Cancer and the microbiota

Gut microbiota in cancer initiation, development and therapy

Cancer has long been associated with genetic and environmental factors, but recent studies reveal the important role of gut microbiota in its initiation and progression. Around 13% of cancers are linked to infectious agents, highlighting the need to identify the specific microorganisms involved. Gut microbiota can either promote or inhibit cancer growth by influencing oncogenic signaling pathways and altering immune responses. Dysbiosis can lead to cancer, while certain probiotics and their metabolites may help reestablish micro-ecological balance and improve anti-tumor immune responses. Research into targeted approaches that enhance therapy with probiotics is promising. However, the effects of probiotics in humans are complex and not yet fully understood. Additionally, methods to counteract harmful bacteria are still in development. Early clinical trials also indicate that modifying gut microbiota may help manage side effects of cancer treatments. Ongoing research is crucial to understand better how gut microbiota can be used to improve cancer prevention and treatment outcomes.

Intratumoral Fusobacterium nucleatum in Pancreatic Cancer: Current and Future Perspectives

The intratumoral microbiome plays a significant role in many cancers, such as lung, pancreatic, and colorectal cancer. Pancreatic cancer (PC) is one of the most lethal malignancies and is often diagnosed at advanced stages. Fusobacterium nucleatum (Fn), an anaerobic Gram-negative bacterium primarily residing in the oral cavity, has garnered significant attention for its emerging role in several extra-oral human diseases and, lately, in pancreatic cancer progression and prognosis. It is now recognized as oncobacterium. Fn engages in pancreatic tumorigenesis and metastasis through multifaceted mechanisms, including immune response modulation, virulence factors, control of cell proliferation, intestinal metabolite interactions, DNA damage, and epithelial-mesenchymal transition. Additionally, compelling research suggests that Fn may exert detrimental effects on cancer treatment outcomes. This paper extends the perspective to pancreatic cancer associated with Fn. The central focus is to unravel the oncogenomic changes driven by Fn in colonization, initiation, and promotion of pancreatic cancer development. The presence of Fusobacterium species can be considered a prognostic marker of PC, and it is also correlated to chemoresistance. Furthermore, this review underscores the clinical research significance of Fn as a potential tumor biomarker and therapeutic target, offering a novel outlook on its applicability in cancer detection and prognostic assessment. It is thought that given the role of Fn in tumor formation and metastasis processes via its FadA, FapA, Fap2, and RadD, new therapies for tumor treatment targeting Fn will be developed.

Immunogenic peptides putatively from intratumor microbes: Opportunities for colorectal cancer treatment

Recent evidence has confirmed the presence of intratumor microbes, yet their impact on the immunopeptidome remains largely unexplored. Here we introduced an integrated strategy to identify the immunopeptidome originated from intratumor microbes. Analyzing 10 colorectal cancer (CRC) patients, we identified 154 putative microbe-derived human leukocyte antigen (HLA)-I ligands. Predominantly bacterial in origin, these peptides were notably abundant in Fusobacterium nucleatum, the most prevalent bacterium differentiating between normal and tumor tissues. We discovered 20 peptides originating from F. nucleatum, thirteen of which, including two peptides shared across multiple patients, were tumor specific. Validation experiments confirmed that the putative microbe-derived peptide could activate CD8+ T cell responses. Our findings indicate that HLA-I molecules are capable of presenting intratumor microbe-derived peptides in CRC, potentially contributing to CD8+ T cell-mediated immunity and suggesting potential strategies for cancer immunotherapy.

Oral Microbiome Signatures as Potential Biomarkers for Gastric Cancer Risk Assessment

BACKGROUND

Gastric cancer (GC) is the fifth leading cause of cancer-related death worldwide. The oral microbiota was investigated for distinguishable characteristics between GC, premalignant gastric conditions (Pre-GC), and control participants.

METHODS

Mouthwash samples from GC, Pre-GC, and control participants at a tertiary care center were prospectively collected. Following DNA extraction and sequencing, analyses of oral microbiome biodiversity and composition were performed, and receiver operating characteristic curves were created to evaluate the discriminative power of oral microbiome signatures.

RESULTS

Oral samples from 98 participants included 30 (30.6%) GC, 30 (30.6%) Pre-GC and 38 (38.8%) controls. Of these, 61 (62.2%) were female, 31 (31.6%) were Hispanic, and 18 (18.3%) were smokers. GC compared to controls demonstrated notable differences in beta diversity (Jensen-Shannon Divergence and Bray-Curtis Dissimilarity, p<0.02). 32 bacterial genera were found to be differentially abundant when comparing GC and controls, and 23 bacterial genera demonstrated differential abundance when comparing Pre-GC and controls (W-statistic >2). Minimal compositional differences between GC and Pre-GC were found, with only three differentially abundant bacterial genera (W-statistic >2). Models were constructed from the most significant bacterial signatures (W-statistic >5). These models discriminated between GC and control oral samples with an AUC of 0.880 (95% CI 0.808, 0.952) and between Pre-GC and control oral samples with an AUC of 0.943 (95% CI 0.887, 0.999).

CONCLUSIONS

Oral rinses of GC and Pre-GC participants exhibited distinct but similar microbiome profiles, distinguishing them from controls. This compositional difference raises the possibility of utilizing these microbial signatures to predict GC risk.

Etiology-Dependent Microbiome Differences in Hepatocellular Carcinoma Development

Chronic liver disease is characterised by persistent inflammation, tissue damage, and regeneration, which leads to steatosis, fibrosis, and, lastly, cirrhosis and hepatocellular carcinoma (HCC). HCC, the most prevalent form of primary liver cancer, is one of the leading causes of cancer-related mortality worldwide. The gut microbiota plays a fundamental role in human physiology, and disturbances in its critical balance are widely recognised as contributors to various pathological conditions, including chronic liver diseases, both infectious and non-infectious in nature. Growing interest in microbiota research has recently shifted the focus towards the study of intratumoural microbiota, referred to as the "oncobiome", which can significantly impact the development and progression of HCC. In this review, we discuss existing research and provide an overview of the microbiota influence on viral hepatitis, particularly in shaping the progression of liver disease caused by the hepatitis B and hepatitis C viruses. We also explore microbial dysbiosis and its contribution to the silent and dangerous progression of non-alcoholic fatty liver disease. Additionally, we address the impact of alcohol on the liver and its interaction with the microbiota, tracing the pathway from inflammation to cirrhosis and cancer. The review emphasises the most common etiologies of hepatocellular carcinoma.

Study of Microbiota Associated to Early Tumors Can Shed Light on Colon Carcinogenesis

An increasingly important role for gut microbiota in the initiation and progression of colorectal cancer (CRC) has been described. Even in the early stages of transformation, i.e., colorectal adenomas, changes in gut microbiota composition have been observed, and several bacterial species, such as pks+Escherichia coli and enterotoxigenic Bacteroides fragilis, have been proposed to drive colon tumorigenesis. In recent years, several strategies have been developed to study mucosa-associated microbiota (MAM), which is more closely associated with CRC development than lumen-associated microbiota (LAM) derived from fecal samples. This review summarizes the state of the art about the oncogenic actions of gut bacteria and compares the different sampling strategies to collect intestinal microbiota (feces, biopsies, swabs, brushes, and washing aspirates). In particular, this article recapitulates the current knowledge on MAM in colorectal adenomas and serrated polyps, since studying the intestinal microbiota associated with early-stage tumors can elucidate the molecular mechanisms underpinning CRC carcinogenesis.

Correlation of Porphyromonas gingivalis with esophageal squamous cell carcinoma: a systematic review

OBJECTIVES

This study aimed to assess the correlation of Porphyromonas gingivalis (P. gingivalis) with esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

This systematic review evaluated case-control, cohort, and cross-sectional studies published between 1990 and 2024 that compared ESCC patients and healthy controls regarding the presence of P. gingivalis, risk of ESCC development, overall survival rate and prognosis of ESCC, lymph node metastasis, clinical stage of the disease, cancer cell proliferation and migration, efficacy of chemotherapy, invasion depth, and cell differentiation. Searching process was conducted in Web of Science, Scopus, PubMed, and Cochrane Library. The quality of included studies was assessed by the Newcastle Ottawa scale (NOS).

