Patent name: A Lactobacillus plantarum CN2018 resistant to Helicobacter pylori infection and its application It is a patent probiotics with excellent performance that was isolated and screened out from Chinese traditional fermented food by researchers of National Functional Food Engineering Technology Research Center of Jiangnan University in 2008. The strain can grow in artificial gastric juice with pH2.5 and in the medium with bile salt concentration of 0.2%, indicating that the strain can maintain high activity in the intestinal tract of the host. Lactobacillus plantarum CN2018 has the strongest ability to inhibit the growth of Helicobacter pylori and can significantly reduce the urease activity of helicobacter pylori. Through the establishment of helicobacter pylori infection animal model, it was found that Lactobacillus plantarum CN2018 could significantly alleviate helicobacter pylori infection in mice, and the anti-Helicobacter pylori IgG antibody level decreased. The content of Helicobacter pylori in gastric tissue was decreased by intervention of Helicobacter pylori colonization. And prevent pathological changes of gastric tissue. At the same time, it can reduce the content of helicobacter pylori in the mouth, adjust the balance of oral flora, and promote oral health. Both live and dead Lactobacillus plantarum CN2018 had inhibitory effect on H. pylori. From the size of the inhibition zone, CN2018, fermentation liquid and dead bacteria all had certain inhibitory effect on H. pylori. The urease activity of Helicobacter pylori significantly decreased after CN2018, fermentation broth and dead bacteria treated h. pylori for 2 hours, and the ability of H. pylori to adsorb intestinal epithelial cells significantly decreased.