The composition of microbial communities in inflammatory periodontal diseases in young adults Tatars

Effects of toothpaste containing inactivated Lacticaseibacillus paracasei Probio-01 on plaque-induced gingivitis and dental plaque microbiota

Plaque-induced gingivitis is an inflammatory response in gingival tissues resulting from bacterial plaque accumulation at the gingival margin. Postbiotics can promote the proliferation of beneficial bacteria and optimise the state of microbiota in the oral cavity. In this study, we investigated the effect of inactivated Lacticaseibacillus paracasei Probio-01 on plaque-induced gingivitis and the dental plaque microbiota. A total of 32 healthy gingival participants (Group N, using blank toothpaste for 3 months) and 60 patients with plaque-induced gingivitis (30 in Group F, using inactivated Probio-01 toothpaste for 3 months, and 30 in Group B, using blank toothpaste for 3 months, respectively) were recruited. Clinical indices, which included bleeding on probing (BOP), gingival index (GI), and plaque index (PI), were used to assess the severity of gingivitis. Furthermore, 16SrDNA amplicon sequencing was used to explore changes in the gingival state and dental plaque microbiota in patients with plaque-induced gingivitis. The results showed that inactivated Probio-01 significantly reduced clinical indices of gingivitis, including BOP, GI, and PI, in participants with plaque-induced gingivitis and effectively relieved gingival inflammation, compared with that observed in the control group (group B). Inactivated Probio-01 did not significantly influence the diversity of dental plaque microbiota, but increased the relative abundance of dental plaque core bacteria, such as Leptotrichia and Fusobacterium (P < 0.05). Strong correlations were observed between the indices and abundance of dental plaque microbiota. Overall, the inactivated Probio-01 significantly reduced the clinical indices of gingivitis and effectively improved gingival inflammation in patients with plaque-induced gingivitis. The activity of inactivated Probio-01 against plaque-induced gingivitis was possibly mediated by its ability to regulate the dental plaque microbiota, as indicated by the close correlation between the plaque microbiota and clinical indices of gingivitis.

Shotgun metagenomic analysis of the oral microbiome in gingivitis: a nested case-control study

Background

Gingivitis, i.e. inflammation of the gums, is often induced by dentalplaque. However, its exact link to the oral microbiota remains unclear.

Methods

In a case-control study involving 120 participants, comprising 60 cases and 60 controls (mean age (SD) 36.6 (7.6) years; 50% males), nested within a prospective multicentre cohort study, we examined theoral microbiome composition of gingivitis patients and their controlsusing shotgun metagenomic sequencing of saliva samples. Participants underwent clinical and radiographic oral health examinations, including bleeding on probing (BOP), at six tooth sites. BOP ≥33%was considered 'generalized gingivitis/initial periodontitis'(GG/IP), and BOP <33% as 'healthy and localized gingivitis'(H/LG). Functional potential was inferred using HUMANn3.

Results

GG/IP exhibited an increase in the abundance of Actinomyces, Porphyromonas, Aggregatibacter, Corynebacterium, Olsenella, and Treponema, whereas H/LG exhibited an increased abundance of Candidatus Nanosynbacter. Nineteen bacterial species and fourmicrobial functional profiles, including L-methionine, glycogen, andinosine-5'-phosphate biosynthesis, were associated with GG/IP. Constructing models with multiple markers resulted in a strong predictive value for GG/IP, with an area under the curve (ROC) of 0.907 (95% CI: 0.848-0.966).

Conclusion

We observed distinct differences in the oral microbiome between the GG/IP and H/LG groups, indicating similar yet unique microbial profiles and emphasizing their potential role in progression of periodontal diseases.

Exploring the Microbiome Landscape of Dental Plaque: A Cross-Sectional Analysis in Periodontal Health and Disease

OBJECTIVE

This study aimed to comprehensively analyze the microbiome of dental plaque in individuals with varying periodontal statuses, encompassing both periodontal health and disease. The primary objectives were to identify microbial markers associated with different clinical conditions, explore variations in microbial diversity, and investigate potential correlations between the oral microbiome and clinical parameters.

METHODS

A cross-sectional design was employed, involving 164 participants aged 18 to 65 years. Inclusion criteria comprised individuals with good oral and systemic health for the periodontal health group and those diagnosed with various stages of periodontal disease for the periodontal disease group. Dental plaque samples were meticulously collected from diverse tooth surfaces, and clinical examinations were conducted to assess periodontal health status. High-throughput sequencing of the 16S ribosomal RNA (rRNA) gene was utilized for microbiome analysis.

RESULTS

Demographic characteristics revealed a balanced distribution between the periodontal health and disease groups. Clinical parameters, including probing depth, clinical attachment loss, and bleeding on probing, exhibited significant differences between the two groups (p < 0.001). Microbial diversity indices indicated a higher diversity in the periodontal health group compared to the disease group (p < 0.001). Analysis of relative abundance of bacterial phyla identified significant variations, with Firmicutes, Bacteroidetes, and Actinobacteria showing differential prevalence between health and disease (p < 0.05). Differentially abundant taxa analysis highlighted specific species associated with each clinical condition, including Prevotella intermedia and Porphyromonas gingivalis. Network analysis revealed complex microbial interactions within the oral microbiome. Functional predictions indicated variations in metabolic capabilities between health and disease, with potential implications for virulence and antibiotic resistance.

