Mucosal-associated invariant T (MAIT) cells are a class of non-classical T lymphocytes defined by their invariant Va7.2-containing MR1-restricted T cell receptor, as well as high expression of CD161. MAIT cells are a sizeable subset of T cells in the human body and have been found across a variety of tissues. At present, the characteristics of MAIT cells in the oral mucosa are poorly defined. In this study, we have analyzed buccal biopsies and matched blood samples from a cohort of healthy volunteers, 20-50 years old, by flow cytometry. The frequency of MAIT cells was similar in the buccal mucosa compared to matched peripheral blood. The representation of MAIT cell subsets defined by CD8 was different, with oral MAIT cells having relatively fewer CD8+ cells. Interestingly, this pattern was reversed in study subjects reporting frequent consumption of bacterially fermented milk products such as yoghurt. In contrast, the frequency of MAIT cells was reduced in study subjects reporting relatively high alcohol consumption. These findings contribute to the knowledge of tissue MAIT cells in the human body and establish a baseline for future studies of oral MAIT cells in health and disease conditions. Furthermore, the findings indicate that the oral MAIT cell population may adapt to dietary and other factors in the local milieu.