Fusobacterium nucleatum in colorectal carcinoma tissue and patient prognosis

Fusobacterium nucleatum upregulates the immune inhibitory receptor PD-L1 in colorectal cancer cells via the activation of ALPK1

Fusobacterium nucleatum is a Gram-negative oncobacterium that is associated with colorectal cancer. The molecular mechanisms utilized by F. nucleatum to promote colorectal tumor development have largely focused on adhesin-mediated binding to the tumor tissue and on the pro-inflammatory capacity of F. nucleatum. However, the exact manner in which F. nucleatum promotes inflammation in the tumor microenvironment and subsequent tumor promotion remains underexplored. Here, we show that both living F. nucleatum and sterile F. nucleatum-conditioned medium promote CXCL8 release from the intestinal adenocarcinoma HT-29 cell line. We determined that the observed pro-inflammatory effect was ALPK1-dependent in both HEK293 and HT-29 cells and that the released F. nucleatum molecule had characteristics that match those of the pro-inflammatory ALPK1 ligand ADP-heptose or related heptose phosphates. In addition, we determined that not only F. nucleatum promoted an ALPK1-dependent pro-inflammatory environment but also other Fusobacterium species such as F. varium, F. necrophorum and F. gonidiaformans generated similar effects, indicating that ADP-heptose or related heptose phosphate secretion is a conserved feature of the Fusobacterium genus. By performing transcriptional analysis of ADP-heptose stimulated HT-29 cells, we found several inflammatory and cancer-related pathways to be differentially regulated, including DNA mismatch repair genes and the immune inhibitory receptor PD-L1. Finally, we show that stimulation of HT-29 cells with F. nucleatum resulted in an ALPK1-dependent upregulation of PD-L1. These results aid in our understanding of the mechanisms by which F. nucleatum can affect tumor development and therapy and pave the way for future therapeutic approaches.

Fusobacterium sphaericum sp. nov., isolated from a human colon tumor adheres to colonic epithelial cells and induces IL-8 secretion

Cancerous tissue is a largely unexplored microbial niche that provides a unique environment for the colonization and growth of specific bacterial communities, and with it, the opportunity to identify novel bacterial species. Here, we report distinct features of a novel Fusobacterium species, F. sphaericum sp. nov. (Fs), isolated from primary colon adenocarcinoma tissue. We acquire the complete closed genome and associated methylome of this organism and phylogenetically confirm its classification into the Fusobacterium genus, with F. perfoetens as its closest neighbor. Fs is phenotypically and genetically distinct, with morphological analysis revealing its coccoid shape, that while similar to F. perfoetens is rare for most Fusobacterium members. Fs displays a metabolic profile and antibiotic resistance repertoire consistent with other Fusobacterium species. In vitro, Fs has adherent and immunomodulatory capabilities, as it intimately associates with human colon cancer epithelial cells and promotes IL-8 secretion. An analysis of the prevalence and abundance of Fs in > 20,000 human metagenomic samples shows that it is a rarely detected member within human stool with variable relative abundance, found in both healthy controls and patients with colorectal cancer (CRC). Our study sheds light on a novel bacterial species isolated directly from the human CRC tumor niche and given its in vitro interaction with cancer epithelial cells suggests that its role in human health and disease warrants further investigation.

Modeling cancer-microbiome interactions in vitro: A guide to co-culture platforms

The biology of cancer is characterized by an intricate interplay of cells originating not only from the tumor mass, but also its surrounding environment. Different microbial species have been suggested to be enriched in tumors and the impacts of these on tumor phenotypes is subject to intensive investigation. For these efforts, model systems that accurately reflect human-microbe interactions are rapidly gaining importance. Here we present a guide for selecting a suitable in vitro co-culture platform used to model different cancer-microbiome interactions. Our discussion spans a variety of in vitro models, including 2D cultures, tumor spheroids, organoids, and organ-on-a-chip platforms, where we delineate their respective advantages, limitations, and applicability in cancer microbiome research. Particular focus is placed on methodologies that facilitate the exposure of cancer cells to microbes, such as organoid microinjections and co-culture on microfluidic devices. We highlight studies offering critical insights into possible cancer-microbe interactions and underscore the importance of in vitro models in those discoveries. We anticipate the integration of more complex microbial communities and the inclusion of immune cells into co-culture systems to more accurately simulate the tumor microenvironment. The advent of ever more sophisticated co-culture models will aid in unraveling the mechanisms of cancer-microbiome interplay and contribute to exploiting their potential in novel diagnostic and therapeutic strategies.

The relationship between the gastric cancer microbiome and clinicopathological factors: a metagenomic investigation from the 100,000 genomes project and The Cancer Genome Atlas

BACKGROUND

Findings from previous gastric cancer microbiome studies have been conflicting, potentially due to patient and/or tumor heterogeneity. The intratumoral gastric cancer microbiome and its relationship with clinicopathological variables have not yet been characterized in detail. We hypothesized that variation in gastric cancer microbial abundance, alpha diversity, and composition is related to clinicopathological characteristics.

METHODS

Metagenomic analysis of 529 GC samples was performed, including whole exome sequencing data from The Cancer Genome Atlas (TCGA) and whole genome sequencing data from the 100,000 Genomes Project. Microbial abundance, alpha diversity, and composition were compared across patient age, sex, tumor location, geographic origin, pathological depth of invasion, pathological lymph node status, histological phenotype, microsatellite instability status, and TCGA molecular subtype.

RESULTS

Gastric cancer microbiomes resembled previous results, with Prevotella, Selenomonas, Stomatobaculum, Streptococcus, Lactobacillus, and Lachnospiraceae commonly seen across both cohorts. Within the TCGA cohort, microbial abundance and alpha diversity were greater in gastric cancers with microsatellite instability, lower pathological depth of invasion, intestinal-type histology, and those originating from Asia. Microsatellite instability status was associated with microbiome composition in both cohorts. Sex and pathological depth of invasion were associated with microbiome composition in the TCGA cohort.

CONCLUSION

The intratumoral gastric cancer microbiome appears to differ according to clinicopathological factors. Certain clinicopathological factors associated with favourable outcomes in gastric cancer were observed to be associated with greater microbial abundance and diversity. This highlights the need for further work to understand the underlying biological mechanisms behind the observed microbiome differences and their potential clinical and therapeutic impact.

The Relationship Between Gut Microbiome Bifidobacterium and Anti-tumor Immune Responses in Esophageal Squamous Cell Carcinoma

BACKGROUND

The Bifidobacterium genus is a prominent bacterial population in the gastrointestinal tract. Previous findings suggest that Bifidobacterium is linked to tumor suppression in mouse models of melanoma. Additionally, when combined with the programmed death-ligand 1 (PD-L1) antibody, it can enhance anti-tumor treatment by increasing tumor-specific T-cell responses and promoting infiltration of antigen-specific T cells into tumors. However, there is a lack of studies on Bifidobacterium in esophageal squamous cell carcinoma (ESCC). This study aimed to investigate the potential impact of Bifidobacterium on this cancer type.

METHODS

We examined 213 samples from ESCC patients who underwent tumor resection. The presence of Bifidobacterium was confirmed using quantitative polymerase chain reaction and fluorescent in situ hybridization (FISH). Patient overall survival (OS) was analyzed with Bifidobacterium positivity. Tumor-infiltrating lymphocytes (TILs) were evaluated via hematoxylin and eosin stains, and immunohistochemistry was used to assess programmed death-1 (PD-1), PD-L1, cluster of differentiation 8 (CD8), and forkhead box P3 (FOXP3) expression. Nutritional status was evaluated via computed tomography scans.

RESULTS

Bifidobacterium positivity showed no correlation with patient OS or TIL levels; however, Bifidobacterium positivity in normal tissue was associated with lower FOXP3 levels, suggesting a potential role in upregulating anti-tumor immune responses. Patients with Bifidobacterium present in peritumor normal tissue exhibited better skeletal muscle area and volume. Conversely, Bifidobacterium positivity in tumor tissue was associated with poorer prognostic nutrition index values, likely due to decreased albumin levels.

CONCLUSION

Bifidobacterium can induce the upregulated anti-tumor immune response and is more prevalent in cases with good nutritional status.

