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In periodontal disease (PD), bacterial biofilms suppress β6 integrin expression transforming growth factor-β1 signaling, resulting in gingival inflammation and bone loss. β6 integrin-null (Itgb6−/−) mice develop spontaneous PD. The aim of this study was to unravel potential differences in oral microbiome in wild-type (WT) and Itgb6−/− FVB mice. Mouse oral microbiome was analyzed from 3- and 6-month-old WT and Itgb6−/−. The periodontal inflammation and spontaneous bone loss were present in 3-month-old and advanced in 6-month-old Itgb6−/− mice. The observed amplicon sequence variants (ASVs) of alpha diversity showed close similarity in 3-month-old and 6-month-old Itgb6−/− mice. Chao1 and ACE methods revealed that the microbiome in Itgb6−/− mice showed less diversity compared to the WT. UniFrac Principal Coordinate analyses (PCoA) showed a clear spatial segregation and clustering between Itgb6−/− and WT mice in general, and between 3-month- and 6-month-old WT mice. Weighted PCoA showed the tight clustering and distinct separation of individual mouse samples within Itgb6−/− and WT. The most abundant microbial classes varied between the sample groups. However, the genus Aggregatibacter significantly increased in the 6-month-old Itgb6−/− mice. β6 integrin-deficient mice develop periodontal inflammation that may relate to dysbiosis in the microbiome that further promotes the disease process. [ABSTRACT FROM AUTHOR]

Background and Objective: The translocation of oral bacteria, including Porphyromonas gingivalis, to the gut has been shown to alter gut microbiome. However, the effect of P. gingivalis on gut microbiome in relation to aging has not been demonstrated. We hypothesize that P. gingivalis has more detrimental effect on gut environment with increased age. The objective of this study is to investigate the effect of P. gingivalis on gut environment using aged mice. Materials and Methods: C57BL/6J mice aged 4 weeks (young) or 76 weeks (old) were divided into four groups: control‐young, control‐old, P. gingivalis‐administered young, and P. gingivalis‐administered old. P. gingivalis was orally administered thrice weekly for 5 weeks. At 30 days after the last P. gingivalis administration, 16S rRNA sequencing was performed to study the gut microbiome. The mRNA and protein expression of intestinal junctional barrier molecules and the levels of the inflammatory cytokines IL‐1β and TNF‐α in the serum were evaluated. Results: Significant differences in the gut microbiomes between the groups, in terms of taxonomic abundance, bacterial diversity, and predicted metagenome function, were observed. A significant reduction in the alpha diversity and in the abundance of beneficial bacteria, such as Akkermansia and Clostridiaceae, in the P. gingivalis‐administered old mice was observed. The mRNA and protein levels of Claudin‐1 and Claudin‐2 in the intestine were significantly elevated, while E‐cadherin was significantly downregulated in the P. gingivalis‐administered old mice, as were the serum levels of IL‐1β and TNF‐α. Conclusion: The effect of P. gingivalis on the gut environment is more pronounced in old mice than in young mice. [ABSTRACT FROM AUTHOR]

Fucoxanthin (Fx), a marine carotenoid found in edible brown algae, is well known for having anticancer properties. The gut microbiota has been demonstrated as a hallmark for colorectal cancer progression in both humans and rodents. However, it remains unclear whether the gut microbiota is associated with the anticancer effect of Fx. We investigated the chemopreventive potency of Fx and its effect on gut microbiota in a mouse model of inflammation-associated colorectal cancer (by azoxymethane/dextran sulfate sodium treatment). Fx administration (30 mg/kg bw) during a 14 week period significantly inhibited the multiplicity of colorectal adenocarcinoma in mice. The number of apoptosis-like cleaved caspase-3high cells increased significantly in both colonic adenocarcinoma and mucosal crypts. Fx administration significantly suppressed Bacteroidlales (f_uc; g_ uc) (0.3-fold) and Rikenellaceae (g_ uc) (0.6-fold) and increased Lachnospiraceae (g_ uc) (2.2-fold), compared with those of control mice. Oral administration of a fecal suspension obtained from Fx-treated mice, aimed to enhance Lachnospiraceae , suppress the number of colorectal adenocarcinomas in azoxymethane/dextran sulfate sodium-treated mice with a successful increase in Lachnospiraceae in the gut. Our findings suggested that an alteration in gut microbiota by dietary Fx might be an essential factor in the cancer chemopreventive effect of Fx in azoxymethane/dextran sulfate sodium-treated mice. [ABSTRACT FROM AUTHOR]

Psychological stress is involved in the development of various oral diseases. Alterations in the levels of cytokines in the saliva of patients with stress-related oral diseases have been reported. However, the inconsistencies in the results of these studies might be attributed to differences in the local and systemic factors in the oral cavities of the patients. We examined the effect of chronic stress on three major inflammatory cytokines Interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in the saliva and salivary glands of chronically stressed mice. Six-week-old C57BL/6 J mice were randomly divided into a control and a stress group. The mice in stress group were exposed to 4 h of stress daily for 10 days and subsequently saliva, as well as the submandibular glands, were collected from both groups. The expression levels of cytokines in the saliva were examined by enzyme-linked immunosorbent assay. The submandibular glands were subjected to histopathological and mRNA expression analyses. IL-1β was significantly elevated in saliva of the chronic stressed mice. Furthermore, the mRNA expression levels of both IL-1β and IL-6 were significantly elevated in the submandibular gland of chronic stressed mice. IL-1β may be a potential salivary biomarker in response to chronic stress in mice. [ABSTRACT FROM AUTHOR]