Tumor-Associated Microbiota in Esophageal Squamous Cell Carcinoma

Non-invasive early detection on esophageal squamous cell carcinoma and precancerous lesions by microbial biomarkers combining epidemiological factors in China

BACKGROUND

Microbiota may be associated with esophageal squamous cell carcinoma (ESCC) development. However, it is not known the predictive value of microbial biomarkers combining epidemiological factors for the early detection of ESCC and precancerous lesions.

METHODS

A total of 449 specimens (esophageal swabs and saliva) were collected from 349 participants with different esophageal statuses in China to explore and validate ESCC-associated microbial biomarkers from genes level to species level by 16S rRNA sequencing, metagenomic sequencing and real-time quantitative polymerase chain reaction.

RESULTS

A bacterial biomarker panel including Actinomyces graevenitzii (A.g_1, A.g_2, A.g_3, A.g_4), Fusobacteria nucleatum (F.n_1, F.n_2, F.n_3), Haemophilus haemolyticus (H.h_1), Porphyromonas gingivalis (P.g_1, P.g_2, P.g_3) and Streptococcus australis (S.a_1) was explored by metagenomic sequencing to early detect the participants in Need group (low-grade intraepithelial neoplasia, high-grade intraepithelial neoplasia and ESCC) vs participants without these lesions as the Noneed group. Significant quantitative differences existed for each microbial target in which the detection efficiency rate was higher in saliva than esophageal swab. In saliva, the area under the curve (AUC) based on the microbial biomarkers (A.g_4 ∩ P.g_3 ∩ H.h_1 ∩ S.a_1 ∩ F.n_2) was 0.722 (95% CI 0.621-0.823) in the exploration cohort. Combining epidemiological factors (age, smoking, drinking, intake of high-temperature food and toothache), the AUC improved to 0.869 (95% CI 0.802-0.937) in the exploration cohort, which was validated with AUC of 0.757 (95% CI 0.663-0.852) in the validation cohort.

CONCLUSIONS

It is feasible to combine microbial biomarkers in saliva and epidemiological factors to early detect ESCC and precancerous lesions in China.

Combining fecal microbiome and metabolomics reveals diagnostic biomarkers for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most predominant subtypes of esophageal cancer. The characteristics of the gut microbiome and its metabolites from patients with ESCC have not been adequately studied and discussed. In this study, 40 fecal samples (20 from ESCC patients and 20 from healthy controls) were analyzed by 16S rRNA gene sequencing and untargeted metabolomics. The data sets were analyzed individually and synthesized using various bioinformatics methods. Alpha and beta diversity indicated significant differences in microbial diversity and abundance between ESCC and healthy control feces. At the genus level, the abundance of Phascolarctobacterium, Sutterella, and Streptococcus was significantly increased in ESCC. At the genus level, linear discriminant analysis effect size identified two biomarkers: Bacteroides_stercoris and Prevotella_copri. Untargeted metabolomics analysis revealed 307 differential metabolites between ESCC and healthy control feces, with indoles and derivatives, tropane alkaloids, lipids, and lipid-like molecules in higher relative abundance in ESCC feces than in healthy control feces. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that unsaturated fatty acids (FAs), ascorbate and aldarate metabolism, and hypoxia-inducible factor 1 signaling pathway were significantly associated with differential metabolite. Phenylethanolamine and despropionyl p-fluoro fentanyl could be used as reliable biomarkers to differentiate ESCC from healthy control. The correlation analysis showed that Prevotella may be involved in the synthesis of fatty acyl, carboxylic acids and derivatives, benzenes and substituted derivatives, organic oxygenates, and indoles and derivatives as metabolites. Fusicatenibacter and Lachnospira may be involved in the degradation of indoles and derivatives. Alistipes, Agathobacter, and Parabacteroides may be involved in the synthesis of indoles and derivatives with strong contributions. There is an intricate relationship between the gut microbiome and the levels of several metabolites (e.g., fatty acyls, carboxylic acids and derivatives, indoles, and derivatives). Microbial-associated metabolites can be used as diagnostic biomarkers in therapeutic exploration. Further analysis revealed that Prevotella, Alistipes, Agathobacter, and Parabacteroides might promote ESCC by regulating the synthesis of indoles and their derivatives. The results of this study provide favorable evidence for the early diagnosis of ESCC and subsequent individualized treatment and targeted interventions.IMPORTANCEWe describe for the first time the differences in fecal microbiome composition and metabolites between patients with esophageal squamous cell carcinoma (ESCC) and healthy controls by 16S rRNA gene sequencing and untargeted metabolomics. The results of this study provide a favorable basis for the early diagnosis of ESCC and subsequent targeted interventional therapy.

Characterization of tumor microbiome and associations with prognosis in intrahepatic cholangiocarcinoma

BACKGROUND

The tumor microbiome has been characterized in several malignancies; however, no previous studies have investigated its role in intrahepatic cholangiocarcinoma (ICC). Hence, we explored the tumor microbiome and its association with prognosis in ICC.

