The aim of this prospective pilot study was to compare culture and microbiome results of the removed tonsils of patients with assumed distant focal disease (11 patients) and those who underwent a tonsillectomy, due to other reasons, such as recurrent tonsillitis, tonsil stones or snoring (nine patients). Aerobic culture was carried out for samples taken from the surface of the tonsils by swabs before tonsillectomy for all 20 patients. The squeezed detritus and the tissue samples of removed tonsils, taken separately for the right and left tonsils, were incubated aerobically and anaerobically. The microbiome composition of tissue samples of removed tonsils was also evaluated. Based on the culture results of the deep samples Staphylococcus aureus was the dominating pathogen, besides a great variety of anaerobic and facultative anaerobic bacteria present in the oral microbiota in those patients who underwent tonsillectomy due to distant focal diseases. Microbiome study of the core tissue samples showed a great diversity on genus and species level among patients of the two groups however, S. aureus and Prevotella nigrescens were present in higher proportion in those, whose tonsils were removed due to distant focal diseases. Our results may support previous findings about the possible triggering role of S. aureus and P. nigrescens leading to distant focal diseases. Samples taken by squeezing the tonsils could give more information about the possible pathogenic/triggering bacteria than the surface samples cultured only aerobically.

Emerging evidence emphasizes the functional impacts of host microbiome on the etiopathogenesis of autoimmune diseases, including rheumatoid arthritis (RA). However, there are limited mechanistic insights into the contribution of microbial biomolecules especially microbial peptides toward modulating immune homeostasis. Here, by mining the metagenomics data of tonsillar microbiome, a deficiency of the encoding genes of lantibiotic peptides salivaricins in RA patients is identified, which shows strong correlation with circulating immune cells. Evidence is provided that the salivaricins exert immunomodulatory effects in inhibiting T follicular helper (Tfh) cell differentiation and interleukin-21 (IL-21) production. Mechanically, salivaricins directly bind to and induce conformational changes of IL-6 and IL-21 receptors, thereby inhibiting the bindings of IL-6 and IL-21 to their receptors and suppressing the downstream signaling pathway. Finally, salivaricin administration exerts both prophylactic and therapeutic effects against experimental arthritis in a murine model of RA. Together, these results provide a mechanism link of microbial peptides-mediated immunomodulation.

Squamous cell carcinoma of the tonsil is one of the most frequent cancers of the oropharynx. The escalating rate of tonsil cancer during the last decades is associated with the increase of high risk-human papilloma virus (HR-HPV) infections. While the microbiome in oropharyngeal malignant diseases has been characterized to some extent, the microbial colonization of HR-HPV-associated tonsil cancer remains largely unknown. Using 16S rRNA gene amplicon sequencing, we have characterized the microbiome of human palatine tonsil crypts in patients suffering from HR-HPV-associated tonsil cancer in comparison to a control cohort of adult sleep apnea patients. We found an increased abundance of the phyla Firmicutes and Actinobacteria in tumor patients, whereas the abundance of Spirochetes and Synergistetes was significantly higher in the control cohort. Furthermore, the accumulation of several genera such as Veillonella, Streptococcus and Prevotella_7 in tonsillar crypts was associated with tonsil cancer. In contrast, Fusobacterium, Prevotella and Treponema_2 were enriched in sleep apnea patients. Machine learning-based bacterial species analysis indicated that a particular bacterial composition in tonsillar crypts is tumor-predictive. Species-specific PCR-based validation in extended patient cohorts confirmed that differential abundance of Filifactor alocis and Prevotella melaninogenica is a distinct trait of tonsil cancer. This study shows that tonsil cancer patients harbor a characteristic microbiome in the crypt environment that differs from the microbiome of sleep apnea patients on all phylogenetic levels. Moreover, our analysis indicates that profiling of microbial communities in distinct tonsillar niches provides microbiome-based avenues for the diagnosis of tonsil cancer.

OBJECTIVE: Aim of our study was to map the adenotonsillar lymphoid tissues\' microbiome identifying its potential etiopathogenetic role in children affected by chronic tonsillitis or tonsillar hypertrophy with Obstructive Sleep Apnea Syndrome (OSAS).
METHODS: In our study, we examined tonsillar swabs from healthy children and children affected by chronic tonsillitis or by tonsillar hypertrophy with Obstructive Sleep Apnea Syndrome (OSAS). Microbiome\'s analysis was performed and bacterial 16Sr RNA gene was sequenced according to metagenomic principles. Variability was described according to the biodiversity concept, indicating species found in a certain environment and changes they undergo adapting to different environmental conditions.
RESULTS: The most significant differences concern variation of microbes in a single sample (alpha diversity) of some phyla in children affected by chronic tonsillitis compared with alpha diversity in healthy children and in children affected by OSAS with tonsillar hyperplasia. Proteobacteria are prevalent in chronic tonsillitis group, Fusobacteria and Spirochete in OSAS and Firmicutes, Actinobacteria, and Bacteroidetes were found in healthy children. Finally, comparison between the groups showed that children with OSAS with tonsillar hypertrophy had a higher presence of the Fusobacterium genus.
CONCLUSIONS: Recurrent upper airway inflammatory and/or infectious processes are polymicrobial; chronicity of such processes appear to be related to variations in microbiome\'s composition and interaction among various taxonomic units. Knowledge of the microbiomes\' composition together with traditional clinical biomarkers can also determine relationships between oropharyngeal microbiome and systemic pathologies to determine preventive changes in lifestyle, eating habits, environmental exposure and use of probiotics.

Porcine tonsils are lympho-epithelial tissues, colonized by numerous bacteria and viruses, that act as a reservoir for both host-specific pathogens and zoonotic pathogens with a high potential of transmission to humans. There are no existing studies describing the development of the tonsillar microbiome. We sequenced 16S rRNA genes from tonsillar samples of pigs to follow the development of the microbial communities from birth through weaning. Samples derived from sows were also analyzed to determine potential sources for the tonsil microbiome in piglets.
The composition of the newborn piglet tonsil microbiome could be differentiated by litter and had strong similarity to the sow teat skin as well as sow vaginal microbiome. The tonsil microbiome in these young piglets was mainly dominated by members of the Pasteurellaceae, Moraxellaceae, and Streptococcaceae families, while there were some transient members of the microbiome that were abundant at specific times, such as Staphylococcaceae in newborns and Fusobacteriaceae and Leptotrichiaceae in weeks 2 and 3. The microbiome initially differed between litters but over the following 3 weeks the communities of different litters converged in composition and then diverged in week 4 due to a combination of changes and stresses associated with weaning, including a shift from milk to a solid diet, in-feed Carbadox® and room change.
A significant portion of the tonsil microbiome was acquired either at birth from the sow vaginal tract or within a few hours post-birth from the sow teat skin. Our data demonstrate a temporal succession in the development of the pig tonsillar microbiome through the first weeks of life, with a convergence in the composition of the microbiome in all piglets by 3 weeks of age. The combination of management practices associated with weaning coincided with dramatic shifts in the tonsillar microbiome.