Maternal Secretor Status and Microbiota Composition

Abstract Background: One mechanism by which early life environment may influence long term health is through modulation of the gut microbiota. It is widely accepted that the optimal source of nutrition in early life is breast milk, with Human Milk Oligosaccharides (HMOs) thought to play an important role in nourishing the developing microbiota. However, mothers with inactive secretor genes have altered HMO composition and quantities in their breast milk. In this pilot study we examine the influence of secretor status and breast-feeding on microbiota composition at 2 to 3 years of age. Methods: 37 children and 17 eligible mothers were recruited. Secretor status was determined from blood and saliva samples using hemagglutination inhibition technique and faecal microbiota composition was examined by 16S rRNA gene sequencing. Results: Secretor status was determined for 28 eligible children with 20 being secretors (S, 71.4%). Eleven of the 17 mothers were secretors (S, 64.7%). Mother’s secretor status had a strong association with their children’s stool microbiota and explained 16.9% of the variation in the weighted UniFrac distances. The children of non-secretor (NS) mothers were found to have increased abundance of Prevotella and OTU related to Prevotella copri compared to children with S-mothers. Our results also suggest that a mother’s secretor status has an even more pronounced effect on the children if they were exclusively breast-fed for at least 4 months of life, with the abundance of Bifidobacterium being higher in the breast-fed children of S-mothers. Interestingly, the relative abundance of Bacteroides plebeius, a bacterium noted for its capacity to utilise sulphated polysaccharides for growth, was decreased in these children. Conclusions: Mother’s secretor status has an impact on children’s microbiota composition at 2 to 3 years of age. This effect was even strongerin children who were exclusively breast-fed for at least 4 months.