1.Antibacterial properties of piezoelectric materials and their applications in stomatology
ZHANG Shujun ; WANG Xiuqing ; HUANG Xiaojing
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(1):86-95
Microbial infections are a prevalent challenge in the prevention and treatment of oral diseases. Antibiotic therapy faces clinical limitations due to its single-target mechanism and tendency to induce resistance with repeated use, necessitating novel antibacterial strategies. Stimuli-responsive antibacterial materials, whose antimicrobial activity can be modulated by external stimuli, offer advantages such as remote controllability, potential for localized precision treatment, and a reduced risk of inducing resistance. Among these materials, mechanical force-triggered piezoelectric materials exhibit significant antibacterial activity in the biomedical field owing to their unique piezoelectric effect, excellent stability, and good biocompatibility. Research has shown that piezoelectric materials can convert mechanical energy into electrical energy in response to external forces, which enables antibacterial effects without requiring an external power source. The underlying mechanisms primarily include direct electric field effects, generation of reactive oxygen species, and immune modulation. Preliminary applications in treating oral infections (e.g., dental caries, periodontitis, and peri-implantitis) have confirmed their stability and biocompatibility, establishing a foundation for clinical translation. However, long-term efficacy and biosafety in the complex oral microenvironment require further validation. Future research should focus on optimizing material preparation protocols to enhance antibacterial efficacy and stability, further investigating the underlying antimicrobial mechanisms, and systematically evaluating their therapeutic outcomes and safety profiles across various types of oral infections. This review summarizes the antibacterial effects, mechanisms, stability, safety, and research progress of piezoelectric materials in the stomatologic field, aiming to provide new insights for further research and application in this area.
2.Investigating Effect of Xianglian Huazhuo Prescription on Cell Cycle and Proliferation in Rats with Chronic Atrophic Gastritis Through TGF-β1/Smads Signaling Pathway
Yican WANG ; Jie WANG ; Yirui CHENG ; Xiaojing LI ; Yibin MA ; Qiuhua LIU ; Ziwei LIU ; Yuxi GUO ; Pengli DU ; Yanru CAI ; Yao DU ; Zheng ZHI ; Bolin LI ; Qian YANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):128-136
ObjectiveTo explore the potential mechanism of Xianglian Huazhuo prescription (XLHZ) in treating chronic atrophic gastritis (CAG) by regulating cell cycle and inhibiting proliferation, using bioinformatics technology and animal experiments. MethodsDifferential expressed genes (DEGs) related to CAG were screened using GEO database and GEO2R tool. Weighted gene co-expression network analysis (WGCNA) was employed to search for hub genes of CAG. These hub genes were intersected with cell cycle proliferation based on GeneCards database. Eenrichment analysis of the intersecting genes was performed to obtain signaling pathways and biological processes related to CAG. Protein protein interaction (PPI) analysis of genes was conducted using the Protein Interaction Platform (STRING) database to search the super hub gene (hub 2.0), and animal experiments were conducted for further validation. Fourteen of 70 male Wistar rats were randomly selected as the normal group, and the remaining 56 rats were prepared by the combined modeling method of "starvation disorder+N-methyl-N-nitro-N-nitrosoguanidine (MNNG) + sodium salicylate". The successfully modeled rats were randomly divided into the model group, XLHZ-H, XLHZ-M, and XLHZ-L groups (36, 18, 9 g·kg-1, respectively), and Morodan group (1.4 g·kg-1). Each group was given corresponding intervention for 60 days. Hematoxylin-eosin (HE) staining was used to observe the histopathological changes of gastric mucosa in rats. The ultrastructure of gastric mucosal tissue cells was observed by transmission electron microscopy. The relative expression levels of TGF-β1, Smad2 and Smad3 proteins, S/G2/M phase marker geminin and proliferation marker MCM2 were detected by Western blot in gastric mucosal tissue, and Spearman correlation analysis was performed. ResultsA total of 15 hub 2.0 genes were identified, including TGF-β1, suggesting the involvement of the TGF-β1 signaling pathway in the CAG pathogenesis. Compared with the normal group, the expressions of TGF-β1, Smad2, geminin and MCM2 proteins in the gastric mucosa tissue of the model group were increased (P<0.05), and the expression of Smad3 protein was decreased (P<0.05). Compared with the model group, the expressions of TGF-β1 and geminin in the gastric mucosa were decreased in the drug groups (P<0.05). The XLHZ-M group, XLHZ-H group and Morodan group had significantly decreased protein expression of Smad2 and MCM2 (P<0.05). The protein expression of Smad3 was significantly increased in XLHZ-M, XLHZ-H, and Morodan groups (P<0.05). Spearman correlation analysis showed that Smad3 was negatively correlated with other indicators, and positively correlated with other indicators (P<0.01). ConclusionXLHZ may inhibit TGF-β1/Smads signaling pathway, regulate cell cycle, and inhibit proliferation in the treatment of CAG.
