Gut Flora

Intestinal Flora Again Implicated in CAD; but This Time, Also CV Events

Steve Stiles

Apr 25, 2013

Our gut microbes are the biggest endocrine organ in our body. They can make biologically active compounds, and they contribute to disease processes.

CLEVELAND, OH — A major dietary source of choline provided in abundance by egg yolks and meat can, after conversion by intestinal bacteria, raise plasma levels of trimethylamine-N-oxide (TMAO), suggests a report published this week^[1]. It also supports earlier evidence that circulating TMAO is proatherogenic and may have potential as a biomarker of later cardiovascular risk.

The new study, actually a pair of prospective clinical studies, complement each other by establishing dietary phosphatidylcholine metabolism by gut flora as a source of circulating TMAO and TMAO levels as predictors of death, MI, and stroke "independent of traditional risk factors, even in low-risk cohorts," according to the authors, led by Dr WH Wilson Tang (Cleveland Clinic, OH).

Their work is detailed in the April 25, 2013 issue of the New England Journal of Medicine. If it sounds familiar, it may be because the same research team published strikingly similar findings two weeks ago in the journal Nature Medicine ^[2], but naming dietary carnitine--also prevalent in red meat--as an ultimate source of TMAO released by intestinal microbiotia.

(Later the same week, heartwire and others reported a meta-analysis^[3] suggesting, notably to a befuddled public, that L-carnitine given as a drug in acute MI could limit infarct size and improve clinical outcomes--proving as little else could that the overall story is more complicated than it seems.The popular press seemed to enjoy itself in covering the study and exploded with stories, of varying accuracy, on how carnitine--also an additive to commercial energy drinks and diet supplements--may help drive the heart-disease risk associated with diets rich in meat)/.../