For children with a normal urinary tract, probiotics were more effective than placebo at reducing the risk for recurrent urinary tract infection (UTI) after the first episode of febrile UTI, according to data published in Journal of the Pediatric Infectious Diseases Society.

A total of 181 children age 4 months to 5 years with a normal urinary tract who had fully recovered from their first febrile UTI were enrolled. Children were randomly assigned 1:1 to receive a probiotic mixture of Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium lactis (n=91) or placebo (n=90) for a total of 18 months.

The results showed the probiotics to be superior to placebo with regard to the primary endpoint of composite cure, defined as UTI-free duration at 18 months. Composite cure was observed in the probiotic and placebo groups at 96.7% and 83.3%, respectively (P =.02; 95% CI, -8.9 to 4.1). The median time to first incidence of UTI recurrence was 3.5 months (range, 1-4 months) for the probiotic group and 6.5 months (range, 2-14 months) for the placebo group (P =.04). Escherichia coli followed by Klebsiella pneumoniae were the main causes of recurrent UTI and this was not significantly different between groups. In addition, no specific adverse events occurred among the children in the probiotics group. In both groups, girls demonstrated higher rates of UTI recurrence compared with boys: 6 girls in the probiotic group and 14 in the placebo group compared with 0 and 2 boys, respectively.

Continue Reading

Study limitations reported by investigators included participant selection, which occurred within the university hospitals’ referral networks, meaning results from community and primary care settings were missed. In addition, the American Academy of Pediatrics guidelines do not recommend routine screening with voiding cystourethrography prevented investigators from fully exploring the effect of vesicoureteral reflux on recurrent UTI and the effectiveness of probiotic prophylaxis according to vesicoureteral reflux grade. Uncircumcised boys were also not included in either study group, which may affect the validity of the analysis and introduce bias. Researchers also did not study whether probiotic therapy reduced colonization of the bowel by virulent E coli.

Related Articles

A major strength of the study was that it was a randomized controlled probiotic-vs-placebo clinical trial of a relatively large pediatric population. This was aided by an adequate follow-up time to assess the role of probiotics in the prevention of recurrent UTIs.

Investigators concluded that when compared with placebo, probiotic prophylaxis reduced the incidence of UTI recurrence significantly in children after a febrile UTI and that this efficacy was more pronounced in girls than in boys. They recommended that in light of the limitations presented, “additional investigation is needed to better understand the risks and benefits of probiotic prophylaxis.” Researchers also recommended that these studies should be powered to assess efficacy in older people and those without vesicoureteral reflux and to determine the best probiotic strains, optimal dosing, and appropriate duration of therapy.


Sadeghi-Bojd S, Naghshizadian R, Mazaheri M, Ghane Sharbaf F, Assadi F. Efficacy of probiotic prophylaxis after the first febrile urinary tract infection in children with normal urinary tracts [published online May 17, 2019]. J Pediatric Infect Dis Soc. doi:10.1093/jpids/piz025