METHODS

One hundred and twenty-one ICC tumor samples and 89 adjacent normal tissues were profiled by 16S rRNA sequencing. Microbial differences between tumor and adjacent nontumoral liver tissues were assessed. Tumor microbial composition was then evaluated to detect its association with prognosis. Finally, a risk score calculated by the tumor microbiota was accessed by the least absolute shrinkage and selector operator method (Lasso) to predict prognosis of ICC.

RESULTS

The tumor microbiome displayed a greater diversity than that in adjacent nontumoral liver tissues. Tumor samples were characterized by a higher abundance of Firmicutes, Actinobacteria, Bacteroidetes, and Acidobacteriota. Higher tumor microbial α diversity was associated with lymph node metastasis and predicted shortened overall survival (OS) and recurrence-free survival (RFS). A total of 11 bacteria were selected to generate the risk score by Lasso. This score showed potential in predicting OS, and was an independent risk factor for OS.

CONCLUSION

In conclusion, our study characterized the tumor microbiome and revealed its role in predicting prognosis in ICC.

An emerging strategy: probiotics enhance the effectiveness of tumor immunotherapy via mediating the gut microbiome

The occurrence and progression of tumors are often accompanied by disruptions in the gut microbiota. Inversely, the impact of the gut microbiota on the initiation and progression of cancer is becoming increasingly evident, influencing the tumor microenvironment (TME) for both local and distant tumors. Moreover, it is even suggested to play a significant role in the process of tumor immunotherapy, contributing to high specificity in therapeutic outcomes and long-term effectiveness across various cancer types. Probiotics, with their generally positive influence on the gut microbiota, may serve as effective agents in synergizing cancer immunotherapy. They play a crucial role in activating the immune system to inhibit tumor growth. In summary, this comprehensive review aims to provide valuable insights into the dynamic interactions between probiotics, gut microbiota, and cancer. Furthermore, we highlight recent advances and mechanisms in using probiotics to improve the effectiveness of cancer immunotherapy. By understanding these complex relationships, we may unlock innovative approaches for cancer diagnosis and treatment while optimizing the effects of immunotherapy.

Upper gastrointestinal tract microbiota with oral origin in relation to oesophageal squamous cell carcinoma

Introduction: Poor oral hygiene is linked to high risks of many systemic diseases, including cancers. Oral dysbiosis is closely associated with poor oral hygiene, causing tooth loss, gingivitis, and periodontitis. We provide a summary of studies and discuss the risk factors for oesophageal squamous cell carcinoma (ESCC) from a microbial perspective in this review.Methods: A literature search of studies published before December 31, 2022 from PubMed, Web of Science, and The Cochrane Library was performed. The search strategies included the following keywords: (1) oral care, oral health, oral hygiene, dental health, dental hygiene, tooth loss, teeth loss, tooth absence, missing teeth, edentulism, tooth brushing, mouthwash, and tooth cleaning; (2) esophageal, esophagus, oesophagus, and oesophageal; (3) cancer, carcinoma, tumor, and neoplasm.Discussion: Poor oral health, indicated by infrequent tooth brushing, chronic periodontitis, and tooth loss, has been associated with an increased risk of squamous dysplasia and ESCC. Oral microbial diversity and composition are profoundly dysregulated during oesophageal tumorigenesis. Similar to the oral microbiota, the oesophageal microbiota varies distinctly in multiple bacterial taxa in ESCC and gastric cardia adenocarcinoma, both of which have high co-occurrence rates in the "Oesophageal Cancer Belt". In addition, the potential roles of oncogenic viruses in ESCC have also been discussed. We also briefly explore the potential mechanisms underlying the tumor-promoting role of dysregulated microbiota for the development of therapeutic targeting strategies.Conclusion: Poor oral health is an established risk indicator of ESCC. The dysbiosis of microbiota in upper gastrointestinal tract that highly resembles the oral microbial ecosystem but with distinct features at individual sites contributes to the development and progression of ESCC.

Microbiome changes in esophageal cancer: implications for pathogenesis and prognosis

Esophageal cancer (EC) is an aggressive malignancy with a poor prognosis. Various factors, including dietary habits, and antacid and antibiotic use, have been shown to influence the esophageal microbiome. Conversely, enrichment and diversity of the esophageal microbiome can also impact its function. Recent studies have revealed prevalent changes in the esophageal microbiome among patients with EC, thus suggesting the potential contribution of the esophageal microbiome to EC development. Additionally, distinct microbiome compositions have been observed in patients with different responses to radiotherapy and chemotherapy, indicating the role of the esophageal microbiome in modulating treatment outcomes. In this review, we have examined previous studies on the esophageal microbiome in healthy individuals and patients with EC or other esophageal diseases, with a focus on identifying microbial communities associated with EC pathogenesis and prognosis. Understanding the role of the microbiome in EC may aid in early detection and optimized treatment strategies, ultimately leading to better outcomes for patients.

