Researchers examined the effect of dietary patterns on HMO concentrations and observed increased oligosaccharide content in mothers on plant-rich diets, suggesting “additional benefits for increasing vegetable consumption”.
Plant-derived macronutrients were among the main dietary components that correlated with HMO status, especially in relation to 3-fucosyllactose (3-FL) levels, along with multiple vitamins and metal ions.
The study authors’ said: “Higher vegetable intake in mothers is associated with lower incidence of allergy in offspring. Our results suggest a beneficial role of eating vegetables with regards to HMO levels in breastmilk.”
HMOs are the third largest component of breastmilk and support the developing immune system of infants, help regulate intestinal microbiota, and inhibit propagation of pathogens.
While diet is a key factor in both maternal and infant health, experts are unclear about its influence on human milk composition and specifically HMO concentrations.
A cohort of 277 healthy women with "adequate dietary intake” were selected for the Chinese study. Mothers provided breastmilk samples at five stages during gestation and up to 400 days postpartum.
HMOs in samples were determined by high-performance anion exchange chromatography with pulsed amperometric detector (HPAEC-PAD) and dietary data collected through food frequency questionnaires (FFQ) on the day of milk collection.
The study focused on six main oligosaccharides representing all major HMO types (fucosylated, sialylated, and acetylated) and 40% of existing oligosaccharides. In all, 82 nutrient data items were calculated.
Analyses identified multiple vitamins and metal ions implicated in HMO synthesis through enzyme modulating activity.
“HMOs are biosynthesized by non-template-directed process glycosyltransferase. Therefore, we hypothesize that in cases where adequate nutrition is present the activity of glycosyltransferases may be a key factor for enhancing HMO concentration,” they authors said.
Vitamins B1 and B2 were positively associated with 2’-fucosyllactose (2’-FL) and the abundance of 2-‘FL and 3-FL, while vitamins A, C and vegetables were considered predictive factors for 3-FL. Moreover, metal elements (such as ferrum, kalium, and manganese) were linked to the sum of all HMOs included in the study, as well as to 3’sialyllactose (3’-SL) along with tocopherol.
“Both vitamins and metal ions are important for the function of enzymes. Multiple vitamins serve as coenzymes, such as vitamin B1 and vitamin B2, and metal ions are also essential for enzymatic activity and may incorporate metal ions into the active site or rely on metals for enzyme activation,” explained the authors.
Results, therefore, also indicate potential benefits of supplementation as “a positive nutrition factor” to enhance HMO concentrations in lactating mothers, they said.
The authors reported a strong association between individual HMO concentrations, secretor status and lactation stages, which corresponds with previous studies.
However, despite the apparent association with HMO levels and nutrient intake, gene regulation was still determined as the major factor in HMO variance.
Cookie consumption was the only factor showing a negative correlation to HMO concentrations, probably due to its high-sugar and high-fat content.
“This is the first time we point out a negative correlation between high-sugar and high-fat foods with HMOs, but the plausible mechanism and possible confounding factors need further research.”
Furthermore, the authors concede that factors other than diet are likely to play a role in HMO status and should be considered in future research.
Published online October 4, 2022: http://doi.org/10.3390/nu14194131
‘Vitamins, Vegetables and Metal Elements Are Positively Associated with Breast Milk Oligosaccharide Composition among Mothers in Tianjin, China’
Authors: X. Li, et al.