Effect of probiotic bacteria on oral Candida in head- and neck-radiotherapy patients: A randomized clinical trial

Mechanisms of action of Lactobacillus spp. in the treatment of oral candidiasis

Candida albicans is often associated with oral candidiasis, and drug-resistance profiles have contributed to an increase in morbidity and mortality. It is known that Lactobacillus spp. acts by competing for adhesion to the epithelium, absorption of nutrients and modulation of the human microbiota. Therefore, they are important to assist in the host's microbiological balance and reduce the growth of Candida spp. Until now, there have been no reports in the literature of reviews correlating to the use of Lactobacillus spp. in the treatment of oral candidiasis. Thus, this review aims to highlight the mechanisms of action of Lactobacillus spp. and methods that can be used in the treatment of oral candidiasis. This is a study carried out through the databases PubMed Central and Scientific Electronic Library Online, using the following keywords: Oral Candidiasis and Lactobacillus. Original articles about oral candidiasis were included, with both in vitro and in vivo analyses, and published from 2012 to 2022. Lactobacillus rhamnosus was the most common microorganism used in the experiments against Candida, acting mainly in the reduction of biofilm, filamentation, and competing for adhesion sites of Candida spp. Among in vivo studies, most researchers used immunosuppressed mouse modelsof Candida infection. The studies showed that Lactobacillus has a great potential as a probiotic, acting mainly in the prevention and treatment of mucosal diseases. Thus, the use of Lactobacillus may be a good strategy for the treatment of oral candidiasis.

Pharmacomicrobiomics in precision cancer therapy: bench to bedside

The burgeoning field of pharmacomicrobiomics offers promising insights into the intricate interplay between the microbiome and cancer, shaping responses to diverse treatment modalities. This review aims to analyze the molecular mechanisms underlying interactions between distinct microbiota types and cancer, as well as their influence on treatment outcomes. We explore how the microbiome impacts antitumor immunity, and response to chemotherapy, immunotherapy, and radiation therapy, unveiling its multifaceted roles in cancer progression and therapy resistance. Moreover, we discuss the challenges hindering the development of microbiome-based interventions in cancer therapy, including standardization, validation, and clinical translation. By synthesizing clinical evidence, we underscore the transformative potential of harnessing pharmacomicrobiomics in guiding cancer treatment decisions, paving the way for improved patient outcomes in clinical practice.

Summary of the best evidence for nutritional support programs in nasopharyngeal carcinoma patients undergoing radiotherapy

Objective

To evaluate and summarize the best evidence for nutritional support in patients receiving radiotherapy for nasopharyngeal carcinoma and to offer guidance for clinical practice.

Background

Patients with nasopharyngeal carcinoma undergoing radiotherapy often experience a high prevalence of malnutrition, and there is a lack of compiled guideline recommendations, which complicates the provision of a reference for clinical nursing.

Methods

A systematic literature search revealed the best evidence of nutritional support for nasopharyngeal carcinoma patients undergoing radiotherapy. Included in the review were various types of literature, such as clinical guidelines, expert consensus, systematic evaluations, meta-analyses, evidence summaries, and original studies. The evidence was graded according to the Australian Joanna Briggs Institute Centre for Evidence-Based Health Care Evidence Pre-Grading System (2016 version). Data were gathered from a range of sources, including BMJ Best Practice, the Scottish Intercollegiate Guidelines Network, the Cochrane Library, Embase, PubMed, Web of Science, CINAL, CNKI, the WanFang database, SinoMed, the Yi Maitong Guidelines Network, Dingxiangyuan, the Chinese Nutrition Society, the European Society for Clinical Nutrition and Metabolism website, and the American Society for Parenteral and Enteral Nutrition website. The search spanned from January 2013 to 2023.

Results

A comprehensive review identified a total of 3,207 articles, comprising six guidelines, eight expert consensus articles, four systematic evaluations, five randomized controlled trials, two cohort trials, and two observational studies. From these articles, we synthesized 63 pieces of evidence spanning six domains: nutritional risk screening and assessment, nutrient requirements, nutritional support, management of nutritional symptoms, functional exercise, and nutritional monitoring and follow-up.

Conclusion

A total of lines of evidence supporting nutritional support for nasopharyngeal carcinoma patients receiving radiotherapy were summarized. However, the evidence should be combined with the actual clinical situation, and it should be validated in the future by combining large-sample and multicenter studies to provide a more scientific and beneficial nutritional support program for nasopharyngeal carcinoma patients receiving radiotherapy.

