Oral biofilm: Systemic and psychiatric implications
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Abstract
The oral cavity, being an excellent residence for a plethora of microbes, forms biofilm in various compartments. Acting as a preferable habitat with rich nutrients and other facilities, it hosts an array of bacteria, along with members of fungi, archaea, protozoa, and viruses that naturally or accidentally reside in the oral cavity. The dysbiosis of oral microbiota induces diseases and disorders in various physiological systems, including cardiovascular, respiratory, digestive, excretory, reproductive, immune, and neurological systems, leading to various diseases and even cancer. Neurological and other disorders contribute to several psychiatric ailments. Hence, oral ill health not only leads to diseases such as periodontitis and tooth loss but might also result in unpredictable diseases, including carcinogenesis. Oral problems also lead to cognitive dysfunction, dementia, and other psychosocial embarrassments. The induction of these deadly diseases might be predicted by analyzing the oral microbial composition; therefore, the overabundance of microbes such as Porphyromonas gingivalis and Fusobacterium in the oral microbiome might be used as the bioindicator of various diseases, proving the unequivocal role of oral biofilm in the onset of various systemic and psychiatric ailments.
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Aas, J. A., Paster, B. J., Stokes, L. N., Olsen, I., and Dewhirst, F. E. (2005). Defining the normal bacterial flora of the oral cavity. Journal of Clinical Microbiology, 43(11), 5721–5732.
Albuquerque-Souza, E., and Sahingur, S. E. (2022). Periodontitis, chronic liver diseases, and the emerging oral‐gut‐liver axis. Periodontology 2000, 89(1), 125–141.
Alves, R. T., and Ribeiro, R. A. (2006). Relationship between maternal periodontal disease and birth of preterm low weight babies. Brazilian Oral Research, 20(4), 318–323.
Arweiler, N. B., and Netuschil, L. (2016). The oral microbiota. In Microbiota of the Human Body: Implications in Health and Disease (Schwiertz, A., Ed.), pp. 45–60. Cham: Springer.
Atarashi, K., Suda, W., Luo, C., Kawaguchi, T., Motoo, I., Narushima, S., Kiguchi, Y., Yasuma, K., Watanabe, E., Tanoue, T., Thaiss, C. A., Sato, M., Toyooka, K., Said, H. S., Yamagami, H., Rice, S. A., Gevers, D., Johnson, R. C., Segre, J. A., Chen, K., Kolls, J. K., Elinav, E., Morita, H., Xavier, R. J., Hattori, M., and Honda, K. (2017). Ectopic colonization of oral bacteria in the intestine drives TH1 cell induction and inflammation. Science, 358, 359–365.
Avila, M., Ojcius, D. M., and Yilmaz, Ö. (2009). The oral microbiota: Living with a permanent guest. DNA and Cell Biology, 28(8), 405–411.
Bahekar, A. A., Singh, S., Saha, S., Molnar, J., and Arora, R. (2007). The prevalence and incidence of coronary heart disease is significantly increased in periodontitis: A meta-analysis. American Heart Journal, 154(5), 830–837.
Barutta, F., Bellini, S., Durazzo, M., and Gruden, G. (2022). Novel insight into the mechanisms of the bidirectional relationship between diabetes and periodontitis. Biomedicines, 10(1), 178.
Beck, J. D., Pankow, J., Tyroler, H. A., and Offenbacher, S. (1999). Dental infections and atherosclerosis. American Heart Journal, 138(5), S528–S533.
Biswas, L. and Götz, F. (2022). Molecular mechanisms of Staphylococcus and Pseudomonas interactions in cystic fibrosis. Frontiers in Cellular and Infection Microbiology, 11, 824042.
Bonaz, B., Bazin, T., and Pellissier, S. (2018). The vagus nerve at the interface of the microbiota-gut-brain axis. Frontiers in Neuroscience, 12, 49.