RESULTS

Of 270 articles, 11 underwent a systematic review with NOS scores ranging from 7 to 9. 5 studies found a correlation between P.gingivalis and overall survival rate of ESCC patients (P < 0.05). 5 studies found a significant correlation between P.gingivalis count and the risk of ESCC development (P < 0.05). 2 studies showed a significant correlation between lymph node metastasis and 3 studies showed a significant correlation between clinical TNM stage and P.gingivalis (P < 0.05).

CONCLUSIONS

High P. gingivalis count increases the risk of development of ESCC, lymph node metastasis, progression to stages 3 and 4, proliferation and migration of cancer cells, and depth of invasion, decreases the overall survival rate and prognosis of the disease, and efficacy of chemotherapy, and results in poorer differentiation of cells.

CLINICAL RELEVANCE

According to our findings, dental clinicians and patients should be informed about the significance of oral hygiene and its relationship with ESCC to prevent future life-threatening diseases.

The RIG-I-like receptor signaling pathway triggered by Staphylococcus aureus promotes breast cancer metastasis

Host microbes are increasingly recognized as key components in various types of cancer, although their exact impact remains unclear. This study investigated the functional significance of Staphylococcus aureus (S. aureus) in breast cancer tumorigenesis and progression. We found that S. aureus invasion resulted in a compromised DNA damage response process, as evidenced by the absence of G1-phase arrest and apoptosis in breast cells in the background of double strand breaks production and the activation of the ataxia-telangiectasia mutated (ATM)-p53 signaling pathway. The high-throughput mRNA sequencing, bioinformatics analysis and pharmacological studies revealed that S. aureus facilitates breast cell metastasis through the innate immune pathway, particularly in cancer cells. During metastasis, S. aureus initially induced the expression of RIG-I-like receptors (RIG-I in normal breast cells, RIG-I and MDA5 in breast cancer cells), which in turn activated NF-κB p65 expression. We further showed that NF-κB p65 activated the CCL5-CCR5 pathway, contributing to breast cell metastasis. Our study provides novel evidence that the innate immune system, triggered by bacterial infection, plays a role in bacterial-driven cancer metastasis.

Exosomal circular RNAs in tumor microenvironment: An emphasis on signaling pathways and clinical opportunities

Exosomes can regulate the malignant progression of tumors by carrying a variety of genetic information and transmitting it to target cells. Recent studies indicate that exosomal circular RNAs (circRNAs) regulate multiple biological processes in carcinogenesis, such as tumor growth, metastasis, epithelial-mesenchymal transition, drug resistance, autophagy, metabolism, angiogenesis, and immune escape. In the tumor microenvironment (TME), exosomal circRNAs can be transferred among tumor cells, endothelial cells, cancer-associated fibroblasts, immune cells, and microbiota, affecting tumor initiation and progression. Due to the high stability and widespread presence of exosomal circRNAs, they hold promise as biomarkers for tumor diagnosis and prognosis prediction in blood and urine. In addition, designing nanoparticles targeting exosomal circRNAs and utilizing exosomal circRNAs derived from immune cells or stem cells provide new strategies for cancer therapy. In this review, we examined the crucial role of exosomal circRNAs in regulating tumor-related signaling pathways and summarized the transmission of exosomal circRNAs between various types of cells and their impact on the TME. Finally, our review highlights the potential of exosomal circRNAs as diagnostic and prognostic prediction biomarkers, as well as suggesting new strategies for clinical therapy.

The oncomicrobiome: New insights into microorganisms in cancer

The discoveries of the oncomicrobiome (intratumoral microbiome) and oncomicrobiota (intratumoral microbiota) represent significant advances in tumor research and have rapidly become of key interest to the field. Within tumors, microorganisms such as bacteria, fungi, viruses, and archaea form the oncomicrobiota and are primarily found within tumor cells, immunocytes, and the intercellular matrix. The oncomicrobiome exhibits marked heterogeneity and is associated with tumor initiation, progression, metastasis, and treatment response. Interactions between the oncomicrobiome and the immune system can modulate host antitumor immunity, influencing the efficacy of immunotherapies. Oncomicrobiome research also faces numerous challenges, including overcoming methodological issues such as low target abundance, susceptibility to contamination, and biases in sample handling and analysis methods across different studies. Furthermore, studies of the oncomicrobiome may be confounded by baseline differences in microbiomes among populations driven by both environmental and genetic factors. Most studies to date have revealed associations between the oncomicrobiome and tumors, but very few have established mechanistic links between the two. This review introduces the relevant concepts, detection methods, sources, and characteristics of the oncomicrobiome. We then describe the composition of the oncomicrobiome in common tumors and its role in shaping the tumor microenvironment. We also discuss the current problems and challenges to be overcome in this rapidly progressing field.

Relationships between bacteria and the mucus layer

The mucus layer on epithelial cells is an essential barrier, as well as a nutrient-rich niche for bacteria, forming a dynamic, functional and symbiotic ecosystem and first line of defense against invading pathogens. Particularly bacteria in biofilms are very difficult to eradicate. The extensively O-glycosylated mucins are the main glycoproteins in mucus that interact with microbes. For example, mucins act as adhesion receptors and nutritional substrates for gut bacteria. Mucins also play important roles in immune responses, and they control the composition of the microbiome, primarily due to the abundance of complex O-glycans. In inflammation or infection, the structures of mucin O-glycans can change and thus affect mucin function, impact biofilm formation and the induction of virulence pathways in bacteria. In turn, bacteria can support host cell growth, mucin production and can stimulate changes in the host immune system and responses leading to healthy tissue function. The external polysaccharides of bacteria are critical for controlling adhesion and biofilm formation. It is therefore important to understand the relationships between the mucus layer and microbes, the mechanisms and regulation of the biosynthesis of mucins, of bacterial surface polysaccharides, and adhesins. This knowledge can provide biomarkers, vaccines and help to develop new approaches for improved therapies, including antibiotic treatments.

Human intestinal microbiome: Role in health and disease

The study of the microbiota and the microbiome, and specifically the intestinal one, has determined great interest due to the possible association of their alterations with numerous diseases. These include entities as diverse as Crohn's disease, autism, diabetes, cancer or situations as prevalent today as obesity. In view of this situation, different recommendations have been performed regarding the use of probiotics, prebiotics, and postbiotics as modulators of the microbiota and the microbiome, seeking both preventive and therapeutic effects, and faecal material transfer (FMT) is proposed as an alternative. The latter has emerged as the only proven beneficial intervention on the intestinal microbiome, specifically in the treatment of recurrent colitis associated with Clostridioides difficile (R-CDI). In the rest of the entities, the lowering of laboratory costs has favored the study of the microbiome, which is resolved by delivering reports with catalogs of microorganisms, metabolites or supposed biomarkers without consensus on their composition associated with healthy or diseased microbiota and the disease. There is still insufficient evidence in any disease for interventions on the microbiome beyond FMT and R-CDI. Multi- and multi-disciplinary work with extensive research and the application of artificial intelligence in this field may shed light on the questions raised currently. Ethical issues must also be resolved in light of possible interventions within the umbrella of personalized medicine.

Investigating the role of the intratumoral microbiome in thyroid cancer development and progression

The intratumoral microbiome (ITM) is in the spotlight due to its possible contribution to the initiation, progression, and invasion of a wide range of cancers. Its precise contribution to cancer tumorigenesis is still elusive, though. Thyroid cancer(TC), the ninth leading cause of cancer globally and the most prevalent endocrine malignancy with a rapidly rising incidence among all cancers, has attracted much attention nowadays. Still, the association between the tumor's microbiome and TC progression and development is an evolving area of investigation with significant consequences for disease understanding and intervention. Therefore, this review offers an appropriate perspective on this emerging concept in TC based on prior studies on the ITM among the most common tumors worldwide, concentrating on TC. Moreover, information on the origin of the ITM and practical methods can pave the way for researchers to opt for the most appropriate method for further investigations on the ITM more accurately.

