Carcinogenic microbiota and its role in colorectal cancer development

PMA1-containing extracellular vesicles of Candida albicans triggers immune responses and colitis progression

Candida albicans (C. albicans) exhibits aberrant changes in patients with colitis, and it has been reported to dominate the colonic mucosal immune response. Here, we found that PMA1 expression was significantly increased in C. albicans from patients with IBD compared to that in healthy controls. A Crispr-Cas9-based fungal strain editing system was then used to knock out PMA1 expression in C. albicans. Compared to WT-C.a, ΔPMA1-C.a could not aggravate colitis. Proteomic analysis showed that PMA1 was transported by extracellular vesicles (EVs) of C. albicans. PMA1-containing EVs aggravated colitis, modulated the migration of cDC2 from the lamina propria to mesenteric lymph nodes, and induced TH17 cell differentiation. Moreover, the adaptor protein CARD9 was critical in PMA1-containing EV-induced colitis, and CARD9-deficient DCs did not induce TH17 cell differentiation or IL-17A production. Mechanically, CARD9 combines with the glycolytic protein GAPDH (aa2-146 domain) through its CARD region. CARD9 deficiency led to decreased enzyme activity of GAPDH and decreased glycolysis of DCs. These findings indicate that PMA1 is a potential virulence factor responsible for the pathogenesis of C. albicans colitis.

Ginsenoside Rh4 inhibits colorectal cancer via the modulation of gut microbiota-mediated bile acid metabolism

INTRODUCTION

Dysbiosis of the gut microbiota is emerging as a pivotal factor in the pathogenesis of colorectal cancer (CRC). Ginsenoside Rh4 (Rh4) is an active compound isolated from ginseng with beneficial effects in modulating intestinal inflammation and gut microbiota dysbiosis, but how Rh4 regulates the gut microbiota to alleviate CRC remains underexplored.

OBJECTIVES

We investigated the impact of Rh4 on CRC and the mechanism of its action in inhibiting CRC via modulation of gut microbiota.

METHODS

We used the AOM/DSS model and employed transcriptomics, genomics and metabolomics techniques to explore the inhibitory impact of Rh4 on CRC. Furthermore, we employed experiments involving antibiotic treatment and fecal microbiota transplantation (FMT) to investigate the role of the gut microbiota. Finally, we elucidated the pivotal role of key functional bacteria and metabolites regulated by Rh4 in CRC.

RESULTS

Our research findings indicated that Rh4 repaired intestinal barrier damage caused by CRC, alleviated intestinal inflammation, and inhibited the development of CRC. Additionally, Rh4 inhibited CRC in a gut microbiota-dependent manner. Rh4 increased the diversity of gut microbiota, enriched the probiotic Akkermansia muciniphila (A. muciniphila), and alleviated gut microbiota dysbiosis caused by CRC. Subsequently, Rh4 regulated A. muciniphila-mediated bile acid metabolism. A. muciniphila promoted the production of UDCA by enhancing the activity of 7α-hydroxysteroid dehydrogenase (7α-HSDH). UDCA further activated FXR, modulated the TLR4-NF-κB signaling pathway, thus inhibiting the development of CRC.

CONCLUSION

Our results confirm that Rh4 inhibits CRC in a gut microbiota-dependent manner by modulating gut microbiota-mediated bile acid metabolism and promoting the production of UDCA, which further activates the FXR receptor and regulates the TLR4-NF-κB signaling pathway. Our results confirm that Rh4 has the potential to be used as a modulator of gut microbiota for preventing and treatment of CRC.

Fusobacterium nucleatum-derived 3-indolepropionic acid promotes colorectal cancer progression via aryl hydrocarbon receptor activation in macrophages

An increasing body of research indicates that Fusobacterium nucleatum (F. nucleatum) significantly influences the onset and progression of colorectal cancer (CRC). Our previous study has shown that F. nucleatum exerts pro-tumorigenic effects through aryl hydrocarbon receptor (AhR) activation. However, the role of its microbial metabolites in regulating immune responses remains unclear. Here, we report for the first time that F. nucleatum-derived 3-Indolepropionic acid (IPA) activates AhR in macrophages, driving M2 polarization and tumor-promoting immunosuppression. We discovered that culture supernatant of F. nucleatum (CSF) robustly activates AhR in macrophages. In co-culture systems, CSF upregulated the expression of the M2 marker CD206 and elevated mRNA levels of CD163, TGF-β, IL-10, and VEGF. In a subcutaneous allograft model, CSF induced an elevated number of CD206+ macrophages and decreased presence of CD8+ T cells within the tumor microenvironment, thereby promoting tumor growth. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed IPA as a novel major AhR-activating metabolite in CSF. Strikingly, IPA recapitulated CSF's effects in promoting tumor cell migration and immunosuppression, both in vitro and in vivo. Critically, the AhR inhibitor CH223191 abolished both IPA-mediated M2 polarization and tumor growth. Our study revealed a novel mechanism by which F. nucleatum-derived IPA reprograms macrophages through AhR activation to fuel CRC progression, providing potential therapeutic targets for CRC treatment and prognosis improvement.

Temporal network analysis of gut microbiota unveils aging trajectories associated with colon cancer

The human gut microbiome's role in colorectal cancer (CRC) pathogenesis has gained increasing recognition. This study aimed to delineate the microbiome characteristics that distinguish CRC patients from healthy individuals, while also evaluating the influence of aging, through a comprehensive metagenomic approach. The study analyzed a cohort of 80 CRC patients and 80 matched healthy controls, dividing participants into a normal and a CRC group, further categorized by age into young, middle-aged, and old-aged subgroups. Extensive metagenomic sequencing of fecal samples allowed for the exploration of both the structural and functional profiles of the microbiome, with findings validated in an independent cohort to ensure robustness. Our results highlight notable differences in microbiome composition between CRC patients and healthy individuals, which exhibit age-dependent variations. Specifically, a higher prevalence of pathogenic bacteria, such as Bacteroides vulgatus, known to drive inflammation and carcinogenesis, was observed in CRC patients, alongside a reduction in beneficial microbes, including Lactobacillus. Functionally, the CRC-associated microbiome showed an increase in pathways related to DNA repair, cell cycle regulation, and metabolic activities, such as the Citrate cycle and Galactose metabolism, underscoring distinct microbial alterations in CRC patients that could influence disease onset and progression. These insights lay a foundation for future research into microbiome-based diagnostics and treatments for CRC.

IMPORTANCE

This study underscores the critical role of the gut microbiome in colorectal cancer (CRC) pathogenesis, particularly in the context of aging. By identifying age-specific microbial biomarkers and functional pathways associated with CRC, our findings provide novel insights into how microbiome composition and metabolic activities influence disease progression. These discoveries pave the way for developing personalized microbiome-based diagnostic tools and therapeutic strategies, potentially improving CRC prevention and treatment outcomes across different age groups. Understanding these microbial dynamics could also inform interventions targeting gut microbiota to mitigate CRC risk and progression.

Characteristics of tongue images and tongue coating bacteria in patients with colorectal cancer

BACKGROUND

Tongue diagnosis can assess the physiological functions and pathological conditions of colorectal cancer (CRC).

OBJECTIVE

To investigate the characteristics of tongue images and the bacteria composition of tongue coating in patients with CRC.

METHODS

A total of 59 CRC patients were enrolled and underwent tongue image analysis using a diagnostic instrument. Third-generation sequencing technique was used to determine tongue coating bacteria. The relationships among tongue images, tongue coating bacteria and clinical information (age, gender, and location) were further analyzed. Statistical analyses were performed to investigate the potential associations between tongue coating microbiota and two key variables (tongue images and age).

RESULTS

CRC patients typically present with four distinct tongue images, including yellow greasy coating, petechiae, white greasy coating, and red tongue with little coating. Notably, the microbiota composition of tongue coatings demonstrates a statistically significant correlation with both tongue diagnostic features and patient age compared to other clinical parameters. Alloprevotella rava may be primary contributors to the formation of yellow greasy coating, while Prevotella intermedia appears to be associated with the development of white greasy coating. Furthermore, Streptococcus parasanguinis might emerged as a potential biomarker for CRC patients under 62 years of age, whereas Prevotella sp. 000163055 appears to be a predominant species in the tongue coating microbiota of CRC patients over 62 years.

