ObjectiveConflicting results have been reported by numerous epidemiological studies investigating the association between Helicobacter pylori (H. pylori) infection and inflammatory bowel disease (IBD). We aimed in this study to assess the possible association between H. pylori infection and IBD and its effects on disease progression.DesignProspective observational study.SettingSpecialised IBD care clinics at Alexandria University Student Hospital in northern Egypt, between March and June 2019.Participants182 patients with IBD.Analysis and outcome measuresParticipants with IBD were screened for H. pylori infection and clinically evaluated at the initial visit and bimonthly for 3 months to record any potential improvement/flare of the IBD condition.ResultsOverall, 90 (49.5%) patients with IBD had evidence of H. pylori infection. The course of IBD did not significantly differ in association with H. pylori infection or IBD treatment strategy. Cox regression analysis revealed that patients aged 20–35 years (HR=6.20 (95% CI: 1.74 to 22.12)) and 35–55 years (557.9 (17.4–17 922.8)), high socioeconomic status (2.9 (1.11–7.8)), daily consumption of fibre-rich food (5.1 (1.32–19.5)), occasional consumption of snacks between meals (2.8 (2.5–70.5)) and eating four meals per day (13.3 (1.0–7.7)) were predictive of IBD flare. By contrast, eating fruits and vegetables showed a strongly protective association (HR=0.001 (95% CI: 0.0002 to 0.02)). The probabilities of improvement of IBD symptoms after 12 weeks of follow-up were comparable in assessments based on H. pylori infection status (0.793 for H. pylori negative vs 0.778 for H. pylori positive) and IBD treatment option (0.811 for conventional therapy vs 0.750 for biological therapy).ConclusionThe association between IBD and H. pylori infection is unresolved and should be further investigated in the context of specific environmental exposures that can influence the development or relapse of IBD.