Revolutionizing head and neck squamous cell carcinoma treatment with nanomedicine in the era of immunotherapy

Head and neck squamous cell carcinoma (HNSCC) is a prevalent malignant tumor globally. Despite advancements in treatment methods, the overall survival rate remains low due to limitations such as poor targeting and low bioavailability, which result in the limited efficacy of traditional drug therapies. Nanomedicine is considered to be a promising strategy in tumor therapy, offering the potential for maximal anti-tumor effects. Nanocarriers can overcome biological barriers, enhance drug delivery efficiency to targeted sites, and minimize damage to normal tissues. Currently, various nano-carriers for drug delivery have been developed to construct new nanomedicine. This review aims to provide an overview of the current status of HNSCC treatment and the necessity of nanomedicine in improving treatment outcomes. Moreover, it delves into the research progress of nanomedicine in HNSCC treatment, with a focus on enhancing radiation sensitivity, improving the efficacy of tumor immunotherapy, effectively delivering chemotherapy drugs, and utilizing small molecule inhibitors. Finally, this article discussed the challenges and prospects of applying nanomedicine in cancer treatment.

Exploring micronutrients and microbiome synergy: pioneering new paths in cancer therapy

The human microbiome is the complex ecosystem consisting of trillions of microorganisms that play a key role in developing the immune system and nutrient metabolism. Alterations in the gut microbiome have been linked to cancer initiation, progression, metastasis, and response to treatment. Accumulating evidence suggests that levels of vitamins and minerals influence the gut environment and may have implications for cancer risk and progression. Bifidobacterium has been reported to reduce the colorectal cancer risk by binding to free iron. Additionally, zinc ions have been shown to activate the immune cells and enhance the effectiveness of immunotherapy. Higher selenium levels have been associated with a reduced risk of several cancers, including colorectal cancer. In contrast, enhanced copper uptake has been implicated in promoting cancer progression, including colon cancer. The interaction between cancer and gut bacteria, as well as dysbiosis impact has been studied in animal models. The interplay between prebiotics, probiotics, synbiotics, postbiotics and gut bacteria in cancer offers the diverse physiological benefits. We also explored the particular probiotic formulations like VSL#3, Prohep, Lactobacillus rhamnosus GG (LGG), etc., for their ability to modulate immune responses and reduce tumor burden in preclinical models. Targeting the gut microbiome through antibiotics, bacteriophage, microbiome transplantation-based therapies will offer a new perspective in cancer research. Hence, to understand this interplay, we outline the importance of micronutrients with an emphasis on the immunomodulatory function of the microbiome and highlight the microbiome's potential as a target for precision medicine in cancer treatment.

Cervicovaginal and gastrointestinal microbiomes in gynecological cancers and their roles in therapeutic intervention

Cancer remains a significant global health concern, and understanding factors that regulate cancer development is important. The microbiome, with its potential role in cancer development, progression, and treatment, has garnered increasing attention in recent years. The cervicovaginal and gastrointestinal microbiomes in females constitute complex biological ecosystems. Although the gut microbiome has been extensively studied, little is known about the cervicovaginal microbiome. The microbiome plays a crucial role in maintaining local microenvironments and tissue homeostasis, but dysbiosis can disrupt this fine balance and contribute to pathological ramifications leading to cancer. This review explores the current understanding of the microbiome's correlation with gynecological cancers and highlights the potential of microbiome-based interventions to improve outcomes in these cancers. In addition, this review underscores the gaps and limitations in the literature, such as findings in specific ethnicities compared with understudied ethnicities. In addition, discrepancies in molecular techniques and terminology (microbiome vs. microbiota) used in the literature are addressed. Emerging evidence linking gynecological cancers and dysbiosis underscores microbiota as a potential target for cancer prevention and therapy. Manipulating the microbiome, such as through the use of probiotics, prebiotics, antibiotics, or vaginal and fecal transplantation, has demonstrated benefits in the treatment of chronic and inflammatory conditions. Further translational research in this field is needed to integrate the benefits of beneficial microorganisms in the fight against gynecological cancers.

Remolding the tumor microenvironment by bacteria augments adoptive T cell therapy in advanced-stage solid tumors

The intricate tumor microenvironment presents formidable obstacles to the efficacy of adoptive T cell therapy in the management of solid tumors by limiting the infiltration and inducing exhaustion of the transferred T cells. Here, we developed a bacterial-based adjuvant approach that augments the efficacy of adoptive T-cell therapy for solid tumor treatment. Our study reveals that intratumor injection of E. coli MG1655 normalizes tumor vasculatures and reprograms tumor-associated macrophages into M1 phenotype that produce abundant CCL5, together facilitating tumor infiltration of adoptively transferred T cells. The depletion of tumor-associated macrophages or CCL5 neutralization in vivo leads to the significantly decreased solid tumor infiltration of adoptive T cells in the presence of bacteriotherapy. This combinatorial therapy, consisting of E. coli adjuvant and adoptive T-cell therapy, effectively eradicates early-stage melanoma and inhibits the progression of pancreatic tumors. Notably, this dual strategy also strengthened the distal tumor control capabilities of adoptive T-cell therapy through the induction of in situ tumor vaccination. This dual therapeutic approach involving bacterial therapy targeting the interior of solid tumors and adoptive T-cell therapy attacking the tumor periphery exhibits potent therapeutic efficacy in achieving the eradication of advanced-stage tumors, including melanoma and hepatocellular carcinoma, by converging attacks from both inside and outside the tumor tissues.

Association between sulfur microbial diet and the risk of esophageal cancer: a prospective cohort study in 101,752 American adults

BACKGROUND

Sulfur microbial diet (SMD) is a dietary pattern closely related to the intestinal load of sulfur-metabolizing microbes in humans. Diet and microbes may play an important role in the carcinogenesis of esophagus. However, epidemiological studies on SMD and esophageal cancer (EC) risk are scarce. Here, we evaluated this association based on a large American cohort.

METHODS

In the cohort of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, a SMD score was calculated to evaluate participants' compliance of SMD pattern, with higher scores presenting greater adherence. Cox hazards regression model was used to explore the association between the SMD score and the incidence of EC, esophageal squamous cell carcinoma (ESCC), and esophageal adenocarcinoma (EA). Subgroup analyses were conducted to figure out potential modifiers interacting with SMD on EC. Sensitivity analyses were used to testify the robustness of our main result.

RESULTS

Among 101,752 participants, 154 EC cases, consisted of 41 ESCC cases and 97 EA cases, were identified with mean follow-up of 8.9 years. In the fully adjusted model, the highest versus the lowest quartiles of the SMD score were found to be associated with an increased risk of EC and ESCC (EC: HRQ4 vs. Q1: 1.64; 95% CI: 1.05, 2.56; P = 0.016 for trend; ESCC: HRQ4 vs. Q1: 2.37; 95% CI: 1.02, 5.47; P = 0.031 for trend), while not significantly associated with increases risk of EA (HRQ4 vs. Q1: 1.41; P = 0.144 for trend). The main result remained through a series of sensitivity analyses. Subgroup analyses showed a stronger association between SMD and EC in participants with no regular consumption of aspirin (HRQ4 vs. Q1: 1.90; 95% CI: 1.04, 3.47) than in those using aspirin regularly (HRQ4 vs. Q1: 1.37; 95% CI: 0.71, 2.66) (P = 0.008 for interaction).

CONCLUSION

Adherence to the SMD pattern may be associated with increased risks of EC and ESCC, particularly for EC in individuals who do not regularly consume aspirin.

Harnessing Gene Editing Technology for Tumor Microenvironment Modulation: An Emerging Anticancer Strategy

Cancer is a multifaceted disease influenced by both intrinsic cellular traits and extrinsic factors, with the tumor microenvironment (TME) being crucial for cancer progression. To satisfy their high proliferation and aggressiveness, cancer cells always plunder large amounts of nutrients and release various signals to their surroundings, forming a dynamic TME with special metabolic, immune, microbial and physical characteristics. Due to the neglect of interactions between tumor cells and the TME, traditional cancer therapies often struggle with challenges such as drug resistance, low efficacy, and recurrence. Importantly, the development of gene editing technologies, particularly the CRISPR-Cas system, offers promising new strategies for cancer treatment. Combined with nanomaterial strategies, CRISPR-Cas technology exhibits precision, affordability, and user-friendliness with reduced side effects, which holds great promise for profoundly altering the TME at the genetic level, potentially leading to lasting anticancer outcomes. This review will delve into how CRISPR-Cas can be leveraged to manipulate the TME, examining its potential as a transformative anticancer therapy.

