Below is a link to MDA Forum where it has also been discussed and there are links to rebuttals that have teased the integrity of this study to show it is nothing more than a set of vague corrolations, some facts and a whole lot of tenuous threads trying to support the hypothesis.
If you want to attack the Paleo communities "Sacred Cow", pun intended, then be prepared for a bun fight, they've poked holes in all the previous red meat studies and this one is no different, it leaks like a sieve:
I picked out this particular rebuttal, just as an example:
http://humanfoodproject.com/from-meat-t ... man-grill/
It presents a fairly moderate disection of the study, last paragraph below.
Humans have been eating meat and thus carnitine for a long time. The question is, are the genes necessary for metabolizing carnitine a recent phenomenon, or have they always been with us? If there is some specific association between Prevotella and the genes capable of metabolizing dietary carnitine, then it appears – possibly – to have been ushered in with the agricultural revolution and has no precedent throughout much of our evolutionary past. How ironic would it be if the microbial ability to metabolize dietary carnitine from red meat is linked to whole-grain consumption! As for my hardcore Paleo eating brothers and sisters, this is the place in the story where you smile. Even if Prevotella is currently serving as a reservoir today, what’s to stop other bacteria from taking up the genetic call of duty to metabolize carnitine if Prevotella were to get depressed at a population level?
As for the title of the Nature Medicine article – “Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis” – a more appropriate title may have been “Researchers get vegan to eat steak – sun rises next day”