The Microbiome Modulates the Immune System to Influence Cancer Therapy

The gut microbiota composition can affect the tumor microenvironment and its interaction with the immune system, thereby having implications for treatment predictions. This article reviews the studies available to better understand how the gut microbiome helps the immune system fight cancer. To describe this fact, different mechanisms and approaches utilizing probiotics to improve advancements in cancer treatment will be discussed. Moreover, not only calorie intake but also the variety and quality of diet can influence cancer patients' immunotherapy treatment because dietary patterns can impair immunological activities either by stimulating or suppressing innate and adaptive immunity. Therefore, it is interesting and critical to understand gut microbiome composition as a biomarker to predict cancer immunotherapy outcomes and responses. Here, more emphasis will be given to the recent development in immunotherapies utilizing microbiota to improve cancer therapies, which is beneficial for cancer patients.

Probing the Potential: Exploring Probiotics as a Novel Frontier in Cancer Prevention and Therapeutics

Cancer has emerged as one of the most prevalent diseases worldwide, with a consistent rise in the number of cases observed over the past few decades. The rising mortality rates associated with cancer have transformed it into a significant global challenge. Despite the presence of various anti-cancer drugs, the complete eradication of cancer remains an elusive goal. The numerous undesirable effects associated with cancer therapy further emphasize the importance of developing an alternative technique of cancer treatment. Recent research has established the beneficial effects of a probiotic diet or supplementation against cancer without displaying any detrimental consequences. An alteration in the gut microbiome balance in humans can result in the development of various diseases, including cancer. Probiotics play a pivotal role in restoring the balance of gut flora, potentially contributing to cancer prevention. Furthermore, they have the capacity to curb the invasion and dissemination of infections that carry the risk of triggering cancer. Probiotics can combat cancer in various ways, such as by eliciting and boosting the immune response, secreting metabolites, preventing cancer cells from metastasizing, inhibiting carcinogenic chemicals, and mitigating their toxicity, etc. The present review intends to outline the significance of probiotics and their underlying mechanisms in combating various cancer types. Additionally, this review highlights the benefits of probiotic use in pre- and post-operative cancer patients.

Implications of oral dysbiosis and HPV infection in head and neck cancer: from molecular and cellular mechanisms to early diagnosis and therapy

Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis and HPV infection in HNCs, presenting the involved taxons, molecular effectors and pathways, as well as the HPV-associated particularities of genetic and epigenetic changes and of the tumor microenvironment occurred in different stages of tumor development. Oral dysbiosis is associated with the evolution of HNCs, through multiple mechanisms such as inflammation, genotoxins release, modulation of the innate and acquired immune response, carcinogens and anticarcinogens production, generation of oxidative stress, induction of mutations. Thus, novel microbiome-derived biomarkers and interventions could significantly contribute to achieving the desideratum of personalized management of oncologic patients, regarding both early diagnosis and treatment. The results reported by different studies are not always congruent regarding the variations in the abundance of different taxons in HNCs. However, there is a consistent reporting of a higher abundance of Gram-negative species such as Fusobacterium, Leptotrichia, Treponema, Porphyromonas gingivalis, Prevotella, Bacteroidetes, Haemophilus, Veillonella, Pseudomonas, Enterobacterales, which are probably responsible of chronic inflammation and modulation of tumor microenvironment. Candida albicans is the dominant fungi found in oral carcinoma being also associated with shorter survival rate. Specific microbial signatures (e.g., F. nucleatum, Bacteroidetes and Peptostreptococcus) have been associated with later stages and larger tumor, suggesting their potential to be used as biomarkers for tumor stratification and prognosis. On the other hand, increased abundance of Corynebacterium, Kingella, Abiotrophia is associated with a reduced risk of HNC. Microbiome could also provide biomarkers for differentiating between oropharyngeal and hypopharyngeal cancers as well as between HPV-positive and HPV-negative tumors. Ongoing clinical trials aim to validate non-invasive tests for microbiome-derived biomarkers detection in oral and throat cancers, especially within high-risk populations. Oro-pharyngeal dysbiosis could also impact the HNCs therapy and associated side-effects of radiotherapy, chemotherapy, and immunotherapy. HPV-positive tumors harbor fewer mutations, as well as different DNA methylation pattern and tumor microenvironment. Therefore, elucidation of the molecular mechanisms by which oral microbiota and HPV infection influence the HNC initiation and progression, screening for HPV infection and vaccination against HPV, adopting a good oral hygiene, and preventing oral dysbiosis are important tools for advancing in the battle with this public health global challenge.