Structural basis for immune cell binding of Fusobacterium nucleatum via the trimeric autotransporter adhesin CbpF

Fusobacterium nucleatum (Fn), a commensal in the human oral cavity, is overrepresented in the colon microbiota of colorectal cancer (CRC) patients and is linked to tumor chemoresistance, metastasis, and a poor therapeutic prognosis. Fn produces numerous adhesins that mediate tumor colonization and downregulation of the host's antitumor immune response. One of these, the trimeric autotransporter adhesin (TAA) CEACAM binding protein of Fusobacterium (CbpF), targets CEACAM1 on T-cells and has been associated with immune evasion of Fn-colonized tumors. Whereas the role of CEACAM1 in homophilic and heterophilic cell interactions and immune evasion is well described, the mechanistic details of its interaction with fusobacterial CbpF remain unknown due to the lack of a high-resolution structure of the adhesin-receptor complex. Here, we present two structures of CbpF alone and in complex with CEACAM1, obtained by cryogenic electron microscopy and single particle analysis. They reveal that CbpF forms a stable homotrimeric complex whose N-terminal part of the extracellular domain comprises a 64 Å long β roll domain with a unique lateral loop extension. CEACAM1 binds to this loop with high affinity via its N-terminal IgV-like domain with a nanomolar dissociation constant as determined by surface plasmon resonance. This study provides a comprehensive structural description of a fusobacterial TAA, illustrates a yet undescribed CEACAM1 binding mode, and paves the way for rational drug design targeting Fn in CRC.

The physical biogeography of Fusobacterium nucleatum in health and disease

Fusobacterium nucleatum (Fn) is an oral commensal inhabiting the human gingival plaque that is rarely found in the gut. However, in colorectal cancer (CRC), Fn can be isolated from stool samples and detected in metagenomes. We hypothesized that ecological characteristics of the gut are altered by disease, enabling Fn to colonize. Multiple genomically distinct populations of Fn exist, but their ecological preferences are unstudied. We identified six well-separated populations in 133 Fn genomes and used simulated metagenomes to demonstrate sensitive detection of populations in human oral and gut metagenomes. In 9,560 samples from 11 studies, Fn population C2 animalis is elevated in gut metagenomes from CRC and Crohn's disease patients and is observed more frequently in CRC stool samples than in the gingiva. Polymorphum, the most prevalent gingival Fn population, is significantly increased in Crohn's stool samples; this effect was significantly stronger in male hosts than in female. We find polymorphum genomes are enriched for biosynthetic gene clusters and fluoride exporters, while C2 animalis are high in iron transporters. Fn populations thus associate with specific clinical and demographic phenotypes and harbor distinct functional features. Ecological differences in closely related groups of bacteria inform microbiome impacts on human health.

IMPORTANCE

Fusobacterium nucleatum is a bacterium normally found in the gingiva. F. nucleatum generally does not colonize the healthy gut, but is observed in approximately a third of colorectal cancer (CRC) patient guts. F. nucleatum's presence in the gut during CRC has been linked to worse prognosis and increased tumor proliferation. Here, we describe the population structure of F. nucleatum in oral and gut microbiomes. We report substantial diversity in gene carriage among six distinct populations of F. nucleatum and identify population disease and body-site preferences. We find the C2 animalis population is more common in the CRC gut than in the gingiva and is enriched for iron transporters, which support gut colonization in known pathogens. We find that C2 animalis is also enriched in Crohn's disease and type 2 diabetes, suggesting ecological commonalities between the three diseases. Our work shows that closely related bacteria can have different associations with human physiology.

Fusobacterium nucleatum in Colorectal Cancer: Ally Mechanism and Targeted Therapy Strategies

Fusobacterium nucleatum (Fn), an oral anaerobic commensal, has recently been identified as a crucial oncogenic contributor to colorectal cancer pathogenesis through its ectopic colonization in the gastrointestinal tract. Accumulating evidence reveals its multifaceted involvement in colorectal cancer initiation, progression, metastasis, and therapeutic resistance to conventional treatments, including chemotherapy, radiotherapy, and immunotherapy. This perspective highlights recent advances in anti-Fn strategies, including small-molecule inhibitors, nanomedicines, and biopharmaceuticals, while critically analyzing the translational barriers in developing targeted antimicrobial interventions. We further propose potential strategies to overcome current challenges in Fn modulation, aiming to pave the way for more effective therapeutic interventions and better clinical outcomes.

Association of Fusobacterium nucleatum with colorectal cancer molecular subtypes and its outcome: a systematic review

Colorectal cancer (CRC) represents a relevant public health problem, with high incidence and mortality in Western countries. CRC can occur as sporadic (65%-75%), common familial (25%), or as a consequence of an inherited predisposition (up to 10%). While unravelling its genetic basis has been a long trip leading to relevant clinical implementation over more than 30 years, other contributing factors remain to be clarified. Among these, micro-organisms have emerged as critical players in the development and progression of the disease, as well as for CRC treatment response. Fusobacterium nucleatum (Fn) has been associated with CRC development in both pre-clinical models and clinical settings. Fusobacteria are core members of the human oral microbiome, while being less prevalent in the healthy gut, prompting questions about their localization in CRC and its precursor lesions. This review aims to critically discuss the evidence connecting Fn with CRC pathogenesis, its molecular subtypes and clinical outcomes.

Intratumoural pks+Escherichia coli is associated with risk of metachronous colorectal cancer and adenoma development in people with Lynch syndrome

BACKGROUND

The adverse gut microbiome may underlie the variability in risks of colorectal cancer (CRC) and metachronous CRC in people with Lynch syndrome (LS). The role of pks+/-Escherichia coli (pks+/-E. coli), Enterotoxigenic Bacteroides fragilis (ETBF), and Fusobacterium nucleatum (Fn) in CRCs and adenomas in people with LS is unknown.

METHODS

A total of 358 LS cases, including 386 CRCs, 90 adenomas, 195 normal colonic mucosa DNA from the Australasian Colon Cancer Family Registry were tested using multiplex TaqMan qPCR. Logistic regression was used to compare the intratumoural prevalence of each bacteria in Lynch CRCs with 1336 sporadic CRCs. Cox proportional-hazards regression estimated the associations of each bacteria with the risk of metachronous CRC and neoplasia.

FINDINGS

Pks+ E. coli (odds ratio [95% confidence interval] = 1.60 [1.08-2.35], P = 0.017), pks-E. coli (3.87 [2.58-5.80], P < 0.001) and Fn (19.47 [13.32-28.87], P < 0.001) were significantly enriched in LS CRCs when compared with sporadic CRCs. Pks+ E. coli in the initial CRC was associated with an increased risk of metachronous CRC (hazard ratio [95% confidence interval] = 2.32 [1.29-4.17], P = 0.005) and metachronous colorectal neoplasia (1.51 [1.02-2.23], P = 0.040) when compared with CRCs without pks+ E. coli.

INTERPRETATION

Pks+ E. coli, pks-E. coli, and Fn are enriched within LS CRCs, suggesting possible roles in CRC development in LS. Having intratumoural pks+ E. coli is associated with increased risk of metachronous CRC, suggesting that, if validated, people with LS might benefit from pks+ E. coli screening and eradication.

FUNDING

This work was funded by an NHMRC Investigator grant (GNT1194896) and a Cancer Australia/Cancer Council NSW co-funded grant (GNT2012914).

Exploring the prognostic and predictive potential of bacterial biomarkers in non-gastrointestinal solid tumors

INTRODUCTION

Standard clinical parameters like tumor size, age, lymph node status, and molecular markers are used to predict progression risk and treatment response. However, exploring additional markers that reflect underlying biology could offer a more comprehensive understanding of the tumor microenvironment (TME). The TME influences tumor development, progression, disease severity, and survival, with tumor-associated bacteria posited to play significant roles. Studies on tumor-associated microbiota have focused on high bacterial-load sites such as the gut, oral cavity, and stomach, but interest is growing in non-gastrointestinal (GI) solid tumors, such as breast, lung, and pancreas. Microbe-based biomarkers, including Helicobacter pylori, human papillomavirus (HPV), and hepatitis B and C viruses, have proven valuable in predicting gastric, cervical, and renal cancers.

AREAS COVERED

Potential of prognostic and predictive bacterial biomarkers in non-GI solid tumors and the methodologies used.

EXPERT OPINION

Advances in techniques like 16S rRNA gene sequencing, qPCR, immunostaining, and in situ hybridization have enabled detailed analysis of difficult-to-culture microbes in solid tumors. However, to ensure reliable results, it is critical to standardize protocols, accurately align reads, address contamination, and maintain proper sample handling. This will pave the way for developing reliable bacterial markers that enhance prognosis, prediction, and personalized treatment planning.

