Objective  To investigate the effect of probiotics on the immune function and clinical efficacy in children with recurrent respiratory tract infection (RRTI).

  Methods  A total of 92 RRTI children were continuously enrolled and were randomly divided into study group and control group, with 46 cases in each group. Both groups were given oral treatment of pidotimod, and the study group added Bifid Triple Viable Bifidobacterium Power, all the children were treated for 3 months, and followed-up time lasted for more than 1 year. The changes of serum C-reactive protein (CRP), procalcitonin(PCT), immunoglobulin G(IgG), pmmunoglobulin A(IgA) and T cell subgroups were compared between the two groups, and the clinical efficacy between the two groups were compared.

  Results  After treatment, serum CRP and PCT concentrations significantly decreased, serum IgG and IgA level significantly increased, the peripheral blood T cell count of CD4⁺ was significantly increased, CD8⁺ was significantly decreased in both groups when compared with that treatment before(P < 0.05). At the same time, the study group showed lower serum CRP and PCT concentration, higher serum IgG and IgA levels, higher peripheral blood CD4⁺ T cell count, and lower CD8⁺ T cell count after treatment, when compare to the control group(P < 0.05). However, there was no statistically difference between two groups in clinical efficiency (P>0.05).

  Conclusion  Probiotics can effectively improve the immune function and reduce the inflammation level in RRTI children.