Intraoral administration of probiotics and postbiotics: An overview of microorganisms and formulation strategies

Abstract The last decade provided significant advances in the understanding of microbiota and its role in human health. Probiotics are live microorganisms with proven benefits for the host and were mostly studied in the context of gut health, but they can also confer significant benefits for oral health, mainly in the treatment of gingivitis. Postbiotics are cell-free extracts and metabolites of microorganisms which can provide additional preventive and therapeutic value for human health. This opens opportunities for new preventive or therapeutic formulations for oral administration. The microorganisms that colonize the oral cavity, their role in oral health and disease, as well as the probiotics and postbiotics which could have beneficial effects in this complex environment were discussed. The aim of this study was to review, analyse and discuss novel probiotic and postbiotic formulations intended for oral administration that could be of great preventive and therapeutic importance. A special attention has been put on the formulation of the pharmaceutical dosage forms that are expected to provide new benefits for the patients and technological advantages relevant for industry. An adequate dosage form could significantly enhance the efficiency of these products.

Dental consensus on HSCT - Part II: dental Care during HSCT

ABSTRACT During the state of immune vulnerability in hematopoietic stem cell transplantation (HSCT), the patient has an increased risk of developing a vast number of complications, including severe problems in the oral cavity. These situations require professional oral care to act in the diagnosis and treatment of these conditions, as well as to develop prevention protocols to minimize patient's complications. Oral mucositis, opportunistic infections, bleeding, specific microbiota, taste, and salivary alterations are complications that can occur during HSCT and interfere with various aspects, such as pain control, oral intake, nutrition, bacteremia and sepsis, days of hospitalization and morbidity. Several guidelines have been published to address the role of professional oral care during the HSCT, we describe a consensus regarding these recommendations.

Research progress on the pathogenesis of Alzheimer disease and microbes / 上海预防医学

Alzheimer disease （AD） is a progressive neurodegenerative disease that often occurs in the elderly. The main symptoms of AD patients are cognitive decline， especially memory deficits， communication problems， impaired performance of activities of daily living， and other behavioral and psychological abnormalities. AD is generally divided into familial AD and sporadic AD. The signature features of AD are the presence of amyloid-beta proteins in extracellular plaques. Senile plaques formed by accumulation of Aβ insoluble fragments and intracellular accumulation of highly phosphorylated tau are neurofibrillary tangles. There is a lot of scientific evidence to confirm that the development of the two signature features of AD may be related to naturally occurring microbes in the human body. This paper reviews the mechanism of intestinal， oral and fungal microbiota involved in the development and progression of AD.

Pediatric inflammatory bowel disease and oral microbiota / 国际儿科学杂志

The oral cavity is continuous with the gastrointestinal tract and oral health may be closely linked with the overall health of the gastrointestinal tract.Inflammatory bowel disease(IBD)is an intestinal disorder characterized by chronic inflammation of unknown etiology, affected by host genetics, immunoregulation, daily diet, and the gut microbiota.Recent studies of the microbiome in IBD suggest that translocation of oral microbes to the gut may be a common feature of the microbial dysbiosis which is a signature of both pediatric Crohn′s disease and ulcerative colitis.Murine studies suggest that translocation of oral bacteria and yeasts to the lower gastrointestinal tract may trigger inflammation in susceptible hosts, providing a mechanistic link to the development of IBD.Oral microbiota may play an important role in the development of IBD.This article reviews the relationship between oral microbiota and pediatric IBD.

Microbioma oral: variabilidad entre regiones y poblaciones / Oral Microbiome: Variability Between Regions and Populations