Combining gut microbiota modulation and immunotherapy: A promising approach for treating microsatellite stable colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and lethal cancers worldwide, ranking third in incidence and second in mortality. While immunotherapy has shown promise in patients with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), its effectiveness in proficient mismatch repair (pMMR) or microsatellite stable (MSS) CRC remains limited. Recent advances highlight the gut microbiota as a potential modulator of anti-tumor immunity. The gut microbiome can significantly influence the efficacy of immune checkpoint inhibitors (ICIs), especially in pMMR/MSS CRC, by modulating immune responses and systemic inflammation. This review explores the role of the gut microbiota in pMMR/MSS CRC, the mechanisms by which it may enhance immunotherapy, and current strategies for microbiota modulation. We discuss the potential benefits of combining microbiota-targeting interventions with immunotherapy to improve treatment outcomes for pMMR/MSS CRC patients.

Probiotics in colorectal cancer prevention and therapy: mechanisms, benefits, and challenges

Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of morbidity worldwide. In Algeria, it ranks second in mortality-related deaths. Poor lifestyle, characterized by a low-fiber diet, insufficient physical activity, tobacco use, and alcohol consumption, is strongly associated with an increased risk of developing this disease. Probiotics have demonstrated anti-inflammatory and antitumor effects in preclinical and clinical studies. The World Health Organization (WHO) and European Food Safety Authority (EFSA) have recognized their safety and effectiveness, classifying them as Generally Recognized as Safe (GRAS) and Qualified Presumption of Safety (QPS), respectively. Probiotics exhibit immunomodulatory effects and maintain the equilibrium of the gut microbiota. However, the evidence for their clinical efficacy is inadequate, and additional research is requisite to establish them as therapeutic agents rather than simply as dietary supplements. Although probiotics are, in most cases, safe, high-risk patients should exercise caution due to the potential risk of infection. This review examines the current knowledge on probiotic strains, their therapeutic potential for colorectal cancer, limitations, and areas where further research is imperative to improve their efficacy.

Characterization of diet-linked amino acid pool influence on Fusobacterium spp. growth and metabolism

The genus Fusobacterium contains multiple proteolytic opportunistic pathogens that have been increasingly linked to colorectal cancer (CRC). "Oncomicrobes" such as these fusobacterial species within the gut microbiota may contribute to CRC onset and/or progression. Protein-rich diets may both directly increase CRC risk and enrich for proteolytic oncomicrobes, including Fusobacterium spp. Individual food substrates vary in amino acid content, and released amino acid content that is not absorbed in the small intestine may influence the growth of colonic proteolytic fermenters. Fusobacteria such as Fusobacterium spp. are known to preferentially metabolize certain amino acids. As such, some foods may better support the growth of these species within the colonic environment than others. To explore this, in this study, we created free amino acid pools (FAAPs) to represent proportions of amino acids in major proteins of three common dietary protein sources (soy, beef, and bovine milk). Growth curves were generated for 39 Fusobacterium spp. strains cultured in a dilute medium supplemented with each of the three FAAPs. Thereafter, amino acid use by 31 of the 39 Fusobacterium spp. strains in each FAAP treatment was assessed. FAAP supplementation increased growth metrics of all Fusobacterium spp. strains tested; however, the strains varied greatly in terms of the FAAP(s) generating the greatest increase in growth. Furthermore, the amino acid utilization strategy was highly variable between strains of Fusobacterium spp. Neither growth metrics nor amino acid utilization could be explained by species classification of Fusobacterium spp. strains. This report expands upon the previous knowledge of fusobacterial amino acid metabolism and indicates that proteolytic oncomicrobial activity should be assessed in the context of available protein sources.IMPORTANCEFusobacterium spp. including F. animalis, F. nucleatum, F. vincentii, and F. polymorphum are common oral commensals with emerging importance in diseases across multiple body sites, including CRC. CRC lesions associated with fusobacteria tend to result in poorer prognosis and increased disease recurrence. While Fusobacterium spp. are thought to colonize after tumorigenesis, little is known about the factors that facilitate this colonization. Protein-rich diets yielding readily metabolized free amino acids within the colon may promote the growth of proteolytic fermenters such as fusobacteria. Here, we show that variable concentrations of free amino acids within pools that represent different dietary protein sources differentially influence fusobacterial growth, including CRC-relevant strains of Fusobacterium spp. This work highlights the high degree of variation in fusobacterial amino acid utilization patterns and suggests differing proportions of dietary amino acids that reach the colon could influence fusobacterial growth.

Interaction between gut microbiota and T cell immunity in colorectal cancer

This review delves into the complex and multi-layered mechanisms that govern the interaction between gut microbiota and T cells in the context of colorectal cancer (CRC), revealing a novel "microbiota-immune regulatory landscape" within the tumor microenvironment. As CRC progresses, the gut microbiota experiences a significant transformation in both its composition and metabolic patterns. On one hand, specific microbial entities within the gut microbiota can directly engage with T cells, functioning as "immunological triggers" that shape T-cell behavior. Simultaneously, microbial metabolites, such as short-chain fatty acids and bile acids, serve as "molecular regulators" that intricately govern T-cell function and differentiation, fine-tuning the immune response. On the other hand, the quorum-sensing mechanism, a recently recognized communication network among bacteria, also plays a pivotal role in orchestrating T-cell immunity. Additionally, the gut microbiota forms an intriguing connection with the neuro-immune regulatory axis, a largely unexplored "territory" in CRC research. Regarding treatment strategies, a diverse array of intervention approaches-including dietary modifications, the utilization of probiotics, bacteriophages, and targeted antibiotic therapies-offer promising prospects for restoring the equilibrium of the gut microbiota, thereby acting as "ecosystem renovators" that impede tumor initiation and progression. Nevertheless, the current research landscape in this field is fraught with challenges. These include significant variations in microbial composition, dietary preferences, and tumor microenvironments among individuals, a lack of large-scale cohort studies, and insufficient research that integrates tumor mutation analysis, gut microbiota investigations, and immune microenvironment evaluations. This review emphasizes the necessity for future research efforts to seamlessly incorporate multiple factors and utilize bioinformatics analysis to construct a more comprehensive "interactive map" of the gut microbiota-T cell relationship in CRC. The aim is to establish a solid theoretical basis for the development of highly effective and personalized treatment regimens, ultimately transforming the therapeutic approach to CRC.

Oral microbiota in colorectal cancer: Unraveling mechanisms and application potential

Colorectal cancer (CRC), with a rising prevalence, is the third most commonly diagnosed cancer and the third leading cause of cancer-related death. Studies have shown that a complex interplay between the development of CRC and alterations in the oral microbiome. Recent advancements in genomics and metagenomics have highlighted the significant roles of certain oral microbes, particularly Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum), in the progression of CRC. However, the detailed mechanisms by which the oral microbiota influence CRC development remain unclear. This review aims to elucidate the role of oral microbiota in CRC progression, evaluate their potential as biomarkers, and explore therapeutic strategies targeting these microbes. This review offers insights into the mechanisms underlying the interaction between oral microbiota and CRC, underscoring the potential of oral microbes as diagnostic and prognostic biomarkers, as well as therapeutic targets. Future research should focus on clarifying the exact pathways and developing innovative therapeutic strategies to enhance the diagnosis and treatment.

Tumor and intratumoral pathogen cascade-targeting photothermal nanotherapeutics for boosted immunotherapy of colorectal cancer

Clinical benefits of immunotherapy in colorectal cancer (CRC) are limited due to the low immunogenicity and immunosuppressive tumor microenvironment. Fusobacterium nucleatum (Fn) is discovered to colonize CRC tumors and dampen immunotherapy by fostering an immunosuppressive TME. Herein, a controllable "Shielding-deshielding" N-acetylgalactosamine (GalNAc)-derived photothermal nanotherapeutic is developed to mediate cascade targeting toward tumor and intratumoral Fn for enhanced photothermal-immunotherapy. This nanotherapeutic can in situ generate near infrared-II laser-activatable photothermal agent by reacting with endogenous hydrogen sulfide in CRC. The Schiff bond-tethered hyaluronic acid coating not only facilitates precise localization within CRC but shieldes GalNAc-mediated liver targeting, which can be deshielded upon a slightly acidic TME to anchor Fn by binding to its lectin Fap2. This cascade-targeting nanotherapeutic enables efficacious tumor accumulation and reinforces photothermal therapy (PTT) efficacy. Notably, PTT efficiently induces immunogenic cell death in CRC cells, leading to augmented immunogenicity and CD8+ T cell activation. Meanwhile, synchronous eradication of Fn facilitates M1 macrophage polarization, and promotes intratumoral infiltration of CD8+ T cell by reducing succinic acid level, thereby further boosting antitumor immunity against both primary and distant tumors. Overall, this study involving cascade targeting-reinforced PTT and intratumoral microorganism modulation offers new insight into effective CRC immunotherapy.

