Western Diet Kills Good Bugs in Stomach, Causes Obesity and Allergies

Megan is a sucker for sustainable agriculture and a good farmers market, she likes writing about food almost as much as eating it.
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A family prepares a meal. The daily diet in Burkina Faso is high in fiber, starch, and plant polysaccharides, and low in animal fat. (Photo: Ambrispuri/Creative Commons)

According to a new study, Westerners are fattened and sickened not only by the amount of food they eat, but also by the type of food.

Western food, the study says, heightens susceptibility to allergies and obesity by lowering levels of healthy bacteria in the gut.

The study compared the fecal matter of 14 healthy African children living in a rural village in Burkina Faso—where conditions are analagous to those of the agricultural revolution 10,000 years ago—with the poop of 15 Italian children from urban Florence.

By comparison, the African children's digestive tracts excreted a far broader range of bacteria, some of which fight inflammation and others that are linked to leanness. Their samples had a lower proportion of microbes associated with obesity in adults and fewer of the bacteria that cause upset stomachs and diarrhea (including E. coli, which is all too common in the States). The rural youngsters also discharged high concentrates of bacteria that aid in the digestion of plant foods and generate fatty acids which boost body energy.

The researchers say the bacteria disparity is no coincidence; common Western health problems like obesity, allergies, autoimmune disease and irritable bowel disease are largely absent in rural African populations. (More prevalent problems in Africa include malnutrition and infection.)

Along with causal diet, the researchers chalk up sickness in the West to excessive hygiene, a cleanliness fixation adopted by Western societies, perhaps to their own detriment.

Lead author of the study, Paolo Lionetti, a pediatric gastroenterologist at Meyer Children Hospital in Florence, Italy, explains:

Western developed countries successfully controlled infectious diseases during the second half of the last century by improving sanitation and using antibiotics and vaccines.

At the same time, a rise in new diseases such as allergic, autoimmune disorders, and inflammatory bowel disease (IBD) both in adults and in children has been observed, and it is hypothesized that improvements in hygiene together with decreased microbial exposure in childhood are considered responsible for this increase.

Compulsive handwashers may be relieved to know that their behavior is not the only factor at play in wiping out beneficial digestive bacteria. The researchers write in their report:

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 lesson in all this? Lionetti says it's crucial that we preserve "this treasure of microbial diversity from ancient rural communities worldwide."

Photo: Ambrispuri/Creative Commons via Flickr


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