Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

CircRNAs in Colorectal Cancer: Unveiling Their Roles and Exploring Therapeutic Potential

Colorectal cancer (CRC) is the most common malignancy of the digestive system. Although research into the causes of CRC's origin and progression has advanced over the past few decades, many details are still not fully understood. Circular RNAs (circRNAs), as a novel regulatory molecule, have been found to be closely involved in various key biological processes in CRC. CircRNAs also have been shown to encode proteins, which could offer new possibilities for therapeutic applications. This ability to produce tumor-specific proteins makes circRNA-based vaccines a potentially valuable approach for targeted cancer treatment. In this review, we summarize recent findings on the various roles of circRNAs in CRC and explore their potential in the development of protein-encoding circRNA vaccines for CRC therapy.

Advances in gut microbiota-related treatment strategies for managing colorectal cancer in humans

Colorectal cancer (CRC) is a major contributor to global cancer-related mortality with increasing incidence rates in both developed and developing regions. Therefore, CRC presents a significant challenge to global health. The development of innovative tools for enhancing early CRC screening and diagnosis, along with novel treatments and therapies for improved management, remains an urgent necessity. CRC is intricately associated with the gut microbiota, which is integral to food digestion, nutrient generation, drug metabolism, metabolite production, immune enhancement, endocrine regulation, neurogenesis modulation, and the maintenance of physiologic and psychological equilibrium. Dysbiosis or imbalances in the gut microbiome have been implicated in various disorders, including CRC. Emerging evidence highlights the critical role of the gut microbiome in CRC pathogenesis and treatment, which presents potential opportunities for early detection and diagnosis. Despite substantial advances in understanding the relationship between the gut microbiota and CRC, significant challenges persist. Gaining a deeper and more detailed understanding of the interactions between the human microbiota and cancer is essential to fully realize the potential of the microbiota in cancer management. Unlike genetic factors, the gut microbiome is subject to modification, offering a promising avenue for the development of CRC treatments and drug discovery. This review provides an overview of the interactions between the human gut microbiome and CRC, while examining prospects for precision management of CRC.

Therapeutic Potential of Prunus Species in Gastrointestinal Oncology

BACKGROUND

Gastrointestinal tract cancers represent a significant worldwide health concern, accounting for almost one-third of cancer-related deaths. The existing chemotherapy drugs used in gastrointestinal cancers are ineffective, so prognosis is poor, recurrence and metastasis rates are high, and survival time remains short, necessitating the development of novel antitumor drugs that exhibit low toxicity and less potential for the development of drug resistance. This challenge is considerable, but evidence from the past decades supports the medicinal properties and functionalities of bioactive compounds such as flavonoids and acid phenolics with anticancer activities. Our purpose was to find data on the relationship between gastrointestinal cancer and bioactive compounds from Prunus species, focusing on their molecular mechanisms of action.

RESULTS

Studies highlight the potential of bioactive compounds from Prunus species to modulate the cancer cell signaling pathways involved in gastrointestinal tumorigenesis.

CONCLUSIONS

The studies reviewed suggest that polyphenols from Prunus species exhibit promising gastrointestinal anticancer activities and could represent an adjunctive therapeutic strategy in cancer treatment. Further studies are necessary to validate these compounds' therapeutic potential and their feasibility as cost-effective treatments for cancer.

Prediction of colorectal cancer based on taxonomic levels of microorganisms and discovery of taxonomic biomarkers using the Grouping-Scoring-Modeling (G-S-M) approach

Colorectal cancer (CRC) is one of the most prevalent forms of cancer globally. The human gut microbiome plays an important role in the development of CRC and serves as a biomarker for early detection and treatment. This research effort focuses on the identification of potential taxonomic biomarkers of CRC using a grouping-based feature selection method. Additionally, this study investigates the effect of incorporating biological domain knowledge into the feature selection process while identifying CRC-associated microorganisms. Conventional feature selection techniques often fail to leverage existing biological knowledge during metagenomic data analysis. To address this gap, we propose taxonomy-based Grouping Scoring Modeling (G-S-M) method that integrates biological domain knowledge into feature grouping and selection. In this study, using metagenomic data related to CRC, classification is performed at three taxonomic levels (genus, family and order). The MetaPhlAn tool is employed to determine the relative abundance values of species in each sample. Comparative performance analyses involve six feature selection methods and four classification algorithms. When experimented on two CRC associated metagenomics datasets, the highest performance metric, yielding an AUC of 0.90, is observed at the genus taxonomic level. At this level, 7 out of top 10 groups (Parvimonas, Peptostreptococcus, Fusobacterium, Gemella, Streptococcus, Porphyromonas and Solobacterium) were commonly identified for both datasets. Moreover, the identified microorganisms at genus, family, and order levels are thoroughly discussed via refering to CRC-related metagenomic literature. This study not only contributes to our understanding of CRC development, but also highlights the applicability of taxonomy-based G-S-M method in tackling various diseases.

