The following is a summary of “Strain-Specificity of Probiotics in Pediatrics: A Rapid Review of the Clinical Evidence,” published in the February 2023 issue of Gastroenterology and Nutrition by Jankiewicz, et al.

Probiotic strain-specificity is commonly regarded as a dogma. Clinical trial data only supported the effects of genus- and species-specific probiotics, though. For a study, researchers sought to evaluate the clinical evidence in support of the idea that probiotics’ effectiveness in children varies depending on the strain.

The Cochrane Library, MEDLINE, and EMBASE databases were searched (up to August 2022) for randomized controlled trials (RCTs) carried out in kids aged 0 to 18 years evaluating the effects of probiotics (well-characterized at the strain level) administered prophylactically or therapeutically for conditions like antibiotic-associated diarrhea, acute diarrhea, necrotizing enterocolitis, respiratory tract infections, Helicobacter pylori infection, and atopic dermatitis. A study could only be considered for the review if at least one other RCT examined the impact of a different strain of the same species against the same comparator, allowing for the examination of strain-specificity. RCTs that lacked sufficient strain-level data were disregarded. Indirect comparisons between therapies were done in the absence of head-to-head strain vs strain RCTs.

There were 23 RCTs that may be included. With one exception (the effectiveness of two strains of Lacticaseibacillus paracasei in lowering the symptoms of atopic dermatitis), no significant variations between the clinical effects of several strains of the same probiotic species were discovered across the 11 comparisons that were conducted.

The best study design for comparing probiotic strains is a head-to-head comparison, however, there aren’t many of these. The study showed that there was inadequate clinical evidence to prove or disprove the idea that probiotic benefits on children are strain-specific based on indirect comparisons.

Reference: journals.lww.com/jpgn/Abstract/2023/02000/Strain_Specificity_of_Probiotics_in_Pediatrics__A.21.aspx