Bostanci, N., Krog, M. C., Hugerth, L. W., Bashir, Z., Fransson, E., Boulund, F., Belibasakis, G. N., Wannerberger, K., Engstrand, L., Nielsen, H. S., and Schuppe-Koistinen, I. (2021). Dysbiosis of the human oral microbiome during the menstrual cycle and vulnerability to the external exposures of smoking and dietary sugar. Frontiers in Cellular and Infection Microbiology, 11, 625229.
Bowland, G. B., and Weyrich, L. S. (2022). The oral-microbiome-brain axis and neuropsychiatric disorders: An anthropological perspective. Frontiers in Psychiatry, 13, 810008.
Brennan, C. A., and Garrett, W. S. (2019). Fusobacterium nucleatum-symbiont, opportunist and oncobacterium. Nature Reviews Microbiology, 17, 156–166.
Bui, F. Q., Almeida-da-Silva, C. L. C., Huynh, B., Trinh, A., Liu, J., Woodward, J., Asadi, H., and Ojcius, D. M. (2019). Association between periodontal pathogens and systemic disease. Biomedical Journal, 42(1), 27–35.
Bulgart, H. R., Neczypor, E. W., Wold, L. E., and Mackos, A. R. (2020). Microbial involvement in Alzheimer disease development and progression. Molecular Neurodegeneration, 15, 42.
Chattopadhyay, I., Verma, M., and Panda, M. (2019). Role of oral microbiome signatures in diagnosis and prognosis of oral cancer. Technology in Cancer Research and Treatment, 18, 1533033819867354.
Chhibber-Goel, J., Singhal, V., Bhowmik, D., Vivek, R., Parakh, N., Bhargava, B., and Sharma, A. (2016). Linkages between oral commensal bacteria and atherosclerotic plaques in coronary artery disease patients. NPJ Biofilms and Microbiomes, 2, 7.
Chukkapalli, S. S., Rivera, M. F., Velsko, I. M., Lee, J. Y., Chen, H., Zheng, D., Bhattacharyya, I., Gangula, P. R., Lucas, A. R., and Kesavalu, L. (2014). Invasion of oral and aortic tissues by oral spirochete Treponema denticola in ApoE−/− mice causally links periodontal disease and atherosclerosis. Infection and Immunity, 82(5), 1959–1967.
Coit, P., and Sawalha, A. H. (2016). The human microbiome in rheumatic autoimmune diseases: A comprehensive review. Clinical Immunology, 170, 70–79.
Contaldo, M., Fusco, A., Stiuso, P., Lama, S., Gravina, A. G., Itro, A., Federico, A., Itro, A., Dipalma, G., Inchingolo, F., Serpico, R., and Donnarumma, G. (2021). Oral micro-biota and salivary levels of oral pathogens in gastro-intestinal diseases: Current knowledge and exploratory study. Microorganisms, 9(5), 1064.
Contaldo, M., Itro, A., Lajolo, C., Gioco, G., Inchingolo, F., and Serpico, R. (2020). Overview on osteoporosis, periodontitis and oral dysbiosis: The emerging role of oral microbiota. Applied Sciences, 10(17), 6000.
Cornejo Ulloa, P., Krom, B. P., and van der Veen, M. H. (2021). Sex steroid hormones as a balancing factor in oral host microbiome interactions. Frontiers in Cellular and Infection Microbiology, 11, 714229.
Deo, P. N., and Deshmukh, R. (2019). Oral microbiome: Unveiling the fundamentals. Journal of Oral and Maxillofacial Pathology, 23(1), 122–128.
Dewhirst, F. E., Chen, T., Izard, J., Paster, B. J., Tanner, A. C. R., Yu, W. H., Lakshmanan, A., and Wade, W. G. (2010). The human oral microbiome. Journal of Bacteriology, 192(19), 5002–5017.