3.Short-term efficacy of low-dose transscleral cyclophotocoagulation for persistent ocular hypertension in acute angle-closure glaucoma
Qiaoyun LI ; Yong JIA ; Baike ZHANG ; Xiaojing GUO ; Cong LU ; Xinli WEI ; Xuemin TIAN
International Eye Science 2026;26(4):706-710
AIM: To evaluate the safety and efficacy of low-dose transscleral cyclophotocoagulation(TSCP)in the management of persistent ocular hypertension after an acute attack of angle-closure glaucoma(AACG).METHODS:This retrospective study enrolled patients diagnosed with persistent ocular hypertension after an acute AACG attack at the No.988 Hospital of the Joint Logistics Support Force of the Chinese PLA between September 2023 and September 2024. All patients underwent low-dose TSCP using a semiconductor diode laser. Subsequent cataract surgery combined with goniosynechialysis was performed once intraocular pressure(IOP)was stabilized. Changes in anterior chamber depth(ACD), best-corrected visual acuity(VA), and IOP were compared before and after TSCP, as well as before and after phacoemulsification. Post-TSCP complications were also documented.RESULTS: A total of 21 patients(21 eyes)were enrolled, including 8 males and 13 females, with a mean age of 67.95±7.25 y. Compared with pre-cyclophotocoagulation values, ACD increased significantly at 3 d post-TSCP(1.49±0.18 vs 1.22±0.21 mm; P<0.001). BCVA and IOP decreased significantly at 1 d post-TSCP, pre-phacoemulsification, 1 wk post-phacoemulsification, and 1 mo post-phacoemulsification compared with pre-TSCP IOP(all P<0.01). Regarding postoperative complications, 2 eyes experienced pain on the day of the procedure, 5 eyes developed mild corneal endothelial folds, 2 eyes exhibited moderate anterior chamber inflammatory reaction, and 12 eyes showed shallow ciliary body detachment. No serious complications occurred during the 1-month follow-up period.CONCLUSION:Low-dose TSCP appears to be an effective bridging therapy for patients with persistent ocular hypertension following an AACG attack. It facilitates rapid IOP reduction, alleviates symptoms, and helps preserve visual function with a favorable safety profile, thereby reducing the risks associated with subsequent intraocular surgery.
