A couple of weeks ago in Bio120, we were assigned to read a very intriguing article by Michael Pollan called, “ Some of My Best Friends are Germs.” In his article, Pollan describes the power and purpose of the microbiome and the significance of different bacteria in our guts, among other interesting topics3. However, one topic that caught my attention was the observed difference in the microbiota present in our microbiomes and others in America and Europe compared to those in Africa. The American and European guts tend to have more Bacteroids and Firmicutes with low levels of Prevotella, whereas African and Amerindian guts have much more diversity in their microbiome and also have high levels of Prevotella3. This interesting fact led me to study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) that may link this difference in microbiota to our diets.
To identify the effects of diet on the microbiome, a study was conducted to compare the gut microbiota of children from the ages of 1-6 years old living in a rural African village called Boulpon to children of the same age group living in Florence, Italy to represent western European children2. According to the study, children from the Boulpon village had diets that consisted of all food that was produced locally, low in fat and animal protein, and rich in starches, fiber, plants, cereals, legumes, vegetables, carbohydrates, fibers, and non-animal proteins. The European diet was characterized by high amounts of animal protein, sugar, and fat, and low in fiber. Breastfeeding was also noted and recorded for the two groups. It was noted that Africans typically breastfeed up to 2 years old while Europeans breastfeed up to 1 year of age2.
After identifying their diets, scientists categorized the microbiota of the children from their fecal matter. The results describe that “More than 94.2% of the sequences in all of the Boulpon and European samples were found to belong to the four most populated bacterial phyla, namely Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria, in agreement with previous studies describing such phyla as those contributing to the majority of human gut microbiota2.” It was further noted the Bacteriodetes were much more popular in the Boulpon children, whereas Firmicutes and Proteobacteria were much more common in European guts2. Researches rationalized that as soon as breastfeeding is substituted by solid foods, the differences in microbiota among the Europeans and Africans begins to increase because Europeans stop breastfeeding sooner than Africans2. This reflects the dietary and environmental separation that results in the difference in abundance of the Bacteriodetes and Firmicutes.
It is later noted in the article that “Exposure to the large variety of environmental microbes associated with a high-fiber diet could increase the potentially beneficial bacterial genomes, enriching the microbiome2.” A decrease in the microbial richness may be an undesirable effect of globalization and eating highly processed, uncontaminated, and very nutritious foods. This decrease in microbial richness can be observed in European as well as American bacterial genomes2. According to their research, “[They] hypothesize that the reduction in richness we observe in European compared with Boulpon children, could indicate how the consumption of sugar, animal fat, and calorie-dense foods in industrialized countries is rapidly limiting the adaptive potential of the microbiota2.”
Another test was conducted to research one’s ability to extract calories from polysaccharides. From their studies they have observed a correlation between polysaccharide-degrading microbiota and the calories that the host can extract from his or her diet, which may influence the survival and fitness of the host. “We can hypothesize that microbiota coevolved with the diet of Boulpon individuals, allowing them to maximize the energy intake from indigestible components, such as plant polysaccharides, by producing high levels of short-chain fatty acids (SCFAs) that supply the host with an additional amount of energy2.”
Overall there is a strong correlation between diet and the microbiota that dominate a person’s gut according to the data collected in this study. There is also a clear message from all of this research that we must protect the diversity of the microbiome and that there is a great importance of these microbiota to our health. Now that you know how your diet can impact your microbiome what can you do? Well, you actually have the opportunity to be a participant in research yourself! “The American Gut” is a project that sets out to compare the microbiota of people from around the U.S. to help collect data to find correlations between environmental factors, like diet, and the micrbiome1. Through this project you can send in some of you own samples and find out what microbiota live in your gut, and find out what you can do to improve your microbiota, while also contributing to data for their research1! For more information go to http://humanfoodproject.com/americangut/.
Source: Human Food Project, American Gut
Here are the simple steps you need to follow to participate in the American Gut project to find out the microbiota that make up you microbial ecosystem!
1. “American Gut.” Human Food Project RSS. N.p., n.d. Web. 03 Mar. 2014.
2. Cavalieri, Duccio, Et Al. “Impact of Diet in Shaping Gut Microbiota Revealed by a Comparative Study in Children from Europe and Rural Africa.” Impact of Diet in Shaping Gut Microbiota Revealed by a Comparative Study in Children from Europe and Rural Africa. Proceedings of the National Academy of Sciences of the United States of America, 17 Aug. 2010. Web. 03 Mar. 2014.
3. Pollan, Michael. “Some of My Best Friends Are Germs.” The New York Times. The New York Times, 18 May 2013. Web. 03 Mar. 2014.