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Showing results for tags 'microbes'.
[Admin Note: I made this new thread as a collector for posts about the recently discovered and previously discussed apparent link between diet, micronutrients choline and carnitine, TMAO production by gut microbes that feed on these micronutrients, and elevated risk of cardiovascular disease. Four posts down is the new post (by me) on the topic. The first four posts come from a different thread. --Dean] In his post about supplements for vegetarians, Michael Rae said: For now, prudence seems to require that vegetarians err on the side of a generous and definitely supplemented intake of choline, ensuring that dietary (to the extent that it can be known) plus supplemental choline is meaningfully higher than the AI of 550 mg for men and 425 mg/day for women. Functional status is still tricky, but one obvious set of markers is the same panel used to establish signs of deficiency in Zeisel’s depletion-repletion study:iv a fivefold or more increase above normal of the muscle-damage enzyme creatine phosphokinase (CPK), or a one-and-a-half or more times normal reading of the liver enzymes aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), or lactate dehydrogenase (LD). Fatty liver, unfortunately, requires a harder-to-access MRI of fat deposits in the organ, to which your doctor is unlikely to consent. The below papers may be a reason dietary choline can be bad for us. NATURE | RESEARCH HIGHLIGHTS CARDIOVASCULAR BIOLOGY Gut microbes raise heart-attack risk Nature 531, 278 (17 March 2016) doi:10.1038/531278b Published online 16 March 2016 http://sci-hub.io/10.1038/531278b Subject terms: Microbiology Cardiovascular biology Gut microbes produce a chemical that enhances clotting in the arteries, increasing the risk of heart attack and stroke. Stanley Hazen of the Cleveland Clinic in Ohio and his colleagues treated human platelets, which form blood clots, with a compound called TMAO. This is made in the body from a waste product of gut microbes, and has been linked to heart disease. The team found that TMAO made the platelets form artery-blocking clots faster. The researchers increased blood TMAO levels in mice by feeding them a diet that was rich in choline, a TMAO precursor, and found that the animals formed clots faster than did those with lower TMAO levels. This effect was not seen in animals that lacked gut microbes or that were treated with antibiotics. When intestinal microbes from mice that produced high levels of TMAO were transplanted into mice with no gut microbes, the recipients' clotting risk increased. The results reveal a link between diet, gut microbes and heart-disease risk, the authors say. Gut Microbial Metabolite TMAO Enhances Platelet Hyperreactivity and Thrombosis Risk. Zhu W, Gregory JC, Org E, Buffa JA, Gupta N, Wang Z, Li L, Fu X, Wu Y, Mehrabian M, Sartor RB, McIntyre TM, Silverstein RL, Tang WH, DiDonato JA, Brown JM, Lusis AJ, Hazen SL. Cell. 2016 Mar 9. pii: S0092-8674(16)30113-1. doi: 10.1016/j.cell.2016.02.011. [Epub ahead of print] PMID: 26972052 http://sci-hub.io/10.1016/j.cell.2016.02.011 Abstract Normal platelet function is critical to blood hemostasis and maintenance of a closed circulatory system. Heightened platelet reactivity, however, is associated with cardiometabolic diseases and enhanced potential for thrombotic events. We now show gut microbes, through generation of trimethylamine N-oxide (TMAO), directly contribute to platelet hyperreactivity and enhanced thrombosis potential. Plasma TMAO levels in subjects (n > 4,000) independently predicted incident (3 years) thrombosis (heart attack, stroke) risk. Direct exposure of platelets to TMAO enhanced sub-maximal stimulus-dependent platelet activation from multiple agonists through augmented Ca2+ release from intracellular stores. Animal model studies employing dietary choline or TMAO, germ-free mice, and microbial transplantation collectively confirm a role for gut microbiota and TMAO in modulating platelet hyperresponsiveness and thrombosis potential and identify microbial taxa associated with plasma TMAO and thrombosis potential. Collectively, the present results reveal a previously unrecognized mechanistic link between specific dietary nutrients, gut microbes, platelet function, and thrombosis risk.