Pterostilbene Exhibited the Anticancer Effect Against 1, 2-Dimethylhydrazine (DMH)-Induced Colorectal Cancer via Alteration of Oxidative Stress, Inflammation and Gut Microbiota

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. The current investigation aimed to assess the chemoprotective effects of pterostilbene against 1,2-dimethylhydrazine (DMH)-induced colorectal cancer in mice. An in-silico study was conducted to perform docking studies against nuclear factor kappa factor (NF-κB). CRC was induced in mice by administering DMH (20 mg/kg) subcutaneously, and the mice were subsequently administered various dosages of pterostilbene (5, 10, and 15 mg/kg). At the end of the study, various biochemical parameters, including inflammatory cytokines, inflammatory markers, and antioxidant enzymes, were examined. Additionally, the mice's stools were collected for the analysis of intestinal microbiota. A total of 5 hydrogen bonds were identified between NF-κB and pterostilbene using LigPlot+. Pterostilbene significantly (p < 0.001) reduced tumor incidence, tumor weight, and increased body weight. Pterostilbene significantly (p < 0.001) altered the levels of lipid peroxidation, reduced glutathione, superoxide dismutase, glutathione peroxidase, and catalase as well as the activity of both phase I and phase II enzymes. Furthermore, pterostilbene significantly (p < 0.001) decreased the levels of proinflammatory cytokines such as tumor necrosis factor-α, interleukin-6, interferon-γ, and interleukin-1β, while increasing the levels of anti-inflammatory cytokines like interleukin-4 and interleukin-10. Pterostilbene considerably suppressed the levels of cyclooxygenase-2 and prostaglandin E2, as well as inducible nitric oxide synthase and simultaneously elevated the levels of apoptosis-related parameters, including caspase-3, caspase-8, and caspase-9. Moreover, pterostilbene significantly reduced the abundance of Staphylococcus in the intestinal microbiota and enhanced the levels of beneficial bacteria, such as Bifidobacterium, Akkermansia, and Lactobacillus. Pterostilbene demonstrated a chemoprotective effect against CRC by effectively reducing oxidative stress, mitigating inflammatory responses, and inducing alterations in gut microbiota levels.

The Gut Microbiota and Colorectal Cancer: Understanding the Link and Exploring Therapeutic Interventions

CRC remains a significant public health challenge due to its high prevalence and mortality rates. Emerging evidence highlights the critical role of the gut microbiota in both the pathogenesis of CRC and the efficacy of treatment strategies, including chemotherapy and immunotherapy. Dysbiosis, characterized by imbalances in microbial communities, has been implicated in CRC progression and therapeutic outcomes. This review examines the intricate relationship between gut microbiota composition and CRC, emphasizing the potential for microbial profiles to serve as biomarkers for early detection and prognosis. Various interventions, such as prebiotics, probiotics, postbiotics, fecal microbiota transplantation, and dietary modifications, aim to restore microbiota balance and shift dysbiosis toward eubiosis, thereby improving health outcomes. Additionally, the integration of microbial profiling into clinical practice could enhance diagnostic capabilities and personalize treatment strategies, advancing the field of oncology. The study of intratumoral microbiota offers new diagnostic and prognostic tools that, combined with artificial intelligence algorithms, could predict treatment responses and assess the risk of adverse effects. Given the growing understanding of the gut microbiome-cancer axis, developing microbiota-oriented strategies for CRC prevention and treatment holds promise for improving patient care and clinical outcomes.

Determination of pentacyclic triterpenes and polyphenols from table olives in colon and plasma and their chemopreventive effects on 1,2-dimethylhydrazine-induced preneoplastic lesions in rat colon

Table olives are a rich dietary source of pentacyclic triterpenes (PT) and polyphenols (P), many of which have demonstrated significant antiproliferative and proapoptotic activities. This study aimed to evaluate the effect of this food on the early stages of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) at 20 mg kg-1. Male Sprague-Dawley rats were administered either water or a suspension of Arbequina table olives (OA; 3.85 g kg-1) by gavage at 10 mL kg-1 for 49 days. Each group was then divided into two subgroups that received subcutaneous injections of the carcinogen (DMH+/Olives- and DMH+/Olives+) or the solvent (DMH-/Olives- and DMH-/Olives+) on days 8, 15, and 22. Analysis by LC-MS of AO enabled us to calculate the administered doses of PT (12.38 mg kg-1) and P (4.02 g kg-1) as well as the colon content of these compounds. At the end of the intervention, we found 5.1% of PT and 0.2% of P of the administered dose in the colonic content of the DMH+/Olives+ group. The highest concentrations were for maslinic and oleanolic acids (321 ± 67 and 84.8 ± 14.3 nmol g-1, respectively) followed by hydroxytyrosol (3.31 ± 0.24 nmol g-1). The supplementation with AO reduced aberrant crypt foci by 54.1%, and mucin depleted foci by 35.7% compared to the control group. The daily consumption of table olives exerts chemopreventive activities by reducing preneoplastic intestinal lesions, which might be explained, at least in part, by the significant concentrations of PT and P remaining in the colon.

