Diets high in fat, sugar and protein, and low in fiber have been associated with increased incidence of noninfectious intestinal diseases all over the world.
Researchers writing in the Proceedings of the National Academy of Science (PNAS), examined differences in gut microbiota in 14 healthy children in rural Burkina Faso and 15 healthy children in urban Italy in an effort to explain the role of gut bacteria in some of these chronic illnesses.
The Burkina Faso children ate a diet high in starch, fiber and plant polysaccharides, and low in fat and animal protein – a diet thought to be similar to that of early human settlements at the time of the birth of agriculture. The Italian children’s diet was typical of the developed world – high in animal protein, sugar, starch, and fat, and low in fiber.
The researchers, from the University of Florence, compared intestinal bacteria in the two populations and found that significant differences developed from the time that breast feeding ceased.
“Our results suggest that diet has a dominant role over other possible variables such as ethnicity, sanitation, hygiene, geography, and climate, in shaping the gut microbiota,” the authors wrote.
“We can hypothesize that the reduction in richness we observe in EU compared with BF 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 microbiota.”
The Burkina Faso children’s diet was based on millet, sorghum, black eyed peas and vegetables, and contributed nearly twice as much fiber as the Italian children’s diet, leading the researchers to suggest that high fiber intake could play a central role in shaping gut microbiota.
And the ratios of gut bacteria for the Italian children have previously been linked to increased risk of obesity – perhaps providing a useful obesity biomarker, the researchers wrote.
They said that the study could prompt further research looking to clarify the relationship between differences in gut microbiota, health and disease, and could also lead to the development of novel probiotic products.
“Both in the Western world and in developing countries diets rich in fat, protein and sugar, together with reduced intake of unabsorbable fibers, are associated with a rapid increase in the incidence of noninfectious intestinal diseases,” they wrote. “…Reduction in microbial richness is possibly one of the undesirable effects of globalization and of eating generic, nutrient-rich, uncontaminated foods.”
The full study is available online here.