Frequency of reactivity for Porphyromonas gingivalis and Prevotella spp. in supra- and subgingival plaques, and periodontal clinical parameters according to subject age

Association between oral frailty and Prevotella percentage in the oral microbiota of community-dwelling older adults who participated in the CHEER Iwamizawa project, Japan

BACKGROUND

Prevotella bacteria are associated with inherent diseases of the oral cavity, such as periodontal disease, and systemic diseases. Oral frailty (OF) has been associated with nursing necessity and death. However, the relationship between OF and oral microbiota has not been fully clarified.

OBJECTIVE

This cross-sectional study investigated the association between OF and Prevotella percentage in the oral microbiota of community-dwelling older adults.

METHODS

Oral bacteria species from saliva were identified in 208 community-dwelling older individuals aged ≥60 years in Japan. The proportion of Prevotella in the oral microbiota was classified into three tertile groups, and its relationship with each test item for OF (number of remaining teeth, masticatory performance, oral diadochokinesis, tongue pressure, difficulties eating tough foods, difficulties swallowing tea or soup, number of applicable OF judgement items, and existence of OF) was examined using ordinal logistic regression analysis.

RESULTS

The Prevotella proportions were classified into lower, middle and upper groups, comprising 70, 69 and 69 participants, respectively. The three groups showed a significant relationship between the number of remaining teeth (odds ratio [OR]: 0.946, 95% confidence interval [CI]: 0.915-0.977), masticatory performance (OR: 0.897, 95% CI: 0.844-0.953), number of applicable OF judgement items (OR: 1.477, 95% CI: 1.14-1.915), and existence of OF (OR: 4.194, 95% CI: 1.519-11.576).

CONCLUSION

The proportion of Prevotella in oral microbiota was high in individuals with OF. Among the older adults, the type of oral microbiota and systemic diseases may be related to the examination and management of oral function decline.

Effect of Probiotic Supplements on the Oral Microbiota-A Narrative Review

Data from systematic reviews and meta-analyses show that probiotics positively impact clinical parameters of oral diseases such as gingivitis, dental caries, and periodontitis. However, the working mechanism of probiotics is not fully understood, but is hypothesized to be mediated by direct and indirect interactions with the oral microbiota and the human host. In the present narrative review, we focused on the microbiological effect of probiotic supplements based on data retrieved from randomized clinical trials (RCTs). In addition, we assessed to what extent contemporary molecular methods have been employed in clinical trials in the field of oral probiotics. Multiple RCTs have been performed studying the potential effect of probiotics on gingivitis, dental caries, and periodontitis, as evaluated by microbial endpoints. In general, results are conflicting, with some studies reporting a positive effect, whereas others are not able to record any effect. Major differences in terms of study designs and sample size, as well as delivery route, frequency, and duration of probiotic consumption, hamper comparison across studies. In addition, most RCTs have been performed with a limited sample size using relatively simple methods for microbial identification, such as culturing, qPCR, and DNA-DNA checkerboard, while high-throughput methods such as 16S sequencing have only been employed in a few studies. Currently, state-of-the-art molecular methods such as metagenomics, metatranscriptomics, and metaproteomics have not yet been used in RCTs in the field of probiotics. The present narrative review revealed that the effect of probiotic supplements on the oral microbiota remains largely uncovered. One important reason is that most RCTs are performed without studying the microbiological effect. To facilitate future systematic reviews and meta-analyses, an internationally agreed core outcome set for the reporting of microbial endpoints in clinical trials would be desirable. Such a standardized collection of outcomes would most likely improve the quality of probiotic research in the oral context.

A retrospective analysis of the role of age and sex in outcomes of non-surgical periodontal therapy at a single academic dental center

