Feeding practice and delivery mode are determinants of vitamin K in the infant gut: An exploratory analysis

Authors: ELLIS, JESSICA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; WANG, MEI - University Of Illinois; FU, XUEYAN - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; FIELDS, CHRISTOPHER - University Of Illinois; DONOVAN, SHARON - University Of Illinois; BOOTH, SARAH - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Current Developments in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2022
Publication Date: 2/12/2022
Citation: Ellis, J.L., Wang, M., Fu, X., Fields, C.J., Donovan, S.M., Booth, S.L. 2022. Feeding practice and delivery mode are determinants of vitamin K in the infant gut: An exploratory analysis. Current Developments in Nutrition. 6(3):nzac019. https://doi.org/10.1093/cdn/nzac019.
DOI: https://doi.org/10.1093/cdn/nzac019

Interpretive Summary: To investigate the origins of distinct fecal vitamin K profiles consistently observed in adults, fecal and breastmilk samples were measured for multiple vitamin K forms at 6 weeks postpartum in breastfeeding or formula-feeding mother and infant dyads, delivered vaginally or by C-section. Feeding practice and delivery mode influenced bacterial vitamin K production in the infant gut whereas the mother's vitamin K status did not. High concentrations of unmetabolized vitamin K in feces of formula-fed infants suggests formula vitamin K content exceeds the absorptive capacity of the infant gut. Further investigation into the role of gut bacterially-produced vitamin K in early life nutrition and health is needed to understand how these early life practices influence the vitamin K status throughout the lifecycle.

Technical Abstract: Background: Infants have low stores of vitamin K at birth. Dietary intake of phylloquinone differs dramatically by infant feeding practice, but the contribution of microbially-produced vitamin K (menaquinones) to infant vitamin K status is not well-understood. Objective: The objective of this study was to investigate determinants of infant fecal vitamin K profiles in mother-infant dyads at 6 weeks postpartum. Methods: Fecal and breastmilk samples were collected from a subsample of breastfeeding (n=23) or formula-feeding (n=23) mother and infant dyads, delivered vaginally (n=26) or by C-section (n=20) in the STRONG Kids 2 cohort. Vitamin K concentrations in breastmilk and feces were analyzed by LC/MS and/or HPLC. Fecal bacterial metagenomes were analyzed to derive taxonomy and vitamin K biosynthetic genes. Multivariate linear modelling was used to assess effects of delivery and feeding modes on infant fecal vitamin K. Results: Breastmilk contained 1.3 +/- 0.2 ng/mL phylloquinone (PK), and formula was reported to contain 52 ng/mL PK. Fecal PK was 38-times higher (p<0.001) in formula-fed than breastfed infants. Infant fecal menaquinones (MKn) MK6, MK7, MK12, and MK13 were higher (p<0.001) in formula-fed than breastfed infants, whereas MK8 predominated in breastfed and was 5-times higher than formula-fed infants. Total MKn were greater (p<0.001) in vaginally delivered than C-section infants. Relative abundances of 33 bacterial species were affected by feeding mode, 2 by delivery mode, and 4 by both (p<0.05). Bacterial gene content of 5/12 vitamin K biosynthetic genes were greater (p<0.05) in breastfed vs formula-fed infants, and 1 differed by delivery mode. Conclusions: Feeding practice and delivery mode influence bacterial vitamin K production in the infant gut. High concentrations of unmetabolized PK in feces of formula-fed infants suggests formula PK content exceeds the absorptive capacity of the infant gut.