An international research collaboration previously found that children with allergy to cow’s milk have markedly different bacteria in their gut than healthy children. To see if those differences contribute to the development of allergies, researchers have taken faecal samples from babies with and without cow’s milk allergies and transplanted them into mice that had been grown in a ‘germ free’ sterile environment.
The ‘germ free’ mice and the mice that received bacteria from children with allergies had anaphylactic reactions when exposed to cow’s milk for the first time, but the mice that received bacteria from healthy children did not have a reaction.
Further investigation showed that one particular species of bacteria, Anaerostipes caccae, appears to have a protective effect. When this species alone was transplanted into the ‘germ free’ mice, they did not suffer allergic reactions to cow’s milk.
A. caccae bacteria produce a short-chain fatty acid called butyrate that has been previously shown to be a crucial nutrient for establishing a healthy microbial community in the gut. Scientists involved in this research have established a start-up company ClostraBio that is developing a synthetic formulation of butyrate, which they hope to test in clinical trials in the future.