CONCLUSION

This study provides a comprehensive analysis of the oral microbiome in periodontal health and disease, revealing significant associations between microbial composition and clinical parameters. The identification of microbial markers and functional insights enhances our understanding of the complex interplay within the oral ecosystem. These findings hold promise for advancing diagnostic and therapeutic approaches tailored to individual microbial profiles.

Periodontal pathogens of the interdental microbiota in a 3 months pregnant population with an intact periodontium

Steroid hormones and the oral microbiota of pregnant women both appear as cumulative risk factors for gingivitis. This cross-sectional study, using real-time PCR, investigated the composition and diversity of the microbiota in interdental spaces of 3 months pregnant women with intact periodontium according the 2018 EFP/AAP classification. Bacteria identified were belonged to the red (Porphyromonas gingivalis Treponema denticola, and Tanerella forsythia), orange (Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Parvimonas micra), and green (Eikenella corrodens and A. actinomycetencomitans) Socransky complexes. Approximatively 109.11 bacteria were counted per interdental space in pregnant women. Bacteria from the red complex represented 33.80% versus 62.81% for the orange group versus 3.39% for the green group of the total number spread over the 3 groups. Dietary habits and physical activity did not have a significant impact on interdental microbiota, although a decrease in the median amount of 9 periodontopathogens was observed when fruit and vegetable consumption increased. Pregnant women who brushed their teeth at least twice a day had lower counts of total bacteria and 9 periodontal pathogens than those who brushed less. In 3 months pregnant women at high risk of periodontal disease (>30% bleeding sites), the dendogram revealed 2 clusters of the 9 periodontopathogens. This provides further support for the "key pathogen" hypothesis, among which Porphyromonas gingivalis plays a key role, indicating that specific bacteria in limited quantities can influence the host immune system and convert the microbiota from symbiotic to dysbiotic to induce inflammatory disorder. As a result, this study reported that 3 months pregnant women with healthy periodontium had high levels of interdental bleeding and a dysbiotic microbiota with periodontal pathogens of the Socransky orange and red complexes. These subjects were therefore potentially at increased risk of developing periodontal disease and, consequently, an adverse pregnancy outcome. So, preventive oral prophylaxis measures, in particular individual interdental prophylaxis, should be implemented as soon as pregnancy is established.

A pattern of microbiological colonization of orthodontic miniscrew implants

INTRODUCTION

Current orthodontic literature reveals a lack of studies on bacterial colonization of orthodontic miniscrew implants (MSI) and their role in the stability of MSI. This study aimed to determine the pattern of microbiological colonization of miniscrew implants in 2 major age groups, to compare it with the microbial flora of gingival sulci in the same group of patients and to compare microbial flora in successful and failed miniscrews.

METHODS

The study involved 102 MSI placed in 32 orthodontic subjects in 2 age groups: (1) aged ≤14 years and (2) aged >14 years. Gingival and peri-mini implant crevicular fluid samples were collected using sterile paper points (International Organization for Standardization no. 35) >3 months and processed by conventional microbiologic culture and biochemical techniques. A microbiologist characterized and identified the bacteria, and the results were subjected to statistical analysis.

RESULTS

Initial colonization was reported within 24 hours, with Streptococci being the dominant colonizer. The relative proportion of anaerobic bacteria over aerobic bacteria increased over time in peri-mini implant crevicular fluid. Group 1 had greater Citrobacter (P = 0.036) and Parvimonas micra (P = 0.016) colonizing MSI than group 2. Failed MSI showed a significantly higher presence of Parvimonas micra (P = 0.008) in group 1 and Staphylococci (P = 0.008), Enterococci (P = 0.011), and Parvimonas micra (P <0.001) in group 2.

CONCLUSIONS

Microbial colonization around MSI is established within 24 hours. Compared to gingival crevicular fluid, peri-mini implant crevicular fluid is colonized by a higher proportion of Staphylococci, facultative enteric commensals and anaerobic cocci. The failed miniscrews showed a higher proportion of Staphylococci, Enterobacter, and Parvimonas micra, suggesting their possible role in the stability of MSI. The bacterial profile of MSI varies with age.

Using Genomics to Decipher the Enigmatic Properties and Survival Adaptation of Candidate Phyla Radiation

Microbial ecology is a critical field for understanding the composition, diversity, and functions of microorganisms in various environmental and health-related processes. The discovery of Candidate Phyla Radiation (CPR) through culture-independent methods has introduced a new division of microbes characterized by a symbiotic/parasitic lifestyle, small cell size, and small genome. Despite being poorly understood, CPRs have garnered significant attention in recent years due to their widespread detection in a variety of environmental and clinical samples. These microorganisms have been found to exhibit a high degree of genetic diversity compared to other microbes. Several studies have shed light on their potential importance in global biogeochemical cycles and their impact on various human activities. In this review, we provide a systematic overview of the discovery of CPRs. We then focus on describing how the genomic characteristics of CPRs have helped them interact with and adapt to other microbes in different ecological niches. Future works should focus on discovering the metabolic capacities of CPRs and, if possible, isolating them to obtain a better understanding of these microorganisms.

