Early antibiotic exposure is an important environmental factor that disrupts the establishment of the infant gut microbiota and leads to microbial dysbiosis. Accumulating epidemiological evidence indicates that exposure to antibiotics early in life (including both prenatal and postnatal periods) is significantly associated with an increased risk of allergic diseases in childhood. As live microorganisms, probiotics hold potential as a preventive strategy against allergies due to their ability to stabilize the intestinal barrier and regulate immune balance (e.g., promoting Th1/Th2 balance, inducing regulatory T cells, and increasing sIgA secretion). However, current studies have mostly focused on general or high-risk infant populations. For the specific high-risk subgroup that has already been exposed to antibiotics early in life, high-quality randomized controlled trial evidence is still lacking regarding whether probiotic intervention can effectively reduce the incidence of allergies and whether it exerts its effects by reshaping the gut microbiota and metabolites disrupted by antibiotics.
This study focuses on breastfed infants who received antibiotics during the early postnatal period (within 30 days after birth) and aims to investigate the effect of a probiotic mixture containing Bifidobacterium longum subsp. infantis R0033, Lactobacillus helveticus R0052, and Bifidobacterium bifidum R0071 on the development of allergic diseases after antibiotic exposure.
Gestational age from 37 weeks to less than 41 weeks;
Birth weight between the 10th and 90th percentiles for gestational age;
Breastfed (exclusively breastfed after achieving stable feeding volume, with willingness to maintain exclusive breastfeeding for at least 3 months);
Postnatal age within 35 days; Consent to participate in this study.
Postnatal Apgar score <7;
Presence of severe congenital malformations or inherited metabolic diseases;
Use of probiotics by the infant or the mother within 2 weeks before enrollment.