The Potential Role of the Microbiome in the Pathogenesis of Nasal Tumors: A Comprehensive Review

Cancers of the nose, and especially the nose vestibule, represent a significant challenge for clinicians due to their rarity, the intricate nature of surrounding vital structures, the nonspecific early symptoms, and the etiological factors that are not completely understood. Emerging research suggests that alterations in the nasal microbiome, also known as microbial dysbiosis, may contribute to the pathogenesis of those malignancies through mechanisms involving chronic inflammation, immune modulation, and cellular changes. The aims of this paper are to review the current literature covering the nasal microbiome's role in carcinogenesis, particularly in the context of squamous cell carcinoma, and to explore how microbial dysbiosis might foster a pro-tumorigenic environment. It further discusses potential future directions for research and therapeutic approaches.

A molecular viewpoint of the intricate relationships among HNSCC, HPV infections, and the oral microbiota dysbiosis

HPV infection and the type of host microbiota play a role in the formation of HNCs. In contrast to other forms of OSCC, where the relationship between HPV and the cancer is less obvious, HPV-HNSCC is a particular type of oropharyngeal cancer. HPV has infected a stratified squamous epithelium, which includes the throat, mouth, anogenital tract, respiratory tract, and skin on the hands and feet. HPV DNA was found in high amounts in the saliva and gargle samples of patients with HPV-related HNSCC. It has been discovered that the specificity of oral mRNA (HPV) and HPV DNA identification varies from 23 % to 82 % in the identification of OPSCCs. The higher rate of HPV transmission through vaginal-oral compared to penile-oral sexual activity may be the reason for the difference in HPV-positive HNSCC patients between males and females. The researchers postulate that HPV-inactive tumours signify an advanced stage of HPV-positive HNSCC, which explains why there are racial disparities in gene expression that correspond to different disease progressions in Black and White patients. The increase of CD8+ T cells in the cancer microenvironment, linked to P16 activation, extends life expectancy in OSCC. tumour markers methylation caused by HPV and suggested using them as possible HNC biomarkers. Fusobacterium levels are much higher in patients with OSCC, while Actinobacteria phylum and Firmicutes are significantly lower. It also serves as a biomarker for notable variations found in Firmicutes, Actinobacteria, Fusobacteriales, Fusobacteriia, Fusobacterium, and Fusobacteriaceae. Therefore, based on this we evidence, we could investigate the role of oral microbiota as a maker for the HPV associated HNSCC.

Gastric microbiome composition accompanied with the Helicobacter pylori related DNA methylation anomaly

Aim: DNA methylation is associated with gastric cancer and Helicobacter pylori (H. pylori) infection, while increasing evidence indicated involvement of other microbes reside in gastric mucosa during gastric tumorigenesis. We investigated bacterial communities in the gastric mucosa accompanied with H. pylori related methylation anomaly.Materials & methods: Gastric mucosa samples from antrum were obtained from 182 cancer-free patients. Bacterial communities were evaluated using 16S rRNA sequencing. The result was correlated with H. pylori related promoter CpG island (CGI) methylation of five genes (IGF2, SLC16A12, SOX11, P2RX7 and MYOD1), LINE1 hypomethylation and telomere length.Results & conclusion: We showed correlation between lower bacterial alpha diversity and higher CGI methylation. Multivariate analysis demonstrated older age (t = 3.46, p = 0.0007), H. pylori infection (t = 9.99, p < 0.0001) and lower bacterial alfa diversity (Shannon index: t = -2.34, p = 0.02) were significantly associated with CGI hypermethylation. In genus or family levels, increased abundance of Helicobacter was associated with hyper CGI methylation with strongest correlation, while decreased abundance of four bacteria (Intrasporangiaceae family, Macellibacteroides, Peptostreptococcus and Dietziaceae family) was also associated with hyper CGI methylation. Our findings suggest the potential correlation between CGI methylation induction and lower bacterial alpha diversity in the gastric mucosa accompanied by H. pylori infection.

Endometrial microbial dysbiosis and metabolic alteration promote the development of endometrial cancer

OBJECTIVE

Emerging evidence suggests that the endometrial microbiome plays important roles in the development of endometrial cancer (EC). Here, we evaluate stage-specific roles of microbial dysbiosis and metabolic disorders in patients with EC, patients with endometrial hyperplasia (EH), and patients afflicted with benign uterine conditions (CK).

METHODS

This prospective cohort study included 33 women with EC, 15 women with endometrial EH, and 15 women with benign uterine conditions (CK) from November 2022 to September 2023. Different typical endometrial samples were imaged with a scanning electron microscope and a transmission electron microscope. The endometrial microbiome was assessed by sequencing the V3-V4 region of the 16S rRNA gene and the ITS1 to fill the gap in relation to the study of the uterine fungal microbiome. Moreover, liquid chromatography-mass spectrometry-based metabolomics was used to identify and quantify metabolic changes among these groups.

RESULTS

The endometrial microbiome revealed that there is a structural microbiome shift and an increase in the α-diversity in the EC and EH cases, distinguishable from the benign cases, especially the fungal community structure. The fungal microbiome from patients with EC and EH was altered relative to controls and dominated by Penicillium sp. By contrast, Sarocladium was more abundant in controls. Significant differences were observed in the composition and content of compounds between benign cases and EC, especially estradiol-like metabolism-related substances. Altered microbiota was correlated with the concentrations of interleukin-6 (IL-6), IL-11, transforming growth factor-beta, and β-glucuronidase activity especially the relative abundance increase of Penicillium sp.

CONCLUSIONS

This study suggested that the endometrial microbiome is complicit in modulating the development of EC such as estrogen activity and a pro-inflammatory response. Our work provides a new insight into the endometrial microbiome from a perspective of stages, which opens up new avenues for EC prognosis and therapy.

Crosstalk Between the Intratumoral Microbiota and the Tumor Microenvironment: New Frontiers in Solid Tumor Progression and Treatment

BACKGROUND

The microbiota plays a significant role in the tumor microenvironment, and its impact on tumor development and treatment outcome cannot be overlooked. Thus, it is essential to comprehend the interactions between the microbiota and the tumor microenvironment.

RECENT FINDINGS

With the advent of next-generation sequencing, microbiota research has advanced significantly in recent years. The interaction between the intratumoral microbiota and the tumor microenvironment is an emerging area of research that holds great promise for understanding and treating solid tumor progression. This crosstalk between the intratumoral microbiota and the tumor microenvironment is a complex process that involves a multitude of factors, including the immune system, cellular signaling pathways, and metabolic processes. The origin of the intratumoral microbiota differs between various solid tumor, and the quantity and diversity of intratumoral microbiota also fluctuate significantly within each solid tumor.

CONCLUSION

The aim of this review is to provide a detailed summary of the intratumoral microbiota in various types of solid tumors. This will include an analysis of their origins, differences, and how they impact the progression of solid tumors. Furthermore, we will emphasize the significant potential that the intratumoral microbiota holds for the diagnosis and treatment of solid tumors.

Microbiota modulate immune repertories in lung adenocarcinoma via microbiota-immunity interactive network

Background

While the resident microbiome of tumors has been shown to be associated with the occurrence and progression of non-small cell lung cancer, there remains a significant knowledge gap in understanding the correlation between the microbial spectrum and immunity response to cancer therapy. In the case of lung adenocarcinoma (LUAD), the tumor microenvironment, encompassing a diverse array of microbes and immune cells, plays a crucial role in modulating therapeutic response. Towards comprehending the underlying mechanism, we present the microbe-immunity interactive networks to delineate the microbiota and immunity repertoires for two distinct molecular subtypes in LUAD.

Methods

We obtained multi-omics data of LUAD patients from the publicly available database. In this study, we conducted a systematic exploration of the microbial and immunological etiology of cancer prognosis, by integrating the microbiome, genome, transcriptome, and clinic data. The mutational signature analysis, transcriptome analysis, gene set enrichment analysis, and microbiota-immunity network analysis were performed.

