From Science Daily:
The development of food allergies in mice can be linked to what their gut bacteria are being fed, reports a study published June 21 in Cell Reports. Rodents that received a diet with average calories, sugar, and fiber content from birth were shown to have more severe peanut allergies than those that received a high-fiber diet. The researchers show that gut bacteria release a specific fatty acid in response to fiber intake, which eventually impacts allergic responses via changes to the immune system.
“We felt that the increased incidence of food allergies in the past ten years had to relate back to our diet and our own microbiome rather than a lack of exposure to environmental microbes–the so-called ‘Hygiene Hypothesis’,” says Laurence Macia, co-senior author on the study with Charles Mackay, both immunologists at Monash University in Australia. “Most researchers in this field look at excess fat as the problem–we were one of the first looking specifically at fiber deficiency in the gut.”
Gut bacteria are known to break down dietary fiber into their byproducts–primarily short-chain fatty acids. Macia and Mackay take this a step forward and show that these fatty acids support the immune system by binding onto specific receptors on T regulatory cells–immune cells known to suppress the immune response. This binding promotes a cascade of events that regulate inflammation in the gut–something that can be out of flux during an allergic reaction to food.
In the study, mice that were bred to have an artificially-induced peanut allergy…