Alterations in the Gut Microbiome of Patients with Food Allergy

Rationale: Alterations in the diversity and composition of the human gut microbiota have been observed in patients with atopic diseases.  We explored the association of the gut microbiome with food allergy (FA) in the pediatric population.

Methods: 12.5 ng of isolated DNA from fecal samples from 29 children with FA (peanut, milk, and/or egg allergy) and 10 healthy, non-atopic controls (C) were amplified using primers specifically for the V3-V4 region of the 16S rRNA gene which is unique to bacteria.   The Mann-Whitney U-test was used for comparison of continuous variables between the two groups.  All analyses were carried out using SAS V9.3. 

Results:  FA and C subjects both had a median age of four years. The phylogentic differences showed that FA subjects had an increased proportion of Actinobacteria when compared to C (median=1.4% vs 0.55%; p<0.04).  Actinobacteria class was more abundant in subjects with FA compared to C (median= 1.4% vs. 0.28%; p<0.02).  At the family level, Alcaligenaceae was significantly less abundant in subjects with FA (median 0% vs. 0.63%; p<0.01) while Bifidobacteriaceae was significantly more abundant in subjects with FA (median=1.11% vs. 0%; p<0.02). Sixteen genera were identified in C while 21 genera were identified in patients with FA.  

Conclusions:  Differences in the gut microbiome in children with food allergy and healthy controls exist and may contribute to the pathogenesis of food allergy or be an association due to other factors. Further studies with larger sample sizes are needed to clarify these observations.