Want to keep heart disease at bay? Improve your gut bacteria
A healthy gut has been linked to a strong immune system, better digestion, improved mood and overall health. According to a new study, one of the good bacteria found in your gut has the potential to reduce the risk of heart disease.
The study done by the Ohio State University researchers reported that the bacteria’s activity in the intestine hampers the production of a chemical linked to the development of clogged arteries that characterise atherosclerosis. The chemical, called trimethylamine or TMA, after it’s manufactured in the gut, enters the bloodstream and travels to the liver - where it is converted into its most harmful form.
As per the study, the researchers traced the bacteria’s behavior to a family of proteins that they suspect could explain other ways that good gut organisms can contribute to human health.
“Over the last decade, it has become apparent that bacteria in the human gut influence our health in many ways. The organism we studied affects health by preventing a problematic compound from becoming a worse one,” said Joseph Krzycki, professor of microbiology at Ohio State and senior author of the study. “It’s too soon to say whether this bacterium could have therapeutic value. But that’s what we’re working toward.”
Scientists see the potential for this microbe, Eubacterium limosum, to be used for therapeutic purposes in the future, although much more work is ahead. Previous research has already shown the bacterium calms inflammation in the gut.
Krzycki and his colleagues discovered that E. limosum interacts with L-carnitine, a chemical compound found in meat and fish, in a different way in the gut, and that interaction eliminates L-carnitine's role in the production of TMA (other nutrients also participate in TMA production in the gut).
The researchers discovered that the bacteria’s beneficial behavior is due to a protein called MtcB, an enzyme that cuts specific molecules off of compounds to help bacteria generate energy and survive. The process is called demethylation and involves the removal of one methyl group - a carbon atom surrounded by three hydrogen atoms - to change a compound’ s structure or function.
“The bacterium does this for its own benefit, but it has the downstream effect of reducing the toxicity of TMA. Up until now, the only known gut microbial reactions with L-carnitine involved converting it into its bad form. We’ve discovered that a bacterium known to be beneficial could remove a methyl group and send the resulting product down another pathway without making any other harmful compounds in the process,” Krzycki said.
In these interactions, L-carnitine functions as a growth substrate - a compound consumed so the organism can live and grow, and also a target for enzyme activity. For the research, the researchers fed E. limosum cultures an assortment of potential substrates, including L-carnitine. Only when offered L-carnitine did the microbe synthesize the MtcB protein specifically to lop off L-carnitine's methyl group -- in essence, MtcB is part of the bacteria's natural way to consume the nutrient, the study added.
The findings, which have been appeared online, will be published in a future edition of the Journal of Biological Chemistry.
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