Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging, yet there is limited understanding of gut microbiome variation in advanced age. Here, we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years, with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations. In addition to two adult-like enterotypes dominated by Bacteroides (ET-Bacteroides) and Prevotella (ET-Prevotella), we identified a novel enterotype dominated by Escherichia (ET-Escherichia), whose prevalence increased in advanced age. Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus (T2DM) or diet. We characterized the distinct taxonomic and functional profiles of ET-Escherichia, and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype, as well as the lowest species diversity. In addition, we carried out a series of correlation analyses and co-abundance network analyses, which showed that several factors were likely linked to the overabundance of Escherichia members, including advanced age, vegetable intake, and fruit intake. Overall, our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population. Considering the different age distribution of each enterotype, these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.
Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Bacteroides ; China ; Diabetes Mellitus, Type 2/microbiology* ; Escherichia coli/classification* ; Gastrointestinal Microbiome/genetics* ; Metagenomics ; East Asian People

BACKGROUND: Periodontitis is characterized by alveolar bone resorption, aggravated by osteoblast dysfunction, and associated with intracellular oxidative stress linked to the nuclear factor erythroid 2-related factor 2 (NRF2) level. We evaluated the molecular mechanism of periodontitis onset and development and the role of NRF2 in osteogenic differentiation. METHODS: Primary murine mandibular osteoblasts were extracted and exposed to Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) or other stimuli. Reactive oxygen species (ROS) and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining were used to detect intracellular oxidative stress. Alkaline phosphatase staining and alizarin red S staining were used to detect the osteogenic differentiation of osteoblasts. Immunofluorescence and western blotting were used to determine the changes in the mitogen-activated protein kinase (MAPK) pathway and related molecule activities. Immunofluorescence colocalization and co-immunoprecipitation were performed to examine the nuclear translocation of NRF2 and its interaction with dual-specific phosphatase 1 (DUSP1) in cells. RESULTS: Ligated tissue samples showed higher alveolar bone resorption rate and lower NRF2 level than healthy periodontal tissue samples. Pg-LPS increased intracellular oxidative stress levels and inhibited osteogenic differentiation, whereas changes in NRF2 expression were correlated with changes in the oxidative stress and osteogenesis rate. NRF2 promoted the dephosphorylation of the MAPK pathway by nuclear translocation and the upregulation of DUSP1 expression, thus enhancing the osteogenic differentiation capacity of mandibular osteoblasts. The interaction between NRF2 and DUSP1 was observed. CONCLUSIONS: NRF2 and its nuclear translocation can regulate the osteogenic differentiation of mandibular osteoblasts under Pg-LPS conditions by interacting with DUSP1 in a process linked to the MAPK pathway. These findings form the basis of periodontitis treatment.
Animals ; NF-E2-Related Factor 2/physiology* ; Lipopolysaccharides/pharmacology* ; Osteoblasts/drug effects* ; Mice ; Porphyromonas gingivalis/chemistry* ; Cell Differentiation ; Osteogenesis ; Dual Specificity Phosphatase 1/metabolism* ; Mandible/cytology* ; Reactive Oxygen Species/metabolism* ; Oxidative Stress ; Periodontitis/metabolism* ; Cells, Cultured ; Male ; Cell Nucleus/metabolism*

OBJECTIVES: To investigate the efficacy of Ag₂Se nanoparticles for eliminating intracellular Porphyromonas gingivalis (P. gingivalis) in esophageal cancer and examine the effect of P. gingivalis clearance on progression of esophageal cancer. METHODS: Ag₂Se nanoparticles were synthesized via a chemical synthesis method. The effects of Ag₂Se nanoparticles on P. gingivalis viability and colony-forming ability were assessed using fluorescence staining and colony formation assays. In a mouse model bearing subcutaneous murine esophageal cancer cell allograft with P. gingivalis infection, the effect of treatment with Ag₂Se nanoparticles on the abundance of P. gingivalis in the tumor tissues was quantified using RNAscope in situ hybridization and quantitative polymerase chain reaction (qPCR), and the changes in tumor volume were monitored. The biosafety of Ag₂Se nanoparticles was assessed by examining liver and kidney functions and pathological changes in the major organs of the mice. RESULTS: Transmission electron microscopy revealed that the synthesized Ag₂Se nanoparticles were uniformly dispersed spherical particles with a diameter around 50 nm. In vitro experiments demonstrated that exposure to Ag₂Se nanoparticles significantly reduced the viability and clonal proliferation capacity of P. gingivalis in a dose-dependent manner. In the tumor-bearing mice, treatment with Ag₂Se nanoparticles significantly reduced the abundance of P. gingivalis in tumor tissues and suppressed tumor cell proliferation. No significant damages to the liver and kidney functions or the major organs were observed in Ag₂Se nanoparticle-treated mice, demonstrating good biocompatibility of Ag₂Se nanoparticles. CONCLUSIONS Ag₂Se nanoparticles exhibit significant bactericidal and inhibitory effects against P. gingivalis, and can effectively eliminate intracellular P. gingivalis to suppress the growth of esophageal cancer allograft in mice, suggesting the potential of Ag₂Se nanoparticles in the treatment of esophageal cancer.
Animals ; Porphyromonas gingivalis/drug effects* ; Mice ; Esophageal Neoplasms/pathology* ; Nanoparticles ; Metal Nanoparticles ; Bacteroidaceae Infections ; Cell Line, Tumor

