Dark chocolate is often said to be good for the health. Now, a study has found one reason why cocoa powder is beneficial for the heart and for weight control. The reason lies in the gut: bacteria forming the gut flora break down chocolate components into molecules that reduce stress on the blood vessels.

These findings were reported during the latest American Chemical Society (ACM) Meeting in Dallas by scientists from Louisiana State University, led by Professor John Finley.

Eating chocolate has been associated with benefits ranging from aphrodisiac effects to curing fatigue. Science has confirmed some of these benefits: the cocoa contained in chocolate may reduce blood pressure and body weight (even if these effects are partially cancelled out by the sugar and milk added in most commercial chocolate). The study presented at the ACM meeting has shown that bacteria in the gut contribute in making chocolate healthy.

The authors passed cocoa powder through a set of test tubes that simulate the environment of the human digestive tract, including bacteria normally present in gut microbiota. The authors found that those bacteria break down some specific components contained in cocoa, called polyphenols. These molecules are too big to be absorbed into the blood, but gut bacteria break them down into smaller chemicals that can pass to the blood. These chemicals have the property of reducing inflammation in cardiovascular tissues.

 “The good (gut) microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate. When you eat dark chocolate, they grow and ferment it, producing compounds that are anti-inflammatory”, said Maria Moore, an undergraduate student and one of the study’s researchers.

The authors now plan to check their conclusions with real patients. They will feed patients cocoa powder and check whether they find the same small molecules in the bloodstream that bacteria produced in the test tubes. This would confirm that bacteria are responsible for the beneficial effects of chocolate.

This is not the first time that scientists have found a connection between chocolate and gut bacteria. As we have previously explained in this blog, chocolate can increase the amount of beneficial bacteria versus harmful ones in the gut.