As a crucial part of the symbiotic system, the gut microbiome has been shown to be a metabolic organ that presents important connections to many diseases and conditions, including cardiovascular diseases (CVD), the world wide leading cause of death. Trimethylamine N‐oxide (TMAO) is a plasma metabolite that is positively correlated with CVD. Trimethylamine (TMA) is produced by gut bacteria from dietary choline, betaine, or L‐carnitine, and is then converted in the liver to TMAO, which in turn affects hepatic and intestinal lipid and cholesterol metabolism. Because eggs are rich in choline, it has been speculated that their consumption may increase plasma TMAO. The objective of this study was to examine the effect of two eggs per day on plasma TMAO level and how it is related with gut microbiome composition in mildly hypercholesterolemic postmenopausal women. In this randomized, cross‐over study, 20 overweight human subjects were given two whole eggs and the equivalent amount of yolk‐free substitute as breakfast for four weeks, in randomized order, with a four‐week washout in between. Fasting blood draws and stool were collected at the beginning and of each treatment period. Plasma TMAO, choline, betaine and other metabolites were analyzed using LC/MS, while gut microbiome composition was analyzed using 16S amplicon sequencing. Plasma choline and betaine were significantly increased after whole egg but not yolk‐free substitute, however TMAO level was not significantly affected by treatments. Gut microbiome composition showed large inter‐individual variability at baseline and in response to the treatments. Parabacteroides, Ruminococcus, and Faecalibacterium were slightly increased after whole egg but not yolk‐free substitute for the majority of the subjects, while Bilophila slightly increased after yolk‐free substitute but not whole egg. The consumption of two eggs per day in overweight, postmenopausal mildly hypercholesterolemic women significantly increased plasma choline and betaine, but not TMAO, with a subtle effect on gut microbiome composition.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
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