Integrated spatial multi-omics profiling of Fusobacterium nucleatum in breast cancer unveils its role in tumour microenvironment modulation and cancer progression

Tumour-associated microbiota are integral components of the tumour microenvironment (TME). However, previous studies on intratumoral microbiota primarily rely on bulk tissue analysis, which may obscure their spatial distribution and localized effects. In this study, we applied in situ spatial-profiling technology to investigate the spatial distribution of intratumoral microbiota in breast cancer and their interactions with the local TME. Using 5R 16S rRNA gene sequencing and RNAscope FISH/CISH on patients' tissue, we identified significant spatial heterogeneity in intratumoral microbiota, with Fusobacterium nucleatum (F. nucleatum) predominantly localized in tumour cell-rich areas. GeoMx digital spatial profiling (DSP) revealed that regions colonized by F. nucleatum exhibit significant influence on the expression of RNAs and proteins involved in proliferation, migration and invasion. In vitro studies indicated that co-culture with F. nucleatum significantly stimulates the proliferation and migration of breast cancer cells. Integrative spatial multi-omics and co-culture transcriptomic analyses highlighted the MAPK signalling pathways as key altered pathways. By intersecting these datasets, VEGFD and PAK1 emerged as critical upregulated proteins in F. nucleatum-positive regions, showing strong positive correlations with MAPK pathway proteins. Moreover, the upregulation of VEGFD and PAK1 by F. nucleatum was confirmed in co-culture experiments, and their knockdown significantly reduced F. nucleatum-induced proliferation and migration. In conclusion, intratumoral microbiota in breast cancer exhibit significant spatial heterogeneity, with F. nucleatum colonization markedly altering tumour cell protein expression to promote progression and migration. These findings provide novel perspectives on the role of microbiota in breast cancer, identify potential therapeutic targets, and lay the foundation for future cancer treatments. KEY POINTS: Intratumoral Fusobacterium nucleatum exhibits significant spatial heterogeneity within breast cancer tissues. F. nucleatum colonization alters the expression of key proteins involved in tumour progression and migration. The MAPK signalling pathway is a critical mediator of F. nucleatum-induced breast cancer cell proliferation and migration. VEGFD and PAK1 are potential therapeutic targets to mitigate F. nucleatum-induced tumour progression.

Emerging roles of intratumoral microbiota: a key to novel cancer therapies

Microorganisms, including bacteria, viruses, and fungi, have been found to play critical roles in tumor microenvironments. Due to their low biomass and other obstacles, the presence of intratumor microbes has been challenging to definitively establish. However, advances in biotechnology have enabled researchers to reveal the association between intratumor microbiota and cancer. Recent studies have shown that tumor tissues, once thought to be sterile, actually contain various microorganisms. Disrupted mucosal barriers and adjacent normal tissues are important sources of intratumor microbiota. Additionally, microbes can invade tumors by traveling through the bloodstream to the tumor site and infiltrating through damaged blood vessels. These intratumor microbiota may promote the initiation and progression of cancers by inducing genomic instability and mutations, affecting epigenetic modifications, activating oncogenic pathways, and promoting inflammatory responses. This review summarizes the latest advancements in this field, including techniques and methods for identifying and culturing intratumor microbiota, their potential sources, functions, and roles in the efficacy of immunotherapy. It explores the relationship between gut microbiota and intratumor microbiota in cancer patients, and whether altering gut microbiota might influence the characteristics of intratumor microbiota and the host immune microenvironment. Additionally, the review discusses the prospects and limitations of utilizing intratumor microbiota in antitumor immunotherapy.

Multiomics insights into BMI-related intratumoral microbiota in gastric cancer

Introduction

Body mass index (BMI) is considered an important factor in tumor prognosis, but its role in gastric cancer (GC) remains controversial. There is a lack of studies exploring the effect of BMI on gastric cancer from the perspective of intratumoral microbiota. This study aimed to compare and analyze the differences in and functions of intratumoral microbiota among GC patients with varying BMIs, aiming to ascertain whether specific microbial features are associated with prognosis in low-BMI (LBMI) gastric cancer patients.

Methods

A retrospective analysis of the clinicopathological features and prognosis of 5567 patients with different BMIs was performed between January 2010 and December 2019. Tumor tissues from 189 GC patients were collected for 16S rRNA sequencing, 64 samples were selected for transcriptome sequencing, and 57 samples were selected for untargeted metabolomic analysis.

Results

Clinical cohort analysis revealed that GC patients with a low BMI presented poorer clinical and pathological characteristics than those with a non-low-BMI (NLBMI). LBMI was identified as a significant independent risk factor for adverse prognosis, potentially exerting immunosuppressive effects on postoperative adjuvant chemotherapy. 16S rRNA sequencing revealed no significant differences in the alpha and beta diversity of the intratumoral microbiota between the two groups of GC patients. However, LEfSe analysis revealed 32 differential intratumoral microbiota between the LBMI and NLBMI groups. Notably, the genus Abiotrophia was significantly enriched in the LBMI group. Further in-depth analysis indicated that the genus Abiotrophia was inversely associated with eosinophils, P2RY12, and SCN4B genes, and positively linked with LGR6 in LBMI gastric cancer patients. Metabolomic assessments revealed that LBMI was positively associated with purine metabolites, specifically guanine and inosine diphosphate (IDP).

Discussion

In conclusion, LBMI is an independent risk factor for poor prognosis in gastric cancer patients and may have an inhibitory effect on postoperative adjuvant chemotherapy. Intratumor flora of gastric cancer patients with different BMI levels differed, with different immune cell infiltration and metabolic characteristics. The genus Abiotrophia may promote gastric cancer development and progression by regulating eosinophils and the purine metabolism pathway, which provides a new idea for the precise treatment of gastric cancer.

Ecology of vertical tumor transmission in the freshwater cnidarian Hydra oligactis

Transmissible tumors are increasingly regarded as a new form of parasitic life, but relatively little is known about the ecology and evolution of their interactions with their host. In this work, we provide new insights into transmission dynamics of vertically transmitted tumors in the freshwater cnidarian Hydra oligactis. First, we found tumoral hydra to be infectious at any age, regardless of whether they were in their asymptomatic or symptomatic phases, with the bacteriome composition remaining constant during both phases. Interestingly, tumor transmission increased with the number of tentacles, particularly for hydras with supernumerary tentacles. Additionally, tumors developed earlier in the offspring from parents with more advanced tumors. Furthermore, despite being direct descendants of tumoral polyps, some hydras never developed tumoral phenotype. The latter exhibited a distinct bacteriome composition, reduced lifespan and a lower tentacle number increase over time. Interestingly, the tumor phenotype expression in these hydras appears to be able to skip generations, as transmission occurred at any age from parents to offspring. We discuss these results in the context of current knowledge on the evolutionary ecology of host-transmissible tumor interactions as well as parasite-host interactions and suggest avenues for further research.

Characteristics of gut microbiota and metabolites in extrahepatic cholangiocarcinoma and their prognostic value for resectable lesions

This study aimed to investigate the relationship between gut microbiota composition, fecal metabolites, and postoperative prognosis in patients with extrahepatic cholangiocarcinoma (eCCA). A total of 53 patients with resectable eCCA and 21 healthy volunteers as a control group were included. 16S rRNA gene sequencing and metabolomic analyses revealed significant differences in the gut microbial community structure and altered fecal metabolites profiles between eCCA patients and healthy controls. Univariate and multivariate Cox regression analyses indicated that factors such as preoperative total bilirubin, indirect bilirubin, and specific metabolites were closely associated with overall survival in patients with eCCA post-surgery. The constructed nomogram model further demonstrated the predictive value of these factors, achieving a C-index of 0.718, with calibration curves confirming its strong predictive performance. In conclusion, gut microbiota composition and fecal metabolites play a crucial role in the surgical prognosis of eCCA patients, providing new insights for clinical prognostic assessment.