Dominy, S. S., Lynch, C., Ermini, F., Benedyk, M., Marczyk, A., Konradi, A., Nguyen, M., Haditsch, U., Raha, D., Griffin, C., Holsinger, L. J., Arastu-Kapur, S., Kaba, S., Lee, A., Ryder, M. I., Potempa, B., Mydel, P., Hellvard, A., Adamowicz, K., Hasturk, H., Walker, G. D., Reynolds, E. C., Faull, R. L. M., Curtis, M. A., Dragunow, M., and Potempa, J. (2019). Porphyromonas gingivalis in Alzheimer’s disease brains: Evidence for disease causation and treatment with small-molecule inhibitors. Science Advances, 5(1), eaau3333.
Donlan, R. M., and Costerton, J. W. (2002). Biofilms: survival mechanisms of clinically relevant microorganisms. Clinical Microbiology Reviews, 15(2), 167–193.
Falcao, A., and Bullón, P. (2019). A review of the influence of periodontal treatment in systemic diseases. Periodontology 2000, 79(1), 117–128.
Flak, M. B., Colas, R. A., Muñoz-Atienza, E., Curtis, M. A., Dalli, J., and Pitzalis, C. (2019). Inflammatory arthritis disrupts gut resolution mechanisms, promoting barrier breakdown by Porphyromonas gingivalis. JCI Insight, 4(13), e125191.
Fu, Z., Cheng, X., Kuang, J., Feng, H., Chen, L., Liang, J., Shen, X., Yuen, S., Peng, C., Shen, B., Jin, Z., and Qiu, W. (2018). CQ sensitizes human pancreatic cancer cells to gemcitabine through the lysosomal apoptotic pathway via reactive oxygen species. Molecular Oncology, 12(4), 529–544.
Fuggle, N. R., Smith, T. O., Kaul, A., and Sofat, N. (2016). Hand to mouth: A systematic review and meta-analysis of the association between rheumatoid arthritis and periodontitis. Frontiers in Immunology, 7, 80.
Goellner, E., and Rocha, C. E. (2020). Anatomy of trigeminal neuromodulation targets: from periphery to the brain. In Neuromodulation for Facial Pain (Slavin K. V., Ed.), pp. 18–34. Basel, Switzerland: Karger AG.
Graves, D. T., Corrêa, J. D., and Silva, T. A. (2019). The oral microbiota is modified by systemic diseases. Journal of Dental Research, 98(2), 148–156.
Grivennikov, S. I., Greten, F. R., and Karin, M. (2010). Immunity, inflammation, and cancer. Cell, 140(6), 883–899.
Hall-Stoodley, L., and Stoodley, P. (2002). Developmental regulation of microbial biofilms. Current Opinion in Biotechnology, 13(3), 228–233.
Hashioka, S., Inoue, K., Hayashida, M., Wake, R., Oh-Nishi, A., and Miyaoka, T. (2018). Implications of systemic inflammation and periodontitis for major depression. Frontiers in Neuroscience, 12, 483.
Idris, A., Hasnain, S. Z., Huat, L. Z., and Koh, D. (2017). Human diseases, immunity and the oral microbiota –Insights gained from metagenomic studies. Oral Science International, 14(2), 27–32.
Isola, G., Williams, R. C., Lo Gullo, A., Ramaglia, L., Matarese, M., Iorio-Siciliano, V., Cosio, C., and Matarese, G. (2017). Risk association between scleroderma disease characteristics, periodontitis, and tooth loss. Clinical Rheumatology, 36, 2733–2741.
Ito, M., Kanno, S., Nosho, K., Sukawa, Y., Mitsuhashi, K., Kurihara, H., Igarashi, H., Takahashi, T., Tachibana, M., Takahashi, H., Yoshii, S., Takenouchi, T., Hasegawa, T., Okita, K., Hirata, K., Maruyama, R., Suzuki, H., Imai, K., Yamamoto, H., and Shinomura, Y. (2015). Association of Fusobacterium nucleatum with clinical and molecular features in colorectal serrated pathway. International Journal of Cancer, 137(6), 1258–1268.
