Probiotics reduce bacterial colonization and gastric inflammation in H. pylori-infected mice

Probiotics are characterized by their ability to interact with commensal microflora in the gastrointestinal tract to produce beneficial health effects. In vitro studies suggest that Lactobacillus species have the potential to suppress the growth of Helicobacter pylori. The goal of this study was to determine if pretreatment of mice with a commercial mixture of live probiotics (L. rhamnosus, strain R0011, and L. acidophilus, strain R0052) would suppress colonization of H. pylori, strain SS1. Thirty C57BL/6 female mice were divided into four groups: Group A was fed sterile water, group B received probiotics in sterile drinking water, group C was challenged orogastrically with H. pylori, and group D was pretreated with probiotics in drinking water prior to and following challenge with H. pylori. Rectal swabs, stomach homogenates, and luminal contents from ileum and colon were plated onto colistin nalidixic acid plates. Serial dilutions of stomach homogenates were plated onto H. pylori-sensitive agar plates and incubated under microaerophilic conditions. Tissue samples from the stomach were analyzed histologically to determine the degree of H. pylori colonization, mucosal inflammation, and epithelial cell apoptosis. Probiotics in drinking water did not affect the overall well-being of mice. Lactobacillus species were excreted in stools over the entire duration of treatment. Pretreatment with probiotics reduced the number of mice with H. pylori growth from stomach homgenates (100 to 50%; P = 0.02). The percentage of mice with moderate-severe H. pylori-induced inflammation in the gastric antrum was reduced with probiotic pretreatment (71 to 29%; P = 0.14). However, pretreatment with probiotics did not prevent H. pylori-induced apoptosis in the gastric mucosa. This preparation of probiotics provided a safe and novel approach for reducing H. pylori colonization and bacterial-induced inflammation of mice.