The present study examined the role of age and sex in the outcomes of non-surgical periodontal therapy (NSPT). De-identified demographic and periodontal characteristics of patients who presented for baseline periodontal evaluation, NSPT, and periodontal re-evaluation were abstracted from electronic health records. Independent associations of age and sex with severe periodontitis defined as ≥ 5 mm clinical attachment loss (CAL) and ≥ 6 mm probing depth (PD) were determined using multinomial logistic regression. The null hypothesis was rejected at α < 0.05. A total of 2866 eligible subjects were included in the analysis. Significantly lower odds of CAL ≤ 4 mm than CAL ≥ 5 mm (reference) were observed in adults aged 35-64 (odds ratio, OR, 0.19; 95% confidence interval, CI 0.13, 0.29) and ≥ 65 years (OR 0.13; 95% CI 0.07, 0.25) compared to those aged 18-34 years. Odds of PD < 4 mm versus PD ≥ 6 mm (reference) were lower in adults aged 35-64 years than those aged 18-34 years (OR 0.71; 95% CI 0.55, 0.90) and higher in females compared to males (OR 1.67; 95% CI 1.14, 2.44). These results suggest more compromised post-NSPT outcomes in older adults and males compared to the respective populations and highlight the need for personalized therapeutic strategies in these populations.

Oral Microbiome in HIV-Infected Women: Shifts in the Abundance of Pathogenic and Beneficial Bacteria Are Associated with Aging, HIV Load, CD4 Count, and Antiretroviral Therapy

Human immunodeficiency virus (HIV)-associated nonacquired immunodeficiency syndrome (AIDS) conditions, such as cardiovascular disease, diabetes, osteoporosis, and dementia are more prevalent in older than in young adult HIV-infected subjects. Although the oral microbiome has been studied as a window into pathogenesis in aging populations, its relationship to HIV disease progression, opportunistic infections, and HIV-associated non-AIDS conditions is not well understood. We utilized 16S rDNA-based pyrosequencing to compare the salivary microbiome in three groups: (1) Chronically HIV-infected women >50 years of age (aging); (2) HIV-infected women <35 years of age (young adult); and (3) HIV-uninfected age-matched women. We also examined correlations between salivary dysbiosis, plasma HIV RNA, CD4⁺ T cell depletion, and opportunistic oral infections. In both aging and young adult women, HIV infection was associated with salivary dysbiosis characterized by increased abundance of Prevotella melaninogenica and Rothia mucilaginosa. Aging was associated with increased bacterial diversity in both uninfected and HIV-infected women. In HIV-infected women with oral coinfections, aging was also associated with reduced abundance of the common commensal Veillonella parvula. Patients taking antiretroviral therapy showed increased numbers of Neisseria and Haemophilus. High plasma HIV RNA levels correlated positively with the presence of Prevotella and Veillonella, and negatively with the abundance of potentially beneficial Streptococcus and Lactobacillus. Circulating CD4⁺ T cell numbers correlated positively with the abundance of Streptococcus and Lactobacillus. Our findings extend previous studies of the role of the microbiome in HIV pathogenesis, providing new evidence that HIV infection is associated with a shift toward an increased pathogenic footprint of the salivary microbiome. Taken together, the data suggest a complex relationship, worthy of additional study, between chronic dysbiosis in the oral cavity, aging, viral burden, CD4⁺ T cell depletion, and long-term antiretroviral therapy.

A cross-sectional study on the periodontal status and prevalence of red complex periodontal pathogens in a Japanese population

This large-scale study cross-sectionally examined the periodontal status and prevalence of "red complex" bacteria (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) in Japanese adults. A total of 977 participants were enrolled in the study. Probing depth (PD), bleeding on probing (BOP), and bone crest level (BCL) were recorded, and the presence of red complex bacteria in the saliva was examined using polymerase chain reaction. The mean BCL value and the percentage of sites with a PD ≥4 mm or the presence of BOP were significantly higher in older participants. The detection rates of P. gingivalis, T. denticola, and T. forsythia were 46.3%, 76.4%, and 61.1%, respectively. The P. gingivalis detection rate significantly increased with age, while those of T. denticola and T. forsythia were comparably high for all age groups. A close correlation between P. gingivalis and the percentage of sites with PD ≥4 mm was indicated by nonlinear canonical correlation analysis. Current smokers exhibited a more advanced disease condition and a significantly higher P. gingivalis detection rate than non-smokers. In conclusion, periodontal condition worsens with age, and P. gingivalis appears to be the red complex bacterium most closely associated with periodontitis.