Cancer stem cells (CSCs) are widely acknowledged as primary mediators to the initiation and progression of tumors. The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years. Porphyromonas gingivalis (P. gingivalis) is increasingly considered to be closely related to the development of oral squamous cell carcinoma (OSCC). Nevertheless, the role of P. gingivalis in the stemness of OSCC cells remains uncertain. Herein, we showed that P. gingivalis was positively correlated with CSC markers expression in human OSCC specimens, promoted the stemness and tumorigenicity of OSCC cells, and enhanced tumor formation in nude mice. Mechanistically, P. gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1 (SCD1) expression, a key enzyme involved in lipid metabolism, which ultimately resulted in enhanced acquisition of stemness. Moreover, SCD1 suppression attenuated P. gingivalis-induced stemness of OSCC cells, including CSCs markers expression, sphere formation ability, chemoresistance, and tumor growth, in OSCC cells both in vitro and in vivo. Additionally, upregulation of SCD1 in P. gingivalis-infected OSCC cells was associated with the expression of KLF5, and that was modulated by P. gingivalis-activated NOD1 signaling. Taken together, these findings highlight the importance of SCD1-dependent lipid synthesis in P. gingivalis-induced stemness acquisition in OSCC cells, suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.
Porphyromonas gingivalis/pathogenicity* ; Stearoyl-CoA Desaturase/metabolism* ; Humans ; Carcinoma, Squamous Cell/pathology* ; Mouth Neoplasms/metabolism* ; Animals ; Neoplastic Stem Cells/microbiology* ; Mice, Nude ; Mice ; Nod1 Signaling Adaptor Protein/metabolism* ; Kruppel-Like Transcription Factors/metabolism* ; Cell Line, Tumor

Periodontal disease is a risk factor for many systemic diseases such as Alzheimer's disease and adverse pregnancy outcomes. Cleft palate (CP), the most common congenital craniofacial defect, has a multifaceted etiology influenced by complex genetic and environmental risk factors such as maternal bacterial or virus infection. A prior case-control study revealed a surprisingly strong association between maternal periodontal disease and CP in offspring. However, the precise relationship remains unclear. In this study, the relationship between maternal oral pathogen and CP in offspring was studied by sonicated P. gingivalis injected intravenously and orally into pregnant mice. We investigated an obvious increasing CP (12.5%) in sonicated P. gingivalis group which had inhibited osteogenesis in mesenchyme and blocked efferocytosis in epithelium. Then glycolysis and H4K12 lactylation (H4K12la) were detected to elevate in both mouse embryonic palatal mesenchyme (MEPM) cells and macrophages under P. gingivalis exposure which further promoted the transcription of metallopeptidase domain17 (ADAM17), subsequently mediated the shedding of transforming growth factor-beta receptor 1 (TGFBR1) in MEPM cells and mer tyrosine kinase (MerTK) in macrophages and resulted in the suppression of efferocytosis and osteogenesis in palate, eventually caused abnormalities in palate fusion and ossification. The abnormal efferocytosis also led to a predominance of M1 macrophages, which indirectly inhibited palatal osteogenesis via extracellular vesicles. Furthermore, pharmacological ADAM17 inhibition could ameliorate the abnormality of P. gingivalis-induced abnormal palate development. Therefore, our study extends the knowledge of how maternal oral pathogen affects fetal palate development and provides a novel perspective to understand the pathogenesis of CP.
Animals ; Female ; Porphyromonas gingivalis ; Pregnancy ; Mice ; Cleft Palate/etiology* ; Glycolysis