Modulating the gut microbiota by probiotics, prebiotics, postbiotics, and fecal microbiota transplantation: An emerging trend in cancer patient care

Treatment resistance, together with acute and late adverse effects, represents critical issues in the management of cancer patients. Promising results from preclinical and clinical research underline the emerging trend of a microbiome-based approach in oncology. Favorable bacterial species and higher gut diversity are associated with increased treatment efficacy, mainly in chemo- and immunotherapy. On the other hand, alterations in the composition and activity of gut microbial communities are linked to intestinal dysbiosis and contribute to high treatment-induced toxicity. In this Review, we provide an overview of studies concerning gut microbiota modulation in patients with solid and hematologic malignancies with a focus on probiotics, prebiotics, postbiotics, and fecal microbiota transplantation. Targeting the gut microbiome might bring clinical benefits and improve patient outcomes. However, a deeper understanding of mechanisms and large clinical trials concerning microbiome and immunological profiling is warranted to identify safe and effective ways to incorporate microbiota-based interventions in routine clinical practice.

Antigingivitis and Antiplaque Effects of Oral Probiotic Containing the Streptococcus salivarius M18 Strain: A Randomized Clinical Trial

We aimed to assess the effect of oral probiotic containing the Streptococcus salivarius M18 strain on gingival inflammation, bleeding on probing, and oral biofilm. Sixty-one consenting participants aged between 18 and 25 with gingivitis were recruited in this double-blind, parallel-group study and randomly divided into the probiotic group (n = 31) and the placebo group (n = 30). Fifty-seven participants completed the entire study protocol, 27 in the probiotic group and 30 in the placebo group. The outcomes were assessed after 4 weeks of intervention and 4 weeks of follow-up. There was a significant decrease in the Gingival Index, with the effect size of 0.58 [95%CI 0.05-1.10], and Turesky modification of the Quigley and Hein Plaque Index, with the effect size of 0.55 [95%CI: 0.02-1.07], in the probiotic group after the intervention. However, after a 4-week follow-up, the only significant treatment outcome was improved gingival condition according to the Gingival Index. The Gingival Bleeding Index also decreased significantly in the probiotic group after the intervention period; after the follow-up, this parameter did not differ significantly in both groups from the baseline values. In the placebo group, there were no significant improvements in the assessed parameters throughout this study. No serious side effects were registered. Within the limitations of this study, we conclude that the use of oral probiotic containing the Streptococcus salivarius M18 strain resulted in a significant improvement in gingival condition and oral hygiene level in young adults with gingivitis. Trial registration NCT05727436. Funding: none.

Manejo odontológico de las manifestaciones orales inducidas por radioterapia de cabeza y cuello

La radioterapia es una de las primeras opciones de tratamiento para el cáncer de cabeza y cuello; sin embargo, puede ocasionar diversas manifestaciones secundarias en la cavidad oral tales como mucositis oral, xerostomía, infecciones orales oportunistas, osteorradionecrosis y trismo. El presente artículo tiene como objetivo describir el manejo preventivo y terapéutico de las complicaciones orales inducidas por radioterapia de cabeza y cuello en la práctica odontológica propuestos hasta la actualidad. Se encontraron diversas medidas que han logrado reducir la incidencia y gravedad de dichas manifestaciones orales; sin embargo, aún existen algunas que requieren de más estudios para confirmar su efectividad. Palabras clave: cáncer de cabeza y cuello; manifestaciones bucales; radioterapia; terapéutica.