Jia, G., Zhi, A., Lai, P. F. H., Wang, G., Xia, Y., Xiong, Z., Zhang, H., Che, N., and Ai, L. (2018). The oral microbiota–A mechanistic role for systemic diseases. British Dental Journal, 224, 447–455.
Jiao, J., Bie, M., Xu, X., Duan, D., Li, Y., Wu, Y., and Zhao, L. (2022). Entamoeba gingivalis is associated with periodontal conditions in Chinese young patients: A cross-sectional study. Frontiers in Cellular and Infection Microbiology, 12, 1020730.
Kaisare, S., Rao, J., and Dubashi, N. (2007). Periodontal disease as a risk factor for acute myocardial infarction. A case-control study in Goans highlighting a review of the literature. British Dental Journal, 203, E5.
Karpiński, T. M. (2019). Role of oral microbiota in cancer development. Microorganisms, 7(1), 20.
Kobayashi, R., Ogawa, Y., Hashizume-Takizawa, T., and Kurita-Ochiai, T. (2020). Oral bacteria affect the gut microbiome and intestinal immunity. Pathogens and Disease, 78(3), ftaa024.
Kriebel, K., Hieke, C., Müller-Hilke, B., Nakata, M., and Kreikemeyer, B. (2018). Oral biofilms from symbiotic to pathogenic interactions and associated disease-connection of periodontitis and rheumatic arthritis by peptidylarginine deiminase. Frontiers in Microbiology, 9, 53.
Li, B., Ge, Y., Cheng, L., Zeng, B., Yu, J., Peng, X., Zhao, J., Li, W., Ren, B., Li, M., Wei, H., and Zhou, X. (2019). Oral bacteria colonize and compete with gut microbiota in gnotobiotic mice. International Journal of Oral Science, 11, 10.
Li, X., Kolltveit, K. M., Tronstad, L., and Olsen, I. (2000). Systemic diseases caused by oral infection. Clinical Microbiology Reviews, 13(4), 547–558.
Lin, D., Hutchison, K. E., Portillo, S., Vegara, V., Ellingson, J. M., Liu, J., Krauter, K. S., Carroll-Portillo, A., and Calhoun, V. D. (2019). Association between the oral microbiome and brain resting state connectivity in smokers. NeuroImage, 200, 121–131.
Lin, W., Jiang, W., Hu, X., Gao, L., Ai, D., Pan, H., Niu, C., Yuan, K., Zhou, X., Xu, C., and Huang, Z. (2018). Ecological shifts of supragingival microbiota in association with pregnancy. Frontiers in Cellular and Infection Microbiology, 8, 24.
Liu, S., Dashper, S. G., and Zhao, R. (2023). Association between oral bacteria and Alzheimer’s disease: A systematic review and meta-analysis. Journal of Alzheimer's Disease, 91(1), 129–150.
Lu, H., Ren, Z., Li, A., Zhang, H., Jiang, J., Xu, S., Luo, Q., Zhou, K., Sun, X., Zheng, S., and Li, L. (2016). Deep sequencing reveals microbiota dysbiosis of tongue coat in patients with liver carcinoma. Scientific Reports, 6, 33142.
Macklis, P., Adams, K., Kaffenberger, J., Kumar, P., Krispinsky, A., and Kaffenberger, B. (2020). The association between oral health and skin disease. The Journal of Clinical and Aesthetic Dermatology, 13(6), 48–53.
Malhotra, T. (2019). Population and oral hygiene (world population day editorial comment). International Healthcare Research Journal, 3(3), 96–98.
Marsh, P. D. (2010). Microbiology of dental plaque biofilms and their role in oral health and caries. Dental Clinics, 54(3), 441–454.
