Gut Bacteria May Convert Choline Into Clot-Enhancing Compound
TUESDAY, April 25, 2017 -- Consuming excess choline raises levels of the bacteria-produced compound trimethylamine N-oxide (TMAO) and increases the tendency of platelets to clump together and form clots, according to a study published online April 24 in Circulation.
Weifei Zhu, Ph.D., from the Cleveland Clinic in Ohio, and colleagues prospectively recruited eight healthy vegans/vegetarians and 10 omnivores with no preceding one-month history of antibiotics or probiotics. Participants were given oral choline supplementation for two months.
The researchers found that both vegans/vegetarians and omnivores had significant (>10-fold) increases in plasma TMAO levels at both one and two months; they also had corresponding enhanced platelet aggregation responses to submaximal adenosine diphosphate. There was a dose-dependent correlation between plasma TMAO levels and platelet function. Change from baseline in TMAO level correlated significantly with change from baseline in platelet aggregation among all subjects. In a subsequent analysis, omnivores who had been examined in the absence of aspirin were started on aspirin for one month before baseline evaluation followed by two months of choline supplementation. Choline correlated with increases in fasting plasma TMAO levels and adenosine diphosphate-dependent platelet aggregation responses, although the degree was attenuated with aspirin therapy.
"These studies show for the first time a direct prothrombotic effect of dietary choline and elevated levels of the gut microbial metabolite TMAO in humans," the authors write. "They also suggest the platelet hyperresponsiveness mediated by elevated TMAO can be attenuated by a low dose of aspirin."
Two authors disclosed financial ties to the biopharmaceutical industry and are named as co-inventors on pending and issued patents held by the Cleveland Clinic relating to cardiovascular diagnostics and therapeutics.
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Posted: April 2017