Microbes, Fecal Bacteria, and Fermentation: Chemists Solve the Mystery of Dark Chocolate Health Benefits

For years we have been hearing how the consumption of dark chocolate can help lower blood pressure and improve our cardiovascular health, but we never really knew why. While many of us were perfectly keen on maintaining our eat-now-ask-later mentality regarding dark chocolate, chemists at the Louisiana State College of Agriculture have finally discovered the precise reason why our tasty, addictive, bittersweet friend is beneficial to our health. The reason, as presented at a meeting of the American Chemical Society, is that “certain bacteria in the stomach gobble the chocolate and ferment it into anti-inflammatory compounds that are good for the heart.”

“We found that there are two kinds of microbes in the gut: the ‘good’ ones and the ‘bad’ ones,” study researcher Maria Moore told the Society. “The good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate,” and “when you eat dark chocolate, they grow and ferment it, producing compounds that are anti-inflammatory.” When the body absorbs these compounds, noted study leader John Finley, Ph.D., they “lessen the inflammation of cardiovascular tissue,” which is beneficial for heart health and reduces the long-term risk of stroke.

Researchers analyzed three cocoa powders using a contraption of retrofitted test tubes that simulated normal human digestion. The remaining non-digestible matter, consisting of polyphenolic compounds and dietary fiber, was then subjected to human fecal bacteria in order to induce anaerobic fermentation. “In our study we found that the fiber is fermented and the large polyphenolic polymers are metabolized to smaller molecules, which are more easily absorbed. These smaller polymers exhibit anti-inflammatory activity,” reported Finley.

This was the first study to research the effects of dark chocolate on stomach bacteria, according to Finley. He also suggested that combining dark chocolate with prebiotics (indigestible dietary fibers found in bananas, whole grains, and onions) can further improve overall health. “When you ingest prebiotics, the beneficial gut microbial population increases and outcompetes any undesirable microbes in the gut, like those that cause stomach problems,” he stated.