Fusobacterium nucleatum confirmed in gastric biopsies of patients without Helicobacter pylori.

[OBJECTIVE] Putative associations between certain bacteria and gastric cancer have been described previously; however, the mechanisms underlying such associations are not thoroughly understood. We aimed to confirm the presence of Fusobacterium nucleatum in the biopsy samples of patients with gastroduodenal diseases, including gastric cancer, with concomitant or without Helicobacter pylori infection.

[RESULTS] Three hundred patients with gastroduodenal disorders, including gastritis, duodenal ulcer, or gastric cancer, were included. One hundred and eighty (60%) patients were negative and 120 (40%) positive for H. pylori. Associations between the presence of H. pylori and age, gender, or other demographics were statistically insignificant (p > 0.05). The prevalence of F. nucleatum infection was determined for the two patient categories: 215 patients (72%) were positive for F. nucleatum; of these cases, 95 showed evidence of, and 120 lacked, concomitant H. pylori infection. Gastric biopsies obtained from patients with gastric cancer but negative for H. pylori revealed a significant prevalence of F. nucleatum infection.