CONCLUSION

Overall, this study emphasizes the variations in the community structure and diversity of tongue coating bacteria in CRC patients through different tongue images. The findings provide novel insights that could enhance the predictive capacity of tongue diagnosis for clinical progression monitoring and contribute to the development of early intervention strategies in CRC management.

Advances in research on the intestinal microbiota in the mechanism and prevention of colorectal cancer (Review)

The intestinal microbiota represents a diverse population that serves a key role in colorectal cancer (CRC) and its treatment outcomes. Advancements in sequencing have revealed notable shifts in microbial composition and diversity among individuals with CRC. Concurrently, animal models have elucidated the involvement of specific microbes such as Lactobacillus fragilis, Escherichia coli and Fusobacterium nucleatum in the progression of CRC. The present review aimed to highlight contributions of intestinal microbiota to the pathogenesis of CRC, the effects of traditional treatments on intestinal microbiota and the potential for microbiota modulation as a therapeutic strategy for CRC.

Gut microbiota protect against colorectal tumorigenesis through lncRNA Snhg9

The intestinal microbiota is a key environmental factor in the development of colorectal cancer (CRC). Here, we report that, in the context of mild colonic inflammation, the microbiota protects against colorectal tumorigenesis in mice. This protection is achieved by microbial suppression of the long non-coding RNA (lncRNA) Snhg9. Snhg9 promotes tumor growth through inhibition of the tumor suppressor p53. Snhg9 suppresses p53 activity by dissociating the p53 deacetylase sirtuin 1 (SIRT1) from the cell cycle and apoptosis regulator 2 (CCAR2). Consequently, the depletion of the microbiota by antibiotics causes upregulation of Snhg9 and accelerates CRC progression. Moreover, Snhg9 is functionally conserved. Human SNHG9 promotes tumor growth via the same mechanism as mouse Snhg9, despite their low sequence similarity.

Kinesin family member 14 expression and its clinical implications in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer globally, causing over 900000 deaths annually. Risk factors include aging, diet, obesity, sedentary lifestyle, tobacco use, genetic predisposition, and inflammatory bowel disease. Despite current treatments, survival rates for advanced CRC remain low, highlighting the need for better therapeutic strategies.

AIM

To evaluate both the clinical significance and the pathological implications of the Kinesin family member 14 (KIF14) expression within CRC specimens. Additionally, this study aims to investigate the interaction between nitidine chloride (NC) and KIF14, considering their potential as therapeutic targets.

METHODS

The expression of the KIF14 protein in CRC was analyzed using immunohistochemical staining. The integration of multicenter high-throughput data facilitated the calculation of the standardized mean difference (SMD) for KIF14 mRNA levels. The assessment of clinical and pathological impact was enhanced by analyzing combined receiver operating characteristic curves, along with measures of sensitivity, specificity, and likelihood ratios. Additionally, clustered regularly interspaced short palindromic repeats knockout screening for cell growth and single-cell sequencing were employed to validate the significance of KIF14 expression in CRC. Survival analysis established the prognostic value of KIF14 in CRC. The molecular mechanism of NC against CRC was elucidated through whole-genome sequencing and enrichment analysis, and molecular docking was utilized to explore the targeting affinity between NC and KIF14.

RESULTS

KIF14 was highly expressed in 208 CRC patients. Data from 17 platforms involving 2436 CRC samples and 1320 noncancerous colorectal tissue controls indicated that KIF14 expression was significantly higher in CRC samples, with an SMD of 1.92 (95%CI: 1.49-2.35). The area under the curve was 0.94 (95%CI: 0.92-0.96), with a sensitivity of 0.85 (95%CI: 0.78-0.90) and a specificity of 0.90 (95%CI: 0.85-0.93). The positive and negative likelihood ratios were 8.38 (95%CI: 5.39-13.02) and 0.17 (95%CI: 0.11-0.26), respectively. At the single-cell level, significant overexpression of KIF14 was observed in CRC cells (P < 0.001), with 35 CRC cell lines dependent on KIF14 for growth. The K-M plots demonstrated that KIF14 possesses prognostic value in CRC patients within the GSE71187 and GSE103679 datasets (P < 0.05). Binding energy calculations indicated that KIF14 is a potential target for NC (binding energy: 10.3 kcal/mol).

CONCLUSION

KIF14 promotes the growth of CRC cells and acts as an oncogenic factor, potentially serving as a therapeutic target for NC in the treatment of CRC.

Temporal and Spatial Metabolic Shifts Revealing the Transition from Ulcerative Colitis to Colitis-Associated Colorectal Cancer

Patients with ulcerative colitis (UC) have a higher risk of developing colorectal cancer (CRC), however, the metabolic shifts during the UC-to-CRC transition remain elusive. In this study, an AOM-DSS-induced three-stage colitis-associated colorectal cancer (CAC) model is constructed and targeted metabolomics analysis and pathway enrichment are performed, uncovering the metabolic changes in this transition. Spatial metabolic trajectories in the "normal-to-normal adjacent tissue (NAT)-to-tumor" transition, and temporal metabolic trajectories in the "colitis-to-dysplasia-to-carcinoma" transition are identified through K-means clustering of 74 spatially and 77 temporally differential metabolites, respectively. The findings reveal two distinct metabolic profile categories during the inflammation-to-cancer progression: those with consistent changes, either increasing (e.g., kynurenic acid, xanthurenic acid) or decreasing (e.g., long-chain fatty acids, LCFAs), and those enriched at specific disease stages (e.g., serotonin). Further analysis of metabolites with consistent temporal trends identifies eicosapentaenoic acid (EPA) as a key metabolite, potentially exerting anti-inflammatory and anti-cancer effects by inhibiting insulin-like growth factor binding protein 5 (IGFBP5). This study reveals novel metabolic mechanisms underlying the transition from UC to CAC and suggests potential targets to delay the progression.

Emerging threat to antibiotic resistance: Impact of mycotoxin deoxynivalenol on gut microbiota and clonal expansion of extensively drug-resistant enterococci

Mycotoxins, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs) are significant environmental pollutants that pose considerable threats to environmental health and human safety through the food chain. This study is the first to investigate the impact of deoxynivalenol (DON), the most common mycotoxin, on antibiotic resistance dynamics in gut microbiota, demonstrating that DON exposure significantly selects for ARB and ARGs. Results indicated that 80.69 % of the ARGs with the highest increase in the DON group were exclusive to gram-positive bacteria, particularly those related to daptomycin. DON exposure enhanced the expression of virulence factors in gram-positive bacteria and increased reactive oxygen species (ROS) production and membrane permeability, compromising bacterial integrity and amplifying resistance mechanisms. DON also boosted the diversity and co-occurrence of ARGs and mobile genetic elements (MGEs), potentially facilitating the horizontal transfer of resistance traits. Notably, the dominant bacterial species isolated from broiler gut microbiota was identified as Enterococcus faecalis, which exhibited clonal expansion of sequence type ST123. This ST123 clone accounted for 86 % of the DON group and was associated with an extensively drug-resistant (XDR) phenotype, showing resistance levels exceeding 128 μg/mL to last-resort antibiotics such as daptomycin, vancomycin, and linezolid. Additionally, DON upregulated the expression of critical daptomycin resistance genes (liaR, walK, liaS, mprF, and cls) in vancomycin-resistant enterococci (VRE) isolates. This study highlights the microbiological and environmental hazards that mycotoxins pose to the antibiotic resistance crisis.

Diet links gut chemistry with cancer risk in C57Bl/6 mice and human colorectal cancer patients

Background & Aims

Western-style diets, characterized by higher fat and protein, and low micronutrient levels, promote the development of colorectal cancer (CRC). Here, we investigate the role of a Western diet on microbiome composition, sulfide production, and intestinal epithelial damage in pre-CRC mice, and validate taxonomic changes in a meta-analysis of human CRC patients.

Methods

NWD1 is a purified Western-style diet that produces sporadic intestinal and colon tumors in wild-type C57BL/6 mice in the absence of genetic or carcinogen exposure. To determine how this diet influences cancer risk by shaping microbial composition and sulfide chemistry, mice were fed NWD1 or a purified control diet for 24 weeks. Microbiome composition, sulfide production, and intestinal stem cell mRNA expression were assessed. Observed microbiome changes were validated in a human CRC meta-analysis.

