You might have heard that red meat is bad for your heart, but why is that? The answer may lie in the gut. Dr. Stanley Hazen, of the Department of Cellular and Molecular Medicine at Cleveland Clinic’s Lerner Research Institute, found that gut bacteria is a key player in red meat’s effect on heart disease risk.

"Gut bacteria produce a compound called trimethylamine N-oxide (TMAO) when they digest choline, lecithin and carnitine, which are nutrients that are abundant in animal products such as red meat and liver, as well as other animal products. High levels of circulating TMAO in the body have been shown to be a powerful tool for predicting future heart attack, stroke and death risk."

The study found that those who consume red meat as their primary source of protein (25% of their daily calories) had a two- to three-fold increase in TMAO levels, compared to participants who relied on either white meat or plant-based foods as their top sources of protein.

In addition to increasing TMAO levels, those participant's kidneys were also less efficient at eliminating the TMAO from the body.

The good news is that after the participants stopped eating a high-red meat diet, their TMAO levels reverted back to normal levels within three to four weeks.

The white meat or plant-based protein diet participants had lower gut microbe creation of TMAO. Also, their kidneys were more efficient at eliminating TMAO, which suggests that these types of diets are healthier for our hearts and bodies.

Regardless of the diet that you follow, food diversity and moderation are always great practices. If you enjoy meat, be sure to look for antibiotic-free or organic options, as poor animal diets can also cause issues for your microbiome.