By Kristen Chandler
A study published over the summer in Cell Reports showed evidence that a simple dietary change could help reduce food allergies. The study, conducted on mice, showed that food allergies were linked to what was feeding the bacteria located in the gut. One of the coauthors of the study, Laurence Macia, stated that the objective of the study resulted from their own belief that the increase of food allergies over the past decade had more to do with microbiome makeup and diet than with environmental causes such as the “hygiene hypothesis.”
Gut bacteria break down dietary fiber into fatty acids. Macia and his coauthor Charles Mackay wanted to study this break down process further and show that the fatty acids help the immune system by fastening onto receptors on T regulatory cells (Tregs). The process sets off a series of events that manages gut inflammation, which can be out of order during an allergic reaction.
The mice in the study were bred so they would have an artificially induced peanut allergy. These mice were put on diet high in fiber in order to regulate a healthy number of gut bacteria. Then, a group of mice that didn’t have microbes were given the bacteria. These mice had not been given any fiber at all but still showed a low allergic response when they were exposed to the peanut allergen. These mice basically created their own response mechanism to fiber and fatty acids. Mice given an average number of calories, sugar and fiber beginning at birth developed more severe allergies to peanuts than mice that were fed high amounts of fiber. The researchers found that the gut bacteria released a certain fatty acid when fiber intake was increased, and these fatty acids affected the allergic responses of the immune system.
In addition, some of the allergy-induced mice were given water rich with short-chain fatty acids a few weeks before they were exposed to the peanut allergen. These mice also had a lower allergic response.
Macia concluded: “My theory is that the beneficial bacteria that predominate under consumption of fiber promotes the development of regulatory T cells, which ensures the bacteria have a healthy, anti-inflammatory system to thrive in.”
Although trials have only been conducted with mice, both authors of the study have positive hopes that the same results would be found in human trials. They also stated that further testing would be necessary before they could begin studying the allergy and fiber relationship in humans. Other factors, like what form of fiber humans would need to be given, would also need to be determined before starting any human clinical trials.
Mackay said the results of this study not only give us information on preventing food allergies, but other inflammatory diseases as well.
This is more exciting news in the world of food allergy research! What do you think about this discovery? Do you agree with the researchers and Mackay—that diet and human microbes take some responsibility for food allergies, or do you stand by the hygiene hypothesis*? Or do you think many factors are responsible for food allergies? We would love to hear from you. Please leave us a comment below.
*Keep in mind that these are only theories backed by scientific findings and not an exact cause or cure. Bottom of Form