Exclusively Breastfed Infant Microbiota Develops over Time and Is Associated with Human Milk Oligosaccharide Intakes.

Ali Sadiq Cheema,Berwin Ashoka Turlach,Michelle Louise Trevenen,Annalee June Furst,Ana Sophia Roman,Lars Bode,Zoya Gridneva,Donna Tracy Geddes,Lisa Faye Stinson,Matthew Scott Payne,Ching Tat Lai

doi:10.3390/ijms23052804

Abstract

Temporal development of maternal and infant microbiomes during early life impacts short- and long-term infant health. This study aimed to characterize bacterial dynamics within maternal faecal, human milk (HM), infant oral, and infant faecal samples during the exclusive breastfeeding period and to document associations between human milk oligosaccharide (HMO) intakes and infant oral and faecal bacterial profiles. Maternal and infant samples (n = 10) were collected at 2–5, 30, 60, 90 and 120 days postpartum and the full-length 16S ribosomal RNA (rRNA) gene was sequenced. Nineteen HMOs were quantitated using high-performance liquid chromatography. Bacterial profiles were unique to each sample type and changed significantly over time, with a large degree of intra- and inter-individual variation in all sample types. Beta diversity was stable over time within infant faecal, maternal faecal and HM samples, however, the infant oral microbiota at day 2–5 significantly differed from all other time points (all p < 0.02). HMO concentrations and intakes significantly differed over time, and HMO intakes showed differential associations with taxa observed in infant oral and faecal samples. The direct clinical relevance of this, however, is unknown. Regardless, future studies should account for intakes of HMOs when modelling the impact of HM on infant growth, as it may have implications for infant microbiota development.

Highlights

All mothers participating in the current study were Caucasian, had delivered vaginally, had not taken antibiotics, and were exclusively breastfeeding at all time points
We found that 11 bacterial Operational taxonomic units (OTUs) (S. epidermidis, S. salivarius, S. mitis, G. haemolysans, V. nakazawae, B. longum subsp. infantis, H. haemolyticus, R. mucilaginosa, Bergeyella sp., H. parainfluenzae and Veillonella sp. oral clone ASCB03) dominated the infant oral microbiota
We found that the concentrations of 13 human milk oligosaccharide (HMO) in secretor mothers and four HMOs in non-secretor mothers decreased across the first four months, except for 3FL, which increased in concentration in both secretor and non-secretor mothers as lactation progressed, which is consistent with reports by Plows et al [125]

Summary

Introduction

The maternal gut and human milk (HM) microbiota contribute to bacterial colonization of the infant gut, which in turn influences both short- and long-term infant health and development [1,2]. Aberrations to the early-life gut microbiota have been linked to various disorders, such as obesity [3], type 1 diabetes [4], allergies [5], asthma [6], and neurological diseases [7]. Nutrition is a key factor in directing the composition and function of the infant gut microbiome [8], with breastfeeding being the most significant factor associated with infant gut bacterial structure and function in early life [9]. Document the temporal assembly of maternal and infant bacterial communities in the early postnatal period to better understand the foundations for life-long health. The infant gut microbiome undergoes temporal compositional changes during early life and by 5 years of age is still developing, having not assumed diversity and composition similar to the adult gut [10]. HM consumption shifts the infant gut microbiome to a state dominated by Bifidobacterium sp

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Discussion

Conclusion