The Influence of the Microbiome on Immunotherapy for Gastroesophageal Cancer

Immunotherapy has shown promise as a treatment option for gastroesophageal cancer, but its effectiveness is limited in many patients due to the immunosuppressive tumor microenvironment (TME) commonly found in gastrointestinal tumors. This paper explores the impact of the microbiome on the TME and immunotherapy outcomes in gastroesophageal cancer. The microbiome, comprising microorganisms within the gastrointestinal tract, as well as within malignant tissue, plays a crucial role in modulating immune responses and tumor development. Dysbiosis and reduced microbial diversity are associated with poor response rates and treatment resistance, while specific microbial profiles correlate with improved outcomes. Understanding the complex interactions between the microbiome, tumor biology, and immunotherapy is crucial for developing targeted interventions. Microbiome-based biomarkers may enable personalized treatment approaches and prediction of patient response. Interventions targeting the microbiome, such as microbiota-based therapeutics and dietary modifications, offer the potential for reshaping the gut microbiota and creating a favorable TME that enhances immunotherapy efficacy. Further research is needed to reveal the underlying mechanisms, and large-scale clinical trials will be required to validate the efficacy of microbiome-targeted interventions.

Global comparative transcriptomes uncover novel and population-specific gene expression in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis and is one of the deadliest gastrointestinal malignancies. Despite numerous transcriptomics studies to understand its molecular basis, the impact of population-specific differences on this disease remains unexplored.

AIMS

This study aimed to investigate the population-specific differences in gene expression patterns among ESCC samples obtained from six distinct global populations, identify differentially expressed genes (DEGs) and their associated pathways, and identify potential biomarkers for ESCC diagnosis and prognosis. In addition, this study deciphers population specific microbial and chemical risk factors in ESCC.

METHODS

We compared the gene expression patterns of ESCC samples from six different global populations by analyzing microarray datasets. To identify DEGs, we conducted stringent quality control and employed linear modeling. We cross-compared the resulting DEG lists of each populations along with ESCC ATLAS to identify known and novel DEGs. We performed a survival analysis using The Cancer Genome Atlas Program (TCGA) data to identify potential biomarkers for ESCC diagnosis and prognosis among the novel DEGs. Finally, we performed comparative functional enrichment and toxicogenomic analysis.

RESULTS

Here we report 19 genes with distinct expression patterns among populations, indicating population-specific variations in ESCC. Additionally, we discovered 166 novel DEGs, such as ENDOU, SLCO1B3, KCNS3, IFI35, among others. The survival analysis identified three novel genes (CHRM3, CREG2, H2AC6) critical for ESCC survival. Notably, our findings showed that ECM-related gene ontology terms and pathways were significantly enriched among the DEGs in ESCC. We also found population-specific variations in immune response and microbial infection-related pathways which included genes enriched for HPV, Ameobiosis, Leishmaniosis, and Human Cytomegaloviruses. Our toxicogenomic analysis identified tobacco smoking as the primary risk factor and cisplatin as the main drug chemical interacting with the maximum number of DEGs across populations.

CONCLUSION

This study provides new insights into population-specific differences in gene expression patterns and their associated pathways in ESCC. Our findings suggest that changes in extracellular matrix (ECM) organization may be crucial to the development and progression of this cancer, and that environmental and genetic factors play important roles in the disease. The novel DEGs identified may serve as potential biomarkers for diagnosis, prognosis and treatment.

Biofilm and Cancer: Interactions and Future Directions for Cancer Therapy

There is a growing body of evidence supporting the significant role of bacterial biofilms in the pathogenesis of various human diseases, including cancer. Biofilms are polymicrobial communities enclosed within an extracellular matrix composed of polysaccharides, proteins, extracellular DNA, and lipids. This complex matrix provides protection against antibiotics and host immune responses, enabling the microorganisms to establish persistent infections. Moreover, biofilms induce anti-inflammatory responses and metabolic changes in the host, further facilitating their survival. Many of these changes are comparable to those observed in cancer cells. This review will cover recent research on the role of bacterial biofilms in carcinogenesis, especially in colorectal (CRC) and gastric cancers, emphasizing the shared physical and chemical characteristics of biofilms and cancer. This review will also discuss the interactions between bacteria and the tumor microenvironment, which can facilitate oncogene expression and cancer progression. This information will provide insight into developing new therapies to identify and treat biofilm-associated cancers, such as utilizing bacteria as delivery vectors, using bacteria to upregulate immune function, or more selectively targeting biofilms and cancer for their shared traits.

Immune checkpoint inhibitors in the treatment of oesophageal squamous cell carcinoma: where are we and where are we going?

Oesophageal squamous cell carcinoma (ESCC) is a kind of malignant tumour with high invasiveness and a poor prognosis. Immunotherapy, especially immune checkpoint inhibitors (ICIs), is a rapidly growing therapeutic method that activates and enhances anti-tumour immunity to treat patients with malignancy. Several clinical trials have confirmed the efficacy of ICIs in the treatment of ESCC. ICIs have been approved for the treatment of patients with ESCC. However, only a subset of patients can obtain excellent benefits from ICI therapy. In recent years, there has been a growing interest in exploring predictive biomarkers of immunotherapy response. In this review, we highlighted the predictive biomarkers for the prognosis of ESCC patients treated with ICIs and pointed out the existing problems and the direction of future research in this field.

