Oral Microbiota and Salivary Levels of Oral Pathogens in Gastro-Intestinal Diseases: Current Knowledge and Exploratory Study

• Main Authors: Maria Contaldo, Alessandra Fusco, Paola Stiuso, Stefania Lama, Antonietta Gerarda Gravina, Annalisa Itro, Alessandro Federico, Angelo Itro, Gianna Dipalma, Francesco Inchingolo, Rosario Serpico, Giovanna Donnarumma
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Microorganisms
• Subjects: oral microbiota; oral dysbiosis; chronic gastritis; microbiome; <i>Fusobacterium nucleatum</i>; <i>Porphyromonas gingivalis</i>
• Online Access: https://www.mdpi.com/2076-2607/9/5/1064

Various bi-directional associations exist between oral health and gastro-intestinal diseases. The oral microbiome plays a role in the gastro-intestinal carcinogenesis and fusobacteria are the most investigated bacteria involved. This paper aims to review the current knowledge and report the preliminary data on salivary levels of <i>Fusobacterium nucleatum</i>, <i>Porphyromonas gingivalis</i> and <i>Candida albicans</i> in subjects with different gastro-intestinal conditions or pathologies, in order to determine any differences. The null hypothesis was “subjects with different gastro-intestinal diseases do not show significant differences in the composition of the oral microbiota”. Twenty-one subjects undergoing esophagastroduodenoscopy or colonscopy were recruited. For each subject, a salivary sample was collected before the endoscopy procedure, immediately stored at −20 °C and subsequently used for genomic bacterial DNA extraction by real-time PCR. Low levels of <i>F. nucleatum</i> and <i>P. gingivalis</i> were peculiar in the oral microbiota in subjects affected by <i>Helicobater pylori</i>-negative chronic gastritis without cancerization and future studies will elucidate this association. The level of <i>C. albicans</i> did not statistically differ among groups. This preliminary study could be used in the future, following further investigation, as a non-invasive method for the search of gastrointestinal diseases and associated markers.