Resumen De acuerdo con la Organización Mundial de la Salud (OMS), 3.58 billones de personas son afectadas por desórdenes orales, donde la caries, seguida de la enfermedad periodontal son las más frecuentes y las principales causas de daño al tejido pulpar y pérdida de órganos dentales. En México, el Sistema de Vigilancia Epidemiológica de Patologías Bucales (SIVEPAB) reportó que el 53% de la población se ve afectada por algún grado de enfermedad periodontal, mientras que en promedio la caries afecta al 93.3% de la población de entre 20 a 85 años y más, así como a alrededor del 50.0% de niños y adolescentes, por lo que ambos padecimientos son considerados un problema de salud pública importante en este país. Adicionalmente, se sabe que el microbioma oral humano está asociado con la salud y la enfermedad bucodental. Entre los géneros bacterianos que comúnmente habitan la cavidad oral humana destacan Streptococcus spp., Lactobacillus spp. y Porphyromonas spp. que, a través del desequilibrio del microbioma oral (disbiosis), se asocian con la caries o la enfermedad periodontal. En vista de que estamos constantemente expuestos a este tipo de infecciones crónicas inflamatorias, se sabe que las bacterias orales se trasladan a otras partes del cuerpo contribuyendo al desarrollo y exacerbación de la inflamación sistémica y otras enfermedades. Ya que existen factores como la ubicación geográfica, además de la disbiosis, la edad, la dieta y la genética, que influyen en la variabilidad del microbioma humano. Es importante analizar la diversidad del microbioma oral desde esta perspectiva, ya que el conocimiento que se tiene hasta el momento aún es escaso; por lo anterior se realizó una búsqueda de artículos publicados entre 2010 y 2020 en poblaciones de Asia, África, América y Europa, con el fin de responder la siguiente pregunta: ¿el factor geográfico tiene un impacto en la composición de la variabilidad del microbioma oral humano?

Abstract According to the World Health Organization (WHO), 3.58 billion people were affected by oral disorders, where caries, followed by periodontal disease are the most frequent and the main causes of damage to pulp tissue and loss of dental organs. In Mexico, the Epidemiological Surveillance System for Oral Pathologies (SIVEPAB) reported that 53% of the population is affected by some degree of periodontal disease, while on average caries affects 93.3% of the population between 20 and 85 years old and older, as well as about 50.0% of children and adolescents, so both conditions are considered an important public health problem in this country. Additionally, the human oral microbiome is known to be associated with oral health and disease. An imbalance in the oral microbiome (dysbiosis) can result in the proliferation of Streptococcus mutans and Porphyromonas gingivalis, linked to caries and periodontal disease. The latter two conditions, the most prevalent oral diseases worldwide, are the main causes of damage to pulp tissue and loss of dental organs. In the presence of these pathologies, constant exposure to the corresponding inflammatory chronic infection could lead to the translocation of oral bacteria to other parts of the body, where they may contribute to the development and/or exacerbation of systemic inflammation and trigger disease. Since age, diet, genetics, and geographical location are known to influence the variability of the human microbiome, it is important to analyze differences in the oral microbiome between distinct populations. Up to now, little attention has been given to this task. The current review carried out for articles published between 2010 and 2020 and describes the human oral microbiome in populations of Asia, Africa, America and Europa, to explore whether geographical differences have an impact on the variability of the human oral microbiome.

Relación entre la disbiosis de la microbiota oral y la enfermedad cardiovascular aterosclerótica / Relationship between oral microbiota dysbiosis and the atherosclerotic cardiovascular disease

Resumen Considerando la alta incidencia de las enfermedades cardiovasculares (ECV) en México y el mundo, la presente revisión proporciona un panorama general sobre la relación entre el desarrollo de periodontitis y la patogenia de estas enfermedades, describiendo aspectos sobre la alteración de la microbiota oral y los mecanismos asociados con el establecimiento de la respuesta inmunitaria local y sistémica en los pacientes con ECV. Además, proporciona las bases para considerar el análisis de la microbiota de la cavidad oral como un blanco terapéutico potencialmente útil en la regulación de la respuesta inmunitaria, lo que permitiría conseguir mejores pronósticos en pacientes con ECV.

Abstract Considering the high incidence of cardiovascular disease (CVD) worldwide, the present review provides a general panorama of the relation between the pathogenesis of these diseases and the development of periodontitis. Specific associations are described between an altered oral microbiota (and associated mechanisms) and the local and systemic immune response in patients with CVD. Additionally, the basis is established for considering an imbalance in the microbiota of the oral cavity as a potentially useful therapeutic target for the regulation of the immune response, which could possibly allow for better therapeutic outcomes in the case of patients with CVD.

Research progress on the effect of radiotherapy of nasopharyngeal carcinoma and head and neck cancer on dental hard tissues and oral microbiota / 中华放射肿瘤学杂志

Nasopharyngeal carcinoma and head and neck cancer are the most common malignant tumors in clinical practice. As the most common treatment for nasopharyngeal carcinoma and head and neck cancer, radiotherapy will inevitably cause damage to normal structures such as dental hard tissues and affect the composition of oral microbiota, although it exerts high inhibitory effect against tumor cells. To provide theoretical basis for preventing or reducing the side effects of nasopharyngeal carcinoma and head and neck cancer after radiotherapy and improving the quality of life in patients, related research progress on the effect of radiotherapy of nasopharyngeal carcinoma and head and neck cancer on dental hard tissues and oral microbiota was reviewed.