Esophageal microflora in esophageal diseases

With the development of endoscopic technology, an increasing number of patients with esophageal disease are being diagnosed, although the underlying pathogenesis of many esophageal diseases remains unclear. In recent years, a large number of studies have demonstrated that the occurrence and development of various intestinal diseases were related to intestinal flora. As a result, researchers have shifted their focus towards investigating esophageal flora to better understand the pathogenesis, early diagnosis, and treatment of esophageal diseases. This paper reviewed the normal esophageal flora and the changes of esophageal flora under different esophageal disease states. It was observed that there are distinct differences in the composition of esophageal microflora among Gastroesophageal Reflux, Barrett's esophagus, eosinophilic esophagitis and normal esophagus. The normal esophageal flora was dominated by gram-positive bacteria, particularly Streptococcus, while the esophageal flora under esophagitis was dominated by gram-negative bacteria. Furthermore, the diversity of esophageal flora is significantly decreased in patients with esophageal cancer. Several potential microbial biomarkers for esophageal cancer have been identified, among which Fusobacterium nucleatum showed a close association with esophageal squamous cell carcinoma's pathological stage and clinical stage.

Evaluation of the Oesophagogastric Cancer-Associated Microbiome: A Systematic Review and Quality Assessment

OBJECTIVE

Oesophagogastric cancer is the fifth most common cancer worldwide, with poor survival outcomes. The role of bacteria in the pathogenesis of oesophagogastric cancer remains poorly understood.

DESIGN

A systematic search identified studies assessing the oesophagogastric cancer microbiome. The primary outcome was to identify bacterial enrichment specific to oesophagogastric cancer. Secondary outcomes included appraisal of the methodology, diagnostic performance of cancer bacteria and the relationship between oral and tissue microbiome.

RESULTS

A total of 9295 articles were identified, and 87 studies were selected for analysis. Five genera were enriched in gastric cancer: Lactobacillus, Streptococcus, Prevotella, Fusobacterium and Veillonella. No clear trends were observed in oesophageal adenocarcinoma. Streptococcus, Prevotella and Fusobacterium were abundant in oesophageal squamous cell carcinoma. Functional analysis supports the role of immune cells, localised inflammation and cancer-specific pathways mediating carcinogenesis. STORMS reporting assessment identified experimental deficiencies, considering batch effects and sources of contamination prevalent in low-biomass samples.

CONCLUSIONS

Functional analysis of cancer pathways can infer tumorigenesis within the cancer-microbe-immune axis. There is evidence that study design, experimental protocols and analytical techniques could be improved to achieve more accurate and representative results. Whole-genome sequencing is recommended to identify key metabolic and functional capabilities of candidate bacteria biomarkers.

Convergent dysbiosis of upper aerodigestive microbiota between patients with esophageal and oral cavity squamous cell carcinoma

The bidirectional association between primary esophageal squamous cell carcinoma (ESCC) and oral cavity squamous cell carcinoma (OSCC) suggests common risk factors and oncogenic molecular processes but it is unclear whether these two cancers display similar patterns of dysbiosis in their upper aerodigestive microbiota (UADM). We conducted a case-control study to characterize the microbial communities in esophageal lavage samples from 49 ESCC patients and oral rinse samples from 91 OSCC patients using 16S rRNA V3-V4 amplicon sequencing. Compared with their respective non-SCC controls from the same anatomical sites, 32 and 45 discriminative bacterial genera were detected in ESCC and OSCC patients, respectively. Interestingly, 20 of them were commonly enriched or depleted in both types of cancer, suggesting a convergent niche adaptation of upper aerodigestive SCC-associated bacteria that may play important roles in the pathogenesis of malignancies. Notably, Fusobacterium, Selenomonas, Peptoanaerobacter and Peptostreptococcus were enriched in both ESCC and OSCC, whereas Streptococcus and Granulicatelia were commonly depleted. We further identified Fusobacterium nucleatum as the most abundant species enriched in the upper aerodigestive SCC microenvironment, and the higher relative abundances of Selenomonas danae and Treponema maroon were positively correlated with smoking. In addition, predicted functional analysis revealed several depleted (eg, lipoic acid and pyruvate metabolism) and enriched (eg, RNA polymerase and nucleotide excision repair) pathways common to both cancers. Our findings reveal a convergent dysbiosis in the UADM between patients with ESCC and OSCC, suggesting a shared niche adaptation of host-microbiota interactions in the pathogenesis of upper aerodigestive tract malignancies.

Esophageal mycobiome landscape and interkingdom interactions in esophageal squamous cell carcinoma

Background

The study purpose was to characterize the mycobiome and its associations with the expression of pathogenic genes in esophageal squamous cell carcinoma (ESCC).

Methods

Patients with primary ESCC were recruited from two central hospitals. We performed internal transcribed spacer 1 (ITS1) ribosomal DNA sequencing analysis. We compared differential fungi and explored the ecology of fungi and the interaction of bacteria and fungi.

Results

The mycobiota diversity was significantly different between tumors and tumor-adjacent samples. We further analysed the differences between the two groups, at the species level, confirming that Rhodotorula toruloides, Malassezia dermatis, Hanseniaspora lachancei, and Spegazzinia tessarthra were excessively colonized in the tumor samples, whereas Preussia persica, Fusarium solani, Nigrospora oryzae, Acremonium furcatum, Golovinomyces artemisiae, and Tausonia pullulans were significantly more abundant in tumor-adjacent samples. The fungal co-occurrence network in tumor-adjacent samples was larger and denser than that in tumors. Similarly, the more complex bacterial-fungal interactions in tumor-adjacent samples were also detected. The expression of mechanistic target of rapamycin kinase was positively correlated with the abundance of N. oryzae and T. pullulans in tumor-adjacent samples. In tumors, the expression of MET proto-oncogene, receptor tyrosine kinase (MET) had a negative correlation and a positive correlation with the abundance of R. toruloides and S. tessarthra, respectively.

