To what extent micronutrients are absorbed from the diet and utilized by the body depends largely on the intestinal flora. Conversely, the type of diet has a favorable or unfavorable effect on the specific microbial colonization of the intestine. One of the most influential studies, that has brought these new findings to worldwide recognition and implementation, is from 2010 (1). It is still used to substantiate scientific statements about the relationship between nutritional practices, intestinal flora and disease frequencies and shall therefore be presented here.
Scientists compared the diet and the composition of the gut flora in 14 children from Burkina Faso (West Africa) and 15 European children from Florence (Italy/Europe).
The diet of the African children (between one and six years old) was based mainly on locally grown grains, beans and vegetables. The diet of European children outweighed animal protein, sugar, starch and fat, while vegetables and other sources of fiber were scarcely consumed. At best, the European infants were breastfed until the first year of life, while peers from Africa were still given breast milk on request up to the age of two. .
A comparison of the composition of the childrens intestinal microbiome showed a different pattern depending on the diet. In the intestine of the Italian children were found significantly more intestinal microbial Firmicutes strains, which are associated with overweight in adulthood. In addition, they had less short-chain fatty acids that protect against inflammation of the digestive tract. Intestinal bacteria such as Xylanibacter or Prevotella were almost completely absent.
The intestine of the children from Burkina Faso, on the other hand, was colonized with a wide variety of different bacterial species, including a high proportion of Bacterioidetes strains, which help to better utilize herbal food. In addition, the intestinal flora of the African children, despite less hygienic living conditions, warded off bacterial infections stronger.
The study authors from the University of Florence concluded from these findings, how important it is to study and maintain microbial biodiversity from regions where the effects of globalization on nutrition are (still) less profound. These contain irretrievable clues to assess the influence of the intestinal flora on the subtle balance between health and disease (2).
- C DE Filippo et al. Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa. PNAS August 17, 2010. 107 (33) 14691-14696; https://doi.org/10.1073/pnas.1005963107 and C DE Filippo et al. Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa. Proc Natl Acad Sci U S A. 2010 Aug 17;107(33):14691-6. doi: 10.1073/pnas.1005963107
- Among the more than 700 follow-up publications are i.a. Feng et al. Gut Microbiota: An Integral Moderator in Health and Disease. Front Microbiol. 2018 Feb 21;9:151. doi: 10.3389/fmicb.2018.00151, TC Fung et al. Interactions between the microbiota, immune and nervous systems in health and disease. Nat Neurosci. 2017 Feb;20(2):145-155. doi: 10.1038/nn.4476. Epub 2017 Jan 16., C. Ridler. Bone: Gut microbiota promote bone growth via IGF1. Nat Rev Endocrinol. 2017 Jan;13(1):5. doi: 10.1038/nrendo.2016.200. and many others.