Dysbiotic oral microbiota contributes to alveolar bone loss associated with obesity in mice

Abstract Periodontal diseases (PD) are inflammatory conditions that affect the teeth supporting tissues. Increased body fat tissues may contribute to activation of the systemic inflammatory response, leading to comorbidities. Some studies have shown that individuals with obesity present higher incidence of PD than eutrophics. Objective: To investigate the impact of obesity on periodontal tissues and oral microbiota in mice. Methodology: Two obesity mice models were performed, one using 12 weeks of the dietary protocol with a high-fat (HF) diet in C57BL/6 mice and the other using leptin receptor-deficient mice (db/db-/-), which became spontaneously obese. After euthanasia, a DNA-DNA hybridization technique was employed to evaluate the microbiota composition and topical application of chlorhexidine (CHX), an antiseptic, was used to investigate the impact of the oral microbiota on the alveolar bone regarding obesity. Results: Increased adipose tissue may induce alveolar bone loss, neutrophil recruitment, and changes in the oral biofilm, similar to that observed in an experimental model of PD. Topical application of CHX impaired bone changes. Conclusion: Obesity may induce changes in the oral microbiota and neutrophil recruitment, which are associated with alveolar bone loss.

Syzygium aromaticum como candidato a bactericida: efectos en la microbiota oral / Syzygium aromaticum as a bactericidal candidate: effects on the oral microbiota

El cavo de olor (Syzygium aromaticum) es un árbol, originario de Indonesia, con altura variable, pero que sobre pasa los 10 metros de altura, perteneciente a la familia de las Myrtaceae y cuyas flores que no han abierto, se convierten en botones, que al secar son los mencionados clavos de olor. Poseen como componente principal el Eugenol, entre otros compuestos orgánicos. Por sus características bioquímicas y organolépticas, le proporcionan varios beneficios para la salud, por actuar como estimulantes, antioxidante, con acción antibacterial, antiespasmódicas, además de su marcada acción analgésica y anestésica. Por su parte, la microbiota oral, está conformada por un amplio conjunto de microorganismos pertenecientes al ecosistema bucal y que a través del equilibrio de los mismos, se logrará un adecuado funcionamiento y desarrollo de las funciones fisiológicas en pro de la salud bucal del individuo. La presente investigación tiene como objetivo examinar los datos específicos en el uso del clavo de olor como agente bactericida en las afecciones bucodentales, encontrándose que si puede ser usado como agente bactericida por su marcado efecto sobre la microbiota oral a nivel de eliminar los microorganismos nocivos presentes en la misma, ya que actúa inhibiendo la recomposición de las proteínas, los ácidos nucleicos y la membrana de la pared celular, cambiando la permeabilidad de las células de los microorganismos, favoreciendo su muerte y a su ves favoreciendo el adecuado equilibrio de la microbiota oral, necesario para la adecuada salud bucodental(AU)

The clove (Syzygium aromaticum) is a tree, native to Indonesia, with variable height, but that exceeds 10 meters in height, belonging to the Myrtaceae family and whose flowers that have not opened, become buttons, that when drying are the aforementioned cloves. Their main component is Eugenol, among other organic compounds. Due to their biochemical and organoleptic characteristics, they provide several health benefits, for acting as stimulants, antioxidant, with antibacterial, antispasmodic action, in addition to their marked analgesic and anesthetic action. For its part, the oral microbiota is made up of a wide set of microorganisms belonging to the oral ecosystem and that through their balance, an adequate functioning and development of physiological functions will be achieved in favor of the oral health of the individual. The objective of this research is to examine the specific data on the use of cloves as a bactericidal agent in oral conditions, finding that it can be used as a bactericidal agent due to its marked effect on the oral microbiota at the level of eliminating harmful microorganisms present in it, since it acts by inhibiting the recomposition of proteins, nucleic acids and the cell wall membrane, changing the permeability of the cells of microorganisms, favoring their death and in turn favoring the proper balance of the oral microbiota, necessary for proper oral health(AU)