Candidate Phyla Radiation, an Underappreciated Division of the Human Microbiome, and Its Impact on Health and Disease

Candidate phyla radiation (CPR) is an emerging division of the bacterial domain within the human microbiota. Still poorly known, these microorganisms were first described in the environment in 1981 as "ultramicrobacteria" with a cell volume under 0.1 μm³ and were first associated with the human oral microbiota in 2007. The evolution of technology has been paramount for the study of CPR within the human microbiota. In fact, since these ultramicrobacteria have yet to be axenically cultured despite ongoing efforts, progress in imaging technology has allowed their observation and morphological description. Although their genomic abilities and taxonomy are still being studied, great strides have been made regarding their taxonomic classification, as well as their lifestyle. In addition, advancements in next-generation sequencing and the continued development of bioinformatics tools have allowed their detection as commensals in different human habitats, including the oral cavity and gastrointestinal and genital tracts, thus highlighting CPR as a nonnegligible part of the human microbiota with an impact on physiological settings. Conversely, several pathologies present dysbiosis affecting CPR levels, including inflammatory, mucosal, and infectious diseases. In this exhaustive review of the literature, we provide a historical perspective on the study of CPR, an overview of the methods available to study these organisms and a description of their taxonomy and lifestyle. In addition, their distribution in the human microbiome is presented in both homeostatic and dysbiotic settings. Future efforts should focus on developing cocultures and, if possible, axenic cultures to obtain isolates and therefore genomes that would provide a better understanding of these ultramicrobacteria, the importance of which in the human microbiome is undeniable.

Treatment With Multi-Species Probiotics Changes the Functions, Not the Composition of Gut Microbiota in Postmenopausal Women With Obesity: A Randomized, Double-Blind, Placebo-Controlled Study

Probiotics are known to regulate host metabolism. In randomized controlled trial we aimed to assess whether interventions with probiotic containing following strains: Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Levilactobacillus brevis W63, Lacticaseibacillus casei W56, Ligilactobacillus salivarius W24, Lactococcus lactis W19, and Lactococcus lactis W58 affect gut microbiota to promote metabolic effects. By 16S rRNA sequencing we analyzed the fecal microbiota of 56 obese, postmenopausal women randomized into three groups: (1) probiotic dose 2.5 × 10⁹ CFU/day (n = 18), (2) 1 × 10¹⁰ CFU/day (n = 18), or (3) placebo (n = 20). In the set of linear mixed-effects models, the interaction between pre- or post-treatment bacterial abundance and time on cardiometabolic parameters was significantly (FDR-adjusted) modified by type of intervention (26 and 19 three-way interactions for the pre-treatment and post-treatment abundance, respectively), indicating the modification of the bio-physiological role of microbiota by probiotics. For example, the unfavorable effects of Erysipelotrichi, Erysipelotrichales, and Erysipelotrichaceae on BMI might be reversed, but the beneficial effect of Betaproteobacteria on BMI was diminished by probiotic treatment. Proinflammatory effect of Bacteroidaceae was alleviated by probiotic administration. However, probiotics did not affect the microbiota composition, and none of the baseline microbiota-related features could predict therapeutic response as defined by cluster analysis. Conclusions: Probiotic intervention alters the influence of microbiota on biochemical, physiological and immunological parameters, but it does not affect diversity and taxonomic composition. Baseline microbiota is not a predictor of therapeutic response to a multispecies probiotic. Further multi-omic and mechanistic studies performed on the bigger cohort of patients are needed to elucidate the cardiometabolic effect of investigated probiotics in postmenopausal obesity.

Reverse Genomics: Design of Universal Epitope Sets to Isolate All Saccharibacteria Members from the Human Oral Cavity

Microorganisms not yet cultured represent a large proportion of the microbes described to date. Progress in sequencing and metagenomic tools continues to increase microbial diversity without providing information on their physiological and pathophysiological characteristics, such as the recent discovery of enigmatic microbes belonging to Candidate Phyla Radiation (CPR). Reverse genomics is a recent technique allowing co-cultivation of a few CPR members, affiliated to the Saccharibacteria phylum, based on the analysis of their already-available genomes. Here, our aim is to designate a common system capable of cultivating any given taxon of this phylum from human samples. We managed to design, in silico, 11 common epitopes for all Saccharibacteria species recovered from the human oral cavity and which can serve as antigens via bioinformatics analyses. These sequences allow the synthesis of target antibodies, sorting Saccharibacteria spp. by flow cytometry and co-culturing them afterwards with adapted hosts. This epitope set can facilitate the cultivation of CPR in general, which in recent years has been considered a challenge for microbiologists, and subsequently contributes to better studying this new branch on the tree of life.