Results

Based on the transcriptome repertories, we classified the patients into two molecular subtypes and observed that the overall survival of molecular subtype 2 (MS2) was notably shortened. We identified the microbial biomarkers in patients that distinguished between these molecular subtypes. The significant up-regulation of γδT and neutrophil in MS2, suggesting the inflammation augmentation and stimulation of γδT activation. What is more, the MS2 are characterized by a correlation network between microbiota biomarkers and γδT cell, which may contribute to suppression of anti-tumor immunity and poor overall survival.

Conclusions

Our findings not only display the repertoires of tumor microbiota and immune cells, but also elucidate the potential contribution of the microbiota-immunity correlation network to unfavorable overall survival and therapeutic resistance, thereby exerting profound implications on future LUAD therapy.

Intratumoral Microbiota: Insights from Anatomical, Molecular, and Clinical Perspectives

The human microbiota represents a heterogeneous microbial community composed of several commensal, symbiotic, and even pathogenic microorganisms colonizing both the external and internal body surfaces. Despite the term "microbiota" being commonly used to identify microorganisms inhabiting the gut, several pieces of evidence suggest the presence of different microbiota physiologically colonizing other organs. In this context, several studies have also confirmed that microbes are integral components of tumor tissue in different types of cancer, constituting the so-called "intratumoral microbiota". The intratumoral microbiota is closely related to the occurrence and development of cancer as well as to the efficacy of anticancer treatments. Indeed, intratumoral microbiota can contribute to carcinogenesis and metastasis formation as some microbes can directly cause DNA damage, while others can induce the activation of proinflammatory responses or oncogenic pathways and alter the tumor microenvironment (TME). All these characteristics make the intratumoral microbiota an interesting topic to investigate for both diagnostic and prognostic purposes in order to improve the management of cancer patients. This review aims to gather the most recent data on the role of the intratumoral microbiota in cancer development, progression, and response to treatment, as well as its potential diagnostic and prognostic value.

Intratumoral microbiota: an emerging force in diagnosing and treating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) ranks among the most prevalent types of cancer in the world and its incidence and mortality are increasing year by year, frequently diagnosed at an advanced stage. Traditional treatments such as surgery, chemotherapy, and radiotherapy have limited efficacy, so new diagnostic and treatment strategies are urgently needed. Recent research has discovered that intratumoral microbiota significantly influences the development, progression, and metastasis of HCC by modulating inflammation, immune responses, and cellular signaling pathways. Intratumoral microbiota contributes to the pathologic process of HCC by influencing the tumor microenvironment and altering the function of immune system. This article reviews the mechanism of intratumoral microbiota in HCC and anticipates the future possibilities of intratumoral microbiota-based therapeutic strategies for HCC management. This emerging field provides fresh insights into early diagnosis and personalized approaches for HCC while holding substantial clinical application potential to improve patient outcomes and tailor interventions to individual tumor profiles.

Exploring the gut microbiome's role in colorectal cancer: diagnostic and prognostic implications

The intricate interplay between the gut microbiome and colorectal cancer (CRC) presents novel avenues for early diagnosis and prognosis, crucial for improving patient outcomes. This comprehensive review synthesizes current findings on the gut microbiome's contribution to CRC pathogenesis, highlighting its potential as a biomarker for non-invasive CRC screening strategies. We explore the mechanisms through which the microbiome influences CRC, including its roles in inflammation, metabolism, and immune response modulation. Furthermore, we assess the viability of microbial signatures as predictive tools for CRC prognosis, offering insights into personalized treatment approaches. Our analysis underscores the necessity for advanced metagenomic studies to elucidate the complex microbiome-CRC nexus, aiming to refine diagnostic accuracy and prognostic assessment in clinical settings. This review propels forward the understanding of the microbiome's diagnostic and prognostic capabilities, paving the way for microbiome-based interventions in CRC management.

Computational Microbiome Pharmacology Analysis Elucidates the Anti-Cancer Potential of Vaginal Microbes and Metabolites

The vaginal microbiome's role in risk, progression, and treatment of female cancers has been widely explored. Yet, there remains a need to develop methods to understand the interaction of microbiome factors with host cells and to characterize their potential therapeutic functions. To address this challenge, we developed a systems biology framework we term the Pharmacobiome for microbiome pharmacology analysis. The Pharmacobiome framework evaluates similarities between microbes and microbial byproducts and known drugs based on their impact on host transcriptomic cellular signatures. Here, we apply our framework to characterization of the Anti-Gynecologic Cancer Vaginal Pharmacobiome. Using published vaginal microbiome multi-omics data from the Partners PrEP clinical trial, we constructed vaginal epithelial gene signatures associated with each profiled vaginal microbe and metabolite. We compared these microbiome-associated host gene signatures to post-drug perturbation host gene signatures associated with 35 FDA-approved anti-cancer drugs from the Library of Integrated Network-based Cellular Signatures database to identify vaginal microbes and metabolites with high statistical and functional similarity to these drugs. We found that Lactobacilli and their metabolites can regulate host gene expression in ways similar to many anti-cancer drugs. Additionally, we experimentally tested our model prediction that taurine, a metabolite produced by L. crispatus, kills cancerous breast and endometrial cancer cells. Our study shows that the Pharmacobiome is a powerful framework for characterizing the anti-cancer therapeutic potential of vaginal microbiome factors with generalizability to other cancers, microbiomes, and diseases.

Tumor microbiota of renal cell carcinoma affects clinical prognosis by influencing the tumor immune microenvironment

Despite reported influences of the intratumoral microbiome on cancer progression, its role in this subtype remains unclear. This study aimed to characterize the microbial landscape and signatures of kidney renal clear cell carcinoma using RNA-Seq data from The Cancer Genome Atlas. Following microbial decontamination, differential microbial analysis was conducted between tumorous and adjacent non-tumorous samples. Compared to non-tumorous samples, tumorous microbiota exhibited reduced α and β diversity and distinct phylum-level communities. Differential microbial analysis between patients exhibiting long and short overall survival revealed ten significant differential microbial genera, with six genera correlating with a positive prognosis (Plasmodium, Babesia, Toxoplasma, Cytobacillus, Alicyclobacillus, Verrucomicrobium) and four with a negative prognosis (Colletotrichum, Leuconostoc, Gluconobacter, and Parabacteroides). Employing Cox regression analysis and support vector machines, a prognosis-related microbiome risk signature was developed, achieving an AUC of 0.809. Based on this risk signature, two microbiome-based subtypes were found to be significantly associated with distinct clinical prognoses and immune microenvironments. These findings were corroborated by significant correlations between prognostic-relevant microorganisms and 30 immune-related differentially expressed genes. Specifically, microbial genera associated with a negative prognosis were linked to a pro-tumor acute inflammatory immune response, whereas genera related to a positive prognosis were associated with an anti-tumor adaptive immune response. In conclusion, microbiome-based subtyping revealed correlations between tumor microbiome, clinical prognosis, and tumor microenvironment, indicating intratumoral microbiota as a promising prognostic biomarker for kidney renal clear cell carcinoma.

Effect of a Novel Food Rich in Miraculin on the Oral Microbiome of Malnourished Oncologic Patients with Dysgeusia

BACKGROUND/OBJECTIVES

Dysgeusia contributes to the derangement of nutritional status in patients with cancer as well as worsening the quality of life. There has been a lack of effective treatments for taste disorders provided by the pharmaceutical industry.

METHODS

This was a pilot randomized, parallel, triple-blind, and placebo-controlled intervention clinical trial in which 31 malnourished patients with cancer and dysgeusia receiving antineoplastic treatment were randomized into three arms [standard dose of DMB (150 mg DMB/tablet), high dose of DMB (300 mg DMB/tablet) or placebo (300 mg freeze-dried strawberry)] for three months. Patients consumed a DMB or placebo tablet before each main meal. Using the nanopore methodology, we analyzed the oral microbiome of patients with cancer using saliva samples.