4.Investigating Effect of Xianglian Huazhuo Prescription on Cell Cycle and Proliferation in Rats with Chronic Atrophic Gastritis Through TGF-β1/Smads Signaling Pathway
Yican WANG ; Jie WANG ; Yirui CHENG ; Xiaojing LI ; Yibin MA ; Qiuhua LIU ; Ziwei LIU ; Yuxi GUO ; Pengli DU ; Yanru CAI ; Yao DU ; Zheng ZHI ; Bolin LI ; Qian YANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(8):128-136
ObjectiveTo explore the potential mechanism of Xianglian Huazhuo prescription (XLHZ) in treating chronic atrophic gastritis (CAG) by regulating cell cycle and inhibiting proliferation, using bioinformatics technology and animal experiments. MethodsDifferential expressed genes (DEGs) related to CAG were screened using GEO database and GEO2R tool. Weighted gene co-expression network analysis (WGCNA) was employed to search for hub genes of CAG. These hub genes were intersected with cell cycle proliferation based on GeneCards database. Eenrichment analysis of the intersecting genes was performed to obtain signaling pathways and biological processes related to CAG. Protein protein interaction (PPI) analysis of genes was conducted using the Protein Interaction Platform (STRING) database to search the super hub gene (hub 2.0), and animal experiments were conducted for further validation. Fourteen of 70 male Wistar rats were randomly selected as the normal group, and the remaining 56 rats were prepared by the combined modeling method of "starvation disorder+N-methyl-N-nitro-N-nitrosoguanidine (MNNG) + sodium salicylate". The successfully modeled rats were randomly divided into the model group, XLHZ-H, XLHZ-M, and XLHZ-L groups (36, 18, 9 g·kg-1, respectively), and Morodan group (1.4 g·kg-1). Each group was given corresponding intervention for 60 days. Hematoxylin-eosin (HE) staining was used to observe the histopathological changes of gastric mucosa in rats. The ultrastructure of gastric mucosal tissue cells was observed by transmission electron microscopy. The relative expression levels of TGF-β1, Smad2 and Smad3 proteins, S/G2/M phase marker geminin and proliferation marker MCM2 were detected by Western blot in gastric mucosal tissue, and Spearman correlation analysis was performed. ResultsA total of 15 hub 2.0 genes were identified, including TGF-β1, suggesting the involvement of the TGF-β1 signaling pathway in the CAG pathogenesis. Compared with the normal group, the expressions of TGF-β1, Smad2, geminin and MCM2 proteins in the gastric mucosa tissue of the model group were increased (P<0.05), and the expression of Smad3 protein was decreased (P<0.05). Compared with the model group, the expressions of TGF-β1 and geminin in the gastric mucosa were decreased in the drug groups (P<0.05). The XLHZ-M group, XLHZ-H group and Morodan group had significantly decreased protein expression of Smad2 and MCM2 (P<0.05). The protein expression of Smad3 was significantly increased in XLHZ-M, XLHZ-H, and Morodan groups (P<0.05). Spearman correlation analysis showed that Smad3 was negatively correlated with other indicators, and positively correlated with other indicators (P<0.01). ConclusionXLHZ may inhibit TGF-β1/Smads signaling pathway, regulate cell cycle, and inhibit proliferation in the treatment of CAG.
5.Analysis of Rheumatoid Arthritis and Periodontitis Multimorbidity from Perspective of Abnormal Collateral Theory
Xiaojing GUO ; Jiuli DING ; Hongyuan SUN ; Lei ZHANG ; Min LIU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):280-287
The multimorbidity of rheumatoid arthritis (RA) and periodontitis (PD) has drawn increasing attention, as both conditions are characterized by chronic inflammation, immune dysregulation, and progressive bone destruction. Modern research confirms that PD is a significant risk factor for RA development, and their coexistence mutually exacerbates disease progression. However, traditional Chinese medicine (TCM) currently lacks a systematic theoretical explanation for this complex multimorbid relationship. This study, based on the TCM theory of abnormal collateral, thoroughly examines the intrinsic connection between RA and PD multimorbidity, proposing "abnormal collateral as the pivot, with accumulated toxins eroding bone" as the core TCM pathogenesis. The research elucidates PD as the "origin of abnormal collateral", where its pathogens act as toxic factors that invade the joints through