Results

Fecal sulfide levels were tripled in NWD1-fed mice ( P< 0.00001 ), concurrent with increased abundance of the sulfidogenic Erysipelotrichaceae family. NWD1-fed mice had increased expression of mitochondrial sulfide oxidation genes in Lgr5 hi intestinal stem cells, demonstrating an adaptive response to elevated sulfide. In a meta-analysis of human CRC studies, we observed that Erysipelotrichaceae were associated with CRC, validating both canonical CRC microbes such as Solobacterium moorei and highlighting the potential contribution of previously unrecognized, disease-associated microbes.

Conclusions

Our analyses connect the risk factors of Western diet, sulfide, and epithelial damage in a pre-cancer mouse model to microbiome changes observed in human CRC patients and suggest that microbial signatures of CRC and gut ecosystem alteration may manifest long before disease development.

Predicting colorectal adenomatous polyps in patients with chronic liver disease: A novel nomogram

BACKGROUND

Colorectal polyps are commonly observed in patients with chronic liver disease (CLD) and pose a significant clinical concern because of their potential for malignancy.

AIM

To explore the clinical characteristics of colorectal polyps in patients with CLD, a nomogram was established to predict the presence of adenomatous polyps (AP).

METHODS

Patients with CLD who underwent colonoscopy at Tianjin Second People's Hospital from January 2020 to May 2023 were evaluated. Clinical data including laboratory results, colonoscopy findings, and pathology reports were collected. Key variables for the nomogram were identified through least absolute shrinkage and selection operator regression, followed by multivariate logistic regression. The performance of the model was evaluated using the area under the receiver area under curve, as well as calibration curves and decision curve analysis.

RESULTS

The study enrolled 870 participants who underwent colonoscopy, and the detection rate of AP in patients with CLD was 28.6%. Compared to individuals without polyps, six risk factors were identified as predictors for AP occurrence: Age, male sex, body mass index, alcohol consumption, overlapping metabolic dysfunction-associated steatotic liver disease, and serum ferritin levels. The novel nomogram (AP model) demonstrated an area under curve of 0.801 (95% confidence interval: 0.756-0.845) and 0.785 (95% confidence interval: 0.712-0.858) in the training and validation groups. Calibration curves indicated good agreement among predicted and actual probabilities (training: χ 2 = 11.860, P = 0.157; validation: χ 2 = 7.055, P = 0.530). The decision curve analysis underscored the clinical utility of the nomogram for predicting the risk of AP.

CONCLUSION

The AP model showed reasonable accuracy and provided a clinical foundation for predicting the occurrence of AP in patients with CLD, which has a certain predictive value.

Effects of fecal microbiota transplantation combined with selenium on intestinal microbiota in mice with colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world. With the development of high-throughput gene sequencing technology, homeostasis imbalance of the intestinal microbiota has been proven to play a key role in the pathogenesis of CRC. Furthermore, fecal bacteria transplantation (FMT) has been shown to alter the intestinal microecology, and is potentially an effective treatment for CRC. Sodium selenite plays an important role in anticancer adjuvant therapy due to its high pro-oxidation characteristics. In this study, a murine CRC tumor model was induced by AOM/DSS, and CRC mice were treated by FMT, sodium selenite, and FMT combined with sodium selenite. The results showed that FMT, sodium selenite, and FMT combined with sodium selenite inhibited the occurrence of CRC in mice, increased the abundance of beneficial intestinal bacteria, produced different microorganisms, and changed the metabolic pathways of the intestinal microbiota. In summary, FMT, sodium selenite, and FMT combined with sodium selenite can inhibit the occurrence of CRC by increasing the abundance of beneficial bacteria and regulating phenotypes and metabolic pathways. Notably, the effect of FMT combined with sodium selenite in reducing the number of tumors, protecting intestinal tissues, and restoring the diversity and richness of the intestinal microbiota is superior to that of FMT alone or sodium selenite alone. The results of this study provide new ideas for the application of FMT and selenium in the treatment of CRC.

Chinese expert consensus on standard technical specifications for a gut microecomics laboratory (Review)

The intestinal microbiota is a complex ecosystem that not only affects various physiological functions, such as metabolism, inflammation and the immune response, but also has an important effect on the development of tumors and response to treatment. The detection of intestinal flora enables the timely identification of disease-related flora abnormalities, which has significant implications for both disease prevention and treatment. In the field of basic and clinical research targeting gut microbiome, there is a need to recognize and understand the laboratory assays for gut microbiomics. Currently, there is no unified standard for the experimental procedure, quality management and report interpretation of intestinal microbiome assay technology. In order to clarify the process, the Tumor and Microecology Committee of China Anti-Cancer Association and the Tumor and Microecology Committee of Hubei Provincial Immunology Society organized relevant experts to discuss and put forward the standard technical specifications for gut microecomics laboratories, which provides a basis for further in-depth research in the field of intestinal microecomics.

Enterotoxigenic Bacteroides fragilis (ETBF) Enhances Colorectal Cancer Cell Proliferation and Metastasis Through HDAC3/miR-139-3p Pathway

Enterotoxigenic Bacteroides fragilis (ETBF) is believed to promote the malignant process of colorectal cancer (CRC), but the underlying molecular mechanism still needs to be revealed. CRC cells (SW480 and HCT-116) were treated with ETBF strain. Cell proliferation, invasion and, migration were evaluated by cell counting kit 8 assay, EdU assay, colony formation assay, transwell assay, and wound healing assay. Protein expression was analyzed by western blot. MicroRNA (miR)-139-3p and histone deacetylase 3 (HDAC3) expression levels in tissues and cells were determined by qRT-PCR. Xenograft tumor model was conducted to evaluate the effect of miR-139-3p on CRC tumor growth. ETBF treatment could promote CRC cell proliferation, invasion and migration. MiR-139-3p expression was decreased by ETBF, and its overexpression reversed the effect of ETBF on CRC cell progression. HDAC3 negatively regulated miR-139-3p expression, and its overexpression facilitated CRC cell behaviors via reducing miR-139-3p expression. Moreover, HDAC3 expression was increased by ETBF, and its knockdown also abolished ETBF-mediated CRC cell progression. Additionally, miR-139-3p overexpression could reduce CRC tumor growth in vivo. ETBF aggravated CRC proliferation and metastasis via the regulation of HDAC3/miR-139-3p axis. The discovery of ETBF/HDAC3/miR-139-3p axis may provide a new direction for CRC treatment.

Elucidating the genotoxicity of Fusobacterium nucleatum-secreted mutagens in colorectal cancer carcinogenesis

BACKGROUND

Fusobacterium nucleatum (F. nucleatum) is one of the key tumorigenic bacteria in colorectal cancer (CRC), yet how F. nucleatum is involved in colorectal cancer carcinogenesis remains unknown.

RESULTS

In the present study, we carried out PathSeq analysis on RNA sequencing data from the 430 primary colon adenocarcinomas in TCGA database to assess the relationship between patients' survival and F. nucleatum abundance. Among patients with cecum and ascending colon tumors, we found that F. nucleatum transcriptome abundance is positively correlated with mutation load. We further demonstrated that patients with both high tumoral abundance of F. nucleatum and high mutation load exhibited poorer survival and DNA damage. We furthermore determined that F. nucleatum-conditioned medium (Fn. CM) induces DNA damage in both in vitro and in vivo studies. In addition, two F. nucleatum-secreted mutagens, namely DL-homocystine and allantoic acid, were identified to lead to DNA damage.

CONCLUSIONS

Our finding delineates the genotoxicity of F.nucleatum-secreted mutagens, which provides a basis for further work to investigate the role of F. nucleatum in the pathogenicity of CRC.

Transformation of colitis and colorectal cancer: a tale of gut microbiota

Intestinal inflammation modifies host physiology to promote the occurrence of colorectal cancer (CRC), as seen in colitis-associated CRC. Gut microbiota is crucial in cancer progression, primarily by inducing intestinal chronic inflammatory microenvironment, leading to DNA damage, chromosomal mutation, and alterations in specific metabolite production. Therefore, there is an increasing interest in microbiota-based prevention and treatment strategies, such as probiotics, prebiotics, microbiota-derived metabolites, and fecal microbiota transplantation. This review aims to provide valuable insights into the potential correlations between gut microbiota and colitis-associated CRC, as well as the promising microbiota-based strategies for colitis-associated CRC.

