According to our findings, the abundance of P. gingivalis or P. intermedia in the oral cavity do not interrupt the associations of Crohn’s disease with salivary IgA antibody responses against P. gingivalis and IgG antibody responses against P. intermedia. Yet, as the present study is the first to demonstrate the salivary Ig antibody responses against periodontitis-associated bacteria, it was not possible for us to discuss the contribution of the aggravated systemic immunological response against these bacteria. Here, CD79A is linked to Crohn disease.