Here’s a great podcast from Dr. Mike Roizen of the Cleveland Clinic, and the transcript is there too:
It is focused on supplements, but includes this important detail about diet:
…food with carnitine, that is red meat and, yes, pork is a red meat, and lecithin, and choline such as egg yolks and cheese, in specific configurations seems to, and does, change the bacteria inside you over a period of as short as one week. And the good news is if you get rid of those foods totally, within one week, your bacteria changes back to healthy bacteria inside you. But when you have, for example, two six ounce steaks in a week, the bacteria that love that steak predominate, and those bacteria produce as their waste product from the carnitine—so it doesn’t matter whether it’s grass fed or not—but they produce from the carnitine an inflammatory substance that is called butyl butane and trimethylamine. The trimethylamine goes to the liver and creates trimethylamine oxide, which ends up causing inflammation and is a more powerful inflammatory agent and cause of heart disease, stroke, and memory loss than is in fact the LDL cholesterol 260. So there isn’t a physician who wouldn’t treat that. You probably should avoid more than four ounces of red meat or an egg yolk or cheese a week.