Objective To explore the regulatory effect of oral probiotics as adjuvant therapy on the imbalance of helper T cell 1(Th1)/helper T cell 2(Th2),intestinal flora and lung function in children with allergic asthma and its clinical efficacy.Methods A retrospective analysis was con-ducted in the clinical data of 122 children with allergic asthma.According to different treatment regi-mens,the children were divided into control group(n=60)and observation group(n=62).The control group received conventional treatment combined with budesonide,while the observation group received oral probiotics as adjunctive therapy in addition to the treatment in the control group.The asthma control effects[Childhood Asthma Control Test(C-ACT)score],intestinal flora(Escherichia co-li,Bifidobacterium,Lactobacillus),relevant lung function indicators[peak expiratory flow as a percentage of predicted value(PEF％pred),fractional exhaled nitric oxide(FeNO),forced expiratory volume in one second as a percentage of predicted value(FEV1％pred)],respiratory mechanics parameters[work of breathing(WOB),airway resistance(Raw),peak inspiratory pressure(PIP),dynamic lung compliance(Cdyn)],levels of sputum adhesion molecules[integrin α4β1,vascular cell ad-hesion molecule-1(VCAM-1),intercellular adhesion molecule-1(ICAM-1)],levels of Th1/Th2 cytokine-related indicators[interleukin-4(IL-4),interferon--y(IFN-γ),the ratio of IFN-γ to IL-4(IFN-γ/IL-4),the ratio of Th1 to Th2(Th1/Th2)],symptom disappearance time,clinical effica-cy,and the incidence of adverse reactions were compared between the two groups.Results After treatment,the observation group demonstrated significantly higher C-ACT scores,overall clinical re-sponse rates,IFN-γ/IL-4 and Th1/Th2 ratios,along with elevated levels of Lactobacillus,Bifidobacterium,PEF％pred,FEV1％pred,Cdyn and IFN-γ compared to the control group(P＜0.05).Conversely,adverse reaction rates,and levels of Escherichia coli,FeNO,Raw,WOB,PIP,integrin α4β1,VCAM-1,ICAM-1 and IL-4 were significantly lower in the observation group(P＜0.05).Symptom resolution time was also shorter in the observation group(P＜0.05).The total Naranjo scale score was 3,indicating a"possible"causal relationship between adverse drug re-actions and probiotic use.Conclusion Oral probiotics as adjunctive therapy can effectively regulate Th1/Th2 imbalance induced by allergic asthma in children,improve clinical outcomes,pulmonary function,respiratory mechanics,intestinal microbiota composition,and sputum adhesion molecule levels.