<;P>;PROBLEM TO BE SOLVED: To provide (1) an oral preparation containing lactobacillus as an active ingredient and having an anti-Helicobacter pylori activity, (2) a method for reinforcing the anti-Helicobacter pylori activity of the lactobacillus, and (3) an agent for reinforcing the anti-Helicobacter pylori activity of the lactobacillus. <;P>;SOLUTION: This oral preparation is provided by using the lactobacillus in combination with at least one selected from the group consisting of Coptis japonica and Phellodendron amurense. <;P>;COPYRIGHT: (C)2011,JPO&INPIT