Current Infections of the Orofacial Region: Treatment, Diagnosis, and Epidemiology

Undoubtedly, diagnosing and managing infections is one of the most challenging issues for orofacial clinicians. As a result of the diversity of symptoms, complicated behavior, and sometimes confusing nature of these conditions, it has become increasingly difficult to diagnose and treat them. It also highlights the need to gain a deeper insight into the orofacial microbiome as we try to improve our understanding of it. In addition to changes in patients' lifestyles, such as changes in diet, smoking habits, sexual practices, immunosuppressive conditions, and occupational exposures, there have been changes in patients' lifestyles that complicate the issue. Recent years have seen the development of new infection treatments due to the increased knowledge about the biology and physiology of infections. This review aimed to provide a comprehensive overview of the types of infections in the mouth, including the types that viruses, fungi, or bacteria may cause. It is important to note that we searched the published literature in the Scopus, Medline, Google Scholar, and Cochran databases from 2010 to 2021 using the following keywords: "Orofacial/Oral Infections," "Viral/Fungal/Bacterial Infections", "Oral Microbiota" And "Oral Microflora" without limiting our search to languages and study designs. According to the evidence, the most common infections in the clinic include herpes simplex virus, human papillomavirus, Candida albicans, Aspergillus, Actinomycosis, and Streptococcus mutans. The purpose of this study is to review the new findings on characteristics, epidemiology, risk factors, clinical manifestations, diagnosis, and new treatment for these types of infectious diseases.

Chemopreventive role of probiotics against cancer: a comprehensive mechanistic review

Probiotics use different mechanisms such as intestinal barrier improvement, bacterial translocation and maintaining gut microbiota homeostasis to treat cancer. Probiotics' ability to induce apoptosis against tumor cells makes them more effective to treat cancer. Moreover, probiotics stimulate immune function through an immunomodulation mechanism that induces an anti-tumor effect. There are different strains of probiotics, but the most important ones are lactic acid bacteria (LAB) having antagonistic and anti-mutagenic activities. Live and dead probiotics have anti-inflammatory, anti-proliferative, anti-oxidant and anti-metastatic properties which are useful to fight against different diseases, especially cancer. The main focus of this article is to review the anti-cancerous properties of probiotics and their role in the reduction of different types of cancer. However, further investigations are in progress to improve the efficiency of probiotics in cancer treatment.

Oral infections in oral cancer survivors: A mini-review

The oral cancer survivors are a group of special individuals whose disease affect anatomical structures with a key role in identity and communication and a fundamental role in basic human functions such as speaking, eating, swallowing and breathing. Thus, quality of life of these individuals can be impaired by the consequences of disease and treatments, in particular surgery and radiotherapy. Among others, infectious conditions of any nature, bacterial, viral, fungal, are a frequent finding among oral cancer survivors. In fact, the peculiar systemic and local conditions of these subjects are known to significantly modify the microbiota, which, besides facilitating opportunistic infections, can affect the cancer microenvironment, as well as alter the effects of the anti-cancer therapies. Similarly, mouth infections can also affect the prognosis of oral cancer survivors. Among the opportunistic infections, fungal are the most common infections affecting these subjects, since neutropenia resulting from cancer, as well as chemotherapy and/or radiotherapy treatments, promote the shift from the carrier state of Candida species, to pathogen state. Treatment of oral candidiasis can be difficult in oral cancer survivors, and good evidence supports clotrimazole as the most effective for prevention, and fluconazole as the one with the best risk-benefit profile. Probiotics, although promising, need better evidence to be considered an effective treatment or preventive measure.

The Effect of Oral Probiotics (Streptococcus Salivarius k12) on the Salivary Level of Secretory Immunoglobulin A, Salivation Rate, and Oral Biofilm: A Pilot Randomized Clinical Trial

We aimed to assess the effect of oral probiotics containing the Streptococcus salivarius K12 strain on the salivary level of secretory immunoglobulin A, salivation rate, and oral biofilm. Thirty-one consenting patients meeting the inclusion criteria were recruited in this double-blind, placebo-controlled, two-arm, parallel-group study and randomly divided into probiotic (n = 15) and placebo (n = 16) groups. Unstimulated salivation rate, concentration of salivary secretory immunoglobulin A, Turesky index, and Papillary-Marginal-Attached index were assessed after 4 weeks of intervention and 2 weeks of washout. Thirty patients completed the entire study protocol. We found no increase in salivary secretory immunoglobulin A levels and salivary flow rates in the probiotic group compared with placebo. Baseline and outcome salivary secretory immunoglobulin A concentrations (mg/L) were 226 ± 130 and 200 ± 113 for the probiotic group and 205 ± 92 and 191 ± 97 for the placebo group, respectively. A significant decrease in plaque accumulation was observed in the probiotic group at 4 and 6 weeks. Within the limitations of the present study, it may be concluded that probiotic intake (Streptococcus salivarius K12) does not affect salivation rates and secretory immunoglobulin A salivary levels but exhibits a positive effect on plaque accumulation. Trial registration NCT05039320. Funding: none.