Martini, A. M., Moricz, B. S., Ripperger, A. K., Tran, P. M., Sharp, M. E., Forsythe, A. N., Kulhankova, K., Salgado-Pabón, W., and Jones, B. D. (2020). Association of novel Streptococcus sanguinis virulence factors with pathogenesis in a native valve infective endocarditis model. Frontiers in Microbiology, 11, 10.
Martínez, M., Postolache, T. T., García-Bueno, B., Leza, J. C., Figuero, E., Lowry, C. A., and Malan-Müller, S. (2022). The role of the oral microbiota related to periodontal diseases in anxiety, mood and trauma-and stress-related disorders. Frontiers in Psychiatry, 12, 814177.
Mason, M. R., Nagaraja, H. N., Camerlengo, T., Joshi, V., and Kumar, P. S. (2013). Deep sequencing identifies ethnicity-specific bacterial signatures in the oral microbiome. PloS ONE, 9(6), e99933.
Mathur, V. P., and Dhillon, J. K. (2018). Dental caries: a disease which needs attention. The Indian Journal of Pediatrics, 85, 202–206.
McCracken, B. A., and Garcia, M. N. (2021). Phylum Synergistetes in the oral cavity: A possible contributor to periodontal disease. Anaerobe, 68, 102250.
Mitchell‐Lewis, D., Engebretson, S. P., Chen, J., Lamster, I. B., and Papapanou, P. N. (2001). Periodontal infections and pre‐term birth: early findings from a cohort of young minority women in New York. European Journal of Oral Sciences, 109(1), 34–39.
Mohammed, H., Varoni, E. M., Cochis, A., Cordaro, M., Gallenzi, P., Patini, R., Staderini, E., Lajolo, C., Rimondini, L., and Rocchetti, V. (2018). Oral dysbiosis in pancreatic cancer and liver cirrhosis: A review of the literature. Biomedicines, 6(4), 115.
Nakano, K., Nomura, R., and Ooshima, T. (2008). Streptococcus mutans and cardiovascular diseases. Japanese Dental Science Review, 44(1), 29–37.
Nagarajan, M., Prabhu, V. R., and Kamalakkannan, R. (2018). Metagenomics: Implications in oral health and disease. In Metagenomics (Nagarajan, M., Ed.), pp. 179–195. London: Academic Press.
Nikolaeva, E. N., Tsarev, V. N., Tsareva, T. V., Ippolitov, E. V., and Arutyunov, S. D. (2019). Interrelation of cardiovascular diseases with anaerobic bacteria of subgingival biofilm. Contemporary Clinical Dentistry, 10(4), 637–642.
Niswade, G. (2022). Biofilm-The mystery of the oral cavity! Journal of Positive School Psychology, 6(2), 6033–6038.
Öğrendik, M. (2017). Periodontal pathogens in the etiology of pancreatic cancer. Gastrointestinal Tumors, 3(3–4), 125–127.
Olsen, I., and Hicks, S. D. (2020). Oral microbiota and autism spectrum disorder (ASD). Journal of Oral Microbiology, 12(1), 1702806.
Paju, S., and Scannapieco, F. A. (2007). Oral biofilms, periodontitis, and pulmonary infections. Oral Diseases, 13(6), 508–512.
Park, S.-Y., Hwang, B.-O., Lim, M., Ok, S.-H., Lee, S.-K., Chun, K.-S., Park, K.-K., Hu, Y., Chung, W.-Y., and Song, N.-Y. (2021). Oral-gut microbiome axis in gastrointestinal disease and cancer. Cancers, 13(9), 2124.
Peng, X., Cheng, L., You, Y., Tang, C., Ren, B., Li, Y., Xu, X., and Zhou, X. (2022). Oral microbiota in human systematic diseases. International Journal of Oral Science, 14, 14.
Perera, M., Al-Hebshi, N. N., Speicher, D. J., Perera, I., and Johnson, N. W. (2016). Emerging role of bacteria in oral carcinogenesis: A review with special reference to perio-pathogenic bacteria. Journal of Oral Microbiology, 8(1), 32762.
