I have a fascination with the human gut microbiome and the role this complex microbial community plays in health and disease. This is an emerging area, not only in the field of microbiology, but also in many areas of biomedical research. This topic appeals to me as a microbiologist and as a health nut. I came across this article published in Science Advances last month (April, 2015) entitled ‘The microbiome of uncontacted Amerindians’ by Clemente et al. This study investigates the fecal, oral and skin bacterial microbiome of members of an isolated Yanomami village, a seminomadic hunter-gather people inhabiting the Amazon jungle who have had no previously reported contact with western civilization.
The fecal microbiome of these isolated hunter-gatherers displayed the greatest diversity ever reported in any human group thus far. The bacterial species detected in the Yanomami samples varied from that of subjects from the U.S, with the Yanomami people having higher intestinal Bacteroidales S24-7, Mollicutes and Verrucomicrobia, members of the families Aeromonadaceae, Oxalobacteraceae, and Methanomassiliicoccaceae, and genera Phascolarctobacterium, Desulfovibrio, Helicobacter, Spirochaeta, and Prevotella. Some of these species, for example, Helicobacter, were completely absent in the feces of U. S. subjects (1).
Similar findings were obtained from a study that compared the gut microbial composition of children aged 1-6 years living in a rural African village to western European children of the same age. The diet of the children in the African village was that of a traditional rural African diet consisting of locally produced, cultivated and harvested grains, legumes and vegetables and occasional animal protein in the form of chicken and termites. A greater microbial richness and biodiversity was found in the African village children compared to the European children (2).
Diet is one of factors that can impact the diversity and composition of the human gut microbiome, along with age, disease states, mode of delivery at birth and antibiotic use. Therefore, these findings are not surprising considering the diet and lifestyle of the Yanomami people and the rural African children compared to the typical Western lifestyle and diet. The unprocessed, unrefined, high fibre, nutrient dense diet of the Yanomami people and African children is clearly having a positive impact on their gut microbiota
The gut microbiota is involved in the development of our immune system, the utilization of energy and nutrients from our diet and the prevention of the establishment of potentially harmful intestinal microbes. Therefore, having a greater diversity in the gut microbiome is likely to have a range of health benefits.
I came across this saying which I think is very appropriate ‘they are what we eat’ – ’they’ being the gut microbiota (3). So keep this in mind the next time you are reaching for that highly processed, packaged snack food. Is that the sort of fuel that is going to promote a diverse and rich microbiome?
- C. Clemente, E. C. Pehrsson, M. J. Blaser, K. Sandhu, Z. Gao, B. Wang, M. Magris, G. Hidalgo, M. Contreras,Ó.Noya-Alarcón, O. Lander, J.McDonald, M. Cox, J. Walter, P. L. Oh, J. F. Ruiz, S. Rodriguez, N. Shen, S. J. Song, J. Metcalf, R. Knight, G. Dantas, M. G. Dominguez-Bello. (2015). The microbiome of uncontacted Amerindians. Sci. Adv. 1: e1500183.
- Filippo, C. D., Cavalieri, D., Paola, M., Ramazzotti, M., Poullet, J. B., Massart, S., Collini, S., Pieraccini, G. and Lionetti, P. (2010). Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa. PNAS. 107: 14691-14696.
- Hold, G. L. (2014). Western lifestyle: a ‘master’ manipulator of the intestinal microbiota? Gut. 63: 5-6.
Image of Yanomami woman and her child, June 1997 from Cmacauley