Helicobacter suis infects the stomachs of both animals and humans, and can induce gastric mucosa-associated lymphoid tissue (MALT) lymphomas. It is known that CXC chemokine ligand 13 (CXCL13) is highly expressed in the Helicobacter-infected mice and gastric MALT lymphoma patients, but the pathway that links the activation of CXCL13 and the formation of gastric MALT lymphomas remains unclear. In this study, we examined whether CXCL13 neutralization would interfere with the formation of gastric lymphoid follicles including B cells, CD4+T cells, dendritic cells (DCs), and follicular DCs (FDCs) in germinal centers to determine the role of CXCL13 in the formation of B-cell aggregates after H. suis infection. Moreover, the expression of genes associated with the lymphoid follicle formation was also effectively suppressed by anti-CXCL13 antibody treatment. These results suggest that the upregulation of CXCL13 has an important role in the development of gastric MALT lymphomas and highlight the potential of anti-CXCL13 antibody for protection against Helicobacter-induced gastric diseases.