Comparative evaluation of antimicrobial potential of herbal extracts on Streptococcus mutans and Enterococcus faecalis An in vitro study / Avaliação comparativa do potencial antimicrobiano de extratos de ervas em Streptococcus mutans e Enterococcus faecalis: estudo in vitro

Though aloe vera extract, green tea extract and coriander oil are proven antimicrobial agents, very little information is available regarding its effects on oral bacteria, Streptococcus mutans, which is responsible for initiating caries and Enterococcus faecalis, responsible for failure of root canal treatment. Objective: To find the antimicrobial activity of aloe vera extract, black tea extract and coriander oil against S. mutans and E. faecalis. Materials and Methods: The agar well diffusion method was used to determine the antibacterial activity of Aloe vera extract, black tea extract and coriander oil. Different concentration of prepared plant extracts and coriander seed oil (50 & 100 µl) was incorporated into the wells and the plates containing S. mutans and E. faecalis were incubated at 37 °C for 24 h. The antibiotic (amoxicillin 30 µl) was used as positive control. Zone Of Inhibition (ZOI) was recorded in each plate. Results: For S. mutans, the maximum ZOI was created by coriander oil with a diameter of 25.00±0.58 mm at 50 µl and for E. faecalis, maximum ZOI was created by aloe vera extract 16.00±0.58 mm at 100 µl concentration which were far better than the control: amoxicillin 30 µl concentration. Conclusion: The extracts of Aloe vera, black tea and coriander oil, showed significant activity against the investigated microbial strains, Streptococcus mutans and Enterococcus faecalis which further helps in the development of new topical agents that help in reducing the numbers of these organisms present in the oral cavity. (AU)

Embora o extrato de aloe vera, extrato de chá verde e óleo de coentro sejam agentes antimicrobianos comprovados, há pouca informação disponível sobre seus efeitos nas bactérias orais, Streptococcus mutans, que é responsável por iniciar cáries e Enterococcus faecalis, responsável pela falha do tratamento de canal radicular. Objetivo: Avaliar a atividade antimicrobiana do extrato de aloe vera, extrato de chá preto e óleo de coentro contra S. mutans e E. faecalis. Materiais e Métodos: O método de difusão em agar foi usado para determinar a atividade antibacteriana do extrato de Aloe vera, extrato de chá preto e óleo de coentro. Diferentes concentrações dos extratos de plantas e óleo de semente de coentro (50 e 100 µl) foram preparados e colocados nos poços e nas placas contendo S. mutans e E. faecalis e foram incubadas a 37°C por 24 h. O antibiótico (amoxicilina 30 µl) foi utilizado como controle positivo. A zona de inibição (ZOI) foi registrada em cada placa. Resultados: Para S. mutans, a ZOI máxima foi obtida com o óleo de coentro com um diâmetro de 25,00 ± 0,58 mm a 50 µl e para E. faecalis, a ZOI máxima foi obtiada pelo extrato de aloe vera 16,00 ± 0,58 mm na concentração de 100 µl, as quais foram melhores do que o controle: concentração de 30 µl de amoxicilina. Conclusão: Os extratos de Aloe vera, chá preto e óleo de coentro apresentaram atividade significativa contra as cepas microbianas investigadas, Streptococcus mutans e Enterococcus faecalis auxiliando no desenvolvimento de novos agentes tópicos visando a redução do número desses organismos presentes no cavidade oral. (AU)

Resistencia a antibióticos ß-lactámicos y eritromicina en bacterias de la cavidad oral / Resistance to ß-lactam Antibiotics and Erythromycin in Bacteria of the Oral Cavity

Resumen Introducción. La microbiota humana como fuente de bacterias y genes de resistencia constituyen un problema de salud pública. En este estudio se investigó la prevalencia de bacilos entéricos Gram negativos resistentes a β-lactámicos y de los Streptococcus del grupo viridans (EGV) con resistencia a eritromicina en la cavidad oral. Métodos. Se realizó un estudio descriptivo de corte transversal con 193 aislamientos de la cavidad oral sana de 178 adultos que asistieron a una Clínica Odontológica de la ciudad de Cali durante el 2018. La evaluación de la sensibilidad antimicrobiana se realizó en 59 bacilos entéricos y 134 EGV y se identificó por PCR los genes que confieren resistencia a β-lactámicos y eritromicina. El análisis estadístico se realizó mediante el empleo del paquete SPSS vs 23. Resultados. El 84,7% de los bacilos entéricos fueron multirresistentes y presentaron genes bla, siendo blaTEM-1 (49,2%) y blaVIM-2 (30,5%,) los más prevalentes. Los EGV fueron resistentes a eritromicina (38,8%) y clindamicina (28,4%). El 18,7% presentaron el fenotipo cMLSβ, 4,5% el iMLSβ y el 14,9% fueron M. El gen ermB se detectó en los cMLSβ, (13,4%) y el gen mef en los M (9,7%). Conclusión. En este estudio se demostró la presencia de EGV y bacilos entéricos resistentes a los antibióticos y portadores de genes de resistencia a eritromicina y genes bla en la cavidad oral sana. La presencia de estas bacterias representa un riesgo para la salud de los individuos portadores y contribuyen a la creciente epidemia de resistencia bacteriana.

