Objective To investigate the protective effects of Ligilactobacillus salivarius Li01(L. salivarius Li01)against DNA damage induced by Helicobacter pylori (Hp), Benzo( a) pyrene (BaP), and Hp + BaP, and to evaluate the probiotic properties of L. salivarius Li01. Methods After 1 week of adaptive feeding, specific pathogenfree male Mongolian gerbils were randomly assigned to groups and subjected to intragastric administration of Hp, BaP,and Hp + BaP for model induction. At week 32 post model establishment, therapeutic L. salivarius Li01 was administered intragastrically. At week 36, peripheral blood samples were collected from each group for the comet assay, while liver tissues were collected and tested for Cyp1a1 gene expression levels. Results Compared with those in the control group, the comet tail length,% tail DNA, and hepatic Cyp1a1 expression levels were significantly increased in the Hp, BaP, and Hp + BaP groups (P<0. 0001). Among these, the comet tail length, olive tail moment,%tail DNA, and hepatic Cyp1a1 expression levels were significantly higher in the Hp + BaP group than in the Hp and BaP groups (P<0. 05). Following intervention with L. salivarius Li01, the comet tail length, olive tail moment,%tail DNA, and hepatic Cyp1a1 expression levels were significantly reduced in each group (P<0. 001). Conclusions Hp infection, BaP exposure, and the Hp + BaP combination induced DNA damage in the peripheral lymphocytes of Mongolian gerbils, with the Hp + BaP combination showing synergistic damage. L. salivarius Li01 had a protective effect against DNA damage caused by Hp, BaP, and Hp + BaP.