Scientists examining links between gut bacteria and food allergies have shown that introducing a specific metabolite into the gut microbiome of mice both prevents allergies and stops existing ones, including peanut allergies.
The US researchers at the University of Chicago knew a specific microbe Clostridia (which has been implicated in food allergies) produces the metabolite butyrate, which helps:
- keep the microbiome in balance by promoting the growth of beneficial bacteria; and
- protect the integrity of the walls lining the gut to keep food from leaking out and potentially causing an allergic reaction in the intestinal mucosa.
Previous attempts to restore Clostridia to the microbiome orally or via faecal implants have not worked, so a team led by Dr Shijie Cao decided to introduce butyrate itself into the distal gut of mice.
Presenting their research at a meeting of the American Chemical Association, Dr Cao explained that because butyrate ‘has a very bad smell, like dog poop and rancid butter, and it also tastes bad, so people wouldn’t swallow it’, his team delivered polymer-wrapped butyrate directly to the mice –to hide the nasty flavour and smell until stomach acid breaks down the protective coating and delivers the butyrate into the lower gut far below taste buds or olfactory sensors.
The easily digestible butyrate, as well as preventing food allergies in mice, also prevented the mice’s anaphylactic response to peanuts – among the most dangerous allergens for humans.
Dr Cao told medicalnewstoday. com his team is now ‘moving towards clinical testing’ of the polymer-wrapped butyrate ‘starting with larger animals before human trials’.
He hopes their research leads to a new and ‘easily digestible means of restoring microbiome function’ so that ‘one day a person with food allergies might find relief simply by tearing open a small packet of polymer-wrapped butyrate, mixing it with water or juice, and drinking’.
Dr Cao’s team also investigated the possible benefit of butyrate injections into specific body areas, rather than oral administration to deliver to the gut.
He noted: ‘We tried to use butyrate as a therapeutic drug and directly deliver it to the lymph node to modulate local immunity. ‘We showed it increased local regulatory T cells and suppressed the activation of myeloid cells in the local lymph nodes. We think this might be useful for addressing local inflammation and diseases such as arthritis.’
His team is also investigating whether their polymer-wrapped butyrate can help relieve inflammatory bowel disease; they report that, so far, it reduces the severity of colitis (swelling of the large intestine) in mice.