Harmony unveiled: Intricate the interplay of dietary factor, gut microbiota, and colorectal cancer-A narrative review

Diet plays a critical role in shaping the gut microbiome, which in turn regulates molecular activities in the colonic mucosa. The state and composition of the gut microbiome are key factors in the development of colorectal cancer. An altered gut microbiome, linked to weakened immune responses and the production of carcinogenic substances, is a significant contributor to colorectal cancer pathogenesis. Dietary changes that involve low-fiber and phytomolecule intake, coupled with higher consumption of red meat, can raise the risk of colorectal cancer. Salutary filaments, which reach the colon undigested, are metabolized by the gut microbiome, producing short-chain fatty acids. Short-chain fatty acids possess beneficial anti-inflammatory and antiproliferative properties that promote colon health. A well-balanced microbiome, supported by beneficial fibers and phytochemicals, can regulate the activation of proto-oncogenes and oncogenic pathways, thereby reducing cell proliferation. Recent research suggests that an overabundance of specific microbes, such as Fusobacterium nucleatum, may contribute to adverse changes in the colonic mucosa. Positive lifestyle adjustments have been demonstrated to effectively inhibit the growth of harmful opportunistic organisms. Synbiotics, which combine probiotics and prebiotics, can protect the intestinal mucosa by enhancing immune responses and decreasing the production of harmful metabolites, oxidative stress, and cell proliferation. This narrative review provides a concise understanding of evolving evidence regarding how diet influences the gut microbiome, leading to the restoration of the colonic epithelium. It underscores the importance of a healthy, plant-based diet and associated supplements in preventing colorectal cancer by enhancing gut microbiome health.

Insights into the enigma of oral streptococci in carcinogenesis

SUMMARYThe genus Streptococcus consists of a taxonomically diverse group of Gram-positive bacteria that have earned significant scientific interest due to their physiological and pathogenic characteristics. Within the genus Streptococcus, viridans group streptococci (VGS) play a significant role in the oral ecosystem, constituting approximately 80% of the oral biofilm. Their primary role as pioneering colonizers in the oral cavity with multifaceted interactions like adherence, metabolic signaling, and quorum sensing contributes significantly to the complex dynamics of the oral biofilm, thus shaping oral health and disease outcomes. Perturbations in oral streptococci composition drive oral dysbiosis and therefore impact host-pathogen interactions, resulting in oral inflammation and representing VGS as an opportunistic pathogen. The association of oral streptococci in tumors across distant organs, spanning the esophagus, stomach, pancreas, and colon, illuminates a potential association between oral streptococci, inflammation, and tumorigenesis. This finding emphasizes the need for further investigations into the role of oral streptococci in mucosal homeostasis and their involvement in carcinogenesis. Hence, here, we review the significance of oral streptococci in biofilm dynamics and how the perturbation may impact mucosal immunopathogenesis in the context of cancer, with a vision of exploiting oral streptococci for cancer intervention and for the development of non-invasive cancer diagnosis.

Effects and mechanisms of N6-methyladenosine RNA methylation in environmental pollutant-induced carcinogenesis

Environmental pollution, including air pollution, plastic contamination, and heavy metal exposure, is a pressing global issue. This crisis contributes significantly to pollution-related diseases and is a critical risk factor for chronic health conditions, including cancer. Mounting evidence underscores the pivotal role of N6-methyladenosine (m6A) as a crucial regulatory mechanism in pathological processes and cancer progression. Governed by m6A writers, erasers, and readers, m6A orchestrates alterations in target gene expression, consequently playing a vital role in a spectrum of RNA processes, covering mRNA processing, translation, degradation, splicing, nuclear export, and folding. Thus, there is a growing need to pinpoint specific m6A-regulated targets in environmental pollutant-induced carcinogenesis, an emerging area of research in cancer prevention. This review consolidates the understanding of m6A modification in environmental pollutant-induced tumorigenesis, explicitly examining its implications in lung, skin, and bladder cancer. We also investigate the biological mechanisms that underlie carcinogenesis originating from pollution. Specific m6A methylation pathways, such as the HIF1A/METTL3/IGF2BP3/BIRC5 network, METTL3/YTHDF1-mediated m6A modification of IL 24, METTL3/YTHDF2 dynamically catalyzed m6A modification of AKT1, METTL3-mediated m6A-modified oxidative stress, METTL16-mediated m6A modification, site-specific ATG13 methylation-mediated autophagy, and the role of m6A in up-regulating ribosome biogenesis, all come into play in this intricate process. Furthermore, we discuss the direction regarding the interplay between pollutants and RNA metabolism, particularly in immune response, providing new information on RNA modifications for future exploration.

Anchang Yuyang Decoction inhibits experimental colitis-related carcinogenesis by regulating PPAR signaling pathway and affecting metabolic homeostasis of host and microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory bowel disease (IBD) presents a risk of carcinogenesis, which escalates with the duration of IBD. Persistent histological inflammation is considered to be the driving factor of colitis carcinogenesis. Effective control of inflammation is helpful to prevent and treat colitis-related colorectal cancer (CAC). Anchang Yuyang Decoction (AYD), a traditional Chinese medicine (TCM) formula, is originated from the ancient prescription of TCM for treating colitis and colorectal cancer. AYD has demonstrated efficacy in treating IBD and potential anti-carcinogenic properties.

AIM OF THE STUDY

This research aims to assess the therapeutic efficacy of AYD in ameliorating experimental colitis-related carcinogenesis induced by AOM/DSS. It further seeks to elucidate its potential mechanisms by integrating multiple omics sequencing approaches.

MATERIALS AND METHODS

A rat model for colitis-related carcinogenesis was developed using azoxymethane (AOM)/dextran sulfate sodium (DSS). UPLC-MS identified AYD's chemical constituents. Rats were administered varying doses of AYD (18.37, 9.19 and 4.59 g/kg) orally for 53 days, with mesalazine as a positive control. The study evaluated anti-carcinogenic effects by examining adenoma number, adenoma load, abnormal crypt foci (ACF), histopathological damage, and tumor-related protein expression. Anti-inflammatory and reparative effects were assessed through body weight, disease activity index (DAI), colon length, spleen index, inflammatory cytokine levels, and tight junction protein expression. The effects on intestinal microbiota and host metabolism were explored through 16S rRNA sequencing, targeted short-chain fatty acid (SCFA) metabonomics, and non-targeted colon metabolomics. Potential AYD targets were identified through transcriptomic sequencing and validated by qRT-PCR and western blotting.

RESULTS

AYD significantly reduced adenoma number, adenoma load, neoplasm-associated lesions, ACF, and tumor-related protein expression (e.g., p53, PCNA) in AOM/DSS-induced rats, thus impeding colitis-related carcinogenesis progression. AYD also alleviated histopathological damage and inflammation, promoting intestinal mucosal barrier repair. Furthermore, AYD modulated intestinal flora structure, enhanced SCFA production, and regulated colon metabolites. Transcriptomic sequencing revealed a significant impact on the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Subsequent qRT-PCR and western blotting experiments indicated AYD's influence in up-regulating PPAR-γ and down-regulating PPAR-α, PPAR-β/δ, and related proteins (thrombomodulin [Thbd], fatty acid binding protein 5 [Fabp5], stearoyl-CoA desaturase 2 [Scd2], phospholipid transfer protein [Pltp]).

CONCLUSIONS

This study demonstrates AYD's ability to inhibit experimental colitis-related carcinogenesis induced by AOM/DSS. Its mechanism likely involves modulation of the PPAR signaling pathway, impacting intestinal microbiota and host metabolic equilibrium.