RESULTS

All patients with cancer and dysgeusia had dysbiosis in terms of lower bacterial diversity and richness. DMB consumption was associated with changes in oral microbiome composition. Neither selected bacteria nor taste perception, type of diet, and cytokine levels were associated with mucositis. Likewise, alcohol and tobacco consumption as well as general and digestive toxicity due to systemic therapy were not associated with specific changes of the oral microbiome, according to logistic binary regression. The standard dose of DMB resulted in a lower abundance of Veillonella compared with the high DMB dose and placebo at 3 months after intervention with DMB. In particular, some species such as Streptococcus parasanguinis, Veillonella parvula, and Streptococcus mutans were less abundant in the DMB standard-dose group. Additionally, the consumption of a standard dose of DMB revealed a negative association between the concentrations of TNF-α and the abundance of species such as Streptococcus thermophilus, Streptococcus pneumoniae, Streptococcus dysgalactiae and Streptococcus agalactiae.

CONCLUSIONS

Accordingly, regular DMB consumption could modify the oral microbiome in patients with cancer and dysgeusia, which may contribute to maintaining an appropriate immune response. However, as the present pilot study involved a small number of participants, further studies are necessary to draw robust conclusions from the data.

Evaluation of an in-house pan-Malassezia quantitative PCR in human clinical samples

Althought Malassezia spp. have been involved in various pathologies, they are an integral part of the cutaneous, gut, oral, ears, nose and throat (ENT) mycobiota. Since Malassezia are difficult to grow in culture, unexhaustive molecular biology methods have been developed to detect them. The aim of the study was to evaluate an in-house pan-Malassezia quantitative polymerase chain reaction (panM-qPCR) on various clinical human samples and determine Malassezia burden in various human mycobiota. The panM-qPCR was designed to target the repeated 28S rDNA gene from all Malassezia species. We used the assay to quantify the Malassezia burden on 361 samples from 161 subjects (80 skin swabs from 10 healthy volunteers (HV), 13 samples from 2 seborrheic dermatitis patients (SD), 90 skin samples from 19 burned patients, 119 stool samples from 89 immunocompromised patients, 59 ENT samples from 41 patients). For HV, the amount of Malassezia was different according to the swabbed areas. Quantification cycle (Cq) in SD is lower than in HV. In burned patients, Cq was significantly lower compared to HV. In stool samples, 6.7% were positive for Malassezia spp. with a high Cq. For the ENT area, a higher proportion of positive specimens were detected in ear samples than in nose samples. Our findings emphasized the importance of qPCR, confirming elevated Malassezia spp. levels on individuals' faces and scalps, increased burden in SD patients and in severely burnt patients than in HV. The pan-MqPCR appears to be a promising tool for studying Malassezia in various human mycobiota.

Integrative Biomarker Panel for Improved Lung Cancer Diagnosis Using Plasma microRNAs and Sputum Bacterial DNA

This study aimed to evaluate if integrating diverse molecular biomarkers in plasma and sputum could improve the diagnosis of lung cancer. The study analyzed miRNAs in plasma and bacterial DNA in sputum from 58 lung cancer patients and 62 cancer-free smokers using droplet digital PCR. The individual plasma miRNA and sputum bacterial biomarkers had sensitivities of 62-71% and specificities of 61-79% for diagnosing lung cancer. A panel of plasma miRNA or sputum bacterial biomarkers produced sensitivities of 79-85% and specificities of 74-82%. An integromic signature consisting of two miRNAs in plasma and three bacterial biomarkers in sputum had a higher sensitivity (87%) and specificity (89%) compared to individual biomarkers. The signature's diagnostic value was confirmed in a validation cohort of 56 lung cancer patients and 59 controls, independent of tumor stage, histological type, and demographic factors. Integrating diverse molecular biomarkers in plasma and sputum could improve the diagnosis of lung cancer.

Beyond the Gut: The intratumoral microbiome's influence on tumorigenesis and treatment response

The intratumoral microbiome (TM) refers to the microorganisms in the tumor tissues, including bacteria, fungi, viruses, and so on, and is distinct from the gut microbiome and circulating microbiota. TM is strongly associated with tumorigenesis, progression, metastasis, and response to therapy. This paper highlights the current status of TM. Tract sources, adjacent normal tissue, circulatory system, and concomitant tumor co-metastasis are the main origin of TM. The advanced techniques in TM analysis are comprehensively summarized. Besides, TM is involved in tumor progression through several mechanisms, including DNA damage, activation of oncogenic signaling pathways (phosphoinositide 3-kinase [PI3K], signal transducer and activator of transcription [STAT], WNT/β-catenin, and extracellular regulated protein kinases [ERK]), influence of cytokines and induce inflammatory responses, and interaction with the tumor microenvironment (anti-tumor immunity, pro-tumor immunity, and microbial-derived metabolites). Moreover, promising directions of TM in tumor therapy include immunotherapy, chemotherapy, radiotherapy, the application of probiotics/prebiotics/synbiotics, fecal microbiome transplantation, engineered microbiota, phage therapy, and oncolytic virus therapy. The inherent challenges of clinical application are also summarized. This review provides a comprehensive landscape for analyzing TM, especially the TM-related mechanisms and TM-based treatment in cancer.

Association between periodontal disease and malignant soft tissue sarcomas

OBJECTIVE

Malignant soft tissue sarcoma (MSTS) is a rare disease, but is seen in patients undergoing orthopedic surgery. Although the association of periodontal disease with various cancers occurring in the oral cavity, gastrointestinal tract, lungs, and prostate, has been reported, the association between periodontal disease and MSTS remains unclear. This study investigated the association between periodontal disease and MSTS in patients undergoing orthopedic surgery.

SUBJECTS AND METHODS

One hundred fifteen patients who underwent orthopedic surgery between 2017 and 2021 were retrospectively enrolled (mean age = 66.8 ± 10.7 years). The patient background was adjusted by the propensity score (PS). Subsequently, the association of periodontal disease with MSTS was analyzed using PS inverse probability of treatment weighting (IPTW). Periodontal status was determined by evaluating the periodontal inflamed surface area, which was calculated by measuring the periodontal probing pocket depth and detecting bleeding on probing.

RESULTS

Multivariate logistic regression analysis after adjustment by the PS showed that severe periodontitis was significantly associated with MSTS (odds ratio 2.81, p = 0.04). Furthermore, IPTW showed that severe periodontitis was significantly associated with MSTS (odds ratio 3.21, p = 0.01).

CONCLUSION

The results indicate an association between periodontal inflammation and MSTS.

Epimedium polysaccharides mitigates Porphyromonas gingivalis-exacerbated intestinal inflammation by suppressing the Th17 pathway and modulating the gut microbiota

This study aimed to investigate the potential alleviating effect of Epimedium polysaccharide (EP) on intestinal inflammation aggravated by Porphyromonas gingivalis (Pg). P. gingivalis, an oral pathogen, may play a role in intestinal inflammation, highlighting the necessity to explore substances capable of inhibiting its pathogenicity. Initially, in vitro screening experiments utilizing co-culturing and quantitative polymerase chain reaction revealed that EP significantly inhibited the growth of P. gingivalis and the levels of virulence genes, including Kgp and RgpA. Subsequent mouse experiments demonstrated that EP notably ameliorated Pg-aggravated weight loss, disease activity index, histopathological lesions, and disruption of intestinal barrier integrity, evidenced by a reduction in tight junction protein levels. Flow cytometry analysis further illustrated that EP attenuated Pg-induced Th17 differentiation and Th17-related cytokines, such as IL-17 and IL-6. Additionally, 16S rRNA amplicon sequencing analysis elucidated that EP significantly mitigated Pg-induced gut microbiota dysbiosis, enriching potentially beneficial microbes, including Akkermansia and Bifidobacterium. The metabolomic analysis provided further insight, indicating that EP intervention altered the accumulation of relevant intestinal metabolites and exhibited correlations with disease indicators. In conclusion, our research suggested that EP holds promise as a prospective therapeutic agent for alleviating P. gingivalis-aggravated intestinal inflammation.

