐up/vomit.ConclusionAn experimental formula containing 2′FL and scFOS was well tolerated in young infants as evidenced by stool consistency, formula intake, anthropometric data and percent feedings with spit‐up/vomit similar to that of infants fed formula without oligosaccharides or HM.Support or Funding InformationThis study was funded by Abbott Nutrition, Abbott Laboratories, Columbus, OH.