Gut microbiome-metabolites axis: A friend or foe to colorectal cancer progression

An expanding corpus of research robustly substantiates the complex interrelation between gut microbiota and the onset, progression, and metastasis of colorectal cancer. Investigations in both animal models and human subjects have consistently underscored the role of gut bacteria in a variety of metabolic activities, driven by dietary intake. These activities include amino acid metabolism, carbohydrate fermentation, and the generation and regulation of bile acids. These metabolic derivatives, in turn, have been identified as significant contributors to the progression of colorectal cancer. This thorough review meticulously explores the dynamic interaction between gut bacteria and metabolites derived from the breakdown of amino acids, fatty acid metabolism, and bile acid synthesis. Notably, bile acids have been recognized for their potential carcinogenic properties, which may expedite tumor development. Extensive research has revealed a reciprocal influence of gut microbiota on the intricate spectrum of colorectal cancer pathologies. Furthermore, strategies to modulate gut microbiota, such as dietary modifications or probiotic supplementation, may offer promising avenues for both the prevention and adjunctive treatment of colorectal cancer. Nevertheless, additional research is imperative to corroborate these findings and enhance our comprehension of the underlying mechanisms in colorectal cancer development.

The pathogenicity of vancomycin-resistant Enterococcus faecalis to colon cancer cells

BACKGROUND

The aim of this study was to investigate the pathogenicity of vancomycin-resistant Enterococcus faecalis (VREs) to human colon cells in vitro.

METHODS

Three E. faecalis isolates (2 VREs and E. faecalis ATCC 29212) were cocultured with NCM460, HT-29 and HCT116 cells. Changes in cell morphology and bacterial adhesion were assessed at different time points. Interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGFA) expression were measured via RT-qPCR and enzyme-linked immunosorbent assay (ELISA), respectively. Cell migration and human umbilical vein endothelial cells (HUVECs) tube formation assays were used for angiogenesis studies. The activity of PI3K/AKT/mTOR signaling pathway was measured by Western blotting.

RESULTS

The growth and adhesion of E. faecalis at a multiplicity of infection (MOI) of 1:1 were greater than those at a MOI of 100:1(p < 0.05). Compared to E. faecalis ATCC 29212, VREs showed less invasive effect on NCM460 and HT-29 cells. E. faecalis promoted angiogenesis by secreting IL-8 and VEGFA in colon cells, and the cells infected with VREs produced more than those infected with the standard strain (p < 0.05). Additionally, the PI3K/AKT/mTOR signaling pathway was activated in E. faecalis infected cells, with VREs demonstrating a greater activation compared to E. faecalis ATCC 29212 (p < 0.05).

CONCLUSION

VREs contribute to the occurrence and development of CRC by promoting angiogenesis and activating the PI3K/AKT/mTOR signaling pathway.

Ginsenoside Rk3 modulates gut microbiota and regulates immune response of group 3 innate lymphoid cells to against colorectal tumorigenesis

The gut microbiota plays a pivotal role in the immunomodulatory and protumorigenic microenvironment of colorectal cancer (CRC). However, the effect of ginsenoside Rk3 (Rk3) on CRC and gut microbiota remains unclear. Therefore, the purpose of this study is to explore the potential effect of Rk3 on CRC from the perspective of gut microbiota and immune regulation. Our results reveal that treatment with Rk3 significantly suppresses the formation of colon tumors, repairs intestinal barrier damage, and regulates the gut microbiota imbalance caused by CRC, including enrichment of probiotics such as Akkermansia muciniphila and Barnesiella intestinihominis, and clearance of pathogenic Desulfovibrio. Subsequent metabolomics data demonstrate that Rk3 can modulate the metabolism of amino acids and bile acids, particularly by upregulating glutamine, which has the potential to regulate the immune response. Furthermore, we elucidate the regulatory effects of Rk3 on chemokines and inflammatory factors associated with group 3 innate lymphoid cells (ILC3s) and T helper 17 (Th17) signaling pathways, which inhibits the hyperactivation of the Janus kinase-signal transducer and activator of transcription 3 (JAK-STAT3) signaling pathway. These results indicate that Rk3 modulates gut microbiota, regulates ILC3s immune response, and inhibits the JAK-STAT3 signaling pathway to suppress the development of colon tumors. More importantly, the results of fecal microbiota transplantation suggest that the inhibitory effect of Rk3 on colon tumors and its regulation of ILC3 immune responses are mediated by the gut microbiota. In summary, these findings emphasize that Rk3 can be utilized as a regulator of the gut microbiota for the prevention and treatment of CRC.

Klebsiella aerogenes exacerbates colon tumorigenesis in the AOM/DSS-induced C57BL/6J mouse

Klebsiella aerogenes (K. aerogenes, KA) is a gram-negative opportunistic pathogen from the Klebsiella species and the Enterobacteriaceae family. However, the impact of K. aerogenes on colorectal cancer (CRC) remains uncertain. A colitis-associated tumorigenesis animal model was established by administering azoxymethane (AOM) and dextran sulfate sodium (DSS) to C57BL/6J mice. The concentration of K. aerogenes gavage in mice was 109 cfu. The study measured the following parameters: tumor formation (number and size), intestinal permeability (MUC2, ZO-1, and Occludin), colonic inflammation (TNF-α, IL-1β, IL-6, and IL-10), proliferation and the fluctuation of the intestinal flora. Under the AOM/DSS-treated setting, K. aerogenes colonization worsened colitis by exacerbating intestinal inflammatory reaction and destroying the mucosal barrier. The intervention markedly augmented the quantity and dimensions of neoplasm in the AOM/DSS mice, stimulated cellular growth, and impeded cellular programmed cell death. In addition, K. aerogenes exacerbated the imbalance of the intestinal microbiota by elevating the abundance of Pseudomonas, Erysipelatoclostridium, Turicibacter, Rikenella, and Muribaculum and leading to a reduction in the abundance of Odoribacter, Alloprevotella, Roseburia, and Lachnospiraceae_NK4A136_group. The presence of K. aerogenes in AOM/DSS-treated mice promoted tumorigenesis, worsened intestinal inflammation, disrupted the intestinal barrier, and caused disturbance to the gut microbiota.

Integrating clinical and cross-cohort metagenomic features: a stable and non-invasive colorectal cancer and adenoma diagnostic model

Background: Dysbiosis is associated with colorectal cancer (CRC) and adenomas (CRA). However, the robustness of diagnostic models based on microbial signatures in multiple cohorts remains unsatisfactory. Materials and Methods: In this study, we used machine learning models to screen metagenomic signatures from the respective cross-cohort datasets of CRC and CRA (selected from CuratedMetagenomicData, each disease included 4 datasets). Then select a CRC and CRA data set from the CuratedMetagenomicData database and meet the requirements of having both metagenomic data and clinical data. This data set will be used to verify the inference that integrating clinical features can improve the performance of microbial disease prediction models. Results: After repeated verification, we selected 20 metagenomic features that performed well and were stably expressed within cross-cohorts to represent the diagnostic role of bacterial communities in CRC/CRA. The performance of the selected cross-cohort metagenomic features was stable for multi-regional and multi-ethnic populations (CRC, AUC: 0.817-0.867; CRA, AUC: 0.766-0.833). After clinical feature combination, AUC of our integrated CRC diagnostic model reached 0.939 (95% CI: 0.932-0.947, NRI=30%), and that of the CRA integrated model reached 0.925 (95%CI: 0.917-0.935, NRI=18%). Conclusion: In conclusion, the integrated model performed significantly better than single microbiome or clinical feature models in all cohorts. Integrating cross-cohort common discriminative microbial features with clinical features could help construct stable diagnostic models for early non-invasive screening for CRC and CRA.

KRAS mutations promote the intratumoral colonization of enterotoxigenic bacteroides fragilis in colorectal cancer through the regulation of the miRNA3655/SURF6/IRF7/IFNβ axis

KRAS mutations are associated with poor prognosis in colorectal cancer (CRC). Although the association between the gut microbiota and CRC has been extensively documented, it is unclear whether KRAS mutations can regulate the gut microbiota. Metagenomics has identified changes in the diversity of the gut microbiota in CRC due to KRAS mutations. Specifically, KRAS mutations positively correlate with the abundance of the bacteroides. Understanding how to regulate the classic carcinogenic bacterium within the bacteroides, such as enterotoxigenic bacteroides fragilis (ETBF), to enhance treatment efficacy of tumors is a key focus of research. Mechanistically, we found that the reduction of miR3655 is indispensable for KRAS mutation-promoted proliferation of CRC and the abundance of ETBF. miR3655 targets SURF6 to inhibit its transcription. Further transcriptomic sequencing revealed that SURF6 promotes intratumoral colonization of ETBF in CRC by inhibiting the nuclear translocation and transcription levels of the IRF7, affecting the activation of the IFNβ promoter. Regulating miR3655 and SURF6 can promote IFNβ secretion in CRC, directly killing ETBF. These data indicate that KRAS mutations affect the intratumoral colonization of ETBF in CRC through the miR3655/SURF6/IRF7/IFNβ axis. This provides new potential strategies for treating CRC associated with KRAS mutations or high levels of ETBF.

