New research suggests that the severity of peanut allergies may be influenced by how bacteria in the gut metabolize allergens. Scientists discovered that specific oral and small intestinal microbes can break down peanut allergens before they trigger severe allergic reactions.
Food-induced anaphylaxis, particularly from peanuts, is a serious immune system reaction. While the human microbiota has been linked to tolerance, its direct role in shaping IgE-mediated responses was unclear. Investigators found that human saliva and jejunal samples contained peanut-degrading bacteria, such as Rothia and Staphylococcus, which fragmented key allergens, reducing their ability to bind IgE and activate mast cells.
In mouse models, colonization with Rothia led to lower levels of intact peanut allergens and attenuated anaphylaxis. Clinically, patients with higher levels of these degrading bacteria showed a higher threshold for allergic reactions. These findings support a model where gut microbiota actively modulate anaphylaxis severity by transforming food allergens. This opens possibilities for microbiota-targeted therapies, like probiotics or microbial enzyme supplements, to complement current allergy management strategies.