A future perspective of HMOs role in Allergy Prevention

Author(s):
Carine Blanchard, PhD

Human Milk Oligosaccharides (HMOs) are the third most abundant component in breastmilk. It has been linked to gut microbiome and immune development, which are both crucial factors in allergic sensitisation. However, observational studies have been inconclusive in establishing the direct link between HMOs and allergy development.

Preclinical studies on the other hand show that components of HMOs, particularly 2’FL, 3’SL, 6’SL and LNT, have been able to modulate allergic responses in animal models. At the same time, HMOs show promise in improving the amount of beneficial bacteria in the gut that allows for better immune response and lowers risk of developing allergies.

Key messages:

• Preclinical data have shown that 2’FL, 3’SL, 6’SL and LNT can modulate allergic response.

• Observation study associating breast milk HMO composition with allergic sensitisation or disease in infants did not reach a consensus.

• HMO-induced cross feeding of bifidobacteria and production of SCFA and metabolites is a first step in the understanding of the mechanism of action.


Human Milk Oligosaccharides (HMOs) are the third most abundant component in breast milk after fat and lactose. More than 200 lactose-based complex and diverse glycans compose this HMO family. HMOs have been shown to improve immune function, strengthen the gut barrier, and promote the growth of beneficial colonic bacteria in infants. Interestingly, the above are also underlying mechanisms involved in allergic sensitisation.

Allergic development is confounded by many genetic and environmental parameters and observational studies looking at the link between allergy and HMO consumption have thus yielded divergent results.