Luminal and mucosal-associated intestinal microbiota in children born to mothers with bronchial asthma during the first year of life

Objective. To study the luminal and mucosal-associated intestinal microbiota (IM) in children at high risk of atopy during the first year of life depe nding on the type of feeding in the early neonatal period. Patients and methods. This prospective, longitudinal, randomized study included pairs of pregnant women and their children. They were divided into two groups: the study group, which consisted of patients with high risk of atopy (39 full-term infants born through vaginal delivery to mothers with bronchial asthma), and the control group, which enrolled patients with low risk of atopy (26 full-term infants born through vaginal delivery to healthy mothers). Depending on the type of feeding in the early neonatal period, subgroups A (exclusively breastfed infants) and B (formula-fed infants) were identified. The intestinal microbiota was examined on day 2-3 and then every 2 months until the child reached the age of 1 year; stool specimens and brushing specimens from the rectum were collected. The luminal and mucosal-associated IM were analyzed using a real-time polymerase chain reaction with group- and species-specific primers in 4 phylums including 31 microorganisms. Results. The IM parameters were influenced by the following: the source of sampling (luminal IM values were higher than that of mucosal-associated IM and increased with the age of children), mass of microorganisms studied (increased with age regardless of the type of feeding in the early neonatal period, but the most diverse IM was noted in children with HRA), the type of infant feeding (had no effect on bacterial mass except for Clostridium dificile, whose mass was higher in exclusively breastfed infants with HRA (F(1.61) = 5.68; p = 0.020; η2 p = 0.09)), and also depended on the child’s age at the time of sampling (F(6.366) = 294.63; p < 0.001 ; η2 p = 0.83) (increased with age) and the source of sampling (higher in mucosal-associated IM) (F(1.61) = 141.12; p < 0.001 ; η2 p = 0.70). The presence of maternal bronchial asthma had the most significant effect on the quantitative and qualitative composition of IM. Conclusion. Children at high risk of atopy had a greater diversity of both the luminal and mucosal-associated intestinal microbiota. The presence of maternal bronchial asthma is the most significant factor modifying the intestinal microbiota of the child. Key words: atopy, bronchial asthma, infants, feeding, luminal and mucosal-associated intestinal microbiota