Eradicating Helicobacter pylori (H. pylori) can cause an imbalance in the microbiota. Dysbiosis of the gut microbiome may produce multiple diseases and bacterial infections. The objective of this study was to investigate the influence of Helicobacter pylori (H. pylori) infection and its eradication on the composition of the oral tongue coating microbiota. A cohort of 35 participants was recruited and categorized into two groups: the H. pylori negative group (N group) consisting of 12 individuals and the H. pylori positive group (23 individuals). Within the H. pylori positive group, subjects were further stratified into the H. pylori pre-eradicated group (HPQ group) and the H. pylori eradicated group (HPH group). H. pylori positive individuals were treated with a quadruple regimen containing bismuth, and tongue coating samples were collected both prior to and following treatment. Concurrently, tongue coating samples were collected from H. pylori negative individuals. High-throughput 16S rRNA sequencing technology was employed to assess the microbial composition of the tongue coating in the N group, HPQ group, and HPH group. Pertinent clinical data were documented.Microbial diversity was found to significantly differ among the N group, HPQ group, and HPH group, as evidenced by variations in Chao1 index, Shannon index, and Partial Least Squares Discriminant Analysis (PLS-DA). The dominant bacterial phyla identified across all groups included Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, Actinobacteria, and Saccharibacteria. At the phylum level, Firmicutes exhibited higher relative abundance in the HPQ group in comparison to both the N group and HPH group. Conversely, Bacteroidetes displayed greater prevalence in the N group and HPH group. Linear Discriminant Analysis Effect Size (LEfSe) analysis indicated a higher abundance of Romboutsia, Rothia, and Turiciactor in the HPQ group. Our study revealed significant disparities in microbial diversity and richness among the three groups. Furthermore, our findings suggest a potential association between the presence of Streptococcus, Rothia and H. pylori positive individuals.