Open pilot trial with the aim to study if 6 months’ of supplementation with Lactobacillus reuteri had any effect on Helicobacter pylori colonisation and gastric mucosal inflammation in humans.

Seven dyspeptic adult patients completed the study. The daily dose of Lactobacillus reuteri ATCC 55730 was 4×10^8 colony forming units (CFU), ingested as 2 tablets twice per day.

Colonisation of Helicobacter pylori was verified by gastric biopsies and C13 urea breath tests (UBT) at inclusion and at the end of the study. Stomach biopsies were taken from four locations and analysed for presence of Helicobacter pylori and grade of inflammation. The biopsies were also analysed for colonisation of Lactobacillus reuteri by using FISH (fluorescence in situ hybridisation) technique and an Lactobacillus reuteri specific beacon probe.

No significant changes in the mean values of UBT were found. The degree of Helicobacter pylori colonisation was also unchanged, as were gastric inflammation scores. FISH showed that 22% of the biopsies (3 individuals) were positive for Lactobacillus reuteri at inclusion and 94% at the end of the study. The increase in Lactobacillus reuteri colonisation was found in all stomach locations.

Conclusion: Lactobacillus reuteri had no effect on Helicobacter pylori colonisation or degree of stomach inflammation. Lactobacillus reuteri was well tolerated and able to colonise the stomach in Helicobacter pylori-infected patients.