Oral bacteria colonize and compete with gut microbiota in gnotobiotic mice

Abstract

The oral microbiota is associated with oral diseases and digestive systemic diseases. Nevertheless, the causal relationship between them has not been completely elucidated, and colonisation of the gut by oral bacteria is not clear due to the limitations of existing research models. The aim of this study was to develop a human oral microbiota-associated (HOMA) mouse model and to investigate the ecological invasion into the gut. By transplanting human saliva into germ-free (GF) mice, a HOMA mouse model was first constructed. 16S rRNA gene sequencing was used to reveal the biogeography of oral bacteria along the cephalocaudal axis of the digestive tract. In the HOMA mice, 84.78% of the detected genus-level taxa were specific to the donor. Principal component analysis (PCA) revealed that the donor oral microbiota clustered with those of the HOMA mice and were distinct from those of specific pathogen-free (SPF) mice. In HOMA mice, OTU counts decreased from the stomach and small intestine to the distal gut. The distal gut was dominated by Streptococcus, Veillonella, Haemophilus, Fusobacterium, Trichococcus and Actinomyces . HOMA mice and human microbiota-associated (HMA) mice along with the GF mice were then cohoused. Microbial communities of cohoused mice clustered together and were significantly separated from those of HOMA mice and HMA mice. The Source Tracker analysis and network analysis revealed more significant ecological invasion from oral bacteria in the small intestines, compared to the distal gut, of cohoused mice. In conclusion, a HOMA mouse model was successfully established. By overcoming the physical and microbial barrier, oral bacteria colonised the gut and profiled the gut microbiota, especially in the small intestine.

Polymicrobial periodontal disease triggers a wide radius of effect and unique virome

“…Studies have discussed issues with oral microbial sampling and detection methods in mouse models since oral murine tissues may exhibit lower bacterial biomass 58 . Mouse studies that have evaluated the oral microbiome with conventional 16S sequencing methods have detected some differences in oral microbiome diversity 59,60 . There have also been a few studies that have examined diversity differences between periodontal disease and healthy subjects in humans using 16s rRNA sequencing.…”

Shifts in the bacterial community of supragingival plaque related to metabolic associated fatty liver disease

“…On the one hand, microbial dysbiosis in the oral cavity is a source of systemic in ammation, which could lead to chronic low-grade in ammation and adversely affects the systemic health of the host [6]. On the other hand, the oral microbiota can in uence the composition of the gut microbiome, which plays important roles in systemic health [24][25][26][27]. Due to the anatomical position, about 10 11 bacteria are swallowed from the oral cavity to the stomach every day [25], cultivation and sequencing techniques have also substantiated the association between the oral and gut microbiomes: Arimatsu et al reported that oral administration of P. gingivalis signi cantly altered the Firmicutes/Bacteroidetes ratio, a signi cant index to evaluate the health status of the gut microbiome [26]; Li et al found that the oral microbiota could overcome physical barriers and colonize the gut in gnotobiotic mice [27].…”

“…It is generally acknowledged that microbial diversity re ects the health status of the host. For example, decreased diversity of gut microbiota indicates functional or metabolic disorders in the host [30], while increased diversity of oral microbiota is reported to imply poor oral [31,32] and holistic health [21][22][23][24][25][26][27][28][29][30][31][32][33] because in a state of poor oral health, gingival bleeding provides a richer nutrient source [25]. In the present study, increased diversity (lower Simpson index and higher Shannon index) of the supragingival microbiota in the MAFLD group was observed, suggesting possible alterations to the nutritional status of supragingival plaque in MAFLD patients.…”

“…Prevotella 2 is a genus of Gram-negative, anaerobic bacteria that exist in the gut and are relevant to multiple disease states, including an increased lifetime risk of cardiovascular disease [30], ankylosing spondylitis [37], and increased levels of C-reactive protein [38]. Considering the consistency between the oral and gut microbiotas [25][26][27], the prevalence of Prevotella 2 in the oral cavity is proposed as a potential marker of systematic diseases including MAFLD. In healthy participants, the genera Neisseria and Bergeyella had the highest LDA scores.…”

The effect of probiotic ice cream consumption on salivary cariogenic bacteria in healthy adults

“…Oral microbiota is one of the most important and complex microbial communities in the human body (Lamont et al, 2018). Moreover, there is an increasing number of evidences demonstrating that oral microbiota dysbiosis is associated not only with oral diseases (Li et al, 2019), including dental caries and periodontal disease (Costalonga and Herzberg, 2014), but also systemic diseases (Graves et al, 2018). Dental caries, one of the most common chronic diseases worldwide, is characterized by the localized destruction of the mineralized tooth tissues caused by bacterial action (Jin et al, 2015;Marsh and Zaura, 2017).…”