"Good" gut microbes revealed as the key to dark chocolate's health benefits
By Darren Quick
March 19, 2014
It has long been known that eating chocolate, particularly dark chocolate, has numerous health benefits. Although various studies have backed this up, the exact reason as to why this is so has remained a mystery. Now researchers from Louisiana State University have provided the answer – gut microbes.
Presenting their findings at the 27th National Meeting & Exposition of the American Chemical Society (ACS), the researchers revealed that, unlike so-called "bad" bacteria in the gut, such as some Clostridia and some E. coli, that are associated with inflammation and can cause gas, bloating, diarrhea and constipation, "good" bacteria, such as Bifidobacterium and lactic acid bacteria, feed on dark chocolate to produce anti-inflammatory compounds.
John Finley, Ph.D., who led the world-first research into the effects of dark chocolate on the various types of bacteria in the stomach, says that when these anti-inflammatory compounds are absorbed by the body, they lessen the long-term risk of stroke by reducing the inflammation of cardiovascular tissue.
Using a series of modified test tubes as a model digestive tract that simulated normal digestion, the team tested three different cocoa powders. Cocoa powder, which is a key ingredient of chocolate, contains several antioxidant compounds and a small amount of dietary fiber, both of which are poorly digested and absorbed in the stomach but are feasted on by good microbes when they reach the colon. Using human fecal bacteria, the team subjected these non-digestible materials to 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," said Finley. "These smaller polymers exhibit anti-inflammatory activity."
Finley says that combining the fiber in cocoa with prebiotics, (non-digestible carbohydrates available in dietary supplements, but also found in food like raw garlic and cooked whole wheat flour that stimulate the growth and/or activity of bacteria in the digestive system), could also help convert antioxidant polyphenolics in the stomach into anti-iflammatory compounds, which he believes is likely to improve a person's 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 said. Finley added that combining dark chocolate with solid fruits, such as pomegranates and acai could also provide even greater health benefits.