Implications of intratumoral microbiota in tumor metastasis: a special perspective of microorganisms in tumorigenesis and clinical therapeutics

Tumor metastasis is the main cause of therapeutic failure and mortality in cancer patients. The intricate metastastic process is influenced by both the intrinsic properties of tumor cells and extrinsic factors, such as microorganisms. Notably, some microbiota have been discovered to colonize tumor tissues, collectively known as intratumoral microbiota. Intratumoral microbiota can modulate tumor progression through multiple mechanisms, including regulating immune responses, inducing genomic instability and gene mutations, altering metabolic pathways, controlling epigenetic pathways, and disrupting cancer-related signaling pathways. Furthermore, intratumoral microbiota have been shown to directly impact tumor metastasis by regulating cell adhesion, stem cell plasticity and stemness, mechanical stresses and the epithelial-mesenchymal transition. Indirectly, they may affect tumor metastasis by modulating the host immune system and the tumor microenvironment. These recent findings have reshaped our understanding of the relationship between microorganims and the metastatic process. In this review, we comprehensively summarize the existing knowledge on tumor metastasis and elaborate on the properties, origins and carcinogenic mechanisms of intratumoral microbiota. Moreover, we explore the roles of intratumoral microbiota in tumor metastasis and discuss their clinical implications. Ongoing research in this field will establish a solid foundation for novel therapeutic strategies and clinical treatments for various tumors.

Periodontitis increases the risk of gastrointestinal dysfunction: an update on the plausible pathogenic molecular mechanisms

Periodontitis is an immuno-inflammatory disease of the soft tissues surrounding the teeth. Periodontitis is linked to many communicable and non-communicable diseases such as diabetes, cardiovascular disease, rheumatoid arthritis, and cancers. The oral-systemic link between periodontal disease and systemic diseases is attributed to the spread of inflammation, microbial products and microbes to distant organ systems. Oral bacteria reach the gut via swallowed saliva, whereby they induce gut dysbiosis and gastrointestinal dysfunctions. Some periodontal pathogens like Porphyromonas. gingivalis, Klebsiella, Helicobacter. Pylori, Streptococcus, Veillonella, Parvimonas micra, Fusobacterium nucleatum, Peptostreptococcus, Haemophilus, Aggregatibacter actinomycetomcommitans and Streptococcus mutans can withstand the unfavorable acidic, survive in the gut and result in gut dysbiosis. Gut dysbiosis increases gut inflammation, and induce dysplastic changes that lead to gut dysfunction. Various studies have linked oral bacteria, and oral-gut axis to various GIT disorders like inflammatory bowel disease, liver diseases, hepatocellular and pancreatic ductal carcinoma, ulcerative colitis, and Crohn's disease. Although the correlation between periodontitis and GIT disorders is well established, the intricate molecular mechanisms by which oral microflora induce these changes have not been discussed extensively. This review comprehensively discusses the intricate and unique molecular and immunological mechanisms by which periodontal pathogens can induce gut dysbiosis and dysfunction.

Adherence to the Mediterranean diet and its protective effects against colorectal cancer: a meta-analysis of 26 studies with 2,217,404 participants

Colorectal cancer (CRC) is a major global health concern and represents a significant public health challenge in Hungary, where it exhibits some of the highest morbidity and mortality rates in the European Union. The Mediterranean diet has been suggested to reduce the incidence of CRC, but comprehensive evidence from diverse study designs is needed to substantiate this effect. A systematic literature search was conducted in PubMed, ClinicalTrials.gov, CENTRAL, and the Web of Science to identify randomized controlled trials and human clinical trials from 2008 to 2024 to identify relevant studies. Statistical analysis was performed using the https://metaanalysisonline.com web application using a random effects model to estimate the pooled hazard rates (HRs). Forest plots, funnel plots, and Z-score plots were utilized to visualize results. We identified 15 clinical trials and 9 case-control studies, encompassing a total of 2,217,404 subjects. The pooled analysis indicated that adherence to the Mediterranean diet significantly reduced the prevalence of CRC (HR = 0.84, 95% CI = 0.78-0.91, p < 0.01). This protective effect was consistent across sexes, with HRs of 0.85 (95% CI = 0.75-0.97, p = 0.01) for males and 0.88 (95% CI = 0.79-0.99, p = 0.03) for females. Case-control studies specifically showed a substantial effect (HR = 0.51, 95% CI = 0.38-0.68, p < 0.01). Notable heterogeneity was observed across studies, yet the a priori information size was substantially below the cumulative sample size, ensuring sufficient data for reliable conclusions. The findings from this meta-analysis reinforce the protective role of the Mediterranean diet against CRC. The results of this meta-analysis will inform dietary interventions designed to mitigate CRC risk, which are conducted within the framework of the Semmelweis Study, an ongoing comprehensive cohort study at Semmelweis University, designed to explore the multifaceted causes of unhealthy aging in Hungary. These interventions aim to explore the practical application of Mediterranean dietary patterns in reducing CRC incidence among the Hungarian population.

Innovative approaches in colorectal cancer screening: advances in detection methods and the role of artificial intelligence

Colorectal cancer (CRC) is the third most prevalent cancer globally and poses a significant health threat, making early detection crucial. This review paper explored emerging detection methods for early screening of CRC, including gut microbiota, metabolites, genetic markers, and artificial intelligence (AI)-based technologies. Current screening methods have their respective advantages and limitations, particularly in detecting precursors. First, the importance of the gut microbiome in CRC progression is discussed, highlighting how specific microbial alterations can serve as biomarkers for early detection, potentially enhancing diagnostic accuracy when combined with traditional screening methods. Next, research on metabolic reprogramming illustrates the relationship between metabolic changes and CRC, with studies developing metabolite-based detection models that show good sensitivity for early diagnosis. In terms of genetic markers, methylated DNA markers like SEPTIN9 have demonstrated high sensitivity, although further validation across diverse populations is necessary. Lastly, AI technology has shown immense potential in improving adenoma detection rates, significantly enhancing the quality of colonoscopic examinations through image recognition techniques. This review aims to provide a comprehensive perspective on new strategies for CRC screening, emphasizing the potential of noninvasive detection technologies and the prospects of AI and genomics in clinical applications. Despite several challenges, this review advocates for future large-scale prospective studies to validate the effectiveness and cost-effectiveness of these new screening methods while promoting the implementation of screening protocols tailored to individual characteristics.

Combinatorial Effects of Cisplatin and PARP Inhibitor Olaparib on Survival, Intestinal Integrity, and Microbiome Modulation in Murine Model

This study investigated the effects of the poly (ADP-ribose) polymerase (PARP) inhibitor Olaparib, alone and in combination with cisplatin, on intestinal integrity, survival, and microbiome composition using a murine model. Statistical analyses were conducted using one-way analysis of variance with Bonferroni correction for multiple comparisons, considering p-values of <0.05 as statistically significant. Microbiome profiling was performed using Qiime 2 software. Histopathological and microbiome analyses revealed Olaparib's protective effects on intestinal integrity, mitigating cisplatin-induced damage. The single administration of cisplatin caused significant histological damage, biochemical disruptions, and dysbiosis, characterized by an increase in pro-inflammatory microbiome, such as Clostridium_sensu_stricto_1, and a decrease in beneficial short-chain fatty acid (SCFA)-producing microbiome. Conversely, the single administration of Olaparib was associated with an increase in SCFA-producing microbiome, such as Lachnospiraceae NK4A136, and exhibited minimal toxicity. The combination administration showed complicated outcomes, as follows: reduced cisplatin-induced cytotoxicity and increased SCFA-producing microbiome ratios, yet the long-term effects revealed reduced survival rates in the cisplatin group and sustained weight gain suppression. These findings emphasize Olaparib's potential in enhancing intestinal barrier integrity, reducing inflammation, and positively modulating microbiome diversity. However, the entangled pharmacodynamic interactions in the combination administration underscore the need for further investigation. The study highlights the potential of microbiome-targeted interventions in improving therapeutic outcomes for both cancer treatment and inflammatory bowel disease management.

Selenium-Enriched Lactiplantibacillus plantarum ZZU 8-12 Regulates Intestinal Microbiota and Inhibits Acute Liver Injury

Intake of certain Lactiplantibacillus strains was recognized as a potential strategy for acute liver injury (ALI) prevention. This study is aimed at developing a selenium-enriched Lactiplantibacillus strain-based ALI prevention strategy. L. plantarum ZZU 8-12 was isolated from human fecal sample and screened out based on its adaption to intestinal microenvironment, inhibitive capability against pathogenic bacteria, and in vivo anti-inflammation response in DSS-induced colitis mice model. The strain was applied as a producer of nano selenium particles to produce selenium-enriched L. plantarum ZZU 8-12. Intake of selenium-enriched L. plantarum ZZU 8-12 upregulated the abundance of short-chain fatty acid-producing genera including Lactiplantibacillus, Phascolarctobacterium, Butyricicoccus, and Clostridiales bacterium in fecal microbiota and thus inhibited ALI induced by CCL4 injection in mice. This study drew the potential for selenium-enriched L. plantarum ZZU 8-12 as an ingredient for ALI protection.