Aging and contribution of MyD88 and TRIF to expression of TLR pathway-associated genes following stimulation with Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

Periodontal disease is a highly complex chronic inflammatory disease of the oral cavity. Multiple factors influence periodontal disease, including socio-economic status, genetics and age; however, inflammation elicited by the presence of specific bacteria in the subgingival space is thought to drive the majority of soft- and hard-tissue destruction. Porphyromonas gingivalis is closely associated with periodontal disease. Toll-like receptors (TLRs) and their intracellular signaling pathways play roles in the host response to P. gingivalis. The focus of the current study was to use microarray analysis to define the contributions of the TLR adaptor molecules myeloid differentiation factor 88 (MyD88) and Toll/interleukin-1 receptor domain-containing adaptor inducing interferon-beta (TRIF), and aging, on the expression of TLR pathway-associated mRNAs in response to P. gingivalis.

MATERIAL AND METHODS

Bone marrow-derived macrophages (BMØ) from wild-type (Wt), MyD88 knockout (MyD88-KO) and Trif(Lps2) [i.e. containing a point mutation in the lipopolysaccharide 2 (Lps2) gene rendering the Toll/interleukin (IL)-1 receptor domain-containing adaptor inducing interferon-beta (TRIF) protein nonfunctional] mice, at 2-and 12-mo of age, were cultured with P. gingivalis. Expression of genes in BMØ cultured with P. gingivalis was determined in comparison with expression of genes in BMØ cultured in medium only.

RESULTS

Using, as criteria, a twofold increase or decrease in mRNA expression, differential expression of 32 genes was observed when Wt BMØ from 2-mo-old mice were cultured with P. gingivalis compared with the medium-only control. When compared with 2-mo-old Wt mice, 21 and 12 genes were differentially expressed (p < 0.05) as a result of the mutations in MyD88 or TRIF, respectively. The expression of five genes was significantly (p < 0.05) reduced in Wt BMØ from 12-mo-old mice compared with those from 2-mo-old mice following culture with P. gingivalis. Age also influenced the expression of genes in MyD88-KO and Trif(Lps2) mice challenged with P. gingivalis.

CONCLUSIONS

Our results indicate that P. gingivalis induces differential expression of TLR pathway-associated genes, and both MyD88 and TRIF play roles in the expression of these genes. Age also played a role in the expression of TLR-associated genes following stimulation of BMØ with P. gingivalis.

Immune response of macrophages from young and aged mice to the oral pathogenic bacterium Porphyromonas gingivalis

Periodontal disease is a chronic inflammatory gum disease that in severe cases leads to tooth loss. Porphyromonas gingivalis (Pg) is a bacterium closely associated with generalized forms of periodontal disease. Clinical onset of generalized periodontal disease commonly presents in individuals over the age of 40. Little is known regarding the effect of aging on inflammation associated with periodontal disease. In the present study we examined the immune response of bone marrow derived macrophages (BMM) from young (2-months) and aged (1-year and 2-years) mice to Pg strain 381. Pg induced robust expression of cytokines; tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10, chemokines; neutrophil chemoattractant protein (KC), macrophage colony stimulating factor (MCP)-1, macrophage inflammatory protein (MIP)-1α and regulated upon activation normal T cell expressed and secreted (RANTES), as well as nitric oxide (NO, measured as nitrite), and prostaglandin E2 (PGE2) from BMM of young mice. BMM from the 2-year age group produced significantly less TNF-α, IL-6 and NO in response to Pg as compared with BMM from 2-months and 1-year of age. We did not observe any difference in the levels of IL-1β, IL-10 and PGE2 produced by BMM in response to Pg. BMM from 2-months and 1-year of age produced similar levels of all chemokines measured with the exception of MCP-1, which was reduced in BMM from 1-year of age. BMM from the 2-year group produced significantly less MCP-1 and MIP-1α compared with 2-months and 1-year age groups. No difference in RANTES production was observed between age groups. Employing a Pg attenuated mutant, deficient in major fimbriae (Pg DPG3), we observed reduced ability of the mutant to stimulate inflammatory mediator expression from BMMs as compared to Pg 381, irrespective of age. Taken together these results support senescence as an important facet of the reduced immunological response observed by BMM of aged host to the periodontal pathogen Pg.