Research progress on edible mushroom polysaccharides as a novel therapeutic strategy for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex condition linked to the gut microbiota, host metabolism, and the immune system. Edible mushroom polysaccharides (EMPs) are gaining attention for their benefits, particularly as prebiotics that help balance gut microbial, a key factor in IBD. With their scalable production, diverse hydrophilic properties, and demonstrated anti-inflammatory effects in both laboratory and animal studies, EMPs show promise for easing IBD symptoms. By supporting a healthy gut microbiome through various mechanisms, EMPs can play an important role in preventing and managing IBD, ultimately benefiting overall health and opening new treatment avenues. This review examines how EMPs affect IBD, focusing on their role in shaping gut microbiota, restoring gut barriers, regulating immune function, and influencing pathways related to colitis. It also explores their impact on the microbiota-gut-multi organ axis and overall host health, as well as the relationship between EMPs preparation, structure, and bioactivity, along with their potential applications in food and medicine. This investigation provides valuable insights into the intricate connections between the gut, immune system, and systemic inflammation system, highlighting how EMPs are key players in this complex interaction.

Solobacterium moorei promotes tumor progression via the Integrin α2/β1-PI3K-AKT-mTOR-C-myc signaling pathway in colorectal cancer

More and more evidences show that the imbalance of intestinal flora homeostasis can contribute to the progression of colorectal cancer (CRC). Solobacterium moorei (S. moorei), an anaerobic Gram-positive bacillus, was found to be enriched in fecal samples from CRC patients. However, the signaling regulatory mechanism of S. moorei promoting CRC progression remain unknown. Three CRC mouse models (ApcMin/+ mice, AOM/DSS-treated mice and subcutaneous colorectal xenograft mice) and two cell lines (DLD-1 and HT-29) were used to investigate the biological functions and molecular mechanisms of S. moorei on tumor progression of CRC in vivo and in vitro. S. moorei abundance increased in fecal samples and tumor tissues, and was significantly positively correlated with tumor staging of CRC. S. moorei promoted tumor progression in various CRC mouse models and it selectively adhered to cancer cells in comparison to colonic mucosal epithelial cells, enhancing CRC cell proliferation and inhibiting cell apoptosis. Mechanistically, S. moorei cellwall protein Cna B-type domain-containing protein binds to integrin α2/β1 on CRC cells, leading to the activation of PI3K-AKT-mTOR-C-myc pathway via phospho-FAK, thereby promoted tumor cell growth and progression. Blockade of integrin α2/β1 abolished S. moorei-mediated oncogenic response in vitro and in vivo. In summary, this study demonstrated that S. moorei promoted tumor progression via the integrin α2/β1-PI3K-AKT-mTOR-C-myc signaling pathway, which is a novel specific pathogen-mediated mechanism that might be a new potential target for CRC prevention, diagnosis, and treatment.

Chitosan nanoparticles of imatinib mesylate coated with TPGS for the treatment of colon cancer: In-vivo & in-vitro studies

The study aimed to develop and evaluate chitosan-based nanoparticles coated with TPGS for the targeted delivery of imatinib mesylate to colon cancer cells. Particle size and zeta potential analysis were within the acceptable range for targeting colon cancer. CS-IMT-TPGS-NPs had a significant positive zeta potential of 30.4 mV, suggesting improved cellular intake. FE-SEM and TEM demonstrated that the nanoparticles appeared spherical, smooth, and did not aggregate, with a visible TPGS coating. XRD confirmed that crystalline imatinib transitioned to an amorphous state during nano formulation. In-vitro tests on HCT-116 cells demonstrated that CS-IMT-TPGS-NPs outperformed free IMT regarding cytotoxicity, apoptosis induction, cellular uptake, and cell migration inhibition. Additionally, the nanoparticles were examined in vitro using mitochondrial membrane potential, DNA fragmentation, GAPDH relative gene expression, ROS estimation, and cell cycle analysis. The effect of therapy on expected colon-associated bacterial strains was also investigated. The biocompatibility of nanoparticles was assessed by hemolysis and platelet aggregation experiments. The anti-inflammatory impact was determined using the HET-CAM test. Non-Fickian diffusion at pH 5.5 resulted in sustained in-vitro drug release, with no initial burst. In-vivo investigations using albino Wistar rats suggest pharmacokinetic properties for produced nanoparticles, whereas histopathological examinations assess acute toxicity.

Impact of antibiotic prophylaxis on gut microbiota in colorectal surgery: insights from an Eastern European stewardship study

Introduction

Antibiotic overuse is driving a global rise in antibiotic resistance, highlighting the need for robust antimicrobial stewardship (AMS) initiatives to improve prescription practices. While antimicrobials are essential for treating sepsis and preventing surgical site infections (SSIs), they can inadvertently disrupt the gut microbiota, leading to postoperative complications. Treatment methods vary widely across nations due to differences in drug choice, dosage, and therapy duration, affecting antibiotic resistance rates, which can reach up to 51% in some countries. In Romania and the Republic of Moldova, healthcare practices for surgical antibiotic prophylaxis differ significantly despite similarities in genetics, culture, and diet. Romania's stricter healthcare regulations result in more standardized antibiotic protocols, whereas Moldova's limited healthcare funding leads to less consistent practices and greater variability in treatment outcomes.

Methods

This study presents the results of a prospective cross-border investigation involving 86 colorectal cancer patients from major oncological hospitals in Romania and Moldova. We analyzed fecal samples collected from patients before and 7 days post-antibiotic treatment, focusing on the V3-V4 region of the 16S rRNA gene.

Results

Our findings indicate that inconsistent antibiotic prophylaxis policies-varying in type, dosage, or therapy duration-significantly impacted the gut microbiota and led to more frequent dysbiosis compared to stricter prophylactic antibiotic practices (single dose, single product, limited time).