collaterals, triggering RA via mechanisms such as molecular mimicry. The dynamic pathological progression of RA-PD multimorbidity can be described as follows: the displacement of Ying and Wei at the microscopic level manifests as immune hyperactivation, leading to collateral malnutrition; heat-toxins traversing collaterals induce collateral hyperactivity, resulting in pathological angiogenesis; ultimately, toxin accumulation at the pivotal abnormal collateral site erodes bone, activating the receptor activator of nuclear factor kappa-B ligand (RANKL)-receptor activator of nuclear factor kappa-B (RANK) signaling pathway-driven osteoclast differentiation. This theoretical framework innovatively integrates modern findings in oral microbiology, immune-inflammation, and bone metabolism, offering a holistic and dynamic perspective to understand the complexity of multimorbidity. Given the limited efficacy of current periodontal treatments for RA and the scarcity of reported TCM compound interventions for multimorbidity, the abnormal collateral theory proposes a systematic intervention strategy centered on "governing diseases through collaterals and regulating collaterals with herbs", along with TCM therapeutic principles such as "unblocking, clearing, and nourishing collaterals". Potential herbal treatments for multimorbidity are also highlighted. Future research should focus on refining TCM syndrome patterns in multimorbid patients and leveraging omics technologies for deeper exploration, thereby providing a theoretical foundation and research direction for TCM in addressing complex multimorbid conditions.
6.Analysis of Rheumatoid Arthritis and Periodontitis Multimorbidity from Perspective of Abnormal Collateral Theory
Xiaojing GUO ; Jiuli DING ; Hongyuan SUN ; Lei ZHANG ; Min LIU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):280-287
The multimorbidity of rheumatoid arthritis (RA) and periodontitis (PD) has drawn increasing attention, as both conditions are characterized by chronic inflammation, immune dysregulation, and progressive bone destruction. Modern research confirms that PD is a significant risk factor for RA development, and their coexistence mutually exacerbates disease progression. However, traditional Chinese medicine (TCM) currently lacks a systematic theoretical explanation for this complex multimorbid relationship. This study, based on the TCM theory of abnormal collateral, thoroughly examines the intrinsic connection between RA and PD multimorbidity, proposing "abnormal collateral as the pivot, with accumulated toxins eroding bone" as the core TCM pathogenesis. The research elucidates PD as the "origin of abnormal collateral", where its pathogens act as toxic factors that invade the joints through collaterals, triggering RA via mechanisms such as molecular mimicry. The dynamic pathological progression of RA-PD multimorbidity can be described as follows: the displacement of Ying and Wei at the microscopic level manifests as immune hyperactivation, leading to collateral malnutrition; heat-toxins traversing collaterals induce collateral hyperactivity, resulting in pathological angiogenesis; ultimately, toxin accumulation at the pivotal abnormal collateral site erodes bone, activating the receptor activator of nuclear factor kappa-B ligand (RANKL)-receptor activator of nuclear factor kappa-B (RANK) signaling pathway-driven osteoclast differentiation. This theoretical framework innovatively integrates modern findings in oral microbiology, immune-inflammation, and bone metabolism, offering a holistic and dynamic perspective to understand the complexity of multimorbidity. Given the limited efficacy of current periodontal treatments for RA and the scarcity of reported TCM compound interventions for multimorbidity, the abnormal collateral theory proposes a systematic intervention strategy centered on "governing diseases through collaterals and regulating collaterals with herbs", along with TCM therapeutic principles such as "unblocking, clearing, and nourishing collaterals". Potential herbal treatments for multimorbidity are also highlighted. Future research should focus on refining TCM syndrome patterns in multimorbid patients and leveraging omics technologies for deeper exploration, thereby providing a theoretical foundation and research direction for TCM in addressing complex multimorbid conditions.
