Gut bacteria changes linked to allergy

Posted on Sun, 10 Jan 16

Researchers have discovered that changes in gut bacteria are common in people with allergies, and suggest that improving gut health may help in the treatment or prevention of allergy.

“Its not you, its me;” said the person with allergies to the peanut. Allergies and sensitivities are an abnormal immunological reaction to what should be harmless substances, such as common foods or pollen. And they are on the increase, “in the US population from 1988–1994 to 2005–2006, self-reported prevalence of physician diagnosed seasonal pollen allergy (hay fever), for example, increased from 8.8% to 11.3%,” point out the authors of a new study that may help understand why the problem is growing.

One theory for the increasing prevalence of allergies is the hygiene hypothesis, which suggests lack of exposure to microbial challenges in modern society is paradoxically making us sick. Further, an extension of the hygiene hypothesis is that poor development and health of your gut bacteria (termed "dysbiosis") due to cesarean births, antibiotic exposure, poor diet and other factors is known to play a role.

So to see if people with allergies have different gut bacteria from those who don’t researchers analyzed data from 1879 adults involved in the American Gut Project. They discovered that “adults with allergies, especially to nuts and seasonal pollen, have low diversity, reduced Clostridiales, and increased Bacteroidales in their gut microbiota.” Interestingly they found that allergies were not related to cesarean birth, suggesting that these bacterial changes may occur later in life. 

“This dysbiosis might be targeted to improve treatment or prevention of allergy” they said. 

Reference:

Hu X, et al. Allergy associations with the adult fecal microbiota: Analysis of the American Gut Project. EBioMedicine. Available online 27 November 2015 [in press]