Preshaw, P. M., and Bissett, S. M. (2019). Periodontitis and diabetes. British Dental Journal, 227, 577–584.
Priyanka, S., Koteshwara, S., and Subappa, A. (2019). Prevalence of maternal periodontitis and its association with preterm and low birth weight infants: A hospital-based study. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, 8(5), 1767–1775.
Pu, C. Y., Seshadri, M., Manuballa, S., and Yendamuri, S. (2020). The oral microbiome and lung diseases. Current Oral Health Reports, 7, 79–86.
Qin, N., Yang, F., Li, A., Prifti, E., Chen, Y., Shao, L., Guo, J., Le Chatelier, E., Yao, J., Wu, L., Zhou, J., Ni, S., Liu, L., Pons, N., Batto, J. M., Kennedy, S. P., Leonard, P., Yuan, C., Ding, W., Chen, Y., Hu, X., Zheng, B., Qian, G., Xu, W., Ehrlich, S. D., Zheng, S., and Li, L. (2014). Alterations of the human gut microbiome in liver cirrhosis. Nature, 513, 59–64.
Ramadan, D. E., Hariyani, N., Indrawati, R., Ridwan, R. D., and Diyatri, I. (2020). Cytokines and chemokines in periodontitis. European Journal of Dentistry, 14(3), 483–495.
Ray, R. R. (2022). Dental biofilm: Risks, diagnostics and management. Biocatalysis and Agricultural Biotechnology, 43, 102381.
Samaranayake, L., and Matsubara, V. H. (2017). Normal oral flora and the oral ecosystem. Dental Clinics, 61(2), 199–215.
Santosh, R. A. B., Muddana, K., and Bakki, S. R. (2021). Fungal infections of oral cavity: diagnosis, management, and association with COVID-19. SN Comprehensive Clinical Medicine, 3, 1373–1384.
Santosh, A. B. R., and Muddana, K. (2020). Viral infections of oral cavity. Journal of Family Medicine and Primary Care, 9(1), 36–42.
Sarkar, P., Malik, S., Laha, S., Das, S., Bunk, S., Ray, J. G., Chatterjee, R., and Saha, A. (2021). Dysbiosis of oral microbiota during oral squamous cell carcinoma development. Frontiers in Oncology, 11, 614448.
Sethi, S., Wrona, C., Eschberger, K., Lobbins, P., Cai, X., and Murphy, T. F. (2008). Inflammatory profile of new bacterial strain exacerbations of chronic obstructive pulmonary disease. American Journal of Respiratory and Critical Care Medicine, 177, 491–497.
Sharma, N., Bhatia, S., Sodhi, A. S., and Batra, N. (2018). Oral microbiome and health. AIMS Microbiology, 4(1), 42–46.
Simpson, C. A., Adler, C., du Plessis, M. R., Landau, E. R., Dashper, S. G., Reynolds, E. C., Schwartz, O. S., and Simmons, J. G. (2020). Oral microbiome composition, but not diversity, is associated with adolescent anxiety and depression symptoms. Physiology and Behavior, 226, 113126.
Tian, J., Liu, C., Zheng, X., Jia, X., Peng, X., Yang, R., Zhou, X., and Xu, X. (2020). Porphyromonas gingivalis induces insulin resistance by increasing BCAA levels in mice. Journal of Dental Research, 99(7), 839–846.
Tuominen, H., and Rautava, J. (2021). Oral microbiota and cancer development. Pathobiology, 88(2),116–126.
Valimaa, H., Savolainen, S., Soukka, T., Silvoniemi, P., Makela, S., Kujari, H., Gustafsson, J. A., and Laine, M. (2004). Estrogen receptor-beta is the predominant estrogen receptor subtype in human oral epithelium and salivary glands. Journal of Endocrinology, 180, 55–62.