FadA antigen of Fusobacterium nucleatum: implications for ceRNA network in colorectal cancer and adenomatous polyps progression

INTRODUCTION

Colorectal cancer (CRC) is the second most common cause of cancer-related deaths globally. The gut microbiota, along with adenomatous polyps (AP), has emerged as a plausible contributor to CRC progression. This study aimed to scrutinize the impact of the FadA antigen derived from Fusobacterium nucleatum on the expression levels of the ANXA2 ceRNA network and assess its relevance to CRC advancement.

MATERIAL AND METHODS

The functions of ANXA2 and LINC00460 in CRC have been partially clarified. According to our previous study to identify shared MicroRNA-Interaction-Targets (MITs) between ANXA2 and LINC00460, TargetScanHuman (V7.2) and miRDB databases have been used respectively. The Bioinformatics and Evolutionary Genomics web tool was employed to intersect the sets of shared microRNAs and their common targets. Then, the ANXA2 ceRNA network was constructed. Subsequently, the mRNA, miRNA, and lncRNA expression levels were examined in intestinal biopsy specimens from 30 healthy controls, 30 Adenoma patients, and 30 cases of CRC stage I using qRT-PCR.

RESULTS

Elevated expression levels of FadA, ANXA2, hsa-let-7a-2, and LINC00460 were observed in CRC specimens, followed by AP cases, in comparison to samples from normal individuals. Application of the Spearman test revealed a strong and significant correlation between FadA and LINC00460 (rS = 0.9311, p < 0.0001). Also, the functional analysis of ANXA2 revealed its impact on CRC progression through JAK-STAT and Hippo signaling pathways.

CONCLUSION

FadA appears to potentiate CRC progression by inducing the upregulation of LINC00460, consequently leading to the hyperexpression of ANXA2 through the ceRNA network.

Unveiling the Interplay Between the Human Microbiome and Gastric Cancer: A Review of the Complex Relationships and Therapeutic Avenues

The human microbiota plays a crucial role in maintaining overall health and well-being. The gut microbiota has been implicated in developing and progressing various diseases, including cancer. This review highlights the related mechanisms and the compositions that influence cancer pathogenesis with a highlight on gastric cancer. We provide a comprehensive overview of the mechanisms by which the microbiome influences cancer development, progression, and response to treatment, with a focus on identifying potential biomarkers for early detection, prevention strategies, and novel therapeutic interventions that leverage microbiome modulation. This comprehensive review can guide future research and clinical practices in understanding and harnessing the microbiome to optimize gastric cancer therapies.

Fusobacterium nucleatum is enriched in invasive biofilms in colorectal cancer

Fusobacterium nucleatum is an oral bacterium known to colonize colorectal tumors, where it is thought to play an important role in cancer progression. Recent advances in sequencing and phenotyping of F. nucleatum have revealed important differences at the subspecies level, but whether these differences impact the overall tumor ecology, and tumorigenesis itself, remain poorly understood. In this study, we sought to characterize Fusobacteria in the tumor microbiome of a cohort of individuals with CRC through a combination of molecular, spatial, and microbiologic analyses. We assessed for relative abundance of F. nucleatum in tumors compared to paired normal tissue, and correlated abundance with clinical and pathological features. We demonstrate striking enrichment of F. nucleatum and the recently discovered subspecies animalis clade 2 (Fna C2) specifically in colon tumors that have biofilms, highlighting the importance of complex community partnerships in the pathogenesis of this important organism.

Oncogenic human papillomavirus and anal microbiota in men who have sex with men and are living with HIV in Northern Taiwan

Few studies have demonstrated the interplay between human immunodeficiency virus (HIV), anal human papillomavirus (HPV), and anal microbiota, especially in persons living with HIV who are men who have sex with men. We, therefore, explored these interrelationships in a cohort of persons living with HIV, mainly comprising men who have sex with men. HPV genotyping using a commercial genotyping kit and ThinPrep cytology interpreted by Bethesda systems was performed on samples from 291 patients. Samples were characterized by high-throughput sequencing of dual-index barcoded 16s rRNA (V3-4). Bacterial diversity was diminished in individuals living with HIV with CD4+ T cells <500 cells/μL and anal cytology yielding atypical squamous cells of undetermined significance or higher grades (ASCUS+) with detectable HPV 16/18 compared with those with CD4+ T cells ≥500 cells/μL with ASCUS+ and HPV 16/18 and those with normal anal cytology or inflammation without HPV 16/18. Enterobacteriaceae, Ruminococcus, and Bacilli were significantly abundant in persons living with HIV with CD4+ T cells <500 cells/μL with ASCUS+ and HPV 16/18. Bacterial diversity, composition, and homogeneity of dispersion were different in individuals living with HIV with low CD4+ T cells with ASCUS+ and HPV 16/18, and understanding the interaction among immunocompromised hosts, oncogenic HPVs, and microbiota is essential, and the contribution of these factors to anal precancerous lesions needs more in-depth exploration.

Fusobacterium nucleatum in tumors: from tumorigenesis to tumor metastasis and tumor resistance

Fusobacterium nucleatum, an anaerobic Gram-negative bacterium primarily residing in the oral cavity, has garnered significant attention for its emerging role in cancer progression and prognosis. While extensive research has revealed mechanistic links between Fusobacterium nucleatum and colorectal cancer, a comprehensive review spanning its presence and metastatic implications in cancers beyond colorectal origin is conspicuously absent. This paper broadens our perspective from colorectal cancer to various malignancies associated with Fusobacterium nucleatum, including oral, pancreatic, esophageal, breast, and gastric cancers. Our central focus is to unravel the mechanisms governing Fusobacterium nucleatum colonization, initiation, and promotion of metastasis across diverse cancer types. Additionally, we explore Fusobacterium nucleatum's adverse impacts on cancer therapies, particularly within the domains of immunotherapy and chemotherapy. Furthermore, this paper underscores the clinical research significance of Fusobacterium nucleatum as a potential tumor biomarker and therapeutic target, offering a novel outlook on its applicability in cancer detection and prognostic assessment.

Intratumor microbiota and colorectal cancer: Comprehensive and lucid review

As a key component of tumor microenvironment, the microbiota has gradually played a key role in cancer research. Particularly in colorectal cancer, the specific population of microbiota within the tumor shows a strong association with the tumor type. Although the existence and potential role of microbiota in tumors have been recognized, the specific associations between the microbiota and tumor tissue and the mechanism of action still need to be further explored. This paper reviews the discovery, origin, and emerging role of the intratumor microbiota in the immune microenvironment and systematically outlines the oncogenic and metastasis-promoting strategies of the intratumor microbiota. Moreover, it comprehensively and holistically evaluates therapeutic strategies and prognostic performance on the basis of the intratumor microbiota, with the goal of providing strong support for future research and clinical practice.

Gut microbiota in cancer initiation, development and therapy

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

Distinct microbes, metabolites, and the host genome define the multi-omics profiles in right-sided and left-sided colon cancer

BACKGROUND

Studies have reported clinical heterogeneity between right-sided colon cancer (RCC) and left-sided colon cancer (LCC). However, none of these studies used multi-omics analysis combining genetic regulation, microbiota, and metabolites to explain the site-specific difference.

METHODS

Here, 494 participants from a 16S rRNA gene sequencing cohort (50 RCC, 114 LCC, and 100 healthy controls) and a multi-omics cohort (63 RCC, 79 LCC, and 88 healthy controls) were analyzed. 16S rRNA gene, metagenomic sequencing, and metabolomics analyses of fecal samples were evaluated to identify tumor location-related bacteria and metabolites. Whole-exome sequencing (WES) and transcriptome sequencing (RNA-seq) were conducted to obtain the mutation burden and genomic expression pattern.

RESULTS

We found unique profiles of the intestinal microbiome, metabolome, and host genome between RCC and LCC. The bacteria Flavonifractor plautii (Fp) and Fusobacterium nucleatum, the metabolites L-phenylalanine, and the host genes PHLDA1 and WBP1 were the key omics features of RCC; whereas the bacteria Bacteroides sp. A1C1 (B.A1C1) and Parvimonas micra, the metabolites L-citrulline and D-ornithine, and the host genes TCF25 and HLA-DRB5 were considered the dominant omics features in LCC. Multi-omics correlation analysis indicated that RCC-enriched Fp was related to the accumulation of the metabolite L-phenylalanine and the suppressed WBP1 signal in RCC patients. In addition, LCC-enriched B.A1C1 was associated with the accumulation of the metabolites D-ornithine and L-citrulline as well as activation of the genes TCF25, HLA-DRB5, and AC079354.1.