Abstract Introduction. The human microbiota as a source of bacteria and resistance genes is a public health problem. This study researched the prevalence of Gram-negative enteric bacilli resistant to β-lactams and erythromycin resistance in the oral cavity. Methods. A descriptive cross-sectional study was carried out with 193 isolates obtained from the oral cavity of 178 healthy adults who were treated at a Dental Clinic in the city of Cali during 2018. The evaluation of antimicrobial sensitivity was performed in 59 enteric bacilli and 134 EGV and the genes that confer resistance to β-lactam and erythromycin were identified by PCR. Statistical analysis was performed using the SPSS statistical package vs. 25.0. Results. 84.7% of the enteric bacilli presented the MDR phenotype and all presented the bla genes, blaTEM-1 (49.2%) and blaVIM-2 (30.5%) being the most prevalent. EGVs were resistant to erythromycin (38.8%) and clindamycin (28.4%). 18.7% presented the cMLSβ phenotype, 4.5% the iMLSβ and 14.9% were M. The ermB gene was detected more frequently in the cMLSβ, (13.4%) and the mef gene in the M (9.7%). Conclusion. This study demonstrated the presence of antibiotics and Gram-negative enteric bacilli resistant to antibiotics and carriers of erythromycin resistance genes and bla genes, respectively in the healthy oral cavity. The presence of these bacteria represents a risk to the health of carrier individuals and contributes to the growing epidemic of bacterial resistance.

Antibacterial, Antifungal and Antiviral Properties of Malpighiaceae Family and Its Potential Impact for Oral Cavity Infectious Diseases

Recently, the impact of oral infections on global human health and their importance in the complications of patients with some chronic conditions have been recognized. Current medical treatments deal with the specificity and resistance of pathogenic strains of the oral cavity made up of by bacteria, fungi and viruses; thus, novel substances are necessary for use as effective drugs. Plants have been a source of active chemical agents since ancient times; however, a number of family plants still remain unstudied. This is the case of Malpighiaceae, a flowering plant family that possesses secondary metabolites that have exhibited a variety of pharmacological effects with promising results. This review has as objective to provide an overview of the extracts and active constituents isolated from species belonging to the Malpighiaceae family, to emphasize their activities against bacteria, fungi and viruses during recent years and their potential impact on the pathogensof the oral cavity.

Diversity of Oral Microflora in Oral and Systemic Diseases: A Brief Review

The oral cavity contains rich and diverse microflora, known as oral microflora. Oral microflora usually presents within the biofilms attached to the various soft and hard tissue surfaces of the oral cavity. Oral microflora is beneficial to us and plays an important role in the normal development of the physiology. It also contributes to host defense; however, it can also have severe adverse effects for overall health. The present article aims to review the information regarding oral microflora in health and diseases. Recent updates regarding the oral microflora contribution in several common oral and systemic diseases are also briefly discussed.

Oral microbiota and inflammatory bowel disease / 华西口腔医学杂志

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with a high incidence but a poor therapeutic outcome. However, IBD is generally caused by complicated interactions between environmental factors and gut microflora in genetically susceptible individuals. In view of a series of oral manifestations in patients with IBD and a high detection rate of oral bacteria among this population, oral microbiota may play an important role in the development of IBD. This article reviews the relationship between oral microbiota and IBD.