Understanding microbial-host interactions in the oral cavity is essential for elucidating oral disease pathogenesis and its systemic implications. In vitro bacteria-host cell coculture models have enabled fundamental studies to characterize bacterial infection and host responses in a reductionist yet reproducible manner. However, existing in vitro coculture models fail to establish conditions that are suitable for the growth of both mammalian cells and anaerobes, thereby hindering a comprehensive understanding of their interactions. Here, we present an asymmetric gas coculture system that simulates the oral microenvironment by maintaining distinct normoxic and anaerobic conditions for gingival epithelial cells and anaerobic bacteria, respectively. Using a key oral pathobiont, Fusobacterium nucleatum, as the primary test bed, we demonstrate that the system preserves bacterial viability and supports the integrity of telomerase-immortalized gingival keratinocytes. Compared to conventional models, this system enhanced bacterial invasion, elevated intracellular bacterial loads, and elicited more robust host pro-inflammatory responses, including increased secretion of CXCL10, IL-6, and IL-8. In addition, the model enabled precise evaluation of antibiotic efficacy against intracellular pathogens. Finally, we validate the ability of the asymmetric system to support the proliferation of a more oxygen-sensitive oral pathobiont, Porphyromonas gingivalis. These results underscore the utility of this coculture platform for studying oral microbial pathogenesis and screening therapeutics, offering a physiologically relevant approach to advance oral and systemic health research.
Coculture Techniques/methods* ; Humans ; Fusobacterium nucleatum/physiology* ; Gingiva/microbiology* ; Keratinocytes/microbiology* ; Host Microbial Interactions ; Mouth/microbiology* ; Host-Pathogen Interactions ; Epithelial Cells/microbiology* ; Cells, Cultured ; Porphyromonas gingivalis

This study investigates the role of Interleukin 17 (IL-17) in exacerbating periapical lesions caused by Porphyromonas gingivalis (Pg) lipopolysaccharides (LPS) in the context of metabolic disease and its potential impact on glucose tolerance. Researchers developed a unique mouse model where mice were monocolonized with Pg to induce periapical lesions. After 1 month, they were fed a high-fat diet (HFD) for 2 months to simulate metabolic disease and oral microbiota dysbiosis. To explore the role of LPS from Pg, wild-type (WT) mice were challenged with purified LPS from Porphyromonas gingivalis, as well as with LPS-depleted and non-depleted Pg bacteria; IL-17 knockout (KO) mice were also included to assess the role of IL-17 signaling. The impact on bone lysis, periapical injury, glucose intolerance, and immune response was assessed. Results showed that in WT mice, the presence of LPS significantly worsened bone lysis, Th17 cell recruitment, and periapical injury. IL-17 KO mice exhibited reduced bone loss, glucose intolerance, and immune cell infiltration. Additionally, inflammatory markers in adipose tissue were lower in IL-17 KO mice, despite increased dysbiosis. The findings suggest that IL-17 plays a critical role in amplifying Pg-induced periapical lesions and systemic metabolic disturbances. Targeting IL-17 recruitment could offer a novel approach to improving glycemic control and reducing type 2 diabetes (T2D) risk in individuals with periapical disease.
Animals ; Porphyromonas gingivalis/immunology* ; Th17 Cells/immunology* ; Lipopolysaccharides/immunology* ; Mice ; Glucose Intolerance/microbiology* ; Interleukin-17/metabolism* ; Mice, Knockout ; Mice, Inbred C57BL ; Disease Models, Animal ; Diet, High-Fat ; Periapical Diseases/microbiology* ; Male ; Dysbiosis