Discussion

We emphasize the need for standardized antibiotic prophylaxis protocols to minimize dysbiosis and its associated risks, promoting more effective antimicrobial use, particularly in low- and middle-income countries (LMICs).

Fabrication of lactoferrin-chitosan-etoposide nanoparticles with melatonin via carbodiimide coupling: In-vitro & in-vivo evaluation for colon cancer

This study presents the development of melatonin-coated lactoferrin-chitosan nanoparticles (ETP-CS-LF-MLT-NPs) using ionic gelation and carbodiimide coupling for colorectal cancer treatment. The nanoparticles were characterized by an average size of 208.7 ± 1.25 nm, a zeta potential of 30.77 ± 1.21 mV, and 82.45 % drug encapsulation efficiency. In vitro drug release studies showed sustained, pH-responsive release, with 98.68 ± 4.12 % released at pH 5.5 over 24 h. The nanoparticles exhibited significant cytotoxicity in HCT116 cells (IC50 = 15.32 μg/mL), inducing ROS generation, apoptosis, and G2/M cell cycle arrest, with notable downregulation of BCL2 gene expression. Enhanced cellular uptake due to lactoferrin targeting improved therapeutic efficacy. In In vivo studies, the nanoparticles demonstrated significant tumor reduction and selective colon accumulation in a DMH-induced colorectal cancer rat model, along with improved pharmacokinetics, showing extended plasma circulation and bioavailability compared to free etoposide. Biocompatibility assays, including hemolysis (<1 %), platelet aggregation, and HET-CAM tests, confirmed the safety profiling of the prepared nanoparticles. The nanoparticles also inhibited Proteus mirabilis (ZOI = 1.9 cm) and exhibited promising effects on the gut microbiome of treated animals. Altogether, ETP-CS-LF-MLT-NPs hold great potential for targeted colorectal cancer therapy, improving drug delivery, tumor targeting, bioavailability, and reducing systemic toxicity.

Interaction of human gut microbiota and local immune system in progression of colorectal adenoma (MIMICA-1): a protocol for a prospective, observational cohort study

Introduction

The current understanding of colorectal carcinogenesis is based on the adenoma-carcinoma sequence, where genetics, intestinal microbiota changes and local immunity shifts seem to play the key roles. Despite the emerging evidence of dysbiotic intestinal state and immune-cell infiltration changes in patients with colorectal adenocarcinoma, early and advanced adenoma as precursors of colorectal cancer, and carcinoma in situ as the following progression, are rather less studied. The newly colon-site adapted AI-based analysis of immune infiltrates is able to predict long-term outcomes of colon carcinoma. Though it could also facilitate the pathologic evaluation of precancerous lesion's potential to progress. Therefore, the purpose of this prospective cohort study (MIMICA-1) is, firstly, to identify the intestinal microbiota and immune infiltration patterns around the normal bowel tissue, early and advanced adenoma, carcinoma in situ, and adenocarcinoma, and secondly, to analyze the immune - microbiome interplay along the steps of conventional colorectal tumorigenesis.

Methods and analyses

This study aims to prospectively recruit 40 patients (10 per group) with confirmed colorectal dysplasia undergoing endoscopic polypectomy, endoscopic mucosal resection for colorectal small (≤1cm), and large (>1cm) adenoma or carcinoma in situ, or biopsy and subsequent colon resection for invasive colorectal cancer, and 10 healthy patients undergoing screening colonoscopy. Stool samples will be collected prior to bowel preparation for the analysis of fecal (luminal) microbiota composition. Biopsy specimens will be taken from the terminal ileum, right colon, left colon, and a pathological lesion in the colon (if present) to assess mucosa-associated microbiota composition and intestinal immunity response. DNA will be extracted from all samples and sequenced using the Illumina MiSeq platform. Unifrac and Bray-Curtis methods will be used to assess microbial diversity. The intestinal immune system response will be examined using digital image analysis where primarily immunohistochemistry procedures for CD3, CD8, CD20 and CD68 immune cell markers will be performed. Thereafter, the count, density and distribution of immunocompetent cells in epithelial and stromal tissue compartments will be evaluated using AI-based platform. The interaction between the microbial shifts and intestinal immune system response in adenoma-carcinoma sequence and the healthy patients will be examined. In addition, fecal samples will be explored for gut microbiota's composition, comparing fecal- and tissue-derived bacterial patterns in healthy gut and along the adenoma-carcinoma sequence.

Discussion

We hypothesize that changes within the human gut microbiota led to detectable alterations of the local immune response and correlate with the progression from normal mucosa to colorectal adenoma and invasive carcinoma. It is expectable to find more severe gut immune infiltration at dysplasia site, though analyzing invasive colorectal cancer we expect to detect broader mucosa-associated and luminal microbiota changes with subsequent local immune response at near-lesion site and possibly throughout the entire colon. We believe that specific compositional differences detected around premalignant colorectal lesions are critically important for its primary role in initiation and acceleration of colorectal carcinogenesis. Thus, these microbial patterns could potentially supplement fecal immunohistochemical tests for the early non-invasive detection of colorectal adenoma. Moreover, AI-based analysis of immune infiltrates could become additional diagnostic and prognostic tool in precancerous lesions prior to the development of colorectal cancer.

