Introduction:
Helicobacter pylori (H. pylori) is a bacterium that causes chronic gastroduodenal infection and affects various systemic diseases. An increase in the blood level of C-reactive protein (CRP; a systemic inflammatory marker), at a low-grade chronic inflammation level, is observed in cases of infection. However, the effect of H. pylori eradication on CRP remains undetermined. Therefore, we aimed to see the circulating CRP levels in eradicated patients through a meta-analysis.

Material and methods:
The PubMed database was searched from its inception to June 2020. Studies that described the CRP levels following H. pylori eradication were collected. A random-effects meta-analysis was then performed using an inverse variance with standardized mean difference.

Results:
A total of 10 eligible studies (642 subjects in total) were available. The median age in the studies was 49.9 years old. The CRP level was 6.0 (median) mg/L before H. pylori eradication and 5.8 (median) mg/L after eradication. From the results of overall meta-analysis, there was found to be a significant reduction in the CRP levels with H. pylori eradication (standardized mean difference: -0.64; 95% confidence interval: -1.02 to -0.27). The result was not similarly confirmed in a subanalysis of the available randomized controlled trials.

Conclusions:
Weak evidence exists in terms of the effects of H. pylori eradication on the reduced CRP levels. Further research is called for.