Asymmetric and symmetric dimethylarginine gingival crevicular fluid levels in periodontitis

Impact of Inflammatory Markers and Senescence-Associated Secretory Phenotype in the Gingival Crevicular Fluid on the Outcomes of Periodontal Regeneration

The aim of this study was to test the molecular expression profile (senescence-associated secretory phenotype; SASP) in gingival crevicular fluid (GCF) prior to surgery in relation to the distribution of clinical success of periodontal regeneration. Forty consecutive patients presenting sites with residual probing pocket depth (PPD) ≥ 6 mm and intrabony defects ≥ 3 mm were treated through a minimally invasive surgical technique. Pre-operatively, GCF was sampled for inflammatory biomarker analysis related to SASP [interleukin (IL)-1β, IL-6, and IL-12; matrix-metalloproteinases (MMP)-8 and -9]. Better or worse responders were classified depending on the achievement of a composite outcome measure at 1-year [COM; PPD ≤ 4 mm and clinical attachment gain (CAL) gain ≥ 3 mm]. Correlation analyses and logistic regression models were performed. Periodontal regeneration led to significant improvements in mean clinical and radiographic parameters. Teeth achieving COM presented significantly lower amounts of SASP factors compared with non-successful teeth. Higher CAL gain, PPD reduction, and radiographic bone fill were negatively correlated with IL-1β and MMP-8 and -9 (p < 0.001), while IL-12 showed a direct relationship with CAL gain (p = 0.005) and PPD reduction (p = 0.038). Sites expressing higher SASP expression in the GCF before periodontal regeneration achieved worse clinical and radiographic outcomes.

High-Throughput Combined Analysis of Saliva Microbiota and Metabolomic Profile in Chinese Periodontitis Patients: A Pilot Study

The onset and progression of periodontitis involves complicated interactions between the dysbiotic oral microbiota and disrupted host immune-inflammatory response, which can be mirrored by the changes in salivary metabolites profile. This pilot study sought to examine the saliva microbiome and metabolome in the Chinese population by the combined approach of 16s rRNA sequencing and high-throughput targeted metabolomics to discover potential cues for host-microbe metabolic interactions. Unstimulated whole saliva samples were collected from eighteen Stage III and IV periodontitis patients and thirteen healthy subjects. Full-mouth periodontal parameters were recorded. The taxonomic composition of microbiota was obtained by 16s rRNA sequencing, and the metabolites were identified and measured by ultra-high performance liquid chromatography and mass spectrometry-based metabolomic analysis. The oral microbiota composition displayed marked changes where the abundance of 93 microbial taxa differed significantly between the periodontitis and healthy group. Targeted metabolomics identified 103 differential metabolites between the patients and healthy individuals. Functional enrichment analysis demonstrated the upregulation of protein digestion and absorption, histidine metabolism, and nicotinate and nicotinamide metabolism pathways in the dysbiotic microbiota, while the ferroptosis, tryptophan metabolism, glutathione metabolism, and carbon metabolism pathways were upregulated in the patients. Correlation analysis confirmed positive relationships between the clinical parameters, pathogen abundances, and disease-related metabolite levels. The integral analysis of the saliva microbiome and metabolome yielded an accurate presentation of the dysbiotic oral microbiome and functional alterations in host-microbe metabolism. The microbial and metabolic profiling of the saliva could be a potential tool in the diagnosis, prognosis evaluation, and pathogenesis study of periodontitis.