Small-molecule drugs of colorectal cancer: Current status and future directions

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the world's fourth most deadly cancer. CRC, as a genetic susceptible disease, faces significant challenges in optimizing prognosis through optimal drug treatment modalities. In recent decades, the development of innovative small-molecule drugs is expected to provide targeted interventions that accurately address the different molecular characteristics of CRC. Although the clinical application of single-target drugs is limited by the heterogeneity and high metastasis of CRC, novel small-molecule drug treatment strategies such as dual/multiple-target drugs, drug repurposing, and combination therapies can help overcome these challenges and provide new insights for improving CRC treatment. In this review, we focus on the current status of a range of small molecule drugs that are being considered for CRC therapy, including single-target drugs, dual/multiple-target drugs, drug repurposing and combination strategies, which will pave the way for targeting CRC vulnerabilities with small-molecule drugs in future personalized treatment.

Entero-toxigenic Bacteroides fragilis contributes to intestinal barrier injury and colorectal cancer progression by mediating the BFT/STAT3/ZEB2 pathway

Our previous findings confirmed the high enrichment of Bacteroides fragilis (BF) in fecal samples from patients with colorectal cancer (CRC). The intestinal mucosal barrier is the first defense of the organism against commensal flora and intestinal pathogens and is closely associated with the occurrence and development of CRC. Therefore, this study aimed to investigate the molecular mechanisms through which BF mediates intestinal barrier injury and CRC progression. SW480 cells and a Caco2 intestinal barrier model were treated with entero-toxigenic BF (ETBF), its enterotoxin (B. fragilis toxin, BFT), and non-toxigenic BF (NTBF). Cell counting kit-8, flow cytometry, wound healing and transwell assays were performed to analyze the proliferation, apoptosis, migration, and invasion of SW480 cells. Transmission electron microscopy, FITC-dextran, and transepithelial electrical resistance (TEER) were used to analyze damage in the Caco2 intestinal barrier model. The Azoxymethane/Dextran Sulfate Sodium (AOM/DSS) animal model was established to evaluate the effect of ETBF on intestinal barrier injury and CRC progression in vivo. ETBF and BFT enhanced the viability, wound healing ratio, invasion, and EMT of SW480 cells. In addition, ETBF and BFT disrupted the tight junctions and villus structure in the intestinal barrier model, resulting in increased permeability and reduced TEER. Similarly, the expression of intestinal barrier-related proteins (MUC2, Occludin and Zo-1) was restricted by ETBF and BFT. Interestingly, the STAT3/ZEB2 axis was activated by ETBF and BFT, and treatment with Brevilin A (a STAT3 inhibitor) or knockdown of ZEB2 limited the promotional effect of ETBF and BFT on the SW480 malignant phenotype. In vivo experiments also confirmed that ETBF colonization accelerated tumor load, carcinogenesis, and intestinal mucosal barrier damage in the colorectum of the AOM/DSS animal model, and that treatment with Brevilin A alleviated these processes. ETBF-secreted BFT accelerated intestinal barrier damage and CRC by activating the STAT3/ZEB2 axis. Our findings provide new insights and perspectives for the application of ETBF in CRC treatment.

Mediterranean diet for cancer prevention and survivorship

Cancer is one of the main noncommunicable diseases in terms of health impact. Factors such as a progressively aging population point to future increases in the incidence of cancer on a global level. The elevated number of affected individuals, together with continuous improvements in cancer prevention and therapy, is creating a growing population of cancer survivors, with often inadequately met needs. Lifestyle is a key modulator of cancer risk and of associated morbidity and mortality, and is included in all approaches to the long-term management of cancer. Diet is a principal component of lifestyle, and most of the available evidence is centered on the Mediterranean diet. Our objective was to provide a narrative review of the evidence on the effect of the Mediterranean diet on cancer risk and health threats related to cancer survivorship. For this purpose, we searched the PubMed database for articles published between January 1, 2000, and June 12, 2023. Current data show that the Mediterranean diet is inversely associated with risk, or is risk neutral, for most types of cancer. Tumors of the digestive system have received preferential interest, but studies have also been published on tumors in other organs. The evidence, however, is meager due to the observational nature of most studies, although it is reassuring that benefit is reproduced in studies performed in different populations and environments. Evidence related to cancer survivors is limited by the paucity of studies, yet several findings regarding survival, recurrence, and short- and long-term morbidity suggest a potential role for the Mediterranean diet that warrants further research.

The role of hyaluronic acid in the design and functionalization of nanoparticles for the treatment of colorectal cancer

Despite advances in new approaches for colorectal cancer (CRC) therapy, intravenous chemotherapy remains one of the main treatment options; however, it has limitations associated with off-target toxicity, tumor cell resistance due to molecular complexity and CRC heterogeneity, which lead to tumor recurrence and metastasis. In oncology, nanoparticle-based strategies have been designed to avoid systemic toxicity and increase drug accumulation at tumor sites. Hyaluronic acid (HA) has obtained significant attention thanks to its ability to target nanoparticles (NPs) to CRC cells through binding to cluster-determinant-44 (CD44) and hyaluronan-mediated motility (RHAMM) receptors, along with its efficient biological properties of mucoadhesion. This review proposes to discuss the state of the art in HA-based nanoparticulate systems intended for localized treatment of CRC, highlighting the importance of the mucoadhesion and active targeting provided by this polymer. In addition, an overview of CRC will be provided, emphasizing the importance of CD44 and RHAMM receptors in this type of cancer and the current challenges related to this disease, and important concepts about the physicochemical and biological properties of HA will also be addressed. Finally, this review aims to contribute to the advancement of accuracy treatment of CRC by the design of new platforms based on by HA.

Control the carcinogenic bacteria with new polysaccharides from agricultural wastes

Agriculture activities industries produce a huge amount of waste every year. Agricultural wastes are a great source of natural polysaccharides characterized by accessibility, biocompatibility, and ease of modification. Finding new safe antibacterial agents has become one of the top priorities of health organizations worldwide. This priority emerged from the antibiotic resistance pathogenic bacteria hazard. Carcinogenic bacteria are one of the most dangerous antibiotic-resistant pathogenic bacteria. This study tries to investigate the antibacterial activity of polysaccharides from some agricultural wastes against carcinogenic bacteria related to gastrointestinal cancers. We determined the antibacterial activity (in terms of minimum inhibitory concentration (MIC)) and the biofilm reduction capacity. We studied the mechanism of the antibacterial activity by determining the effect of the MIC of the extracted polysaccharides on the plasma membrane permeability and the bacterial DNA content. All extracted polysaccharides showed effective antibacterial activity with low MICs ranging from 2 to 20 μg/mL. The barely straw polysaccharides showed the highest MIC (19.844 μg/mL) against Bacteroides fragilis, while the grape bagasse showed the lowest MIC (2.489 μg/mL) against Helicobacter pylori. The extracted polysaccharide showed high antibiofilm activity. Their capacity to reduce the formation of the pathogenic biofilm ranged from 75 to 95%. Regarding the antibacterial mechanism, the extracted polysaccharides showed destructive action on the DNA and the plasma membrane permeability. The bacterial DNA change percent after the treatment with the different polysaccharides ranged from 29% to -58%. The plasma membrane permeability increased by a high percentage, ranging from 92% to 123%. Agricultural waste polysaccharides are a promising antibacterial agent against antibiotic-resistant carcinogenic bacteria.