Research status and development of digestive system microecology and pancreatic cancer / 中华消化外科杂志

Pancreatic cancer is a highly malignant tumor of the digestive system, also known as "the king of cancer" . Its incidence is increasing year by year worldwide. At present, there is still a lack of effective screening methods for pancreatic cancer, and the early symptoms are not obvious. Most pancreatic cancer is diagnosed in the late stage, and the best time for surgery has been lost, and patients often have poor response to radiotherapy, chemotherapy and targeted therapy, so the prognosis is very poor. The occurrence and development of pancreatic cancer are closely related to genetic background, environmental factors, basic diseases and living habits. So far, although certain risk factors have been identified, such as smoking, obesity, alcohol, chronic pancreatitis, type 2 diabetes mellitus, and family history, the cause of pancreatic cancer is still not very clear. In recent years, more and more studies have shown that in addition to the already recognized risk factors for pancreatic cancer, there is a certain relationship between digestive microecological disorders and the progression of pancreatic cancer. The authors review the research status of digestive system microecology and pancreatic cancer, in order to understand the role of digestive system microecology disorders in the occurrence and development of pancreatic cancer, thus providing a new way to effectively improve the prognosis of pancreatic cancer.

Research status and development of digestive system micro-ecology and pancreatic cancer / 中华消化外科杂志

Pancreatic cancer is a highly malignant tumor of the digestive system,also known as "the king of cancer".Its incidence is increasing year by year worldwide.At present,there is still a lack of effective screening methods for pancreatic cancer,and the early symptoms are not obvious.Most pancreatic cancer is diagnosed in the late stage,and the best time for surgery has been lost,and patients often have poor response to radiotherapy,chemotherapy and targeted therapy,so the prognosis is very poor.The occurrence and development of pancreatic cancer are closely related to genetic background,environmental factors,basic diseases and living habits.So far,although certain risk factors have been identified,such as smoking,obesity,alcohol,chronic pancreatitis,type 2 diabetes mellitus,and family history,the cause of pancreatic cancer is still not very clear.In recent years,more and more studies have shown that in addition to the already recognized risk factors for pancreatic cancer,there is a certain relationship between digestive microecological disorders and the progression of pancreatic cancer.The authors review the research status of digestive system microecology and pancreatic cancer,in order to understand the role of digestive system microecology disorders in the occurrence and development of pancreatic cancer,thus providing a new way to effectively improve the prognosis of pancreatic cancer.

Roles of Oral, Gastric and Duodenal Microbiota in Liver Cirrhosis / 胃肠病学

With the development of gene sequencing, there are growing concerns on the role of digestive tract microbiota in liver cirrhosis and its complications. Most studies focus on the application of change of gut microbiota, probiotics and antibiotic therapy in liver cirrhosis, however, studies on oral, gastric and duodenal microbiota in liver cirrhosis are rare. This article reviewed the roles of oral, gastric and duodenal microbiota in liver cirrhosis for providing some new ideas for the treatment of liver cirrhosis and its complications.

Identification of the Salivary Microbiota of Patients with Oral Cancer in Antofagasta- Chile by Molecular Diagnosis of the 16S rRNA Gene / Identificación de la Microbiota de Saliva de Pacientes con Cáncer Oral de Antofagasta por Diagnóstico Molecular del Gen ARNr 16S

ABSTRACT: Oral cancer, is part of several cancers that affect head and neck, and that according to numerous studies shows an increase of approximately 3-5 % of all cancers. In the last 10 years there has been an increased interest in saliva for its use as a diagnostic tool, due to its easy access, and non-invasive sample collection, unlike blood samples. Studies of metagenomics to the microbiota of oral cancer patients have shown the presence of some groups in greater proportion, it is postulated that they could be used as markers especially in the saliva of these patients. In Antofagasta the number of patients with this type of cancer increases each year. However, there are no studies on the changes that affect the oral microbiota in these patients. The objective of this study is to contribute to the knowledge of the microbiota present in the saliva of patients with oral cancer in the region of Antofagasta, limiting this study exclusively to the group of cultivable anaerobic bacteria. The strains identified are related to the group of Streptococcus mitis / oralis, S. anginosus and S. gordoni, only one strain is grouped near the cluster that includes S. australis and S. parasanguinis. 36.4 % of the molecularly identified isolates, are closely related to the S. anginosus species described in the literature in oropharyngeal tumors. The same percentage is obtained for the taxa related to the cluster that includes S. mitis, proposed in other studies as a diagnostic indicator in subjects with oral squamous cell carcinoma.

