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.