Role of the intratumoral microbiome in tumor progression and therapeutics implications

Microbes are widely present in various organs of the human body and play important roles in numerous physiological and pathological processes. Nevertheless, owing to multiple limiting factors, such as contamination and low biomass, the current understanding of the intratumoral microbiome is limited. The intratumoral microbiome exerts tumor-promoting or tumor-suppressive effects by engaging in metabolic reactions within the body, regulating signaling cancer-related pathways, and impacting both host cells function and immune system. It is important to emphasize that intratumoral microbes exhibit substantial heterogeneity in terms of composition and abundance across various tumor types, thereby potentially influencing diverse aspects of tumorigenesis, progression, and metastasis. These findings suggest that intratumoral microbiome have great potential as diagnostic and prognostic biomarkers. By manipulating the intratumoral microbes to employ cancer therapy, the efficacy of chemotherapy or immunotherapy can be enhanced while minimizing adverse effects. In this review, we comprehensively describe the composition and function of the intratumoral microbiome in various human solid tumors. Combining recent advancements in research, we discuss the origins, mechanisms, and prospects of the clinical applications of intratumoral microbiome.

No evident causal association between Helicobacter pylori infection and colorectal cancer: a bidirectional mendelian randomization study

Observational studies have reported a correlation between Helicobacter pylori infection and colorectal cancer (CRC); however, the underlying cause has remained unclear. This research was aimed at determining whether there is a correlation between H. pylori infection and CRC by measuring the prevalence of H. pylori CagA antibodies and VacA antibodies. Using data from many genome-wide association studies (GWAS), we conducted a Mendelian randomization (MR) study with two sample GWAS. Then, we used bidirectional MR to evaluate the association between H. pylori infection and CRC for identifying causation. The most common method of analysis was the inverse variance-weighted technique. In addition, we performed supplementary analyses using the weighted median technique and MR-Egger regression. Horizontal pleiotropic outliers were identified and corrected using the MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) method. Genetically predicted anti-H. pylori IgG seropositivity was not causally associated with CRC [odds ratio (OR): 1.12; 95% confidence interval (CI): 0.98-1.27, P = 0.08] and neither were H. pylori VacA antibody levels (OR = 0.96, 95% CI: 0.90-1.02, P = 0.25) or H. pylori CagA antibody levels (OR = 1.00, 95% CI: 0.93-1.07, P = 0.92). Furthermore, reverse MR analysis did not reveal evidence for a causal effect of CRC on H. pylori infection. The weighted median, the MR-Egger method, and MR-PRESSO yielded identical results. Using genetic data, MR analysis showed there was no evidence for a causal association between seroprevalence of H. pylori infection and CRC. The relationship between H. pylori infection and CRC requires further research.

Mediterranean diet and olive oil, microbiota, and obesity-related cancers. From mechanisms to prevention

Olive oil (OO) is the main source of added fat in the Mediterranean diet (MD). It is a mix of bioactive compounds, including monounsaturated fatty acids, phytosterols, simple phenols, secoiridoids, flavonoids, and terpenoids. There is a growing body of evidence that MD and OO improve obesity-related factors. In addition, obesity has been associated with an increased risk for several cancers: endometrial, oesophageal adenocarcinoma, renal, pancreatic, hepatocellular, gastric cardia, meningioma, multiple myeloma, colorectal, postmenopausal breast, ovarian, gallbladder, and thyroid cancer. However, the epidemiological evidence linking MD and OO with these obesity-related cancers, and their potential mechanisms of action, especially those involving the gut microbiota, are not clearly described or understood. The goals of this review are 1) to update the current epidemiological knowledge on the associations between MD and OO consumption and obesity-related cancers, 2) to identify the gut microbiota mechanisms involved in obesity-related cancers, and 3) to report the effects of MD and OO on these mechanisms.

A Narrative Literature Review on Sepsis: A Primary Manifestation of Colorectal Neoplasm

Sepsis and colorectal cancer (CRC) exhibit a complex relationship that warrants further exploration. This review delves into the interplay of factors between sepsis and CRC, uncovering shared pathophysiological traits and potential bacterial associations. Understanding these connections could pave the way for earlier diagnosis, improved management, and enhanced outcomes in CRC patients. The role of immune system dysfunction, hypoalbuminemia, and specific microbial imbalances, such as Streptococcus bovis and Clostridium septicum, are discussed. Recognizing sepsis in CRC patients is crucial for timely intervention, and tailored approaches encompassing antibiotic therapy, source control measures, and cancer treatment are essential for comprehensive care. Monitoring biomarkers and ratios can provide valuable insights into complications and overall health outcomes. A multidisciplinary approach involving various specialists is necessary to address the global burden of CRC and its association with sepsis while exploring novel interventions, such as fecal microbiota transplantation and personalized care. We conducted a thorough search using reputable databases such as PubMed, Scopus, and Google Scholar to investigate the connection between sepsis and CRC. We refined our search terms, utilized sidebar filters, and examined references in selected articles. This meticulous process helped us create a comprehensive literature review and gain valuable insights into this relationship.

The role of gut microbiota and drug interactions in the development of colorectal cancer

The human gut microbiota is a complex ecosystem regulating the host's environmental interaction. The same functional food or drug may have varying bioavailability and distinct effects on different individuals. Drugs such as antibiotics can alter the intestinal flora, thus affecting health. However, the relationship between intestinal flora and non-antibiotic drugs is bidirectional: it is not only affected by drugs; nevertheless, it can alter the drug structure through enzymes and change the bioavailability, biological activity, or toxicity of drugs to improve their efficacy and safety. This review summarizes the roles and mechanisms of antibiotics, antihypertensive drugs, nonsteroidal anti-inflammatory drugs, lipid-lowering drugs, hypoglycemic drugs, virus-associated therapies, metabolites, and dietary in modulating the colorectal cancer gut microbiota. It provides a reference for future antitumor therapy targeting intestinal microorganisms.

Cellular and Molecular Mechanisms of the Tumor Stroma in Colorectal Cancer: Insights into Disease Progression and Therapeutic Targets

Colorectal cancer (CRC) is a major health burden worldwide and is the third most common type of cancer. The early detection and diagnosis of CRC is critical to improve patient outcomes. This review explores the intricate interplay between the tumor microenvironment, stromal interactions, and the progression and metastasis of colorectal cancer. The review begins by assessing the gut microbiome's influence on CRC development, emphasizing its association with gut-associated lymphoid tissue (GALT). The role of the Wnt signaling pathway in CRC tumor stroma is scrutinized, elucidating its impact on disease progression. Tumor budding, its effect on tumor stroma, and the implications for patient prognosis are investigated. The review also identifies conserved oncogenic signatures (COS) within CRC stroma and explores their potential as therapeutic targets. Lastly, the seed and soil hypothesis is employed to contextualize metastasis, accentuating the significance of both tumor cells and the surrounding stroma in metastatic propensity. This review highlights the intricate interdependence between CRC cells and their microenvironment, providing valuable insights into prospective therapeutic approaches targeting tumor-stroma interactions.

Microbiota composition and its impact on DNA methylation in colorectal cancer

Colorectal cancer is a complex disease resulting from the interaction of genetics, epigenetics, and environmental factors. DNA methylation is frequently found in tumor suppressor genes to promote cancer development. Several factors are associated with changes in the DNA methylation pattern, and recently, the gastrointestinal microbiota could be associated with this epigenetic change. The predominant phyla in gut microbiota are Firmicutes and Bacteroidetes; however, an enrichment of Bacteroides fragilis, Fusobacterium nucleatum, and Streptococcus bovis, among others, has been reported in colorectal cancer, although the composition could be influenced by several factors, including diet, age, sex, and cancer stage. Fusobacterium nucleatum, a gram-negative anaerobic bacillus, is mainly associated with colorectal cancer patients positive for the CpG island methylator phenotype, although hypermethylation in genes such as MLH1, CDKN2A, MTSS1, RBM38, PKD1, PTPRT, and EYA4 has also been described. Moreover, Hungatella hathewayi, a gram-positive, rod-shaped bacterium, is related to hypermethylation in SOX11, THBD, SFRP2, GATA5, ESR1, EYA4, CDX2, and APC genes. The underlying epigenetic mechanism is unclear, although it could be implicated in the regulation of DNA methyltransferases, enzymes that catalyze the transfer of a methyl group on cytosine of CpG sites. Since DNA methylation is a reversible event, changes in gut microbiota could modulate the gene expression through DNA methylation and improve the colorectal cancer prognosis.