Conclusion

This study revealed the landscape of the esophageal mycobiome characterized by an altered fungal composition and bacterial and fungal ecology in ESCC.

Effects of chemotherapy and immunotherapy on microbial diversity in TME and engineered bacterial-mediated tumor therapy

Tumor microbiota is a group of microorganisms located in tumor tissues with rich diversity that can promote tumorigenesis and development, and different types of tumors have different tumor microbiotas, which has important implications for tumor research, detection, and clinical treatment. In this review, we examine the diversity of the tumor microbiota, discuss the impact of chemotherapy and immunotherapy on tumor microbiota diversity, and summarize recent advances in the use of genetically engineered bacteria for the treatment of tumors. In addition, we propose key questions that need to be further addressed by the tumor microbiota.

Intratumoral microbiome and gastrointestinal cancers

Emerging studies have revealed the role of microbiota in regulating tumorigenesis, development, and response to antitumor treatment. However, most studies have focused on gut microbiota, and little is known about the intratumoral microbiome. To date, the latest research has indicated that the intratumoral microbiome is a key component of the tumor microenvironment (TME), and can promote a heterogeneous immune microenvironment, reprogram tumor metabolism to affect tumor invasion and metastasis. In this review, we will summarize existing studies on the intratumoral microbiome of gastrointestinal cancers and reveal their crosstalk. This will provide a better understanding of this emerging field and help to explore new therapeutic approaches for cancer patients by targeting the intratumoral microbiome.

Esophageal cancer and bacterial part of gut microbiota - A multidisciplinary point of view

There is an urgent need to search for new screening methods that allow early detection of esophageal cancer and thus achieve better clinical outcomes. Nowadays, it is known that the esophagus is not a sterile part of the gastrointestinal tract. It is colonized with various microorganisms therefore a "healthy" esophageal microbiome exists. The dysbiotic changes of esophageal microbiome can lead to the development of esophageal diseases including esophageal cancer. There is a strong consensus in the literature that the intestinal microbiome may be involved in esophageal carcinogenesis. Recently, emphasis has also been placed on the relationship between the oral microbiome and the occurrence of esophageal cancer. According to recent studies, some of the bacteria present in the oral cavity, such as Tannerella forsythia, Streptococcus anginosus, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum may contribute to the development of this cancer. Moreover, the oral microbiome of patients with esophageal cancer differs significantly from that of healthy individuals. This opens new insights into the search for a microbiome-associated marker for early identification of patients at high risk for developing this cancer.

Predictive value of the presence of Prevotella and the ratio of Porphyromonas gingivalis to Prevotella in saliva for esophageal squamous cell carcinoma

Background

Imbalance of oral salivary microbiota has been linked to the pathogenesis of a variety of systemic diseases, and oral bacterial species have been shown to be useful biomarkers for systemic diseases.This study aimed to characterize the alterations of oral microbiota in patients with esophageal squamous cell carcinoma (ESCC) and to evaluate the diagnostic performance of oral microbial biomarkers for ESCC.

Methods

The relative abundance of flora in saliva samples was analyzed by 16S rDNA sequencing, and differences in the species present in samples from ESCC patients and healthy controls (HCs) were identified by analyzing species diversity and performing LEfSe analysis. Receiver operating characteristic (ROC) curve analysis was applied to evaluate the diagnostic performance of the characteristic bacteria individually and in combination.

Results

Differences in bacterial diversity indexes were observed for the saliva of ESCC patients versus HCs (P<0.05), but principal coordinate analysis did not detect a significant difference in the composition of oral microbiota between ESCC patients and HCs (P>0.05). LEfSe analysis showed that Leptotrichia, Porphyromonas (Pg), Streptococcus, Rothia, Lactobacillus and Peptostreptococcus were more abundant in ESCC patient saliva than in HC saliva, whereas Haemophilus, Alloprevotella (All), Prevotella_7, Prevotella (Pre), Prevotella_6, Pasteurellaceae and Pasteurellales were significantly less abundant in ESCC patient saliva (P<0.05). From ROC curve analysis, Pg could detect ESCC with an area under the ROC curve (AUC) of 0.599, sensitivity of 62.2%, and specificity of 70%, whereas the ratio of Pg/Pre had an AUC of 0.791, sensitivity of 93.3%, and specificity of 62.3%. Moreover, the combination of the Pg/Pre and Pg/All ratios showed further improved diagnostic performance for ESCC (AUC=0.826) and even good sensitivity and specificity for the diagnosis of early ESCC (68.2% and 86%, respectively; AUC=0.786).

Conclusion

This study shows that Pg in saliva can be used as a characteristic marker of ESCC, and the ratios of Pg/Pre and Pg/All offered significantly improved diagnostic performance, especially for early ESCC.

