It’s always nice to find out that a food we enjoy eating — something we might even consider to be a treat — is actually healthy and beneficial for us to eat. For example, if you like dark chocolate, then there’s some good news for you. Earlier this week it was reported that eating dark chocolate may potentially decrease a person’s long-term chance of having a stroke. How does this work? It actually has to do with the microbiomes in our guts.
Microbiomes are collections of microbes, such as bacteria and yeast, which live in a certain area. The gut microbiome has been previously found to be related to aging, as well as obesity, autoimmune diseases, infections, and other medical conditions. And now we may be able to thank our hard-working gut microbes for making dark chocolate be beneficial for us to snack on.
So how does the microbiome turn this tasty treat into something that may possibly decrease a person’s stroke risk? Basically, the researchers found that some gut bacteria can turn parts of dark chocolate into anti-inflammatory compounds. Dark chocolate contains various polyphenol compounds (which basically means they have multiple, large aromatic groups, which have a certain ring structure). These polyphenol compounds include flavanols and, specifically, catechin, which is an antioxidant, but they’re poorly absorbed in the gut… without the help of bacteria. The researchers grew human fecal bacteria (obtained from generous lab members pooping in a cup) with cocoa powder in conditions similar to what’s found in the human gut (such as an oxygen-free, or anaerobic, environment). When they did this, they found that the bacteria help break the large polyphenol compounds down into smaller molecules that can be readily absorbed by the gut. In addition, these smaller molecules have anti-inflammatory properties.
This basically means that when you eat foods like chocolate that feed these beneficial types of bacteria (such as lactic acid bacteria and Bifidobacterium), these bacteria will grow better and make more helpful bacteria, and possibly more anti-inflammatory molecules. These molecules may help heart health and consequently reduce stroke risk. (Some other gut bacteria, specifically Clostridia and types of E. coli, correlate with inflammation, which can be associated with having digestive problems, such as being bloated, and having diarrhea and constipation.)
Note that a paper has not actually been published on the findings, which were announced earlier this week at the American Chemical Society meeting in Dallas, Texas (which my husband attended, as he is a biochemistry professor at the Metropolitan State University of Denver). Additionally, these studies have only been done in “test tube” environments, and still need to be replicated in an actual animal. Lastly, the authors stress that the beneficial effects of eating cocoa powder may not be equivalent to gorging on tons of bars of dark chocolate — the helpful polyphenol compounds may be destroyed in the manufacturing process, not to mention chocolate bars have a lot of added sugar and fat compared to plain cocoa powder.
So while diet-related findings often tell us what we should not be eating, it’s nice to know that some foods we enjoy eating were good to eat all along.
Check out the further reading, below, for previous gut micribiome-related Bytes!
For further reading:
- Esther Landhuis’s article “ScienceShot: Why is Dark Chocolate Good for You? Ask Your Gut” in Science
- Tracy Vence’s article “Gut Microbes Gobble Cocoa”
- ScienceDaily’s article “Precise reason for health benefits of dark chocolate: Thank hungry gut microbes”
- Teisha J. Rowland’s Biology Bytes articles “Aging and the Gut Microbiome” and “The Importance of ‘The Little Guys:’ Our Gut Microbiome”
- Teisha J. Rowland’s book Biology Bytes: Digestible Essays on Stem Cells and Modern Medicine