The emerging role of bacterial extracellular vesicles in human cancers

Bacterial extracellular vesicles (BEVs) have emerged as pivotal mediators between bacteria and host. In addition to being crucial players in host homeostasis, they have recently been implicated in disease pathologies such as cancer. Hence, the study of BEVs represents an intriguing and rapidly evolving field with substantial translational potential. In this review, we briefly introduce the fundamentals of BEV characteristics, cargo and biogenesis. We emphatically summarize the current relationship between BEVs across various cancer types, illustrating their role in tumorigenesis, treatment responses and patient survival. We further discuss the inherent advantages of BEVs, such as stability, abundance and specific cargo profiles, that make them attractive candidates for non-invasive diagnostic and prognostic approaches. The review also explores the potential of BEVs as a strategy for cancer therapy, considering their ability to deliver therapeutic agents, modulate the tumour microenvironment (TME) and elicit immunomodulatory responses. Understanding the clinical significance of BEVs may lead to the development of better-targeted and personalized treatment strategies. This comprehensive review evaluates the current progress surrounding BEVs and poses questions to encourage further research in this emerging field to harness the benefits of BEVs for their full potential in clinical applications against cancer.

Periodontal pathogens and cancer development

Increasing evidence suggests a significant association between periodontal disease and the occurrence of various cancers. The carcinogenic potential of several periodontal pathogens has been substantiated in vitro and in vivo. This review provides a comprehensive overview of the diverse mechanisms employed by different periodontal pathogens in the development of cancer. These mechanisms induce chronic inflammation, inhibit the host's immune system, activate cell invasion and proliferation, possess anti-apoptotic activity, and produce carcinogenic substances. Elucidating these mechanisms might provide new insights for developing novel approaches for tumor prevention, therapeutic purposes, and survival improvement.

The MCIB Model: A Novel Theory for Describing the Spatial Heterogeneity of the Tumor Microenvironment

The tumor microenvironment (TME) can be regarded as a complex and dynamic microecosystem generated by the interactions of tumor cells, interstitial cells, the extracellular matrix, and their products and plays an important role in the occurrence, progression and metastasis of tumors. In a previous study, we constructed an IEO model (prI-, prE-, and pOst-metastatic niche) according to the chronological sequence of TME development. In this paper, to fill the theoretical gap in spatial heterogeneity in the TME, we defined an MCIB model (Metabolic, Circulatory, Immune, and microBial microenvironment). The MCIB model divides the TME into four subtypes that interact with each other in terms of mechanism, corresponding to the four major links of metabolic reprogramming, vascular remodeling, immune response, and microbial action, providing a new way to assess the TME. The combination of the MCIB model and IEO model comprehensively depicts the spatiotemporal evolution of the TME and can provide a theoretical basis for the combination of clinical targeted therapy, immunotherapy, and other comprehensive treatment modalities for tumors according to the combination and crosstalk of different subtypes in the MCIB model and provide a powerful research paradigm for tumor drug-resistance mechanisms and tumor biological behavior.

Causal relationship between 150 skin microbiomes and prostate cancer: insights from bidirectional mendelian randomization and meta-analysis

Background

Despite relevant research, the relationship between skin microbiomes and prostate cancer remains controversial. This study utilizes bidirectional Mendelian randomization (MR) analysis combined with meta-analysis to explore the potential link between the two.

Objective

This study aims to identify the causal relationship between 150 skin microbiomes and prostate cancer (PCa) using bidirectional Mendelian randomization (MR) and meta-analysis.

Methods

This study employed a comprehensive Bidirectional Two-sample MR analysis using publicly available genetic data to ascertain the relationship between 150 skin microbiomes and PCa. We conducted extensive sensitivity analyses, tests for heterogeneity, and assessments of horizontal pleiotropy to ensure the accuracy of our results. Subsequently, we conducted a meta-analysis to strengthen our conclusions' robustness further. Finally, we performed reverse causal verification on the positive skin microbiomes and PCa.

Results

After conducting a meta-analysis and multiple corrections of the MR analysis results, our findings reveal a correlation between Neisseria in dry skin and PCa risk, identifying it as a risk factor. The IVW result shows an Odds Ratio (OR) of 1.009 (95% Confidence Interval [CI]: 1.004-1.014, P = 0.027). Furthermore, the reverse MR analysis indicates the absence of an inverse causal relationship between the two. Apart from the identified skin microbiome, no significant associations were found between the other microbiomes and PCa.

Conclusions

The study identified a correlation between Neisseria in dry skin, one of the 150 skin microbiomes, and the risk of developing PCa, establishing it as a risk factor for increased susceptibility to PCa.

mbDriver: identifying driver microbes in microbial communities based on time-series microbiome data

Alterations in human microbial communities are intricately linked to the onset and progression of diseases. Identifying the key microbes driving these community changes is crucial, as they may serve as valuable biomarkers for disease prevention, diagnosis, and treatment. However, there remains a need for further research to develop effective methods for addressing this critical task. This is primarily because defining the driver microbe requires consideration not only of each microbe's individual contributions but also their interactions. This paper introduces a novel framework, called mbDriver, for identifying driver microbes based on microbiome abundance data collected at discrete time points. mbDriver comprises three main components: (i) data preprocessing of time-series abundance data using smoothing splines based on the negative binomial distribution, (ii) parameter estimation for the generalized Lotka-Volterra (gLV) model using regularized least squares, and (iii) quantification of each microbe's contribution to the community's steady state by manipulating the causal graph implied by gLV equations. The performance of nonparametric spline-based denoising and regularized least squares estimation is comprehensively evaluated on simulated datasets, demonstrating superiority over existing methods. Furthermore, the practical applicability and effectiveness of mbDriver are showcased using a dietary fiber intervention dataset and an ulcerative colitis dataset. Notably, driver microbes identified in the dietary fiber intervention dataset exhibit significant effects on the abundances of short-chain fatty acids, while those identified in the ulcerative colitis dataset show a significant correlation with metabolism-related pathways.

Comparison of Tissue and Urine Microbiota in Male, Intervention Naive Patients with and without Non-Invasive Bladder Cancer

INTRODUCTION

To investigate the presence of dysbiosis in patients with naive bladder cancer.

METHODS

Twelve male patients with non-invasive bladder cancer and twelve age-matched healthy males had midstream urine and tissue samples taken. A history of endourological interventions was determined as an exclusion criterion, ensuring that the study was designed solely with naïve participants. The bacterial 16s ribosomal RNA V3-V4 regions were used to examine urine and tissue samples. We compared the microbiota composition of the bladder cancer and control groups.

RESULTS

Escherichia Shigella (p < 0.001), Staphylococcus (p < 0.001), Delftia (p < 0.001), Acinetobacter (p < 0.001), Corynebacterium (p < 0.001), and Enhydrobacter (p < 0.001) were abundant in bladder cancer tissue samples. Escherichia Shigella (p < 0.001), Ureaplasma (p < 0.001), Lactobacillus (p = 0.005), Stenotrophomonas (p < 0.001), Streptococcus (p < 0.001), Corynebacterium (p < 0.001), and Prevotella (p = 0.039) were abundant in bladder cancer urine samples. Midstream urine has a sensitivity of 83% for detecting dysbiotic bacteria in cancer tissue.

CONCLUSIONS

Our research is the first microbiota study of bladder cancer done with naive patients who have never had an endourological intervention. Escherichia Shigella, Staphylococcus, Acinetobacter, Enhydrobacter, Delftia, Corynebacterium, and Pseudomonas were detected as dysbiotic bacteria in bladder cancer. The sensitivity of the midstream urine sample in detecting dysbiosis in tissue is 83%.

Dysbiosis in Human Urinary Microbiota May Differentiate Patients with a Bladder Cancer

Recent interest in noninvasive diagnostic approaches has highlighted the potential of urinary microbiota as a novel biomarker for bladder cancer. This study investigated the urinary microbiota of 30 bladder cancer patients and 32 healthy controls using a specific NGS protocol that sequences eight hypervariable regions of the 16S rRNA gene, providing detailed insights into urinary microbiota composition. The relative abundance of microbial compositions in urine samples from cancer patients and healthy controls was analyzed across various taxonomic levels. No notable differences were highlighted at the phylum, class, order, and family levels. At the genus level, 53% of detected genera were represented in either cancer patients or healthy controls. Microbial diversity was significantly lower in cancer patients. The differential analysis identified five genera, Rhodanobacter, Cutibacterium, Alloscardovia, Moryella, and Anaeroglobus, that were significantly more abundant in cancer patients. Notably, Rhodanobacter was present in 20 cancer samples but absent in healthy controls. Conversely, 40 genera, including Lactobacillus, Propionibacterium, and Bifidobacterium, exhibited reduced abundance in cancer patients. These findings suggest that some genera may serve as potential biomarkers for bladder cancer, highlighting the need for further research to explore their roles in disease pathogenesis and their potential applications in diagnostics and therapeutics.

