Researchers from New York City and Chicago say they've discovered that a type of bacteria commonly found in the intestines of humans and rodents seems to protect mice from food allergies.

The same bacteria, the new findings say, are among those reduced by antibiotic use in early childhood -- a fact that fits in with a growing body of work suggesting a link between the lack of such gut microbes and a staggering increase in the number of food allergies and other conditions, such as obesity and autoimmune disease.

Food allergies, according to the new work, published online in the journal Proceedings of the National Academy of Sciences, have jumped about 50 percent in children since 1997, said a story in Science magazine.

Various theories have attempted to explain the rising incidence rate, including one that notes the contemporary lifestyle, which includes a diet very different from our ancestors' and a great amount antibiotic use, and a spike in births through cesarean section, has greatly impacted the composition of microbes in the guts of many people in developed countries.

An average child in the United States, for instance, has taken three courses of antibiotics by the time he or she is aged 2 years, says Martin Blaser, an infectious disease specialist and microbiologist at New York University in New York City.

A team of scientists led by Cathryn Nagler, an immunologist at the University of Chicago in Illinois, confirmed that mice given antibiotics early in life were far more susceptible to peanut sensitization, a model of human peanut allergy. Then, they introduced a solution containing Clostridia, a common bacteria naturally found in the intestinal tracts of mammals and administered bacteria into the rodents' mouths and stomachs. And the rodents' sensitivity to food allergens disappeared

Then again, when the scientists introduced a different kind of healthy bacteria, called Bacteroides, into similarly allergy-prone mice, they didn't see the same effect.

The researchers ultimately determined that Clostridia organisms were having a surprising effect on the mouse intestines.

Acting through certain immune cells, the bacteria helped keep peanut proteins that can cause allergic reactions out of the bloodstream.

"The bacteria are maintaining the integrity of the [intestinal] barrier," Nagler said in the release.

The research, Blaser said, "opens up new territory," extending the "frontier of how the microbiome is involved" in immune responses and the roles played by specific bacteria.

In a related study, Blaser and his research group reported earlier this month in the journal Cell that giving mice penicillin soon after birth changed their gut microbiome, or, community of microbes that live in animal bodies, and made them much more likely to be obese as adults.

Nagler and her university, for their part, have filed for a patent application on the new findings with the end goal to "interrupt [the allergy] process by manipulating the microbiota" with a new probiotic product that includes Clostridia and could offer allergy sufferers a new kind of therapy.