Background <p>Despite limited researches revealed potential relationship between dietary habits and diseases in recent years, there is still a lack of systematic understanding of the relationship between dietary fiber intake and Helicobacter pylori (H. pylori) infection. This study aim to investigate the relationship between dietary fiber intake and H. pylori infection, and to evaluate their impact on all-cause mortality.</p> Methods <p>This study was conducted based on data from the National Health and Nutrition Examination Survey (NHANES, 1999-2000). We employed logistic regression analyses, cox regression analysis and restricted regression cubic spline(RCS) analysis to assess the association between dietary fiber intake and H. pylori infection, as well as all-cause mortality in individuals with or without H. pylori infection.</p> Results <p>A total of 3803 participants were included in our analysis. We found that dietary fiber intake was negatively associated with seropositive for H. pylori even after adjusting for potential confounders. In addition, higher dietary fiber intake was collated to the lower all-cause mortality in seropositive to H. pylori patient with HR of 0.60 (95% CI 0.47, 0.75). In addition, there is a nonlinear relationship between dietary fiber intake and all-cause mortality only in seropositive for H. pylori individuals.</p> Conclusion <p>An increase in dietary fiber intake was correlated with a lower risk of seropositive for H. pylori and lower all-cause mortality in US population. Additional work is needed to clarify the precise mechanisms underlying the association between dietary fiber intake and H. pylori infection.</p>