Registration

The study is registered at the Australian New Zealand Clinical Trials Registry (ACTRN12624000976583) https://www.anzctr.org.au/.

Helminths in alternative therapeutics of inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is a nonspecific chronic inflammation of the gastrointestinal tract. Despite recent advances in therapeutics and newer management strategies, IBD largely remains untreatable. Helminth therapy is a promising alternative therapeutic for IBD that has gained some attention in the last two decades. Helminths have immunomodulatory effects and can alter the gut microbiota. The immunomodulatory effects include a strong Th2 immune response, T-regulatory cell response, and the production of regulatory cytokines. Although concrete evidence regarding the efficacy of helminth therapy in IBD is lacking, clinical studies and studies done in animal models have shown some promise. Most clinical studies have shown that helminth therapy is safe and easily tolerable. Extensive work has been done on the whipworm Trichuris, but other helminths, including Schistosoma, Trichinella, Heligmosomoides, and Ancylostoma, have also been explored for pre-clinical and animal studies. This review article summarizes the potential of helminth therapy as an alternative therapeutic or an adjuvant to the existing therapeutic procedures for IBD treatment.

Unraveling the complexities of colorectal cancer and its promising therapies - An updated review

Colorectal cancer (CRC) continues to be a global health concern, necessitating further research into its complex biology and innovative treatment approaches. The etiology, pathogenesis, diagnosis, and treatment of colorectal cancer are summarized in this thorough review along with recent developments. The multifactorial nature of colorectal cancer is examined, including genetic predispositions, environmental factors, and lifestyle decisions. The focus is on deciphering the complex interactions between signaling pathways such as Wnt/β-catenin, MAPK, TGF-β as well as PI3K/AKT that participate in the onset, growth, and metastasis of CRC. There is a discussion of various diagnostic modalities that span from traditional colonoscopy to sophisticated molecular techniques like liquid biopsy and radiomics, emphasizing their functions in early identification, prognostication, and treatment stratification. The potential of artificial intelligence as well as machine learning algorithms in improving accuracy as well as efficiency in colorectal cancer diagnosis and management is also explored. Regarding therapy, the review provides a thorough overview of well-known treatments like radiation, chemotherapy, and surgery as well as delves into the newly-emerging areas of targeted therapies as well as immunotherapies. Immune checkpoint inhibitors as well as other molecularly targeted treatments, such as anti-epidermal growth factor receptor (anti-EGFR) as well as anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies, show promise in improving the prognosis of colorectal cancer patients, in particular, those suffering from metastatic disease. This review focuses on giving readers a thorough understanding of colorectal cancer by considering its complexities, the present status of treatment, and potential future paths for therapeutic interventions. Through unraveling the intricate web of this disease, we can develop a more tailored and effective approach to treating CRC.

Oat Beta-Glucans Modulate the Gut Microbiome, Barrier Function, and Immune Responses in an In Vivo Model of Early-Stage Colorectal Cancer

Oat beta-glucans (OBGs) are known for their beneficial effects on gut health, including anti-inflammatory and prebiotic effects. The aim of this study was to evaluate the impact of two doses (1% or 3% w/w) of dietary low-molar-mass OBG supplementation on colorectal cancer (CRC) development, immune cell profiles, intestinal barrier protein expression, and microbiota composition in a rat model of CRC induced by azoxymethane (AOM). Microbiome analysis revealed significant differences between the control and CRC groups. OBG supplementation influenced microbial diversity and abundance, particularly increasing the population of beneficial bacteria, such as Lachnospiraceae and Ruminococcaceae, associated with butyrate production. However, higher doses of OBG (3%) led to a decrease in butyrate-producing bacteria and a shift toward higher levels of Akkermansia muciniphila and Enterococcus faecalis. Immune cell profiling showed a higher percentage of T lymphocytes (CD3+) in rats fed a diet supplemented with 3% OBG, both in the intraepithelial (IEL) and lamina propria lymphocytes (LPLs). Immunohistochemical analysis of the large intestine revealed a significantly elevated expression of intestinal barrier proteins, i.e., claudin 3 and 4 in rats receiving 1% OBG, while claudin 7 expression was reduced in early-stage CRC. Gene expression analysis also revealed a significant downregulation of Cldn1 in CRC rats. These findings suggest that dietary OBG supplementation modulates the gut microbiota, immune response, and intestinal barrier integrity, with potential implications for nutritional CRC development prevention and treatment strategies.

The bacterial microbiome and cancer: development, diagnosis, treatment, and future directions

The term "microbiome" refers to the collection of bacterial species that reside in the human body's tissues. Sometimes, it is used to refer to all microbial entities (bacteria, viruses, fungi, and others) which colonize the human body. It is now generally acknowledged that the microbiome plays a critical role in the host's physiological processes and general well-being. Changes in the structure and/or function of the microbiome (dysbiosis) are linked to the development of many diseases including cancer. The claim that because of their negatively charged membrane, cancer cells are more vulnerable to some bacteria than normal cells and that is how the link between these bacteria and cancer evolved has been refuted. Furthermore, the relationship between the microbiome and cancer is more evident in the emerging field of cancer immunotherapy. In this narrative review, we detailed the correlation between the presence/absence of specific bacterial species and the development, diagnosis, prognosis, and treatment of some types of cancer including colorectal, lung, breast, and prostate cancer. In addition, we discussed the mechanisms of microbiome-cancer interactions including genotoxin production, the role of free radicals, modification of signaling pathways in host cells, immune modulation, and modulation of drug metabolism by microbiome. Future directions and clinical application of microbiome in the early detection, prognosis, and treatment of cancer emphasizing on the role of fecal transplantation, probiotics, prebiotics, and microbiome biomarkers were also considered.