Comparison of tumor-associated and nontumor-associated esophageal mucosa microbiota in patients with esophageal squamous cell carcinoma

Esophageal microbiota plays important roles in esophageal squamous cell carcinoma (ESCC). The aims of this study were to clarify the changes in the bacterial community during ESCC development and identify latent pathogenic bacteria which may contribute to esophageal carcinogenesis and progression. Fresh tumor and nontumor esophageal mucosal samples were collected from 31 men with ESCC. High-throughput 16s rRNA sequencing was performed, and the operational taxonomic unit data and bacterial classification annotation were obtained and analyzed. The Ace, Chao, Shannon, Simpson indexes, and operational taxonomic unit numbers were higher in nontumor tissues than in tumor tissues, although without statistical significance. There were 4 phyla and 28 genera found to show significant differences between tumor and nontumor samples. The general probiotic Lactobacillus was 1.98-fold higher in nontumor tissues, while the general pathogenic genera Fusobacterium was 4.35-fold higher in tumor tissues. For tumor tissue samples, the genera Treponema and Brevibacillus were significantly higher in N1 and N2 stages, respectively, and Acinetobacter was significantly higher in T3 stage. For nontumor tissues, the genus Fusicatenibacter was significantly higher in T2 stage, and Corynebacterium, Aggregatibacter, Saccharimonadaceae-TM7x, and Cupriavidus were significantly higher in T4 stage. Additionally, bacteria related to nitrotoluene degradation were enriched in nontumor tissues, while bacteria related to base excision repair were enriched in tumor tissues. The relative abundance of several phyla and genera are different between tumor and nontumor tissue samples. The altered bacterial microbiota is correlated with different tumor stages and some microbes may take part in the carcinogenesis and development of ESCC.

Characteristics and interplay of esophageal microbiota in esophageal squamous cell carcinoma

Background

Esophageal microbiota may influence esophageal squamous cell carcinoma (ESCC) pathobiology. Therefore, we investigated the characteristics and interplay of the esophageal microbiota in ESCC.

Methods

We performed 16S ribosomal RNA sequencing on paired esophageal tumor and tumor-adjacent samples obtained from 120 primarily ESCC patients. Analyses were performed using quantitative insights into microbial 2 (QIIME2) and phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2). Species found to be associated with ESCC were validated using quantitative PCR.

Results

The microbial diversity and composition of ESCC tumor tissues significantly differed from tumor-adjacent tissues; this variation between subjects beta diversity is mainly explained by regions and sampling seasons. A total of 56 taxa were detected with differential abundance between the two groups, such as R. mucilaginosa, P. endodontalis, N. subflava, H. Pylori, A. Parahaemolyticus, and A. Rhizosphaerae. Quantitative PCR confirmed the enrichment of the species P. endodontalis and the reduction of H. Pylori in tumor-adjacent tissues. Compared with tumor tissue, a denser and more complex association network was formed in tumor-adjacent tissue. The above differential taxa, such as H. Pylori, an unclassified species in the genera Sphingomonas, Haemophilus, Phyllobacterium, and Campylobacter, also participated in both co-occurrence networks but played quite different roles. Most of the differentially abundant taxa in tumor-adjacent tissues were negatively associated with the epidermal growth factor receptor (EGFR), erb-b2 receptor tyrosine kinase 2 (ERBB2), erb-b2 receptor tyrosine kinase 4 (ERBB4), and fibroblast growth factor receptor 1 (FGFR1) signaling pathways, and positively associated with the MET proto-oncogene, receptor tyrosine kinase (MET) and phosphatase and tensin homolog (PTEN) signaling pathways in tumors.

Conclusion

Alterations in the microbial co-occurrence network and functional pathways in ESCC tissues may be involved in carcinogenesis and the maintenance of the local microenvironment for ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09771-2.

Intratumor microbiome in cancer progression: current developments, challenges and future trends

Cancer is a complicated disease attributed to multifactorial changes, which causes difficulties with treatment strategies. Various factors have been regarded as the main contributors, and infectious etiological factors have recently attracted interest. Several microbiomes contribute to carcinogenesis, cancer progression, and modulating cancer treatment by inducing cancerous epithelial cells and chronic inflammation. Most of our knowledge on the role of microbiota in tumor oncogenesis and clinical efficiency is associated with the intestinal microbiome. However, compelling evidence has also confirmed the contribution of the intratumor microbiome in cancer. Indeed, the findings of clinical tumor samples, animal models, and studies in vitro have revealed that many intratumor microbiomes promote tumorigenesis and immune evasion. In addition, the intratumor microbiome participates in regulating the immune response and even affects the outcomes of cancer treatment. This review summarizes the interplay between the intratumor microbiota and cancer, focusing on the contribution and mechanism of intratumor microbiota in cancer initiation, progression, and potential applications to cancer therapy.