Prevalence of different fungal species in Saliva and Swab samples of patients undergoing Radiotherapy for Oral Cancer

Oral cancer is one of the leading causes of morbidity and mortality globally. There is a lack of studies on the growth of different Candida species in swab pre and post-radiotherapy. Hence, this study aimed to determine different Candida species in the oral cavity of patients who undergo radiotherapy. The study included 50 patients with oral cancer scheduled to undergo radiotherapy. Both saliva and swab samples were collected from all the patients before and after two- and six weeks of starting the radiotherapy. Similar inoculation was performed using the salivary swabs and incubated aerobically at 37°C for 48h. After 48h, culture plates were removed from the incubator and observed for the growth of different fungal species based on the color of the colonies. The culture of samples from patients with oral cancer resulted in the growth of 68% of Candida species in saliva and 44% in swab before initiating radiation. Unlike baseline findings, Candida albicans were identified in a higher number in swab samples (44%) than saliva (24%) post two weeks of radiotherapy. All saliva samples were positive to candida species, in which Candida albicans shows high prevalence (24%). After six weeks of radiotherapy, in the swab, 30% of samples were positive for Candida albicans, and 18% of samples were positive for non-albicans species. Before radiotherapy, at two weeks and six weeks of radiotherapy, saliva samples showed a higher prevalence of Candidal species compared to swab samples. The combination of other Candida species was also higher in saliva samples compared to swab samples during radiotherapy.

Probiotic Supplements on Oncology Patients' Treatment-Related Side Effects: A Systematic Review of Randomized Controlled Trials

Cancer affects more than 19.3 million people and has become the second leading cause of death worldwide. Chemo- and radiotherapy, the most common procedures in these patients, often produce unpleasant treatment-related side effects that have a direct impact on the quality of life of these patients. However, innovative therapeutic strategies such as probiotics are being implemented to manage these complications. Thus, this study aimed to evaluate the efficacy of probiotics supplements as a therapeutic strategy in adult oncology treatment-related side effects. A systematic review of randomized controlled trials was conducted in PubMed, Scielo, ProQuest and OVID databases up to and including January 2021, following the PRISMA guidelines. The quality of the included studies was assessed by the Jadad Scale. Twenty clinical trials published between 1988 and 2020 were included in this review. Seventeen studies (85%) revealed predominantly positive results when using probiotics to reduce the incidence of treatment-related side effects in oncology patients, while three studies (15%) reported no impact in their findings. This study sheds some light on the significance of chemotherapy and radiotherapy in altering the composition of gut microbiota, where probiotic strains may play an important role in preventing or mitigating treatment-related side effects.

The immunomodulating role of probiotics in the prevention and treatment of oral diseases

Probiotics are defined as non-pathogenic live microorganisms which, when administered in appropriate amounts, are beneficial to the health of the host. Currently, the group of probiotic microorganisms includes bacteria that produce lactic acid of the genera Lactobacillus and Bifidobacterium, belonging to the so-called LAB (lactic acid bacteria) groups, and the yeast Saccharomyces boulardii. Probiotics have a protective role in Candida spp. oral infection and especially colonization. Lactobacillus limits the progression of chronic periodontitis by inhibiting the secretory activity of Th17 lymphocytes, which in the pathogenesis of this disease are responsible for an excessive cytokine response causing adverse changes in periodontal tissues. A meta-analysis of the results of studies on the clinical evaluation of the effectiveness of probiotics in the treatment of gingivitis showed that the use of probiotics improved the condition of the gums in the course of the therapeutic process. Regular use of probiotics during orthodontic treatment significantly reduces the number of bacteria from the Streptococcus mutans group in the patient’s saliva and significantly inhibits the expression of inflammatory mediators and an excessive immune response. The main mechanisms of the action of probiotics, such as elimination and inhibition of the growth of pathogenic microorganisms through competition for receptor sites and the secretion of metabolites with antibacterial activity, as well as the stimulation of specific and non-specific immune responses by activating T lymphocytes, and stimulating the production of cytokines, make it possible to also effectively use pro-health bacteria in oral diseases.