MedWire News: Many patients diagnosed with 'unexplained' ulcers in their small intestine, called the duodenum, may actually be infected with the ulcer-causing bug Helicobacter pylori, and can be successfully treated with antibiotic therapy, researchers have found.

Dr Antonio Pietroiusti, from Tor Vergata University in Rome, Italy, and colleagues explain that stomach tissue samples, or biopsies, are usually used to identify Helicobacter pylori infection in people with ulcers in their duodenum.

If these tests prove negative, such patients are given treatment with stomach acid-suppressing drugs, instead of the antibiotics used to eradicate Helicobacter pylori.

However, they add that some studies have suggested that duodenal ulcer patients who test negative for Helicobacter pylori infection with the stomach biopsy method often respond well to antibiotic treatment, indicating that stomach biopsies do not always identify infection in the small intestine.

For the current investigation, the team studied 608 patients with duodenal ulcers. Using the stomach biopsy method, 42 of these patients tested negative for Helicobacter pylori infection.

However, further tests on tissue samples taken from the patients' duodenums, combined with breath tests, revealed that 18 of these 42 patients had Helicobacter pylori bacteria in their small intestines, but not in their stomachs.

These patients then underwent Helicobacter pylori eradication therapy with antibiotics and most of their ulcers healed.

Dr Pietroiusti and team conclude: "In this study, we show that a substantial proportion of duodenal ulcer patients who should be classified as H. pylori negative on the basis of the findings of gastric [stomach] biopsies carry the organism in the duodenum, and that eradication treatment induces persistent healing of the ulcer in the vast majority of them.

"This finding may change current views in the management of these patients."

The research is published in the American Journal of Gastroenterology.