An interventional study of Probiotic mixture and Placebo in Antibiotic, Allergic Diseases and Infants, sponsored by Peking University Third Hospital. Not yet recruiting at 1 site in China. Open to participants aged 1 Day to 35 Days, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-11.
Sponsored by Peking University Third Hospital · Not applicable, Interventional, and Prevention
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.
Allergic diseases are a major global public health problem, affecting approximately 30%-40% of the population. Food allergy (FA) often represents the starting point of the atopic march in children and can subsequently progress to atopic dermatitis, asthma, allergic rhinitis, and other conditions, severely impacting quality of life. Early life is a critical "window period" for the development and maturation of the immune system, in which the gut microbiota plays a central role. The interaction between the gut microbiota and the host immune system is essential for the establishment of immune tolerance.
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. The underlying mechanism may involve antibiotic-induced disruption of the gut microbiota, which in turn affects immune balance and skews the immune response toward a Th2-dominant (allergy-prone) phenotype. However, the specific host-microbiota interactions involved have not yet been fully elucidated.
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 secretory IgA 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 on the development of allergic diseases after antibiotic exposure.
The study plans to enroll infants with early-life antibiotic exposure as the study population. Starting at 1 month of age, they will be randomly assigned to a probiotic intervention group or a placebo group, while infants who have never received antibiotics will be included as a control group.
Infants in the intervention group will receive an oral probiotic formulation for 8 weeks, whereas those in the placebo group will receive a placebo without probiotics. During the one-year follow-up period, the occurrence of food allergic diseases in each group will be documented in detail, including the time of onset, type, and severity of symptoms. In addition, growth and development indicators, gut microbiota composition, and metabolomic profiles will be regularly monitored to further explore the potential mechanisms of action of the probiotic intervention.
Peking University Third Hospital is the lead sponsor of 735 studies on the registry; 262 are open to participants now.
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Exclusion Criteria:
The control group consists of full-term healthy newborns who have not received antibiotics within 30 days after birth. No intervention will be given; they will only be followed up for the occurrence of allergic diseases and infectious diseases within the first year of life. During the follow-up period, four stool samples will be collected for the analysis of gut microbiota and their metabolites.
The probiotic intervention group will recruit full-term newborns who have received antibiotics within 30 days after birth. Starting at 5 weeks of age, they will receive an 8-week course of an oral probiotic mixture (containing Bifidobacterium longum subsp. infantis R0033, Lactobacillus helveticus R0052, and Bifidobacterium bifidum R0071). They will be followed up for the occurrence of allergic diseases and infectious diseases within the first year of life. During the follow-up period, four stool samples will be collected for the analysis of gut microbiota and their metabolites.
Dietary Supplement: Probiotic mixture
The placebo group will recruit full-term newborns who have received antibiotics within 30 days after birth. Starting at 5 weeks of age, they will receive an 8-week course of an oral placebo without the probiotic. They will be followed up for the occurrence of allergic diseases and infectious diseases within the first year of life. During the follow-up period, four stool samples will be collected for the analysis of gut microbiota and their metabolites.
Other: Placebo
Oral probiotic mixture for 8 weeks, once daily, one sachet per day
Oral a placebo without probiotics for 8 weeks, once daily, one sachet per day.
Incidence of allergic diseases in infants
Compare the incidence of allergic diseases between the antibiotic-exposed group and the control group, and analyze the effects of antibiotic exposure intensity, frequency, and type on the development of allergic diseases. Furthermore, compare the incidence of allergic diseases among the probiotic intervention group, the placebo group, and the control group.
Time frame: Follow up until the enrolled infants reach 1 year of age.
Changes in gut microbiota composition in the antibiotic-exposed group
Compare the changes in gut microbiota composition of infants in the antibiotic-exposed group at enrollment (1 month of age) and at 3, 6, and 12 months of age, compare the differences in gut microbiota composition among the three groups, and analyze the effect of antibiotic exposure intensity on gut microbiota composition.
Time frame: At enrollment (1 month of age) and at 3, 6, and 12 months of age
Changes in fecal metabolites in infants of the probiotic intervention group
Compare the changes in fecal metabolites between the probiotic intervention group and the placebo group, and explore the potential mechanisms by which specific probiotic intervention induces alterations in gut metabolites.
Time frame: At 3, 6, and 12 months of age
Growth curves of infants in the antibiotic-exposed group and the control group
Compare the growth curves and developmental parameters between the antibiotic-exposed group and the control group.
Time frame: At 3, 6, 9, and 12 months of age.
Proportion of infectious diseases in infants of the antibiotic-exposed group and the control group
Compare the frequency, types, and proportion of infectious diseases between the antibiotic-exposed group and the control group.
Time frame: Follow up until the infant reaches 1 year of age.
Plan to share: No
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Peking University Third Hospital