Rotavirus immunisation status affects the efficacy of GG for the treatment of children with acute diarrhoea: a meta-analysis.

The efficacy of GG (LGG) for the treatment of children with acute gastroenteritis has been debated based on most recent evidence. Previous evidence demonstrated that LGG mainly benefits children with Rotavirus infection compared to other aetiologies. However, Rotavirus immunisation (RVI) has been implemented worldwide since 2006. We aimed to investigate whether the efficacy of LGG in children with gastroenteritis vary according to RVI status. The MEDLINE, Embase and Cochrane library databases were searched for relevant randomised controlled trials (RCT) up to April 2022. The duration of diarrhoea and episodes lasting >48 h were considered as primary outcomes. The date of vaccine introduction and RVI coverage were reviewed for all countries where trials were conducted. Among the 15 RCTs included in the analysis (n=3,465), only 5 showed a low risk of bias. In RCT conducted before the introduction of RVI (n=2,932), LGG was effective in reducing the duration of diarrhoea compared with placebo or standard care (Median -23.80 h, 95% confidence interval (CI) -36.59 to -11.02]). Only 2 RCTs (n=1,072) reported data of populations partially immunised against Rotavirus with an overall coverage of 44 and 67%, respectively. In this population, LGG showed no efficacy in reducing the duration of diarrhoea (Median -5.34, 95%CI -12.9 to 2.22). Similarly, LGG reduced the risk of diarrhoea lasting >48 h in children not immunised against Rotavirus (RR 0.73, 95%CI 0.54-0.99), but not in population partially immunised (RR 0.98, 95%CI 0.87 to 1.11). The implementation of RVI might affect the efficacy of LGG modifying local epidemiology and susceptibility of the target population to selected probiotics.