RESUMEN: El de cáncer oral, es parte de un grupo de cáncer que afecta cabeza y cuello, y que según demuestran numerosos estudios va en aumento corresponde aproximadamente al 3-5 % de todos los cánceres. En los últimos 10 años la saliva ha aumentado su interés para su uso como diagnóstico debido a su fácil acceso y recolección no invasiva, a diferencia la sangre. Estudios de metagenómica a la microbiota de pacientes con cáncer bucal han demostrado la presencia de algunos grupos en mayor proporción, se postula que podrían ser utilizados como marcadores especialmente en la saliva de estos pacientes. En Antofagasta el número de pacientes con este tipo de cáncer aumenta cada año, sin embargo no hay estudios sobre los cambios que afectan a la microbiota bucal de estos pacientes. El objetivo de este estudio es contribuir al conocimiento de la microbiota presente en la saliva de los pacientes con cáncer bucal en la región de Antofagasta acotando este estudio exclusivamente al grupo de bacterias anaerobias cultivables. Las cepas identificadas se relacionan con el grupo de Streptococcus mitis/oralis, S. anginosus y S. gordoni, sólo una cepa se agrupa cerca del cluster que incluye a S. australis y S. parasanguinis. Un 36,4 % de los aislados identificados molecularmente se relacionan cercanamente a la especie S. anginosus descrita en la bibliografía en tumores orofaríngeos y el mismo porcentaje se obtiene para los taxones relacionados al cluster que agrupa a S. mitis, propuesto en otros estudios como indicador diagnóstico en sujetos con carcinoma oral de células escamosas.

Changes in Oral Microbiota in Patients Receiving Radical Concurrent Chemoradiotherapy for The Head and Neck Squamous Cell Carcinoma

Radiotherapy (RT) is a mainstay in the treatment of head and neck squamous cell carcinoma (HNSCC). For locally advanced HCSCC, concurrent chemoradiotherapy (CCRT) benefits HCSCC patients in terms of better survival and loco-regional control. In this study, we evaluated changes in oral microbiota in patients, who received CCRT for head and neck cancer. Oral rinsed samples were weekly collected before and during CCRT and at 4 weeks following treatment from HNSCC patients, who had received 70 Gy of radiation delivered to the primary sites for over 7 weeks and concurrent chemotherapy. Oral microbiota changes in three patients were analyzed by next-generation sequencing using 16S rRNA 454 pyrosequencing. On an average, 15,000 partial 16S rRNA gene sequences were obtained from each sample. All sequences fell into 11 different bacterial phyla. During early CCRT, the microbial diversity gradually decreased. In a patient, who did not receive any antibiotics during the CCRT, Firmicutes and Proteobacteria were the most abundant phylum. During the early CCRT, proteobacteria gradually decreased while Firmicutes increased. During the late CCRT, firmicutes gradually decreased while Bacteroides and Fusobacteria increased. In all the patients, yellow complex showed a gradual decrease, while orange and red complex showed a gradual increase during the CCRT. At 4 weeks after CCRT, the recovery of oral microbiota diversity was limited. During CCRT, there was a gradual increase in major periodontopathogens in association with the deterioration of the oral hygiene. Henceforth, it is proposed that understanding oral microbiota shift should provide better information for the development of effective oral care programs for patients receiving CCRT for HNSCC.

Salivary microbial communities associated with severe early childhood caries / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the salivary microbial profiles of healthy subjects and those with severe early childhood caries (S-ECC) by using high-throughput sequencing.</p><p><b>METHODS</b>Salivary samples were obtained from children with S-ECC (group C, n=24) and healthy children (group H, n=24). Total metagenomic DNA was extracted, and DNA amplicons of the V1-V3 hypervariable region of the 16S rRNA gene were generated and subjected to 454 sequencing. The characteristics of oral microbial communities from the two groups were compared based on microbial diversity and taxonomy assignment.</p><p><b>RESULTS</b>First, the microbial richness was significantly higher in group C than group H (P<0.05). Second, the microbial community structure was significantly different for the groups H and C (P<0.01). In addition, caries microbiota was significantly conserved in group C (P<0.001). High expression of suspected cariogenic microorganisms in group C (P<0.1) and health related microorganisms in group H (P<0.1) were identified. Finally, models of caries risk assessment were proposed to distinguish caries from healthy subjects with over 70% accuracy.</p><p><b>CONCLUSIONS</b>Salivary microbiota and certain taxa, such as caries-associated taxa (Prevotella), may be useful to screen/assess the children's risk of developing caries.</p>