Effects of Lactobacillus gasseri OLL 2716 (LG21) on Helicobacter pylori infection in children

Sir, Eradication therapies for Helicobacter pylori infection are not yet satisfactory, although many therapeutic strategies have been studied to improve the eradication rate for this infection. Children rarely have symptoms of this infection and, therefore, are a suitable group in which to assess therapies that are non-aggressive compared with those used for adults. 1 The use of probiotics in the field of H. pylori infection has been proposed for improving eradication rates and to attenuate antibiotic-related complications. 2 However, the scientific basis for the prophylactic and therapeutic actions of probiotics has yet to be established. Michetti et al. 3 reported that a whey-based culture super-natant of Lactobacillus acidophilus La1 had a partial, acid-independent, long-term suppressive effect on H. pylori in humans. Sakamoto et al. 4 reported recently that Lactobacillus gasseri OLL 2716 (LG21) is effective in both suppressing H. pylori infection and reducing gastric mucosal inflammation in patients with H. pylori infection. There is, however, no study that examines the effects of probiotics in children with H. pylori infection, who are known to have a different gastric inflammation from that in adults 5 and need non-aggressive therapies for H. pylori infection. Therefore, to investigate the effects of probiotics on H. pylori infection in children, we administered yogurt containing LG21 to 12 children with H. pylori infection, for 8 weeks, and then performed a [ 13 C]urea breath test (UBT). We also measured the levels of faecal H. pylori antigens and serum pepsinogen I and II before, and at 4 and 10 weeks after, ingestion. The subjects, five boys and seven girls, ranged in age from 7.4 to 15.8 years (mean age 12.1 years). All subjects were diagnosed with H. pylori infection based on positive results from a [ 13 C]UBT and histological and culture examinations of the gastric mucosa. The study was approved by our institutional review board, and informed parental consent was obtained before all examinations. The subjects each received 120 g of yogurt containing LG21 twice daily for 8 weeks. Compliance with the ingestion of yogurt was monitored by parents using a diary. None of the subjects had undergone previous eradication therapy for H. pylori nor had any used antimicrobial drugs or proton-pump inhibitors during the previous month or during the study. The [ 13 C]UBT was performed by administering 2 mg/kg (maximum 100 mg) of [ 13 C]urea before, and at 4 and 10 weeks after, the …