Fatty acid profile driven by maternal diet shapes the composition of human breast milk microbiota

Authors: MARSH, ALAN - University Of North Carolina; AZCARATE-PERIL, M. ANDREA - University Of North Carolina; ALJUMAAH, MASHAEL - University Of North Carolina; NEVILLE, JESSICA - East Carolina University; PERRIN, MARYANNE - University Of North Carolina Greensboro; Dean, Lisa; WHEELER, MICHAEL - East Carolina University; HINES, IAN - East Carolina University; PAWLEK, ROMAN - East Carolina University

Submitted to: Frontiers in Microbiomes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2022
Publication Date: 11/14/2022
Citation: Marsh, A., Azcarate-Peril, M., Aljumaah, M., Neville, J., Perrin, M.T., Dean, L.L., Wheeler, M.D., Hines, I.N., Pawlek, R. 2023. Fatty acid profile driven by maternal diet shapes the composition of human breast milk microbiota. Frontiers in Microbiomes. 1:1041752. https://doi.org/10.3389/frmbi.2022.1041752.
DOI: https://doi.org/10.3389/frmbi.2022.1041752

Interpretive Summary: The composition of the fatty acids in breast milk are known to be influenced by the diet of the mother which in turn influence the bacteria present in the milk that the baby receives when feeding. The bacteria in the milk will determine the microbiome of the baby's intestinal tract. This study examined the fatty acids in the mother's milk when the subject consumed a vegetarian (plants products only, no animal protein), vegan (plant products and dairy and egg products but no meat protein), or an omnivore (plant and animal protein including meat) diet. Breast milk samples were evaluated from 72 human subjects. The goal of the study was to determine if the mother's diet had an effect on the fatty acids in her breast milk and if that would in turn influence the bacteria that she would pass on to her baby. The same types of bacteria commonly found in the intestinal tract were found regardless of the diet consumed. It was found that the higher fat (omnivore) diet resulted in higher levels of trans fatty acids and unsaturated fatty acids in the breast milk. This resulted in higher levels of several types of bacteria associated with the intestinal microbiome. This result was partially attributed to an enzyme (2,4-dichlorophenol 6-monooxygenase) being more active. The study showed that a mother's diet does influence the fatty acids present in her breast milk and these fatty acids will influence the amounts of healthy bacteria passed on to her baby during breast feeding.

Technical Abstract: Little is known regarding the impact of diet on the breast milk microbiome. We hypothesized that vegan, vegetarian, and omnivore diets would impact the human milk microbiota. We also aimed to explore associations between human milk fatty acid concentrations and microbial composition. A cross-sectional microbiome diversity analysis of human milk samples (N = 72) was performed using 16S rRNA amplicon sequencing. Human milk microbial diversity was not associated with diet type. However, analysis of microbiome in relation to fatty acid profiles revealed significant differences in the overall composition of the human milk microbiota between high (> 0.7% of total fat) and low (< 0.7%) trans-fatty acid groups (TF) (p = 0.039, pairwise PERMANOVA p = 0.035), high (> 40%) versus low (< 40%) saturated fatty acids (UniFrac p = 0.083, PERMANOVA p = 0.094), and high (>60%) versus low (<60%) unsaturated fatty acids (UF) (UniFrac p = 0.094, PERMANOVA p = 0.093). 84% of samples from omnivore mothers were in the high TF group compared to only 12% of samples from vegans. Gut-associated species (Faecalibacterium, Blautia, Roseburia and Subdoligranulum) and Lactobacillus were characteristic of both high UF and TF groups, but not the low-fat groups. Functional analysis revealed 2,4-dichlorophenol 6-monooxygenase was differentially abundant in the high UF group. Although microbiome diversity did not differ by diet type, TF breast milk content differed by diet group, highlighting the relationship between maternal diet and the microbial profile of human milk.