The “INSPIRE” project and the research as well as the results it generated demonstrate the global variation of HMOs, both the quantity of total HMOs in milk and their individuality. Furthermore, the percentage of secretor to non-secretor mothers is also different depending on location, even within the same ethnicity.
Relationships are present between HMOs and the milk microbiome, especially in non-secretory mothers and the relationship seems to be location/site specific. For example, the relationship of total HMO and relative abundance of Staphylococcus. In addition, there is a relationship between HMO and immune factors in milk, such as IgG and IgM being positively associated with Sialic HMOs. Hence, it is clear HMOs are related to variety of factors in the breastmilk.