Cross-talk between the microbiome and chronic inflammation in esophageal cancer: potential driver of oncogenesis

Esophageal cancer (EC) is frequently considered a lethal malignancy and is often identified at a later stage. It is one of the major causes of cancer-related deaths globally. The conventional treatment methods like chemotherapy, radiotherapy, and surgery offer limited efficacy and poor clinical outcome with a less than 25% 5-year survival rate. The poor prognosis of EC persists despite the growth in the development of diagnostic and therapeutic modalities to treat EC. This underlines the need to elucidate the complex molecular mechanisms that drive esophageal oncogenesis. Apart from the role of the tumor microenvironment and its structural and cellular components in tumorigenesis, mounting evidence points towards the involvement of the esophageal microbiome, inflammation, and their cross-talk in promoting esophageal cancer. The current review summarizes recent research that delineates the underlying molecular mechanisms by which the microbiota and inflammation promote the pathophysiology of esophageal cancer, thus unraveling targets for potential therapeutic intervention.

Crosstalk between the gut microbiome and clinical response in locally advanced thoracic esophageal squamous cell carcinoma during neoadjuvant camrelizumab and chemotherapy

Background

The gut microbiome is associated with the response to immunotherapy in a variety of advanced cancers. However, the influence of the gut microbiome on locally advanced esophageal squamous cell carcinoma (ESCC) during programmed cell death protein 1 (PD-1) antibody immunotherapy plus chemotherapy is not clearly demonstrated. To explore the crosstalk between the gut microbiome and clinical response in locally advanced thoracic ESCC during neoadjuvant camrelizumab and chemotherapy

Methods

Patients who were diagnosed with locally advanced thoracic ESCC and had not received treatment were enrolled. The treatment regimen was two cycles of camrelizumab combined with carboplatin and albumin paclitaxel before surgery. The research endpoints were pathological complete response (pCR) and major pathological response (MPR). Fecal samples were collected at three time points: before neoadjuvant therapy, after two cycles of neoadjuvant therapy, and after surgery. We performed 16S ribosomal ribonucleic acid (rRNA) V3–V4 sequencing of the gene amplicons of fecal samples, as well as bacterial diversity and differential abundance analyses.

Results

A total of 46 patients were recruited, and 44, 42, and 35 fecal samples were collected at the three time points, respectively. Statistically significant differences were observed in the amplicon sequence variant (ASV)-level alpha diversity indices, including Chao1, Shannon, and Good’s coverage, between the three time points. The non-pCR-enriched gut microbiota included Proteobacteria, Dialister, Aeromonadales, Pseudomonadales, Thermi, Deinococci, Moraxellaceae, Rhodocyclales, Rhodocyclaceae, and Acinetobacter. The non-MPR-enriched gut microbiota included Pseudomonadales and the mitochondria family. The MPR-enriched gut microbiota included the Barnesiellaceae, Pyramidobacter, Dethiosulfovibrionaceae, Odoribacteraceae, Butyricimonas, Prevotella, Barnesiella, and Odoribacter. Patients with ≥3 grade adverse events (AEs) exhibited enrichment in the Succiniclasticum, Nakamurella, Rhizobium, Granulicella, Phyllobacteriaceae, Pelagibacteraceae, Actinosynnemataceae, Aquirestis, Flavisolibacter, Chelativorans, Coxiellaceae Acidicapsa, Acidobacteriaceae, Lentzea, Staphylococcus, Plesiomonas, Dysgonomonas, Pseudonocardia, and Ellin6075.

Conclusions

We found that the diversity of the gut microbiome declined after neoadjuvant PD-1 antibody immunotherapy plus chemotherapy and surgery. Patients with pCR had different types and proportions of gut microbiota before treatment compared to those without pCR. We also observed the difference between patients with or without ≥ grade 3 AEs. The taxonomic features of the gut microbiome are potential biomarkers that could predict the pathological response and AEs.

Characterization of Esophageal Microbiota in Patients With Esophagitis and Esophageal Squamous Cell Carcinoma

Microbial imbalances have been well elucidated in esophageal adenocarcinoma. However, few studies address the microbiota in esophageal squamous cell carcinoma (ESCC) and esophagitis (ES). We aimed to explore the association of esophageal microbiota with these patients. Esophageal tissues were obtained from healthy controls and ES and ESCC patients undergoing upper endoscopy. 16S rRNA gene sequencing was applied to analyze the microbiome. The α and β diversity differences were tested by Tukey test and partial least squares-discriminant analysis (PLS-DA), respectively. Linear discriminant analysis effect size (LEfSe) analysis was performed to assess taxonomic differences between groups. A total of 68 individuals were enrolled (control = 21, ES = 15, ESCC = 32). Microbial diversity was significantly different between the ESCC patients and healthy controls by Chao1 index, Shannon index, and PLS-DA. Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria were the five dominant bacterial phyla among the three groups. Megamonas, Collinsella, Roseburia, and Ruminococcus_2 showed a significantly continuous decreasing trend from the control group to the ESCC group at the genus level. When compared with the control group, decreased Fusobacteria at phylum level and Faecalibacterium, Bacteroides, Curvibacter, and Blautia at genus level were detected. ESCC samples also displayed a striking reduction of Bacteroidetes, Faecalibacterium, Bacteroides, and Blautia in comparison with the ES patients. LEfSe analysis indicated a greater abundance of Streptococcus, Actinobacillus, Peptostreptococcus, Fusobacterium, and Prevotella in the ESCC group. Our study suggests a potential association between esophageal microbiome dysbiosis and ESCC and provides insights into potential screening markers for esophageal cancer.

