HMOs are unique carbohydrates that make up about 10% of the dry weight of mother’s milk. HMOs are not easily digested, so experts postulate that their purpose is to jump-start the infant’s microbiome as prebiotics.
There are over 130 different HMOs, and 2’-FL (2’-fucosyllactose) is the most abundant. As a result, it’s the most studied and the one that is already commercially available from a number of different suppliers, including dsm-firmenich, Novonesis (formerly Chr. Hansen), IFF (formerly DuPont), BASF and Friesland Campina, to name but a few.
As you would expect, the majority of the science to date has focused on infants, with a study published in Gut (He et al., 2016, Vol. 65, pp. 33–46) by scientists from Harvard Medical School indicating that 2’-FL could reduce the inflammatory response to pathogenic bacteria.
In addition, a 2017 paper by scientists from the Università di Palermo (Italy) and Nestlé reported that infants fed formula with 2′-FL and lacto-N-neotetraose (LNnT), another HMO, had lower levels of bronchitis and required fewer antibiotics (Journal of Pediatric Gastroenterology and Nutrition).
Results of a study published in the Journal of Nutrition in 2016 by scientists at Abbott Nutrition found that infants fed a formula with 2’-FL had levels of inflammatory cytokines similar to those observed for breast feeding and significantly lower than those observed for infants fed a control formula containing no 2’-FL.
Another Abbott study, this one published in 2023 in Nutrients found that infant formula with 2′-FL could modulate an infant’s microbiome to support immune homeostasis. The data also showed that 2’-FL can elevate the production of secondary microbial metabolites in the infant’s microbiome to levels closer to that seen in breastfed infants.
Through the ages
There is also data published in the scientific literature on the potential benefits in adults, with a 2016 study published in the British Journal of Nutrition (Elison et al. Vol. 116, pp. 1356-1368) concluding: “HMO supplementation specifically modified the adult gut microbiota with the primary impact being substantial increases in relative abundance of Actinobacteria and Bifidobacterium in particular and a reduction in relative abundance of Firmicutes and Proteobacteria.”
The University of Cincinnati is planning a pilot and feasibility study of 2′-FL as a dietary supplement in IBD patients. The study will examine the effects of 1 g, 5 g or 10 g 2′-FL (vs placebo) as a dietary supplement in pediatric and young adult IBD patients.
At the other end of the age spectrum, the bifidogenic effects of HMOs may also make these prebiotics interesting to aging populations, which are characterized by declining Bifidobacteria levels.
Combining 2’-FL with oligofructose may also produce important benefits in adults, according to findings published in the American Journal of Clinical Nutrition last year. Scientists from the University of Reading in the UK reported that the prebiotic combination could alter the microbial composition and alleviate stress-induced mood state in adults.
“This is the first study to demonstrate that intake of OF [oligofructose] and 2’FL can result in noticeable differences in microbial modulation and substantial improvements in mood,” they wrote.
More recently, researchers from Texas A&M University, the University of Memphis, and the University of California Davis reported that daily supplementation of 2′-Fucosyllactose (2′-FL) reduces body fat percentage and lessens the loss of fat-free mass in overweight individuals participating in a 12-week diet and exercise program.
The study, published in Nutrients, also found the human milk oligosaccharide (HMO) promoted beneficial changes in resting fat oxidation, peak aerobic capacity, IL-4 and platelet aggregation and improved participants’ ratings of quality of life.
Beyond 2’-FL
With a potential pipeline of over 130 HMOs to explore, interest has expanded beyond 2-‘FL. There is already data around LNnT, while some companies have achieved regulatory approval for 3-fucosyllactose (3-FL), 6’-sialyllactose (6’-SL), 3’-sialyllactose (3’-SL), and Lacto-N-tetraose (LNT)
The value of exploring the full range of HMOs was highlighted in a recent study led by scientists from the Children’s Hospital Los Angeles. Writing in the American Journal of Clinical Nutrition, they reported that analysis of the 19 most abundant HMOs in human milk samples taken one and six months after birth showed that consuming higher concentrations of LNnT, LNT, lacto-N-fucopentaose (LNFP)-III, 6’-SL and 2’-FL and lower concentrations of sialyllacto-N-tetraose (LST) b, LNFP-II, fucodisialyllacto-N-hexaose and 3-FL led to higher cognitive scores at two years of age.
Additional analysis revealed that the dominant effect was exerted by LNFP-III and LSTb.
“Our results also underscore the benefits of extending lactation, as exposure to HMOs at 6 months continued to positively influence cognition,” the researchers wrote.
“Although this study helped advancing the understanding of the role of HMOs in cognition, further research is needed to replicate our findings in the broader population and explore longitudinal effects and underlying mechanisms. These findings have implications for targeted nutritional interventions and public health initiatives aimed at supporting optimal cognitive development in infancy.”