CONCLUSION

Our findings identify previously unknown links between intestinal microbiota alterations, metabolites, and host genomics in RCC vs. LCC, suggesting that it may be possible to treat colorectal cancer (CRC) by targeting the gut microbiota-host interaction. Video Abstract.

Intratumoral Fusobacterium nucleatum in Pancreatic Cancer: Current and Future Perspectives

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

A Longitudinal Dynamic Change in LMR Can Be a Biomarker for Recurrence in Fusobacterium Nucleatum-Positive Colorectal Cancer Patients

Purpose

This study assessed lymphocyte-to-monocyte ratio (LMR) changes to predict postoperative recurrence in Fusobacterium nucleatum-positive (Fn-positive) CRC patients.

Patients and Methods

Clinical information and paraffin tissue specimens were collected from a retrospective cohort of 332 patients. The abundance of Fn in tumor tissue was measured using a quantitative polymerase chain reaction. We evaluated the prognostic value and diagnostic performance of the dynamic changes of LMR from pre-operative to post-treatment (pr-LMR-po) and the dynamic alterations of LMR from pre-operative to post-treatment to pre-end of follow-up (pr-LMR-f) in predicting recurrence in Fn-positive CRC.

Results

In the total cohort and adjuvant therapy group cohort, pr-LMR-po independently predicted recurrence-free survival in Fn-positive CRC patients. In the adjuvant therapy group, pr-LMR-po (High-High vs Low-Low: HR: 3.896, 95% CI: 1.503-10.095, p=0.005) was particularly significant. Meanwhile, pr-LMR-f can serve as a predictive biomarker for Fn-positive CRC recurrence, especially in the adjuvant therapy group cohort where the c-statistic for pr-LMR-f was 0.825 (95% CI: 0.804-0.8251), with a sensitivity of 83.6% and a specificity of 79.3%. Compared to the overall adjuvant therapy group cohort, the prognostic performance of pr-LMR-f was superior in the Fn-positive CRC adjuvant therapy group cohort (AUC: 0.825 VS 0.711). Finally, we constructed a prediction model combining pr-LMR-f and CEA. After internal validation using the bootstrap resampling, the model had an AUC of 0.9295, a sensitivity of 94%, and a specificity of 72.7% in the Fn-positive CRC adjuvant therapy group cohort.

Conclusion

This study found that pr-LMR-po predicts Fn-positive CRC prognosis, and pr-LMR-f may predict Fn-positive CRC recurrence.

Impact of Fusobacterium nucleatum in the treatment of cancer, including radiotherapy and its future potential in esophageal cancer

Despite advances in multimodality therapy, including surgery, chemotherapy, radiation therapy and chemoradiation, the fatality rate for esophageal cancer remains high. Specifically, Fusobacterium nucleatum, due to its aggregation capacity, has shown a tendency to form biofilms. The biofilm-forming capabilities of microbial communities are of utmost importance in the context of cancer treatment, as they have been shown to drive significant losses in the efficaciousness of various cancer treatments. Therefore, elucidating the dynamics of F. nucleatum will be important for the development of effective treatments for esophageal cancer. Therefore, this review summarizes the current knowledge of F. nucleatum, its involvement in cancer and its impact on chemotherapy and radiation therapy. In conclusion, further research on the role of F. nucleatum is essential for the continued advancement of the treatment of esophageal cancer and patient care.

Association of Fusobacterium nucleatum infection with colorectal cancer in Kazakhstani patients

Objectives

Fusobacterium nucleatum is a gram-negative anaerobic bacillus associated with colorectal cancer (CRC). We aimed to determine the abundance of F. nucleatum and other CRC-associated bacteria using quantitative real-time polymerase chain reaction (qPCR) analysis to detect the possible correlations between tumor and normal tissues and the relationships between patients' clinical characteristics, diet, and CRC-associated bacteria.

Methods

A total of 249 biopsy samples of tumor and paired normal tissues were collected from patients with CRC. Biopsy samples were screened for detection of F. nucleatum using qPCR targeting nusG gene. Bacteroides fragilis, Escherichia coli, and Streptococcus gallolyticus were also detected in the samples using species-specific genes.

Results

The frequencies of detection of F. nucleatum in the tumor and normal tissues of patients with CRC were 43.37 and 24.1%, respectively (P < 0.05). Statistical analysis using cycle threshold (Ct) values from qPCR data and clinical characteristics showed that tumor size, tumor location, and processed meat consumption were significantly correlated with the abundance of F. nucleatum (P < 0.05). The significance of the prevalence of B. fragilis and E. coli in tumor tissues was marginally higher than that in normal tissues (P < 0.1), and the consumption of processed/red meat affected the prevalence of these bacteria (P < 0.05).

Conclusions

Our results showed an association between the presence of F. nucleatum in tumor tissues and CRC, indicating that F. nucleatum may be a potential marker for CRC diagnosis. F. nucleatum is enriched in CRC tissues and is associated with CRC development.

An Empirical Dietary Pattern Associated With the Gut Microbial Features in Relation to Colorectal Cancer Risk

BACKGROUND & AIMS

Epidemiologic evidence for dietary influence on colorectal cancer (CRC) risk through the gut microbiome remains limited.

METHODS

Leveraging 307 men and 212 women with stool metagenomes and dietary data, we characterized and validated a sex-specific dietary pattern associated with the CRC-related gut microbial signature (CRC Microbial Dietary Score [CMDS]). We evaluated the associations of CMDS with CRC risk according to Fusobacterium nucleatum, pks+Escherichia coli, and enterotoxigenic Bacteroides fragilis status in tumor tissue using Cox proportional hazards regression in the Health Professionals Follow-Up Study (1986-2018), Nurses' Health Study (1984-2020), and Nurses' Health Study II (1991-2019).

RESULTS

The CMDS was characterized by high industrially processed food and low unprocessed fiber-rich food intakes. In 259,200 participants, we documented 3854 incident CRC cases over 6,467,378 person-years of follow-up. CMDS was associated with a higher risk of CRC (Ptrend < .001), with a multivariable hazard ratio (HRQ5 vs Q1) of 1.25 (95% CI, 1.13-1.39). The association remained after adjusting for previously established dietary patterns, for example, the Western and prudent diets. Notably, the association was stronger for tumoral F nucleatum-positive (HRQ5 vs Q1, 2.51; 95% CI, 1.68-3.75; Ptrend < .001; Pheterogeneity = .03, positivity vs negativity), pks+E coli-positive (HRQ5 vs Q1, 1.68; 95% CI, 0.84-3.38; Ptrend = .005; Pheterogeneity = .01, positivity vs negativity), and enterotoxigenic Bacteroides fragilis-positive CRC (HRQ5 vs Q1, 2.06; 95% CI, 1.10-3.88; Ptrend = .016; Pheterogeneity = .06, positivity vs negativity), compared with their negative counterparts.

CONCLUSIONS

CMDS was associated with increased CRC risk, especially for tumors with detectable F nucleatum, pks+E coli, and enterotoxigenic Bacteroides fragilis in tissue. Our findings support a potential role of the gut microbiome underlying the dietary effects on CRC.

Functional links between the microbiome and the molecular pathways of colorectal carcinogenesis

Colorectal cancer (CRC) is a common cancer, with a concerning rise in early-onset CRC cases, signalling a shift in disease epidemiology. Whilst our understanding of the molecular underpinnings of CRC has expanded, the complexities underlying its initiation remain elusive, with emerging evidence implicating the microbiome in CRC pathogenesis. This review synthesizes current knowledge on the intricate interplay between the microbiome, tumour microenvironment (TME), and molecular pathways driving CRC carcinogenesis. Recent studies have reported how the microbiome may modulate the TME and tumour immune responses, consequently influencing cancer progression, and whilst specific bacteria have been linked with CRC, the underlying mechanisms remains poorly understood. By elucidating the functional links between microbial landscapes and carcinogenesis pathways, this review offers insights into how bacteria orchestrate diverse pathways of CRC development, shedding light on potential therapeutic targets and personalized intervention strategies.

