COVID-19 associated oral and oropharyngeal microbiome: Systematic review and meta-analysis

Microbiota of Saliva: A Non-invasive Diagnostic Tool

Potential of salivary microbiota as a non-invasive diagnostic tool for various diseases are explained in the present review. Traditional diagnostic methods rely on blood, which has limitations in terms of collection and biomarker specificity. We discuss the concept of normal flora and how disruptions in oral microbiota can be indicative of diseases. Saliva, harboring a diverse microbial community, offers promise as a diagnostic biomarker source for oral and non-oral conditions. We delve into the role of microbial dysbiosis in disease pathogenesis and the prospects of using biological indicators like dysbiosis for diagnosis, prediction, and monitoring. This review also emphasizes the significance of saliva microbiota in advancing early disease detection and timely intervention. We addressed the following research question and objectives: Can the microbiota of saliva serve as a non-invasive diagnostic tool for the early detection and monitoring of both oral and non-oral diseases? To achieve this, we will explore the normal flora of microorganisms in the oral cavity, the impact of microbial dysbiosis, and the potential of using specific pathogenic microorganisms as biomarkers. Additionally, we will investigate the correlation between oral and non-oral diseases by analyzing total saliva or site-specific dental biofilms for signs of symbiosis or dysbiosis. This research seeks to contribute valuable insights into the development of a non-invasive diagnostic approach with broad applications in healthcare.

Altered oral microbiome, but normal human papilloma virus prevalence in cartilage-hair hypoplasia patients

BACKGROUND

Cartilage-hair hypoplasia (CHH) is a rare syndromic immunodeficiency with metaphyseal chondrodysplasia and increased risk of malignancy. In this cross-sectional observational study, we examined HPV status and oral microbiome in individuals with CHH. Oral brush samples were collected from 20 individuals with CHH (aged 5-59 years) and 41 controls (1-69 years). Alpha HPVs (43 types) were tested by nested PCR followed by bead-based probe hybridization. Separately, beta-, gamma-, mu- and nu- HPV types were investigated, and a genome-based bacterial microbiome sequencing was performed.

RESULTS

We found a similar alpha HPV prevalence in individuals with CHH (45%) and controls (36%). The HPV types of individuals with CHH were HPV-16 (25%), 27, 28, and 78, and of controls HPV-3, 16 (21%), 27, and 61. Beta HPV positivity and combined beta/gamma/mu/nu prevalence was detected in 11% and 11% of individuals with CHH and in 5% and 3% of the controls, respectively. Individuals with CHH differed from the controls in bacterial microbiota diversity, richness, and in microbial composition. Individuals with CHH had lower abundance of species Mitsuokella sp000469545, Parascardovia denticolens, Propionibacterium acidifaciens, UMGS1907 sp004151455, Salinicola halophilus, Haemophilus_A paraphrohaemolyticus, Fusobacterium massiliense, and Veillonella parvula, and higher abundance of Slackia exigua.

CONCLUSIONS

Individuals with CHH exhibit similar prevalence of HPV DNA but different bacterial microbiota on their oral mucosa compared to healthy controls. This may partly explain the previously observed high prevalence of oral diseases in CHH, and regular oral examination is warranted.

Full-length 16S rDNA sequencing based on Oxford Nanopore Technologies revealed the association between gut-pharyngeal microbiota and tuberculosis in cynomolgus macaques

Tuberculosis (TB) is an infectious disease caused by the Mycobacterium tuberculosis complex (Mtbc), which develops from asymptomatic latent TB to active stages. The microbiome was purposed as a potential factor affecting TB pathogenesis, but the study was limited. The present study explored the association between gut-pharyngeal microbiome and TB stages in cynomolgus macaques using the full-length 16S rDNA amplicon sequencing based on Oxford Nanopore Technologies. The total of 71 macaques was divided into TB (-) control, TB (+) latent and TB (+) active groups. The differential abundance analysis showed that Haemophilus hemolyticus was decreased, while Prevotella species were increased in the pharyngeal microbiome of TB (+) macaques. In addition, Eubacterium coprostanoligenes in the gut was enriched in TB (+) macaques. Alteration of these bacteria might affect immune regulation and TB severity, but details of mechanisms should be further explored and validated. In summary, microbiota may be associated with host immune regulation and affect TB progression. The findings suggested the potential mechanisms of host-microbes interaction, which may improve the understanding of the role of microbiota and help develop therapeutics for TB in the future.

Herpesviruses and SARS-CoV-2: Viral Association with Oral Inflammatory Diseases

The oral cavity is a niche for diverse microbes, including viruses. Members of the Herpesviridae family, comprised of dsDNA viruses, as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an ssRNA virus, are among the most prevalent viruses infecting the oral cavity, and they exhibit clinical manifestations unique to oral tissues. Viral infection of oral mucosal epithelia triggers an immune response that results in prolonged inflammation. The clinical and systemic disease manifestations of HHV have been researched extensively, and several recent studies have illuminated the relationship between HHV and oral inflammatory diseases. Burgeoning evidence suggests the oral manifestation of SARS-CoV-2 infection includes xerostomia, dysgeusia, periodontal disease, mucositis, and opportunistic viral and bacterial infections, collectively described as oral post-acute sequelae of COVID-19 (PASC). These diverse sequelae could be a result of intensified immune responses initially due to the copious production of proinflammatory cytokines: the so-called "cytokine storm syndrome", facilitating widespread oral and non-oral tissue damage. This review explores the interplay between HHV, SARS-CoV-2, and oral inflammatory diseases such as periodontitis, endodontic disease, and peri-implantitis. Additionally, the review discusses proper diagnostic techniques for identifying viral infection and how viral diagnostics can lead to improved overall patient health.