Results of a prospective and longitudinal study conducted among schoolchildren were recently published in Allergology International, describing the association between the gut microbiome and the effectiveness of oral immunotherapy (OIT) for dairy cow’s milk allergy (CMA). Thirty-two children with IgE-mediated CMA received OIT for a period of 13 months, followed by a 2-week period of complete dairy avoidance. The primary outcome being measured was sustained unresponsiveness (SU), i.e., the ability to tolerate without any symptoms a cumulative total dose of cow’s milk of ≥44.4 ml administered by a double-blind placebo-controlled food challenge (DBPCFC), after 2 weeks of complete milk avoidance. Unfortunately, the rate of successful SU following OIT for food allergies is low once OIT is stopped, which is why this study attempted to examine multiple factors, such as changes to the microbiome, which may have influenced the treatment’s effectiveness.
Only 7 (22%) of the children achieved SU after the 2-week avoidance period. Children were less likely to have treatment success if they had higher levels of milk- and casein-specific IgE antibodies initially, and if they were undergoing concurrent treatment of atopic dermatitis or asthma (children with uncontrolled asthma/dermatitis were excluded from the study). For example, the likelihood of achieving SU was 91% and 84% lower with a current diagnosis of dermatitis or asthma, respectively. Microbiome testing revealed that a greater abundance (and increase) of Bifidobacterium was associated with a higher likelihood of SU, as were higher fecal levels of specific monosaccharides associated with mucins, a bacterial energy source. Previous research has found a reduced abundance of Bifidobacterium among children with CMA, warranting controlled studies using probiotics (Bifidobacterium) as a potential means of amplifying OIT treatment success.