AUTHOR=Wzatek Martin , Bahammam Shaima , Buiga Petronela , Haddad Kendal , Sima Corneliu 

TITLE=Oral Neutrophil Free Fatty Acid Receptors Expression May Link Oral Host and Microbiome Lipid Metabolism

JOURNAL=Frontiers in Oral Health

VOLUME=Volume 3 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/oral-health/articles/10.3389/froh.2022.821326

DOI=10.3389/froh.2022.821326

ISSN=2673-4842

ABSTRACT=In health, commensal bacteria from oral biofilms stimulate polymorphonuclear neutrophil (PMN) recruitment in gingival sulci and the oral cavity. Oral PMN (oPMN) are short lived cells with low pro-survival gene expression. In periodontitis, oPMN accumulate in higher numbers, have extended lifespan and sustain non-resolving inflammation. We hypothesize that short and long chain free fatty acids (SCFA, LCFA) and lipid mediator resolvin E1 (RvE1) modulate host’ ability to control biofilms and resolve inflammation. Our objective was to measure oPMN surface expression of receptors FFAR2 (binds bacteria derived SCFA), FFAR4 (binds LCFA, EPA and DHA), and ERV1 (binds RvE1) in health, and to assess gender differences.  We included 20 periodontally healthy individuals 20-80 years old (10 males, 10 females), who were asked to 1) answer a targeted health-nutritional questionnaire; 2) provide an oral saline rise.  oPMN isolated by sequential filtration were labeled with fluorophore-conjugated antibodies against CD11b, CD14, CD16, CD66b, ERV1, FFAR2, FFAR4 and analyzed by flow cytometry. Statistical analyses: Two-way ANOVA, Tukey, Pearson correlation. Oral rinses contained 80% oPMN of which 60% were ERV1+ and FFAR2+, and 10% FFAR4+, with no gender differences. Females had more oPMN ERV1 compared to males. Both genders had higher ERV1 compared to FFAR2 and FFAR4. CD66b+CD16high oPMN expressed less ERV1 and FFAR2 compared to CD66b+CD16low. There were positive correlations between oPMN ERV1 and FFAR2 expression and between ERV1+ and FFAR2+ oPMN and fish intake. These findings will help to better understands how oral host and microbiome interactions maintain periodontal health.