Association of general health and lifestyle factors with the salivary microbiota – Lessons learned from the ADDITION-PRO cohort

Abstract

IntroductionPrevious research indicates that the salivary microbiota may be a biomarker of oral as well as systemic disease. However, clarifying the potential bias from general health status and lifestyle-associated factors is a prerequisite of using the salivary microbiota for screening.Materials & MethodsADDDITION-PRO is a nationwide Danish cohort, nested within the Danish arm of the Anglo-Danish-Dutch Study of Intensive treatment in People with Screen-Detected Diabetes in Primary Care. Saliva samples from n=746 individuals from the ADDITION-PRO cohort were characterized using 16s rRNA sequencing. Alpha- and beta diversity as well as relative abundance of genera was examined in relation to general health and lifestyle-associated variables. Permutational multivariate analysis of variance (PERMANOVA) was performed on individual variables and all variables together. Classification models were created using sparse partial-least squares discriminant analysis (sPLSDA) for variables that showed statistically significant differences based on PERMANOVA analysis (p < 0.05).ResultsGlycemic status, hemoglobin-A1c (HbA1c) level, sex, smoking and weekly alcohol intake were found to be significantly associated with salivary microbial composition (individual variables PERMANOVA, p < 0.05). Collectively, these variables were associated with approximately 5.8% of the observed differences in the composition of the salivary microbiota. Smoking status was associated with 3.3% of observed difference, and smoking could be detected with good accuracy based on salivary microbial composition (AUC 0.95, correct classification rate 79.6%).ConclusionsGlycemic status, HbA1c level, sex, smoking and weekly alcohol intake were significantly associated with the composition of the salivary microbiota. Despite smoking only being associated with 3.3% of the difference in overall salivary microbial composition, it was possible to create a model for detection of smoking status with a high correct classification rate. However, the lack of information on the oral health status of participants serves as a limitation in the present study. Further studies in other cohorts are needed to validate the external validity of these findings.

Genome-wide association study identifies host genetic variants influencing oral microbiota diversity and metabolic health

“…In addition, the genetic variant rs197620 was associated with higher risk of periodontitis and the genetic variant rs17793860 was associated with lower risk of stroke. In a recent study from our group, Poulsen et al showed a positive association between abundance of Rothia and glycosylated hemoglobin levels 34 . Other investigators showed that abundance of Rothia associate to childhood dental caries 23 , and history of colorectal cancer 35 .…”

“…A detailed description of saliva sample collection has been provided in a recent publication 34 . In brief, saliva was collected from 786 participants at Steno Diabetes Center Copenhagen, Copenhagen, Denmark.…”

Effect of different forms of tobacco on the oral microbiome in healthy adults: a systematic review

“…Screening of articles by title and abstract and reviewing of full text resulted in 36 eligible articles for full text ( Figure 1 ). Of the 36 articles, nine were from the United States of America ( 18 – 26 ), six were from India ( 15 , 27 – 31 ), five were from the United Arab Emirates ( 32 – 36 ),three were from China ( 37 – 39 ), two from Japan ( 40 , 41 ) and others including Brazil ( 42 ), Jordan ( 43 ), Hungary ( 44 ), Croatia ( 45 ), Iran ( 46 ), Germany ( 47 ), Denmark ( 48 ), Italy ( 49 ), Sudan ( 50 ), Ireland ( 51 ) and Korea ( 52 ).…”

“…Prevotella and Veillonella, mostly independently, were also found as predominant genus in tobacco users (21, 24, 31, 34, 37, 38, 42-44, 49, 51), while another data reported a significant depletion in the saliva and supragingival plaques of smokeless tobacco users (50). Neisseria was also observed to be higher among other genera in smokers in two studies conducted in China and Denmark (38,48). The detailed findings are presented in Table 2.…”

Unexpected lower level of oral periodontal pathogens in patients with high numbers of systemic diseases

“…Notably, most patients had either not been treated for periodontal disease in a year or more prior, or had never received any form of periodontal therapy at all. Important confounders of saliva microbiome diversity, active caries, periodontal disease and antibiotic usage had been adjusted and controlled for, and the other contributors to taxa diversity, such as tobacco usage (estimated at 3% of the variability of the saliva microbiome) were also considered ( Belstrøm, 2020 ; Poulsen et al, 2022 ; Stewart et al, 2018 ). Diet, which is thought to contribute though to a lesser degree to the oral microbiome makeup, was not monitored ( Wade, 2021 ; Wells et al, 2022 ) ( Sekundo et al, 2022 ).…”