MONDAY, Aug. 2, 2010 (HealthDay News) -- Children in an African village who ate a largely vegetarian diet and were breast-fed until the age of 2 had vastly different gut bacteria than children in a European city who ate a Western diet and were breast-fed about only half that time.
And the gut bacteria that dominated those small Western stomachs may predispose these children to become obese and develop allergies later in life, according to new research from Italian scientists in the Aug. 2-6 issue of the Proceedings of the National Academy of Sciences.
While this study didn't actually look at obesity levels or allergies, which have also been linked to changes in gut flora, the findings do point again to the havoc Western diets and lifestyles are playing on health, said Mario Ciani, chair of natural science at Mercy College in Dobbs Ferry, N.Y.
"The problem is we eat too much cheap, convenient food because it's our lifestyle and that can contribute to allergies," added Marianne Grant, a registered dietitian and health educator at Texas A&M Health Science Center Coastal Bend Health Education Center in Corpus Christi.
The huge number and diversity of "good" microbes residing in the human gut actually helps people digest and process the foods they eat.
According to background information in the study, humans' diet and gut flora transformed dramatically with the Neolithic age and the beginning of agriculture and less nomadic lifestyles about 10,000 years ago.
With the change in the food supply, the number and type of gut bacteria also transformed and may have contributed to more diseases.
More gut changes took place with the introduction of antibiotics, vaccines and better hygiene in the 20th century. And these changes coincided with more allergic and autoimmune conditions.
These authors, from the University of Florence, compared fecal samples from 15 healthy children from the village of Nanoro, in the West African nation of Burkina Faso, with that of an equivalent number of children living in the city of Florence.
The children were aged 1 through 6 and had been free of antibiotics and probiotics (potentially beneficial bacteria) for at least six months. The researchers also had information on the children's diets, provided by their parents.
The rural village of Nanoro was selected because it is relatively isolated and the diet of cereals, legumes and vegetables with little meat protein (chickens and termites in the rainy season) is closer to that of the Neolithic age.
Predictably, the Italian children ate a lot of sugar, fat and meat, and ate more calories than their African counterparts (1,512 calories a day vs. 996 calories a day among 2-to-6 year olds).
DNA analyses revealed that Italian children had more microbes linked with obesity and fewer fatty acids, which can cut down on inflammation. Overall, the population of microbes was less diverse in the Western children.
The study suggests that diet may trump factors such as sanitation, geography and climate in determining the make-up of gut microflora.
This is not the first time that the Western lifestyle taking over the globe has been suggested to influence gut microflora. A previous study found that the mix of bacteria in a baby's gut may predict whether that infant will become overweight or obese later in life.
Another found that giving antibiotics to infants increases the odds that the child will develop asthma.
"The [new study] didn't shed a lot of new, new light, but it definitely verified that a difference in colonization is associated with a low-fat, low-sugar, lower-designer-food-type diet," Ciani said.
"Our bodies are still stuck in hunter/gatherer day. We're supposed to be eating more fruits and vegetables and we should be doing a lot of physical activity to compensate," added Grant. "I tell people that if you want fried chicken now, you go to the drive-through and get it. If you wanted fried chicken then, you had to hunt, find the chicken, kill it, bring it back, pluck its feathers, clean out the innards and cook it. And if you wanted it fried, you had to have ground your own flour."
There's more on how the digestive tract works at the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.