Friday, October 14, 2016
Absorption and Excretion of Human Milk Oligosaccharides in Premature Infants and its Influence on Intestinal Microbiota
Human milk oligosaccharides (HMOs) are a major component of human milk and may have beneficial influence on the infant intestinal microbiota through selective consumption of commensal bacteria or by binding to invasive bacteria and subsequently reducing their capacity to cause sepsis and urinary tract infections. Premature infants are at increased risk of necrotising enterocolitis (NEC) and sepsis due to alterations in their intestinal microbiota (dysbiosis). A study published in the journal Pediatric Research evaluated the influence of HMOs on the intestinal microbiota of premature infants.
The study analysed the HMO composition in milk, urine, and faecal specimens of 14 exclusively breastfed premature infants and their mothers. Mass spectrometry was used to analyse HMO composition and next generation sequencing was used to analyse the stool specimens.
The percentages of fucosylated and sialylated HMOs in the evaluated specimens were highly variable between individuals but similar in urine, faeces, and milk within the mother–baby dyads, suggesting differences in absorption capacity. Secretor status predictions based on the percentages of 2’FL and LDFT showed that of the 14 mothers enrolled, 8 were secretors and 6 were non-secretors. The content of specific HMO structures in urine and faeces was related to secretor status of the mother, with premature infants of non-secretor mothers showing greater levels of Proteobacteria and reduced levels of Firmicutes. Alterations in Proteobacteria and Firmicutes in faecal microbiota were linked to specific HMO structures in urine, stool, and milk.
Intestinal microbiota may be influenced by the structure of HMOs in premature infants. While a reduction in NEC and sepsis causing pathogens may be due to specific HMOs in secretor mothers, other HMOs may result in increased dysbiosis in premature infants.
News Source: Underwood M, Gaerlan S, De Leoz M, et al. Human milk oligosaccharides in premature infants: absorption, excretion, and influence on the intestinal microbiota. Pediatr Res. 2015;78(6):670-677.