Altered microbial diversity and composition of multiple mucosal organs in cervical cancer patients

OBJECTIVES

The aim of this study was to characterize the microbiome of multiple mucosal organs in cervical cancer (CC) patients.

METHODS

We collected oral, gut, urinary tract, and vaginal samples from enrolled study participants, as well as tumor tissue from CC patients. The microbiota of different mucosal organs was identified by 16S rDNA sequencing and correlated with clinical-pathological characteristics of cervical cancer cases.

RESULTS

Compared with controls, CC patients had reduced α-diversity of oral and gut microbiota (pOral_Sob < 0.001, pOral_Shannon = 0.049, pOral_Simpson = 0.013 pFecal_Sob = 0.030), although there was an opposite trend in the vaginal microbiota (pVaginal_Pielou = 0.028, pVaginal_Simpson = 0.006). There were also significant differences in the β-diversity of the microbiota at each site between cases and controls (pOral = 0.002, pFecal = 0.037, pUrine = 0.001, pVaginal = 0.001). The uniformity of urine microbiota was lower in patients with cervical squamous cell carcinoma (pUrine = 0.036) and lymph node metastasis (pUrine_Sob = 0.027, pUrine_Pielou = 0.028, pUrine_Simpson = 0.021, pUrine_Shannon = 0.047). The composition of bacteria in urine also varied among patients with different ages (p = 0.002), tumor stages (p = 0.001) and lymph node metastasis (p = 0.002). In CC cases, Pseudomonas were significantly enriched in the oral, gut, and urinary tract samples. In addition, Gardnerella, Anaerococcus, and Prevotella were biomarkers of urinary tract microbiota; Abiotrophia and Lautropia were obviously enriched in the oral microbiota. The microbiota of tumor tissue correlated with other mucosal organs (except the gut), with a shift in the microflora between mucosal organs and tumors.

CONCLUSIONS

Our study not only revealed differences in the composition and diversity of the vaginal and gut microflora between CC cases and controls, but also showed dysbiosis of the oral cavity and urethra in cervical cancer cases.

Emerging roles of intratumor microbiota in cancer: tumorigenesis and management strategies

The intricate interplay between the host and its microbiota has garnered increasing attention in the past decade. Specifically, the emerging recognition of microorganisms within diverse cancer tissues, previously presumed sterile, has ignited a resurgence of enthusiasm and research endeavors. Four potential migratory routes have been identified as the sources of intratumoral microbial "dark matter," including direct invasion of mucosal barriers, spreading from normal adjacent tissue, hematogenous spread, and lymphatic drainage, which contribute to the highly heterogeneous features of intratumor microbiota. Importantly, multitudes of studies delineated the roles of intratumor microbiota in cancer initiation and progression, elucidating underlying mechanisms such as genetic alterations, epigenetic modifications, immune dysfunctions, activating oncogenic pathways, and inducing metastasis. With the deepening understanding of intratumoral microbial composition, novel microbiota-based strategies for early cancer diagnosis and prognostic stratification continue to emerge. Furthermore, intratumor microbiota exerts significant influence on the efficacy of cancer therapeutics, particularly immunotherapy, making it an enticing target for intervention in cancer treatment. In this review, we present a comprehensive discussion of the current understanding pertaining to the developmental history, heterogeneous profiles, underlying originations, and carcinogenic mechanisms of intratumor microbiota, and uncover its potential predictive and intervention values, as well as several inevitable challenges as a target for personalized cancer management strategies.

The role of KLF5 in gut microbiota and lung adenocarcinoma: unveiling programmed cell death pathways and prognostic biomarkers

Lung adenocarcinoma (LUAD) is the most important subtype of lung cancer. It is well known that the gut microbiome plays an important role in the pathophysiology of various diseases, including cancer, but little research has been done on the intestinal microbiome associated with LUAD. Utilizing bioinformatics tools and data analysis, we identified novel potential prognostic biomarkers for LUAD. To integrate differentially expressed genes and clinical significance modules, we used a weighted correlation network analysis system. According to the Peryton database and the gutMGene database, the composition and structure of gut microbiota in LUAD patients differed from those in healthy individuals. LUAD was associated with 150 gut microbiota and 767 gut microbiota targets, with Krüppel-like factor 5 (KLF5) being the most closely related. KLF5 was associated with immune status and correlated well with the prognosis of LUAD patients. The identification of KLF5 as a potential prognostic biomarker suggests its utility in improving risk stratification and guiding personalized treatment strategies for LUAD patients. Altogether, KLF5 could be a potential prognostic biomarker in LUAD.

Roles of intralesional bacteria in the initiation and progression of oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the predominant form of head and neck cancer, often diagnosed at late stages, resulting in a poor prognosis. Recent studies indicate a potential association between OSCC and microbial presence. Microorganisms have been identified in various tumors and lesions, including OSCC and oral potentially malignant disorders (OPMDs). Intralesional microbiota are considered important components of the tumor microenvironment (TME) and may contribute to carcinogenesis.

METHODS

Sources were collected through thorough searches of databases PubMed and Embase. The review focused on microbial characteristics, potential origins, and their impact on cancer progression.

RESULTS

Bacteria display varying abundance and diversity throughout the stages of OSCC and OPMDs. Intraleisional bacteria may have diverse sources, including not only oral plaque and saliva but also potentially the gut. Intralesional bacteria have both pro-carcinogenic and anti-carcinogenic effects, affecting processes like cell proliferation, invasion, and immune response.

CONCLUSIONS

Intralesional microbiota are crucial in OSCC and OPMDs, influencing both disease progression and treatments. Despite their significance, challenges like inconsistent sampling and microbial identification remain. Future research is required to fully understand their role and improve clinical applications.

The role of the gut microbiome in regulating the response to immune checkpoint inhibitor therapy

Immune checkpoint inhibitors (ICIs) have revolutionised cancer therapy, yet the proportion of patients who achieve long-term disease control remain suboptimal. Over the past decade, the gut microbiome has been shown to influence immune-mediated tumour suppression as well as responses to ICI therapies. Compositional differences in gut microbiome may account for the differences in outcomes from immune checkpoint blockade. Identifying microbiota species associated with favourable/unfavourable outcomes and modelling their dynamics throughout the course of ICI treatment could help develop predictive biomarkers of immunotherapy response, and manipulating the gut microbiome represent a novel approach to enhancing ICI effectiveness. Clinically, this raises the prospect of using gut microbiome-based therapies to overcome primary resistance to ICIs, mitigate the effects of microbiome-altering drugs such as antibiotics or proton pump inhibitors, and improve overall survival in patients across numerous different cancer types.

Staphylococcus aureus lipid factors modulate melanoma cell clustering and invasion

The microbiome can influence cancer development and progression. However, less is known about the role of the skin microbiota in melanoma. Here, we took advantage of a zebrafish melanoma model to probe the effects of Staphylococcus aureus on melanoma invasion. We found that S. aureus produces factors that enhance melanoma invasion and dissemination in zebrafish larvae. We used a published in vitro 3D cluster formation assay that correlates increased clustering with tumor invasion. S. aureus supernatant increased clustering of melanoma cells and was abrogated by a Rho-Kinase inhibitor, implicating a role for Rho-GTPases. The melanoma clustering response was specific to S. aureus but not to other staphylococcal species, including S. epidermidis. Our findings suggest that S. aureus promotes melanoma clustering and invasion via lipids generated by the lipase Sal2 (officially known as GehB). Taken together, these findings suggest that specific bacterial products mediate melanoma invasive migration in zebrafish.