Fish Consumption Linked to Increased Trimethylamine-N-Oxide Production
Recent research has identified Trimethylamine-N-oxide (TMAO) as a predictive risk factor for heart disease in cardiac patients. A study conducted by researchers with Cornell University looked at the effects of animal food sources on production of TMAO and found that fish yielded the highest increases in circulating TMAO.
Participants in the study included 40 healthy men between the ages of 21 and 50 with a BMI between 20 and 29.9 kg/m2. The researchers collected blood and urine samples from all of the men. Following that, the men were given one of four meals: three eggs; 6 oz of fish; 6 oz of beef; or a control meal of fruit. Each meal was consumed on a single day, in random order, and meals were separated by a one-week period.
The researchers collected blood samples again at 15 and 30 minutes, one hour, two hours, four hours, and six hours after each meal. The participants also provided urine samples throughout the six-hour study period. At the 4.5-hour mark, the men were provided with a snack of applesauce and water. They did not eat or drink anything (other than water) aside from what was provided by the researchers during the study period.
The researchers found that fish produced a higher circulating and urinary Trimethylamine-N-oxide concentration than eggs, beef, or fruit. TMAO is a biomarker of heart disease and is found in high levels in fish.
The researchers also performed an analysis of the participants genes and found that those who were producing high levels of TMAO also had higher levels of firmicutes than bacteriodetes in their gut, as well as less gut microbiota diversity. In humans, the gut bacteria firmicutes helps convert the nutrient choline, from eggs, and carnitine, from meat, into TMAO. From this, the researchers concluded that higher levels of Trimethylamine-N-oxide might be a biomarker of differences in the gut microbiome, suggesting that healthy people and those with heart disease may have different gut microbiota.
The study was published online ahead of print on July 5, 2016, in Molecular Nutrition & Food Research.
Only 30% of the human gut bacteria has been mapped but previous studies have found that having a varied composition of bacteria in your digestive system is essential for good gut health and for good health overall. If you’re looking to improve gut bacteria diversity, consider taking a prebiotic or probiotic supplement. A recent study also found that exercise may help boost gut bacteria diversity.