7.Effects of Xiebai San on the Morphological Structures of Lung and Intestinal Tissues and Expression Levels of PI3K and Akt in Rats with Allergic Asthma
Jing SONG ; Zongtong YANG ; Xiaojing LI ; Zifa LI ; Fengyun SU ; Dongchuan XU ; Zaiyun SUI
Laboratory Animal and Comparative Medicine 2026;46(2):191-204
ObjectiveTo investigate the mechanism by which Xiebai San regulates respiratory tract and intestinal mucosal immunity in rats with allergic asthma. MethodsForty male SD rats were randomly divided into four groups based on body weight: control group, model group, positive control group, and Xiebai San group. The model group, positive control group, and Xiebai San group were sensitized with ovalbumin to establish a rat model of allergic asthma. From day 21 (the aerosol challenge phase), each group received daily gavage interventions simultaneously: the positive control group was administered dexamethasone (0.068 mg/kg), the Xiebai San group received Xiebai San solution (2 g/mL, 11.3 mL/kg), while the control and model groups were given an equal volume of normal saline, once daily for 14 consecutive days. After euthanasia, lung and intestinal tissues were collected. Hematoxylin and eosin staining was used to observe histopathological changes. Transmission electron microscopy was employed to examine tissue ultrastructure. Immunohistochemistry was applied to detect the positive reaction areas of phosphatidyl-inositol 3-kinase (PI3K) and protein kinase B (Akt) proteins. Total protein and total RNA were extracted from lung and intestinal tissues, then the protein and mRNA expression levels of PI3K and Akt genes were detected by Western blotting and real-time quantitative PCR, respectively. ResultsHistopathological results showed alveolar emphysema accompanied by inflammatory cell infiltration, and intestinal mucosal injury with inflammatory cell infiltration in the model group as compared with the control group; the cellular structure of lung tissues was disrupted in the model group, with reduced organelles, while the ultrastructural lesions in the intestine were relatively mild. Compared with the model group, Xiebai San group exhibited milder pathological changes in lung tissues, with occasional alveolar wall damage and a small amount of inflammatory cell infiltration; the intestinal mucosal structure was improved, glands were arranged regularly, and pathological changes such as tissue loosening and inflammatory infiltration were alleviated; the cellular structure of lung tissues was relatively intact with reduced severity of lesions, and no ultrastructural pathological changes were observed in intestinal tissues. Immunohistochemistry and Western blotting results showed that compared with the control group, the specific positive reaction areas of PI3K and Akt in lung and intestinal tissues were significantly increased in the model group (all P<0.001); meanwhile, the protein expression levels of PI3K and Akt were significantly upregulated (all P<0.05). Compared with the model group, the positive area of Akt protein in lung tissue was significantly reduced in the Xiebai San group (P<0.001), and the positive area of PI3K in intestinal tissue was also significantly decreased (P<0.000 1). Additionally, the protein expression levels of PI3K and Akt in lung and intestinal tissues were significantly downregulated (all P<0.01). Real-time quantitative PCR results showed that compared with the control group, the mRNA expression levels of PI3K and Akt genes in lung and intestinal tissues were significantly elevated in the model group (all P<0.05). Compared with the model group, the mRNA expression levels of PI3K and Akt genes in lung and intestinal tissues were significantly reduced in the Xiebai San group (all P<0.05). ConclusionXiebai San exerts protective effects on rats with allergic asthma by inhibiting the expression of key nucleic acids and proteins in the PI3K-Akt signaling pathway in lung and intestinal tissues, improving the morphological structure of lung tissue, and maintaining intestinal mucosal integrity, and regulating intestinal mucosal immune function.
