D1.431 - Associations of the composition of intestinal microbiota with the initial manifestations of IgE-mediated food allergy in children 6-12 months old

Intestinal dysbiosis during critical periods of ontogenesis is known to create prerequisites for the formation of delayed pathology. However, associations of changes in intestinal microbiota in infants with allergic diseases with certain allergens has not been sufficiently studied.

Aim was to analyze the relationships between the composition of intestinal microbiota and quantitative and qualitative characteristics of food sensitization in children with allergy aged 6-12 months.

The composition of intestinal microbiota (bacteriological method), levels of sensitization (ISAC IMMUNOCAP) in infants 6-12 months with food allergy manifestations were studied. The data obtained has been subjected to correlation analysis.

We observed 56 full-term infants, 42 (75%) of which had hereditary allergy burden. Some patients had a history of factors disrupting the formation of microbiocenosis: birth by cesarean section (n=15; 27%), perinatal use of antibiotics (n=12; 21%), early termination of exclusive breastfeeding (n=30; 54%). Allergy symptoms were more often manifested by skin (n=46; 82%), less often - gastrointestinal (n=28; 50%).

Immunological tests revealed an increase in sIgE - in 18 (32%) children, including egg white (n=10; 18%), CMP (n=5; 9%).

When assessing intestinal microbiota, a decrease in the levels of Lactobacterium spp. was detected in 27 (48%) children, Bifidobacterium spp. – in 8 (14%), Escherichia coli typical - in 14 (25%), an increased content of Klebsiella spp. was detected in 21 (38%), Clostridium spp. – in 5 (9%), Enterobacter spp. - in 5 (9%), Escherichia coli lactose-negative - in 11 (20%), Citrobacter spp. - in 4 (7%), Escherichia coli hemolytic – in 7 (13%).

Positive associations were revealed between sIgE to CMP (Bos d 4, Bos d 8), egg white (Gal d 4) and increased content of Escherichia coli hemolytic (R = 0.31; 0.35; 0.37), and also between Clostridium spp. and the presence of sIgE to cow's milk casein (Bos d 8) and egg white lysozyme (Gal d 4) (R = 0,30; 0,32). 

Associations between the increased content of opportunistic microorganisms in intestinal microbiota and the presence of specific sensitization to egg protein and CMP is the rationale for probiotic correction of microbiota in children with food allergy. The predominance of egg protein and CMP antigens among the etiological factors of IgE-mediated food allergy indicates an insufficient formation of tolerance to these nutrients at the present time of their introduction into the infant's diet.