Enhanced CRC Growth in Iron-Rich Environment, Facts and Speculations

The contribution of nutritional factors to disease development has been demonstrated for several chronic conditions including obesity, type 2 diabetes, metabolic syndrome, and about 30 percent of cancers. Nutrients include macronutrients and micronutrients, which are required in large and trace quantities, respectively. Macronutrients, which include protein, carbohydrates, and lipids, are mainly involved in energy production and biomolecule synthesis; micronutrients include vitamins and minerals, which are mainly involved in immune functions, enzymatic reactions, blood clotting, and gene transcription. Among the numerous micronutrients potentially involved in disease development, the present review will focus on iron and its relation to tumor development. Recent advances in the understanding of iron-related proteins accumulating in the tumor microenvironment shed light on the pivotal role of iron availability in sustaining pathological tumor hallmarks, including cell cycle regulation, angiogenesis, and metastasis.

Fecal Microbiota Transplantation: Insights into Colon Carcinogenesis and Immune Regulation

Colorectal cancer (CRC) constitutes a significant global health challenge, with recent studies underscoring the pivotal role of the gut microbiome in its pathogenesis and progression. Fecal microbiota transplantation (FMT) has emerged as a compelling therapeutic approach, offering the potential to modulate microbial composition and optimize treatment outcomes. Research suggests that specific bacterial strains are closely linked to CRC, influencing both its clinical management and therapeutic interventions. Moreover, the gut microbiome's impact on immunotherapy responsiveness heralds new avenues for personalized medicine. Despite the promise of FMT, safety concerns, particularly in immunocompromised individuals, remain a critical issue. Clinical outcomes vary widely, influenced by genetic predispositions and the specific transplantation methodologies employed. Additionally, rigorous donor selection and screening protocols are paramount to minimize risks and maximize therapeutic efficacy. The current body of literature advocates for the establishment of standardized protocols and further clinical trials to substantiate FMT's role in CRC management. As our understanding of the microbiome deepens, FMT is poised to become a cornerstone in CRC treatment, underscoring the imperative for continued research and clinical validation.

Probiotics and the Role of Dietary Substrates in Maintaining the Gut Health: Use of Live Microbes and Their Products for Anticancer Effects against Colorectal Cancer

The gut microbiome is an important and the largest endocrine organ linked to the microbes of the GI tract. The bacterial, viral and fungal communities are key regulators of the health and disease status in a host at hormonal, neurological, immunological, and metabolic levels. The useful microbes can compete with microbes exhibiting pathogenic behavior by maintaining resistance against their colonization, thereby maintaining eubiosis. As diagnostic tools, metagenomic, proteomic and genomic approaches can determine various microbial markers in clinic for early diagnosis of colorectal cancer (CRC). Probiotics are live non-pathogenic microorganisms such as lactic acid bacteria, Bifidobacteria, Firmicutes and Saccharomyces that can help maintain eubiosis when administered in appropriate amounts. In addition, the type of dietary intake contributes substantially to the composition of gut microbiome. The use of probiotics has been found to exert antitumor effects at preclinical levels and promote the antitumor effects of immunotherapeutic drugs at clinical levels. Also, modifying the composition of gut microbiota by Fecal Microbiota Transplantation (FMT), and using live lactic acid producing bacteria such as Lactobacillus, Bifidobacteria and their metabolites (termed postbiotics) can contribute to immunomodulation of the tumor microenvironment. This can lead to tumor-preventive effects at early stages and antitumor effects after diagnosis of CRC. To conclude, probiotics are presumably found to be safe to use in humans and are to be studied further to promote their appliance at clinical levels for management of CRC.

Oral Microbial Translocation Genes in Gastrointestinal Cancers: Insights from Metagenomic Analysis

Along with affecting oral health, oral microbial communities may also be endogenously translocated to the gut, thereby mediating the development of a range of malignancies in that habitat. While species-level studies have proven the capability of oral pathogens to migrate to the intestine, genetic evidence supporting this mechanism remains insufficient. In this study, we identified over 55,000 oral translocation genes (OTGs) associated with colorectal cancer (CRC) and inflammatory bowel disease (IBD). These genes are primarily involved in signal transduction and cell wall biosynthesis and show consistency in their functions between IBD and CRC. Furthermore, we found that Leclercia adecarboxylata, a newly discovered opportunistic pathogen, has a significantly high abundance in the gut microbiota of colorectal cancer patients. OTGs of this pathogen were enriched in 15 metabolic pathways, including those associated with amino acid and cofactor metabolism. These findings, for the first time, provide evidence at the genetic level of the transfer of oral pathogens to the intestine and offer new insights into the understanding of the roles of oral pathogens in the development of gastrointestinal cancers.