Prevalence of four putative periodontopathic bacteria in saliva of a group of Brazilian children with mixed dentition: 1-year longitudinal study

AIM

This study aimed at evaluating the prevalence of putative periodontal pathogens (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella nigrescens, Treponema denticola) in saliva of children with mixed dentition at two different time points, correlating these findings with a clinical parameter of gingival health.

DESIGN

Polymerase chain reaction (PCR) detection was used to determine the prevalence of these bacteria in saliva of 64 children in 2003 and 60 children in 2004. Gingival health was assessed by gingival index.

RESULT

Sixty-two (96.9%) and 50 (83.3%) children presented low gingival inflammation, whereas 2 (3.1%) and 10 (16.7%) had moderate scores in 2003 and 2004, respectively. Majority of the children (81.3% in 2003 and 73.3% in 2004) had detectable levels of at least one of the bacteria. The prevalence found was of 4.7% and 1.7% for A. actinomycetemcomitans, 6.3% and 8.3% for P. gingivalis, 23.4% and 48.3% for P. nigrescens (P < 0.05), and 71.9% and 50% for T. denticola (P < 0.05) in 2003 and 2004, respectively. No significant relationship between gingival index and presence of these bacteria and combination of different species was found.

CONCLUSION

A high percentage of children harboured at least one of the putative periodontal pathogens in saliva, but presented periodontally healthy conditions.

What has ageing to do with periodontal health and disease?

Periodontitis is a multi-factorial disease and in most cases also a disease with a chronic progression. Exposure to factors which contribute to periodontitis occurs over a long period, so that at the time of diagnosis it may be difficult to identify and evaluate what co-factors have contributed to its development. These include exposure to bacteria and viruses, inflammation, genetic factors, health behaviours and a variety of social factors, socio-economic status, behavioural and nutritional habits, the ability to cope with stress and the ability of the immune system to fight infections. Many patients in their 50s also experience other conditions such as heart disease, diabetes mellitus, or rheumatoid arthritis and recent reports on the associations and potential biological mechanisms by which periodontitis can be linked to other systemic diseases suggest that the patient with periodontitis is a challenged individual. Neither individuals nor their oral health care providers are currently prepared for the challenges in oral health care as the expectation of successful ageing with remaining and aesthetically functional teeth is increasing. The scientific evidence is, however, growing, and while the opportunities to prepare for successful ageing exist they must be included in the educational process of both current and future oral health care providers and their patients.

Detection and quantification of herpesviruses in Kostmann syndrome periodontitis using real-time polymerase chain reaction: a case report

BACKGROUND/AIMS

Kostmann syndrome, or severe congenital neutropenia, is an autosomal recessive disease of neutrophil production and is associated with severe periodontal pathology. The aim of this study was to determine whether human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) contribute to the pathogenesis of Kostmann syndrome periodontitis.

METHODS

Supragingival plaque and saliva samples were taken from a 6-year-old boy and his 3-year-old sister suffering from Kostmann syndrome, and from two age- and gender-matched healthy children serving as controls. The samples were taken before and 24 months after periodontal treatment. Real-time polymerase chain reaction (TaqMan Real-Time PCR) assay was used to quantify HCMV and EBV DNA.

RESULTS

EBV was detected in baseline samples from the Kostmann syndrome patients but not in samples from the healthy control subjects. HCMV was only detected in the saliva of the boy with Kostman syndrome at baseline. Herpesviruses numbers decreased dramatically in the post-treatment samples.

CONCLUSION

EBV and HCMV were detected in the two subjects with Kostmann syndrome periodontitis. The results of the study indicate that nonsurgical treatment of Kostmann syndrome periodontitis can reduce supragingival and salivary herpes viral loads.

Microbiological diagnostic testing in the treatment of periodontal diseases

A variety of microbiological diagnostic tests are available for clinicians to use for evaluation of patients with periodontal disease. Each one has its own unique set of advantages and disadvantages, and probably the most useful information for the clinician can be obtained using a combination of the various analytic methods. The tests appear to have their greatest utility when used on patients with chronic or aggressive periodontitis who do not respond favorable to conventional mechanical therapy. The major limitation of all microbiological tests is that the information obtained is relevant to the site sampled, and may not be representative of the microflora of the entire dentition. However, since it is often only specific sites that do not respond to initial therapy, knowing the constituents of the microflora that populate these sites is clinically relevant.