1. Dietary vitamin K is remodeled by gut microbiota and influences community composition.
- Author
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Ellis JL, Karl JP, Oliverio AM, Fu X, Soares JW, Wolfe BE, Hernandez CJ, Mason JB, and Booth SL
- Subjects
- Adult, Animals, Bacteria growth & development, Bioreactors, Diet, Feces microbiology, Female, Fermentation, Humans, Male, Mice, Mice, Inbred C57BL, Middle Aged, Vitamin K 2 metabolism, Vitamin K 3 metabolism, Vitamin K Deficiency microbiology, Young Adult, Bacteria metabolism, Cecum microbiology, Dietary Supplements, Gastrointestinal Microbiome physiology, Vitamin K administration & dosage, Vitamins administration & dosage
- Abstract
Vitamins have well-established roles in bacterial metabolism. Menaquinones (MKn, n = prenyl units in sidechain) are bacterially produced forms of vitamin K produced by the gut microbiota and consumed in the diet. Little is known about the influence of dietary vitamin K quinones on gut microbial composition and MKn production. Here, male and female C57BL6 mice were fed a vitamin K deficient diet or vitamin K sufficient diets containing phylloquinone (PK, plant-based vitamin K form), MK4, and/or MK9. DNA was extracted from cecal contents and 16S sequencing conducted to assess microbial composition. Cecal microbial community composition was significantly different in vitamin K deficient female mice compared to females on vitamin K sufficient diets (all p < .007). Parallel trends were seen in male mice, but were not statistically significant (all p > .05 but <0.1). Next, stable isotope-labeled vitamin K quinones were supplemented to male and female C57BL6 mice (
2 H7 PK,13 C11 MK4,2 H7 MK7,2 H7 MK9) and to an in vitro fermentation model inoculated with human stool (2 H7 PK,2 H7 MK4,2 H7 MK9, or vitamin K precursor2 H8 -menadione). Vitamin K quinones in feces and culture aliquots were measured using LC-MS. In vivo , supplemented vitamin K quinones were remodeled to other MKn (2 H7 - or13 C6 -labeled MK4, MK10, MK11, and MK12), but in vitro only the precursor2 H8 -menadione was remodeled to2 H7 MK4,2 H7 MK9,2 H7 MK10, and2 H7 MK11. These results suggest that dietary vitamin K deficiency alters the gut microbial community composition. Further studies are needed to determine if menadione generated by host metabolism may serve as an intermediate in dietary vitamin K remodeling in vivo .- Published
- 2021
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