Thai Fermented Soybean (Thua-Nao) Prevents Early Stages of Colorectal Carcinogenesis Induced by Diethylnitrosamine and 1,2-Dimethylhydrazine Through Modulations of Cell Proliferation and Gut Microbiota in Rats

BACKGROUND

Thua-nao is a traditional fermented soybean product widely consumed in the northern areas of Thailand. There has been little research on the biological activity of Thua-nao, particularly its anticancer properties.

OBJECTIVES

The objective of this study was to examine the cancer chemopreventive effects of dried Thua-nao on liver and colorectal carcinogenesis induced by carcinogens in rats.

METHODS

Rats were injected with diethylnitrosamine (DEN) and 1,2-dimethylhydrazine (DMH) to induce preneoplastic lesions. Rats orally received dried Thua-nao for 13 weeks. The preneoplastic lesions, including glutathione S-transferase placental form (GST-P)-positive foci and aberrant crypt foci (ACF), were evaluated in the liver and colon, respectively. The cancer chemopreventive mechanisms of dried Thua-nao on liver and colorectal carcinogenesis were examined.

RESULTS

Dried Thua-nao administration suppressed colorectal aberrant crypt foci. Moreover, dried Thua-nao reduced proliferation cell nuclear antigen (PCNA)-positive cells in the colon. Interestingly, dried Thua-nao modulated the gut microbiota in DEN- and DMH-induced rats. Isoflavones, including genistein and daidzein, represent promising chemopreventive agents in dried Thua-nao.

CONCLUSIONS

In conclusion, these results highlight the cancer chemopreventive effect of dried Thua-nao in DEN and DMH-induced colorectal carcinogenesis through cell proliferation reduction and gut microbiota modulation.

Inhibitory Effect of Lactobacillus Paracasei CMU-Pb-L5 In a Subcutaneous Transplanted Tumor Model of Colorectal Cancer

Lactobacillus paracasei (L.p) is a prevalent probiotic strain within the Lactobacillus genus, which has robust intestinal colonization capabilities. Previous studies have demonstrated the anticancer properties of L.p both in vivo and in vitro. However, the mechanisms underlying its anticancer activity in vivo remain unclear. This study established a subcutaneous transplanted tumor model of colorectal cancer (CRC) in mice to investigate the impact of L.p CMU-Pb-L5. Various parameters including tumor volume, tumor weight, histological alterations in tumor tissue, levels of polyamines and immune-related cytokines in serum, as well as the expression of polyamine metabolism-related and apoptosis-related proteins were evaluated. The results suggested that L.p CMU-Pb-L5 exhibited inhibitory effects on tumor cell proliferation, promotion of tumor cell apoptosis, reduction in polyamine levels, and enhancement of the immune response in CRC mice. To sum up, these results suggested that L.p CMU-Pb-L5 holds promise for potential clinical applications in the treatment of CRC.

Personalised medicine based on host genetics and microbiota applied to colorectal cancer

Colorectal cancer (CRC) ranks second in incidence and third in cancer mortality worldwide. This situation, together with the understanding of the heterogeneity of the disease, has highlighted the need to develop a more individualised approach to its prevention, diagnosis and treatment through personalised medicine. This approach aims to stratify patients according to risk, predict disease progression and determine the most appropriate treatment. It is essential to identify patients who may respond adequately to treatment and those who may be resistant to treatment to avoid unnecessary therapies and minimise adverse side effects. Current research is focused on identifying biomarkers such as specific mutated genes, the type of mutations and molecular profiles critical for the individualisation of CRC diagnosis, prognosis and treatment guidance. In addition, the study of the intestinal microbiota as biomarkers is being incorporated due to the growing scientific evidence supporting its influence on this disease. This article comprehensively addresses the use of current and emerging diagnostic, prognostic and predictive biomarkers in precision medicine against CRC. The effects of host genetics and gut microbiota composition on new approaches to treating this disease are discussed. How the gut microbiota could mitigate the side effects of treatment is reviewed. In addition, strategies to modulate the gut microbiota, such as dietary interventions, antibiotics, and transplantation of faecal microbiota and phages, are discussed to improve CRC prevention and treatment. These findings provide a solid foundation for future research and improving the care of CRC patients.

Microbiota and other detrimental metabolites in colorectal cancer

Increasing scientific evidence demonstrates that gut microbiota plays an essential role in the onset and development of Colorectal cancer (CRC). However, the mechanisms by which these microorganisms contribute to cancer development are complex and far from completely clarified. Specifically, the impact of gut microbiota-derived metabolites on CRC is undeniable, exerting both protective and detrimental effects. This paper examines the effects and mechanisms by which important bacterial metabolites exert detrimental effects associated with increased risk of CRC. Metabolites considered include heterocyclic amines and polycyclic aromatic hydrocarbons, heme iron, secondary bile acids, ethanol, and aromatic amines. It is necessary to delve deeper into the mechanisms of action of these metabolites in CRC and identify the microbiota members involved in their production. Furthermore, since diet is the main factor capable of modifying the intestinal microbiota, conducting studies that include detailed descriptions of dietary interventions is crucial. All this knowledge is essential for developing precision nutrition strategies to optimise a protective intestinal microbiota against 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.