Fusobacterium Nucleatum Promotes Microsatellite Instability in Colorectal Carcinoma Through Up-regulation of miRNA-155-5p-Targeted Inhibition of MSH6 via the TLR4/NF-κB Signaling Pathway

Fusobacterium nucleatum (Fn) is significantly associated with poor prognosis in colorectal carcinoma (CRC), however, mechanisms of Fn in DNA mismatch repair (MMR) and microsatellite instability (MSI) in CRC have not been fully elucidated. Clinical samples are collected to analyze the relationship between Fn abundance and microsatellite stability. Tumor cells are treated with Fn to detect the expression of proteins related to toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (Myd88), mutS homolog 6 (MSH6), and nuclear factor-κB (NF-κB) signaling pathways, respectively. Combined with the prediction results from TargetScan, the regulatory role of microRNA upstream of MSH6 is demonstrated. The effect of this regulatory axis on CRC development is demonstrated using a nude mouse tumor model. Compared with microsatellite stability (MSS)-type CRC patients, MSI-type showed higher Fn abundance. Fn treatment of CRC cells activated TLR4/Myd88/NF-κB signaling pathway, transcriptionally activating miRNA-155-5p expression, thereby negatively regulating MSH6. Fn treatment accelerated the malignant progression of CRC in mice, and this process is inhibited by miRNA-155-5p antagomir. Fn in CRC upregulated miRNA-155-5p by activating TLR4/NF-κB signaling to inhibit MSH6, and this regulatory pathway may affect MSS of cancer cells.

The role of Fusobacterium nucleatum in the pathogenesis of colon cancer

Previously, many studies have reported changes in the gut microbiota of patients with colorectal cancer (CRC). While CRC is a well-described disease, the relationship between its development and features of the intestinal microbiome is still being understood. Evidence linking Fusobacterium nucleatum enrichment in colorectal tumor tissue has prompted the elucidation of various molecular mechanisms and tumor-promoting attributes. In this review we highlight various aspects of our understanding of the relationship between the development of CRC and the alteration of intestinal microbiome, focusing specifically on the role of F. nucleatum. As the amount of F. nucleatum DNA in CRC tissue is associated with shorter survival, it may potentially serve as a prognostic biomarker, and most importantly may open the door for a role in CRC treatment.

Does Fusobacterium in Colorectal Cancer Sites Originate From the Oral Cavity? A Pilot Study

OBJECTIVES

Fusobacterium can contribute to oral diseases, but also pose as a systemic risk factor. This genus, and especially F. nucleatum, can be found in colorectal cancer (CRC) tissue and is involved in multiple aspects of this type of cancer. Previous studies indicated a possible oral origin of these bacteria; however, stronger evidence is needed to reach a definitive conclusion. This pilot study aimed to establish a method to successfully compare, at the strain level, fusobacteria from the oral cavity and CRC resection material for future cohort studies of CRC patients.

MATERIAL AND METHODS

In a first cohort of eight periodontitis patients, gingival crevicular fluid and saliva were collected. Fusobacterium was isolated on two different media. In a second cohort, saliva and CRC resection material were collected from ten CRC patients. These samples were used for screening of Fusobacterium with culturing, 16S rRNA gene profiling and a PCR-based approach.

RESULTS

In the first cohort, different Fusobacterium species were identified in GCF and saliva samples. However, as the total yield of Fusobacterium seemed slightly higher in saliva samples, it was therefore preferred for subsequent sample collection. Thus, in the second cohort, patient-matched saliva and CRC resection material were screened for Fusobacterium and this showed that nine patients were culture-positive in the saliva samples; however, no Fusobacterium could be isolated from the resection material. On the other hand, 16S rRNA gene profiling of the resection material indicated that eight CRC patients were positive for Fusobacterium. All eight of these patients carried Fusobacterium in their saliva, indicated by both marker gene PCR and culture-based screening.

CONCLUSIONS

These pilot results are compatible with data from previous studies, indicating a possible link between oral and CRC-associated Fusobacterium, and a more in-depth analysis of specific strains and their characteristics in a larger cohort is justified.

TRIAL REGISTRATION

The protocol was registered at clinicaltrials.gov (NCT05945082).

New Insights into Mucosa-Associated Microbiota in Paired Tumor and Non-Tumor Adjacent Mucosal Tissues in Colorectal Cancer Patients

BACKGROUND/OBJECTIVE

Colorectal cancer (CRC) is one of the most common cancers worldwide. Increasing scientific evidence supports the idea that gut microbiota dysbiosis accompanies colorectal tumorigenesis, and these changes could be causative. Implementing gut microbiota analysis in clinical practice is limited by sample type, sequencing platform and taxonomic classification. This article aims to address these limitations, providing new insights into the microbiota associated with CRC pathogenesis and implementing its analyses in personalized medicine.

METHODS

To that aim, we evaluate differences in the bacterial composition of 130 paired tumor and non-tumor adjacent tissues from a cohort of CRC patients from the Biobank of the University of Navarra, Spain. The V3-V4 region of the 16S rRNA gene was amplified, sequenced using the MinION platform, and taxonomically classified using the NCBI database.

RESULTS

To our knowledge, this is the first study to report an increased relative abundance of Streptococcus periodonticum and a decreased relative abundance of Corynebacterium associated with CRC. Genera such as Fusobacterium, Leptotrichia and Streptococcus showed higher relative abundances in tumor than in non-tumor tissues, as previously described in the literature. Specifically, we identified higher levels of Fusobacterium animalis, Fusobacterium nucleatum, Fusobacterium polymorphum and S. periodonticum in tumor tissues. In contrast, genera such as Bacteroides and Corynebacterium showed lower relative abundances in tumor tissues. There were also differences at the taxonomic level between tumor locations.

CONCLUSIONS

These results, consistent with previous studies, further support the hypothesis that Leptotrichia and Fusobacterium contribute to CRC progression, with F. nucleatum and F. animalis proposed as key CRC pathogenic taxa. Overall, these results contribute to a better understanding of the CRC-associated microbiota, addressing critical barriers to its implementation in personalized medicine.

Exploring the role of Fusobacterium nucleatum in colorectal cancer: implications for tumor proliferation and chemoresistance

Fusobacterium nucleatum (Fn) has been extensively studied for its connection to colorectal cancer (CRC) and its potential role in chemotherapy resistance. Studies indicate that Fn is commonly found in CRC tissues and is associated with unfavorable prognosis and treatment failure. It has been shown that Fn promotes chemoresistance by affecting autophagy, a cellular process that helps cells survive under stressful conditions. Additionally, Fn targets specific signaling pathways that activate particular microRNAs and modulate the response to chemotherapy. Understanding the current molecular mechanisms and investigating the importance of Fn-inducing chemoresistance could provide valuable insights for developing novel therapies. This review surveys the role of Fn in tumor proliferation, metastasis, and chemoresistance in CRC, focusing on its effects on the tumor microenvironment, gene expression, and resistance to conventional chemotherapy drugs. It also discusses the therapeutic implications of targeting Fn in CRC treatment and highlights the need for further research.

Unveiling the Power of Gut Microbiome in Predicting Neoadjuvant Immunochemotherapy Responses in Esophageal Squamous Cell Carcinoma

The role of the gut microbiome in enhancing the efficacy of anticancer treatments like chemotherapy and radiotherapy is well acknowledged. However, there is limited empirical evidence on its predictive capabilities for neoadjuvant immunochemotherapy (NICT) responses in esophageal squamous cell carcinoma (ESCC). Our study fills this gap by comprehensively analyzing the gut microbiome's influence on NICT outcomes. We analyzed 16S rRNA gene sequences from 136 fecal samples from 68 ESCC patients before and after NICT, along with 19 samples from healthy controls. After NICT, marked microbiome composition changes were noted, including a decrease in ESCC-associated pathogens and an increase in beneficial microbes such as Limosilactobacillus, Lacticaseibacillus, and Staphylococcus. Baseline microbiota profiles effectively differentiated responders from nonresponders, with responders showing higher levels of short-chain fatty acid (SCFA)-producing bacteria such as Faecalibacterium, Eubacterium_eligens_group, Anaerostipes, and Odoribacter, and nonresponders showing increases in Veillonella, Campylobacter, Atopobium, and Trichococcus. We then divided our patient cohort into training and test sets at a 4:1 ratio and utilized the XGBoost-RFE algorithm to identify 7 key microbial biomarkers-Faecalibacterium, Subdoligranulum, Veillonella, Hungatella, Odoribacter, Butyricicoccus, and HT002. A predictive model was developed using LightGBM, which achieved an area under the receiver operating characteristic curve (AUC) of 86.8% [95% confidence interval (CI), 73.8% to 99.4%] in the training set, 76.8% (95% CI, 41.2% to 99.7%) in the validation set, and 76.5% (95% CI, 50.4% to 100%) in the testing set. Our findings underscore the gut microbiome as a novel source of biomarkers for predicting NICT responses in ESCC, highlighting its potential to enhance personalized treatment strategies and advance the integration of microbiome profiling into clinical practice for modulating cancer treatment responses.