Trimethylamine N-Oxide From Gut Microbiota in Chronic Kidney Disease Patients: Focus on Diet

Low-protein diet is the recommended nutritional intervention for nondialysis chronic kidney disease (CKD) patients because excess protein intake can damage kidney function and produce uremic toxins. Some of these toxins are generated from amino acids breakdown by gut microbiota as p-cresyl sulfate and indoxyl sulfate that have been clearly associated with cardiovascular mortality in CKD patients. Another uremic toxin, trimethylamine N-oxide (TMAO), a degradation product of choline and L-carnitine (which come mainly from animal protein such as red meat and eggs) is now considered as a proatherogenic metabolite. In the present review, we will highlight the relationship between TMAO, diet and cardiovascular aspects, and the potential concerns about TMAO in nondialysis CKD patients.