Gut Microbiota for Esophageal Cancer: Role in Carcinogenesis and Clinical Implications

Esophageal cancer (EC) is a common malignant tumor of the upper digestive tract. The microbiota in the digestive tract epithelium comprises a large number of microorganisms that adapt to the immune defense and interact with the host to form symbiotic networks, which affect many physiological processes such as metabolism, tissue development, and immune response. Reports indicate that there are microbial compositional changes in patients with EC, which provides an important opportunity to advance clinical applications based on findings on the gut microbiota. For example, microbiota detection can be used as a biomarker for screening and prognosis, and microorganism levels can be adjusted to treat cancer and decrease the adverse effects of treatment. This review aims to provide an outline of the gut microbiota in esophageal neoplasia, including the mechanisms involved in microbiota-related carcinogenesis and the prospect of utilizing the microbiota as EC biomarkers and treatment targets. These findings have important implications for translating the use of gut microbiota in clinical applications.

Characterization of the Oral and Esophageal Microbiota in Esophageal Precancerous Lesions and Squamous Cell Carcinoma

Important evidence indicates that the microbiota plays a key role in esophageal squamous cell carcinoma (ESCC). Here, paired saliva and brush specimens were obtained from 276 participants undergoing upper gastrointestinal endoscopic examination before or during screening for upper gastrointestinal (UGI) cancer. The esophageal microbiota was investigated by 16S rRNA gene profiling and next-generation sequencing. We observed that as the disease progressed, the α diversity in the saliva and cell brush samples decreased. Linear discriminant analysis effect size (LEfSe) results showed that in both the saliva and cell brush specimens, Granulicatella, Rothia, Streptococcus, Gemella, Leptotrichia and Schaalia were common biomarkers in patients with low-grade dysplasia, Lactobacillus was a common biomarker in patients with high-grade dysplasia, and Bosea, Solobacterium, Gemella, and Peptostreptococcus were common biomarkers in patients with esophageal cancer. The top 3 genera in the saliva and cell brush specimens had areas under the curve (AUCs) of 87.16 and 89.13%, respectively, to distinguish ESCC patients from normal people. The PICRUSt2 results identified in brush samples that patients with ESCC had decreased nitrate reductase functions. Our results suggest that future studies can focus on the function of the characteristic bacteria in ESCC.

The baseline oral microbiota predicts the response of locally advanced oral squamous cell carcinoma patients to induction chemotherapy: A prospective longitudinal study

PURPOSE

Among oral squamous cell carcinoma (OSCC) patients who receive docetaxel, cisplatin, and 5-fluorouracil (TPF) induction chemotherapy, those with a favorable pathological response tend to obtain satisfactory clinical outcomes, while the total population exhibit no survival benefit. Thus, there is an urgent need to improve the therapeutic effect of TPF by applying personalized treatment according to distinct biomarkers.

METHODS AND MATERIALS

In the present study, we collected oral rinse samples from 44 OSCC patients enrolled in our prospective multicenter random phase II trial before TPF induction chemotherapy to conduct 16S rRNA gene sequencing and metagenomic analysis. Patients were administrated with two cycles of TPF induction chemotherapy (75 mg/m² cisplatin and 75 mg/m² docetaxel on day 1 and 750 mg/m² fluorouracil from the first to the fifth day), and then divided into responsive and nonresponsive groups according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.

RESULTS

In the 16S rRNA gene sequence analysis, Fusobacterium and Mycoplasma were more enriched in the nonresponsive group, while Slackia was more enriched in the responder group at the genus level. In the metagenomic shotgun sequencing analysis, Fusobacterium nucleatum was more enriched in the nonresponsive group. Functional analysis showed that the platinum drug resistance pathway and microRNAs in cancer and RNA degradation pathways were remarkably associated with patient sensitivity to induction chemotherapy.

CONCLUSIONS

Our data suggest that the oral microbiome may play an important role in the OSCC patient sensitivity to TPF induction chemotherapy and offer novel potential biomarkers for predicting the response to TPF induction chemotherapy.

Microbial characteristics across different tongue coating types in a healthy population

Background The physical appearance of tongue coatings is vital for traditional Chinese medicine (TCM) to diagnose health and disease status. The microbiota of different tongue coatings could also influence coating formation and be further associated with specific diseases. Previous studies have focused on bacteria from different tongue coatings in the context of specific diseases, but the normal variations in healthy individuals remain unknown.Aim: We examined the tongue microbiota by metagenomics in 94 healthy individuals classified into eight different tongue types.Results: The overall composition of the tongue coating microbiome is not drastically different among different coating types, similar to the findings of previous studies in healthy populations. Further analysis revealed microbiota characteristics of each coating type, and many of the key bacteria are reported to be implicated in diseases. Moreover, further inclusion of diabetic patients revealed disease-specific enrichment of Capnocytophaga, even though the same tongue coatings were studied.Conclusions: This work revealed the characteristic compositions of distinctive tongue coatings in a healthy population, which serves as a basis for understanding the tongue coating formation mechanism and provides a valuable reference to further investigate disease-specific tongue coating bacterial markers.