OBJECTIVES: This study aimed to observe the effects of initial periodontal therapy on the level of neutrophil extracellular traps (NETs) in gingival crevicular fluid (GCF) of patients with severe periodontitis and to analyze the factors related to the formation of NETs. METHODS: Thirty-one patients with stage Ⅲ-Ⅳ periodontitis were recruited. Clinical periodontal parameters, including plaque index (PLI), gingival index (GI), probing depth (PD), and clinical atta-chment loss (CAL), were recorded before and 6-8 weeks after initial periodontal therapy. Levels of NETs in GCF were detected by immunofluorescence staining. Quantities of total bacteria, Porphyromonas gingivalis (P. gingivalis), Aggregatibacter actinomycetemcomitans (A. actionomycetemcomitans) and Prevotella intermedia (P. intermedia)in unattached subgingival plaque were determined by real-time quantitative PCR, and levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in GCF were explored by enzyme-linked immunosorbent assay. In addition, the correlations between the level of NETs and the above indicators were analyzed. RESULTS: After initial periodontal therapy, the level of NETs in GCF, PLI, GI, PD, and CAL; quantities of total bacteria, P. gingivalis, A. actinomycetemcomitans, and P. itermedia; and levels of IL-8 and TNF-α significantly decreased (P<0.05). We observed strong positive correlations between the level of NETs and PLI, GI, PD, CAL, the amount of total bacteria, P. gingivalis, TNF-α, and IL-8 (P<0.05). CONCLUSIONS Initial periodontal therapy might decrease the level of NETs in GCF from patients with severe periodontitis, which might be positively correlated with the quantities of P. gingivalis andthe levels of TNF-α and IL-8 in GCF.
Humans ; Gingival Crevicular Fluid ; Extracellular Traps/metabolism* ; Porphyromonas gingivalis/isolation & purification* ; Aggregatibacter actinomycetemcomitans/isolation & purification* ; Periodontitis/metabolism* ; Tumor Necrosis Factor-alpha/analysis* ; Prevotella intermedia/isolation & purification* ; Interleukin-8/analysis* ; Male ; Female ; Middle Aged ; Periodontal Index ; Adult

: Bacteroides, as one of the most abundant and diverse genera in the human gut, is regarded as a window into the study of gut microbiota-host interactions. Currently, CRISPR/Cas-based gene editing systems targeting Bacteroides have been widely applied, while the large size of Cas nucleases limits their potential application scenarios (such as in situ gut Bacteroides editing based on phage delivery). Therefore, this study aims to develop a compact and highly efficient genetic editing tool in Bacteroides., We developed a miniaturized CRISPR/Cas gene editing system for human gut Bacteroides. First, the editing capabilities of different miniaturized CRISPR/Cas systems, including AsCas12f, CasΦ2, and ISDge10, were evaluated in Bacteroides fragilis. Subsequently, the editing capability of AsCas12f was assessed across various Bacteroides species, and the size of this system was further optimized. The results demonstrated that the CRISPR/AsCas12f genome editing system exhibited the highest editing efficiency in B. fragilis. The CRISPR/AsCas12f system achieved efficient genome editing in B. fragilis, Bacteroides thetaiotaomicron, and Phocaeicola vulgatus. Furthermore, with a repair template of 500 bp homologous arms, the editing efficiency remained as high as 94.7%. In conclusion, CRISPR/AsCas12f can serve as a chassis tool enzyme for the development of Bacteroides-based miniature gene editors and derivative technologies, laying a foundation for the further development of gene editing technology for Bacteroides.
CRISPR-Cas Systems/genetics* ; Gene Editing/methods* ; Bacteroides/genetics* ; Humans ; Gastrointestinal Microbiome/genetics* ; Bacteroides fragilis/genetics*

Parabacteroides distasonis is a gram-negative bacterium initially isolated from a clinical specimen in the 1930s. The strain was re-classified to form the new genus Parabacteroides in 2006. P. distasonis can regulate intestinal barrier function and plays a key role in immune response and metabolic regulation of bodies. Traditional Chinese medicine(TCM) is closely related to the intestinal microbiota. Polysaccharides, saponins, and other ingredients of TCM can treat diseases by interacting with P. distasonis, but the specific mechanisms underlying these processes are still unclear, requiring further exploration. This study reviewed the roles and related mechanisms of P. distasonis in inflammatory-immune diseases, metabolic diseases, cardiovascular disease, neuropsychiatric diseases, cancer, and other diseases and summarized the relevant research results of TCM to prevent and treat diseases by regulating P. distasonis. This study provides a reference for subsequent exploration of P. distasonis and research on the interaction between TCM and intestinal microbiota.
Humans ; Gastrointestinal Microbiome/drug effects* ; Medicine, Chinese Traditional ; Animals ; Bacteroidetes ; Drugs, Chinese Herbal/pharmacology*