8.Construction and Validation of a Clinical Prediction Model for Inflammatory Remission Outcome of Bushen Zhiwang Decoction(补肾治尪汤)in the Treatment of Rheumatoid Arthritis with Liver and Kidney Deficiency Syndrome
Zihan WANG ; Xiaojing LIU ; Yanyu CHEN ; Tianyi LAN ; Huilan YANG ; Hongwei YU ; Qingwen TAO ; Yuan XU
Journal of Traditional Chinese Medicine 2026;67(5):523-533
ObjectiveTo construct and validate a clinical prediction model for inflammatory remission outcomes in rheumatoid arthritis (RA) patients with liver and kidney deficiency syndrome treated with Bushen Zhiwang Decoction (补肾治尪汤, BZD) based on metabolomics. MethodsA prospective cohort study was conducted, enrol-ling 60 RA patients with liver and kidney deficiency syndrome. All patients were treated with BZD and conventional-dose oral conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) for 12 months. Clinical data were collected, and the change in disease activity score in 28 joints (DAS28) after treatment compared with baseline (△DAS28) was used as the primary outcome and grouping criterion. Peripheral blood samples were collected before treatment to analyze plasma metabolites. Differential analysis and least absolute shrinkage and selection operator (LASSO) regression were used to preliminarily screen differential metabolites, followed by machine learning algorithms to further identify a core metabolite combination. Based on the expression levels of the core metabolite combination, a novel metabolite index, namely the metabolomics-based inflammatory remission score (Met-IRS), was calculated using standar-dized metabolite values, and its clinical applicability was evaluated. A clinical prediction model was constructed by integrating clinical characteristics and Met-IRS, and the model performance was assessed. ResultsAmong the 60 patients, those with △DAS28 ≥ 0.27 were assigned to the high inflammatory remission group, while those with △DAS28 < 0.27 were assigned to the low inflammatory remission group, with 30 cases in each group. Compared to the low inflammatory remission group, the high inflammatory remission group showed a higher frequency of methotrexate use and a lower positive rate of rheumatoid factor (RF) (P<0.05). Seven core metabolites were identified as the optimal combination, including mangiferic acid, fatty acid-hydroxy fatty acid ester 40∶6, fatty acid-hydroxy fatty acid ester 18∶0, fatty acid-hydroxy fatty acid ester 36∶1, glucosylceramide, lysophosphatidylcholine 22∶5, and pregnanetriol ketone. The calculated Met-IRS comprehensively reflected the characteristics of differential metabolites and demonstrated clinical applicability. Met-IRS was significantly higher in the high inflammatory remission group than in the low inflammatory remission group, and was positively correlated with high inflammatory remission outcomes (P<0.05). Based on the variables Met-IRS, methotrexate use, leflunomide use, and RF positivity, a clinical prediction model for inflammatory remission in RA treatment (Cj-RTRM) was constructed. Model performance evaluation demonstrated that the model had good clinical predictive ability, with an area under the receiver operating characteristic curve (AUC) of 0.880, sensitivity 0.967, specificity 0.700 and Youden's index 0.667. ConclusionThe clinical prediction model Cj-RTRM constructed based on the metabolomics-based inflammatory remission score Met-IRS can effectively predict clinical inflammatory remission outcomes in RA patients treated with BZD and accurately identify the advantageous population for this treatment. This model provides guiding evidence for dynamic inflammation monitoring, targeted management, and identification of populations with advantages in traditional Chinese medicine.