Three specific gut bacteria in the occurrence and development of colorectal cancer: a concerted effort

Colorectal cancer (CRC), which develops from the gradual evolution of tubular adenomas and serrated polyps in the colon and rectum, has a poor prognosis and a high mortality rate. In addition to genetics, lifestyle, and chronic diseases, intestinal integrity and microbiota (which facilitate digestion, metabolism, and immune regulation) could promote CRC development. For example, enterotoxigenic Bacteroides fragilis, genotoxic Escherichia coli (pks+ E. coli), and Fusobacterium nucleatum, members of the intestinal microbiota, are highly correlated in CRC. This review describes the roles and mechanisms of these three bacteria in CRC development. Their interaction during CRC initiation and progression has also been proposed. Our view is that in the precancerous stage of colorectal cancer, ETBF causes inflammation, leading to potential changes in intestinal ecology that may provide the basic conditions for pks+ E. coli colonization and induction of oncogenic mutations, when cancerous intestinal epithelial cells can further recruit F. nucleatum to colonise the lesion site and F. nucleatum may contribute to CRC advancement by primarily the development of cancer cells, stemization, and proliferation, which could create new and tailored preventive, screening and therapeutic interventions. However, there is the most dominant microbiota in each stage of CRC development, not neglecting the possibility that two or even all three bacteria could be engaged at any stage of the disease. The relationship between the associated gut microbiota and CRC development may provide important information for therapeutic strategies to assess the potential use of the associated gut microbiota in CRC studies, antibiotic therapy, and prevention strategies.

Incidence of Breast Cancer and Enterococcus Infection: A Retrospective Analysis

Background

Enterococci role in the microbiome remains controversial, and researches regarding enterococcal infection (EI) and its sequelae are limited. The gut microbiome has shown to play an important role in immunology and cancer. Recent data have suggested a relationship between the gut microbiome and breast cancer (BC).

Methods

Patients in a Health Insurance Portability and Accountability Act (HIPAA) compliant national database (2010 - 2020) were used for this retrospective study. International Classification of Disease (ICD) Ninth and Tenth Codes, Current Procedural Terminology (CPT), and National Drug Codes were used to identify BC diagnosis and EI. Patients were matched for age, sex, Charlson comorbidity index (CCI), antibiotic treatment, obesity, and region of residence. Statistical analyses were implemented to assess significance and estimate odds ratio (OR).

Results

EI was associated with a decreased incidence of BC (OR = 0.60, 95% confidence interval (CI): 0.57 - 0.63) and the difference was statistically significant (P < 2.2 × 10-16). Treatment for EI was controlled for in both EI and noninfected populations. Patients with a prior EI and treated with antibiotics were compared to patients with no history of EI and received antibiotics. Both populations subsequently developed BC. Results remained statistically significant (P < 2.2 × 10-16) with an OR of 0.57 (95% CI: 0.54 - 0.60). In addition to standard matching protocol, obesity was controlled for in both groups by exclusively containing obese patients, but one group with prior EI and the other without. In obese patients, a lower incidence of BC was shown in the infected group compared to the noninfected group. Results were statistically significant (P < 2.2 × 10-16) with an OR of 0.56 (95% CI: 0.53 - 0.58). Age of BC diagnosis with and without a prior EI was analyzed and demonstrated increased BC incidence with increasing age in both groups, but less in the EI group. Incidence of BC based on region was analyzed, which showed lower BC incidence across all regions in the EI group.

Conclusion

This study shows a statistically significant correlation between EI and decreased incidence of BC. Further exploration is needed to identify and understand not only the role of enterococcus in the microbiome, but also the protective mechanism(s) and impact of EI on BC development.

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.

A literature review on the potential clinical implications of streptococci in gastric cancer

Streptococcus is widely found in nature and the human body, and most species are not pathogenic. In recent years, studies have found that Streptococcus is associated with gastric cancer. Streptococcus was found to be enriched in the oral cavity, stomach and intestine of gastric cancer patients and found to be increased in gastric cancer tissues, suggesting that Streptococcus may be the pathogenic bacteria underlying gastric cancer. This review discusses the discovery of Streptococcus, the relationship between Streptococcus and gastric cancer, and the possible carcinogenic mechanism of Streptococcus and summarizes the progress of the research on the role of Streptococcus in gastric cancer to provide new ideas for the early detection, diagnosis and treatment of gastric cancer.

Clinical Significance of Serum Haptoglobin and Protein Disulfide-Isomerase A3 in the Screening, Diagnosis, and Staging of Colorectal Cancer

Objective: This study aims to explore the clinical significance of haptoglobin (HP) and protein disulfide-isomerase A3 (PDIA3) in human serum in the screening, diagnosis and staging of colorectal cancer (CRC), and to provide novel screening approaches featuring high specificity, sensitivity, and accuracy for early screening and diagnosis of clinical colorectal cancer. Methods: 88, 77, and 36 blood specimens were respectively harvested from colorectal cancer patients, colorectal polyp patients, and normal subjects (the health examination) who requested medical assistance from our hospital between Oct2019 and February 2022. The serum contents of HP and PDIA3 in each sample were determined through an enzyme linked immunosorbent assay (ELISA). This step was taken to analyze the differences among different specimen groups in terms of the serum contents of HP and PDIA3, to analyze the relationships between the expression levels of HP and PDIA3 and the pathological characteristics of colorectal cancer, and to explore the critical role of HP and PDIA3 in the screening, diagnosis, and staging of colorectal cancer. Results: Serum contents of HP and PDIA3 were higher in colorectal cancer patients, with statistical differences (p < 0.05), than those in the colonic polyp patients and healthy subjects. Receiver operating characteristic (ROC) curve demonstrated that the cut-offs of HP and PDIA3 serum contents indicating colorectal cancer were 149 ug/ml and 66 ng/ml respectively. The individually and jointly tested AUCs of HP (0.802) and PDIA3 (0.727) were higher than those of serum CEA and CA199, the sensitivity and specificity of HP were 64.8 and 91.2%, the sensitivity and specificity of PDIA3 were 65.9 and 71.7%. Moreover, the contents of HP and PDIA3 increased alongside disease progression, with differences (p < 0.05). Conclusion: Our research indicated that joint testing of HP and PDIA3 was of reference value for progressive stage and reliable biological indicators of colorectal cancer screening.

The Emerging Roles of Human Gut Microbiota in Gastrointestinal Cancer

The gut microbiota is composed of a large number of microorganisms with a complex structure. It participates in the decomposition, digestion, and absorption of nutrients; promotes the development of the immune system; inhibits the colonization of pathogens; and thus modulates human health. In particular, the relationship between gut microbiota and gastrointestinal tumor progression has attracted widespread concern. It was found that the gut microbiota can influence gastrointestinal tumor progression in independent ways. Here, we focused on the distribution of gut microbiota in gastrointestinal tumors and further elaborated on the impact of gut microbiota metabolites, especially short-chain fatty acids, on colorectal cancer progression. Additionally, the effects of gut microbiota on gastrointestinal tumor therapy are outlined. Finally, we put forward the possible problems in gut microbiota and the gastrointestinal oncology field and the efforts we need to make.

The Role of Microbiome in Brain Development and Neurodegenerative Diseases

Hundreds of billions of commensal microorganisms live in and on our bodies, most of which colonize the gut shortly after birth and stay there for the rest of our lives. In animal models, bidirectional communications between the central nervous system and gut microbiota (Gut-Brain Axis) have been extensively studied, and it is clear that changes in microbiota composition play a vital role in the pathogenesis of various neurodevelopmental and neurodegenerative disorders, such as Autism Spectrum Disorder, Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Amyotrophic Lateral Sclerosis, anxiety, stress, and so on. The makeup of the microbiome is impacted by a variety of factors, such as genetics, health status, method of delivery, environment, nutrition, and exercise, and the present understanding of the role of gut microbiota and its metabolites in the preservation of brain functioning and the development of the aforementioned neurological illnesses is summarized in this review article. Furthermore, we discuss current breakthroughs in the use of probiotics, prebiotics, and synbiotics to address neurological illnesses. Moreover, we also discussed the role of boron-based diet in memory, boron and microbiome relation, boron as anti-inflammatory agents, and boron in neurodegenerative diseases. In addition, in the coming years, boron reagents will play a significant role to improve dysbiosis and will open new areas for researchers.