Vieira, A. T., Castelo, P. M., Ribeiro, D. A., and Ferreira, C. M. (2017). Influence of oral and gut microbiota in the health of menopausal women. Frontiers in Microbiology, 8, 298600.
Wade, W. G. (2013). The oral microbiome in health and disease. Pharmacological Research, 69(1), 137–143.
Wahid, A., Chaudhry, S., Ehsan, A., Butt, S., and Khan, A. A. (2013). Bidirectional relationship between chronic kidney disease and periodontal disease. Pakistan Journal of Medical Sciences, 29(1), 211–215.
Wang, R. R., Xu, Y. S., Ji, M. M., Zhang L., Dong, L., Lang, Q., Zhang, L., Ji, G., and Liu, B. C. (2019). Association of the oral microbiome with the progression of impaired fasting glucose in a Chinese elderly population. Journal of Oral Microbiology, 11(1), 1605789.
Watanabe, I., Kuriyama, N., Miyatani, F., Nomura, R., Naka, S., Nakano, K., Ihara, M., Iwai, K. Matsui, D., Ozaki, E., Koyama, T., Nishigaki, M., Yamamoto, T., Tamura, A., Mizuno, Y., Akazawa, K., Takada, A. Takeda, K., Yamada, K. Nakagawa, M., Tanaka, T., Kanamura, N., Friedland, R. P., and Watanabe, Y. (2016). Oral Cnm-positive Streptococcus mutans expressing collagen binding activity is a risk factor for cerebral microbleeds and cognitive impairment. Scientific Reports, 6, 38561.
Wingfield, B., Lapsley, C., McDowell, A., Miliotis, G., McLafferty, M., O’Neill, S. M., Coleman, S., McGinnity, T. M., Bjourson, A. J., and Murray, E. K. (2021). Variations in the oral microbiome are associated with depression in young adults. Scientific Reports, 11(1), 15009.
Yan, X., Yang, M., Liu, J., Gao, R., Hu, J., Li, J., Zhang, L., Shi, Y., Guo, H., Cheng, J., Razi, M., Pang, S., Yu, X., and Hu, S. (2015). Discovery and validation of potential bacterial biomarkers for lung cancer. American Journal of Cancer Research, 5(10), 3111–3122.
Yaseen, A., Mahafzah, A., Dababseh, D., Taim, D., Hamdan, A. A., Al-Fraihat, E., Hassona, Y., Şahin, G. Ö., Santi-Rocca, J., and Sallam, M. (2021). Oral colonization by Entamoeba gingivalis and Trichomonas tenax: A PCR-based study in health, gingivitis, and periodontitis. Frontiers in Cellular and Infection Microbiology, 11, 782805.
Ye, C., and Kapila, Y. (2021). Oral microbiome shifts during pregnancy and adverse pregnancy outcomes: Hormonal and immunologic changes at play. Periodontology 2000, 87(1), 276–281.
Zarco, M. F., Vess, T. J., and Ginsburg, G. S. (2012). The oral microbiome in health and disease and the potential impact on personalized dental medicine. Oral Diseases, 18(2), 109–120.
Zhang, S., Kong, C., Yang, Y., Cai, S., Li, X., Cai, G., and Ma, Y. (2020). Human oral microbiome dysbiosis as a novel non-invasive biomarker in detection of colorectal cancer. Theranostics, 10(25), 11595–11606.
Zhao, H., Chu, M., Huang, Z., Yang, X., Ran, S., Hu, B., Zhang, C., and Liang, J. (2017). Variations in oral microbiota associated with oral cancer. Scientific Reports, 7, 11773.
Zhou, S., Gravekamp, C., Bermudes, D., and Liu, K. (2018). Tumour-targeting bacteria engineered to fight cancer. Nature Reviews Cancer, 18, 727–743.
Zorba, M., Melidou, A., Patsatsi, A., Ioannou, E., and Kolokotronis, A. (2020). The possible role of oral microbiome in autoimmunity. International Journal of Women's Dermatology, 6(5), 357–364.