Background: Gut microbiota plays a role in the development of natural tolerance to cow’s milk allergy (CMA).
Objective: To compare the gut microbiota of IgE-CMA patients to those of patients with other IgE-mediated food allergies and to examine changes to the gut microbiota in CMA patients undergoing milk oral immunotherapy (OIT).
Methods: Fecal samples were collected from 172 allergic patients (54 CMA patients and 118 other food allergic patients and an age-matched control group (n=40). Samples were collected at baseline and then at each monthly up-dosing OIT round. Gut microbiome was profiled by bacterial 16S rRNA sequencing on an Illumina MiSeq platform and microbiome analyses performed using QIIME (Quantitative Insights into Microbial Ecology). Alpha (within sample) and Beta (between sample) diversity were calculated.
Results: A preliminary analysis was performed on approximately half of the samples obtained. At baseline, allergic patients (milk and nuts) were significantly different from the control group. Milk allergic patients had significantly higher abundance of Actinobacteria, and lower abundance of Bacteroidetes as compared to age-matched controls. Milk and nut allergies` distances of the PCoA weighted and unweighted UniFrac revealed that the nuts allergic group was significantly more clustered together than milk allergic patients (p<0.001). Finally significant differences between bacterial operational taxonomic units in the milk allergy group before treatment versus after treatment were noted.
Conclusions: These results suggest that milk-allergic patients have a specific microbiota signature and provide the building blocks to evaluate the potential for dietary intervention or fecal transplantation to improve milk desensitization.