9.Relationship between childhood adversity and depression: cumulative effects, sensitive windows, and interactions with later environments
Juan WANG ; Xiaojing LI ; Wanjun GUO
Sichuan Mental Health 2026;39(2):106-111
Childhood adversity is a risk factor for developing depressive symptoms or suffering from depressive disorders across the life course. However, existing evidence has focused on the analysis of the association between childhood adversity and depression from a single theoretical perspective, and there is a lack of comprehensive understanding of its multiple action pathways. By systematically summarizing the cumulative risk model, sensitive-period model, recency model, risk chain model, and the stress sensitization, stress amplification, and stress inoculation hypotheses, as well as the emerging pubertal stress recalibration hypothesis, this article attempts to construct an integrated theoretical framework to elucidate the internal logical synergy among these models. Furthermore, by reviewing relevant empirical evidence, this article analyzes the applicability and limitations of different theoretical models in illustrating the underlying psychopathological mechanisms of depression. The current evidence suggests that the impact of childhood adversity on the risk of psychopathology may be driven by a complex dynamic process involving the interaction of exposure timing, cumulative load, response boundaries of biological systems, and modification by later environments. Future research should utilize longitudinal cohorts and multimodal data within a unified analytical framework to comprehensively examine the multiple pathways through which childhood adversity affects the risk of depression. This will provide a reference for precisely identifying high-risk populations, targeting "recalibration windows" represented by adolescence, developing focused intervention strategies, and ultimately blocking the cascading effects of early life adversity as early as possible. [Funded by the "Pioneer" and "Leading Goose" R&D program of Zhejiang Province (number, 2024C03006)]
10.Bacterial community characteristics in water from public baths in Shanghai and their association with Legionella pneumophila contamination based on 16S rRNA sequencing and random forest model
Lisha SHI ; Jian CHEN ; Xiaojing LI ; Yiming ZHENG ; Lijun ZHANG
Journal of Environmental and Occupational Medicine 2026;43(1):82-88
Background The contamination of public baths with Legionella pneumophila contamination has become a growing public health concern in recent years. However, research on its association with bacterial community characteristics in water samples remains limited. The integration of 16S rRNA sequencing and random forest modeling provides a new approach to elucidate the bacterial community characteristics of public bath water and their association with Legionella pneumophila contamination. Objective To investigate the bacterial community structure and diversity of public bath water in Shanghai, explore the association between Legionella pneumophila contamination and bacterial community characteristics, and identify key bacterial genera associated with contamination, thereby providing a scientific basis for formulating hygiene management regulations for public bath water. Methods From February to March 2023, water samples were collected from ten public baths in Shanghai which were selected based on business scale, regional distribution, and functional differences. Water quality parameters were evaluated, and the samples were categorized into Legionella-positive and Legionella-negative groups based on the detection results of Legionella pneumophila. The bacterial community structure, α-diversity, and β-diversity were analyzed using 16S rRNA sequencing. Redundancy analysis (RDA) was employed to examine the relationship between physicochemical factors and bacterial community diversity. A random forest model was employed to identify key bacterial genera distinguishing the two groups, with the importance of genera being evaluated based on the mean decrease accuracy (MDA). Results The oxygen consumption in the Legionella-positive group was significantly lower than that in the Legionella-negative group (mean values: 1.85 mg·L−1 vs. 6.81 mg·L−1, P< 0.05), while no significant differences were observed in other physicochemical indicators. The sequencing results revealed a total of 27 bacterial phyla and 454 bacterial genera, with Proteobacteria (63.00%) being the dominant phylum. The dominant genera included Pelomonas (8.50%), Acidovorax (8.13%), Mycobacterium (7.93%), and Acinetobacter (6.59%). The α-diversity analysis indicated that bacterial community richness (Chao1 and ACE indices) was significantly higher in the Legionella-positive group than in the Legionella-negative group (P<0.01). The β-diversity analysis showed no significant difference in the bacterial community structure between the two groups (P>0.05). The RDA analysis demonstrated that the bacterial community diversity was positively correlated with pH and negatively correlated with oxygen consumption and free residual chlorine. The RDA1 and RDA2 explained 23.92% and 21.30% of the bacterial community diversity, respectively. The random forest model identified 20 key genera significantly influencing the microbial community distribution between the two groups, including unclassified_Bradyrhizobiaceae (MDA=2.42), Meiothermus (MDA=2.37), and Flavihumibacter (MDA=2.26). Conclusion The diversity of bacterial communities in public bath water is influenced by pH, oxygen consumption, and free residual chlorine. Samples contaminated with Legionella pneumophila exhibit greater microbial richness and contain characteristic key bacterial genera that contribute to community differences. Machine learning random forest technology helps identify these distinctive key bacterial genera. The findings provide a basis for carrying out risk early warning strategies in such settings.


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