The effect of cranberry supplementation on Helicobacter pylori eradication in H. pylori positive subjects: a systematic review and meta-analysis of randomised controlled trials

Helicobacter pylori infection is one of the most common chronic bacterial infections. Cranberry has been suggested for H. pylori eradication. We aimed to conduct the first meta-analysis to summarise current evidence on effects of cranberry supplementation on H. pylori eradication in H. pylori positive subjects. We searched the online databases up to December 2020. Four randomised clinical trials (RCT) were included with human subjects, investigating the effect of cranberry on H. pylori eradication. The pooled results were expressed as the OR with 95 % CI. Based on five effect sizes with a total sample size of 1935 individuals, we found that according to the OR, there was a positive effect of cranberry supplementation on H. pylori eradication, increasing the chance of H. pylori eradication by 1 center dot 27 times, but this relationship was not statistically significant (overall OR: 1 center dot 27; 95 % CI 0 center dot 63, 2 center dot 58). The results also indicated the moderate between-study heterogeneity (I-2 = 63 center dot 40 %; P = 0 center dot 03) of the studies. However, there were no significant differences in some subgroup analyses in the duration of treatment, the duration of follow-up and the Jadad score. Our findings revealed that although cranberry had a positive effect on H. pylori eradication in adults, this effect was not statistically significant. Due to the small number of included studies and moderate heterogeneities, the potential of cranberry supplementation on H. pylori eradication should be validated in large, multicentre and well-designed RCT in the future.