Could environmental exposure and climate change Be a key factor in the rising incidence of early onset colorectal cancer?

The emergence of early onset colorectal cancer (EOCRC) is believed to result from the complex interplay between external environmental factors and internal molecular processes. This review investigates the potential association between environmental exposure to chemicals and climate change and the increased incidence of EOCRC, focusing on their effects on gut microbiota (GM) dynamics. The manuscript explores the birth cohort effect, suggesting that individuals born after 1950 may be at higher risk of developing EOCRC due to cumulative environmental exposures. Furthermore, we also reviewed the impact of environmental pollution, including particulate matter and endocrine disrupting chemicals (EDCs), as well as global warming, on GM disturbance. Environmental exposures have the potential to disrupt GM composition and diversity, leading to dysbiosis, chronic inflammation, and oxidative stress, which are known risk factors associated with EOCRC. Particulate matter can enter the gastrointestinal tract, modifying GM composition and promoting the proliferation of pathogenic bacteria while diminishing beneficial bacteria. Similarly, EDCs, can induce GM alterations and inflammation, further increasing the risk of EOCRC. Additionally, global warming can influence GM through shifts in gut environmental conditions, affecting the host's immune response and potentially increasing EOCRC risk. To summarize, environmental exposure to chemicals and climate change since 1950 has been implicated as contributing factors to the rising incidence of EOCRC. Disruptions in gut microbiota homeostasis play a crucial role in mediating these associations. Consequently, there is a pressing need for enhanced environmental policies aimed at minimizing exposure to pollutants, safeguarding public health, and mitigating the burden of EOCRC.

Induction of Cell Death by Bifidobacterium infantis DS1685 in Colorectal and Breast Cancers via SMAD4/TGF-Beta Activation

Therapeutic advancements in treatments for cancer, a leading cause of mortality worldwide, have lagged behind the increasing incidence of this disease. There is a growing interest in multifaceted approaches for cancer treatment, such as chemotherapy, targeted therapy, and immunotherapy, but due to their low efficacy and severe side effects, there is a need for the development of new cancer therapies. Recently, the human microbiome, which is comprised of various microorganisms, has emerged as an important research field due to its potential impact on cancer treatment. Among these microorganisms, Bifidobacterium infantis has been shown to significantly improve the efficacy of various anticancer drugs. However, research on the role of B. infantis in cancer treatment remains insufficient. Thus, in this study, we explored the anticancer effect of treatment with B. infantis DS1685 supernatant (BI sup) in colorectal and breast cancer cell lines. Treatment with BI sup induced SMAD4 expression to suppress cell growth in colon and breast cancer cells. Furthermore, a decrease in tumor cohesion was observed through the disruption of the regulation of EMT-related genes by BI sup in 3D spheroid models. Based on these findings, we anticipate that BI sup could play an adjunctive role in cancer therapy, and future cotreatment of BI sup with various anticancer drugs may lead to synergistic effects in cancer treatment.

Predictive modeling of colorectal cancer using exhaustive analysis of microbiome information layers available from public metagenomic data

This study aimed to compare the microbiome profiles of patients with colorectal cancer (CRC, n = 380) and colorectal adenomas (CRA, n = 110) against generally healthy participants (n = 2,461) from various studies. The overarching objective was to conduct a real-life experiment and develop a robust machine learning model applicable to the general population. A total of 2,951 stool samples underwent a comprehensive analysis using the in-house MetaBakery pipeline. This included various data matrices such as microbial taxonomy, functional genes, enzymatic reactions, metabolic pathways, and predicted metabolites. The study found no statistically significant difference in microbial diversity among individuals. However, distinct clusters were identified for healthy, CRC, and CRA groups through linear discriminant analysis (LDA). Machine learning analysis demonstrated consistent model performance, indicating the potential of microbiome layers (microbial taxa, functional genes, enzymatic reactions, and metabolic pathways) as prediagnostic indicators for CRC and CRA. Notable biomarkers on the taxonomy level and microbial functionality (gene families, enzymatic reactions, and metabolic pathways) associated with CRC were identified. The research presents promising avenues for practical clinical applications, with potential validation on external clinical datasets in future studies.

Importance of diet and intestinal microbiota in the prevention of colorectal cancer - colonoscopy early screening diagnosis

Colorectal cancer is a term used to describe colon and rectal cancer, which is the third most common type of cancer. A MEDLINE and PubMed search resulted in the inclusion of manuscripts written in the last 10 years, using keywords relevant to the topic of the manuscript. By analyzing the aim of the searched studies and manuscripts, adequate articles were included that described the stated problem. The frequency of colorectal cancer varies with climate, nutrition, and many other factors, primarily endogenous, hereditary, intestinal microbiome, as well as external factors, such as exposure of the individual to stress, and bad eating habits. Colon cancer and rectal cancer or colorectal cancer in general in the early stages of the disease, may not show symptoms or are barely noticeable. Colorectal cancer symptoms will most often not develop until the disease has progressed to stage 2 or beyond. Regular screening tests for colon or rectal cancer, especially colonoscopy, are recommended as part of a regular checkup for people aged 50 years or younger who are at high risk due to a family history of the disease or other cancers. Diet and colonoscopy as an early screening method play an important role in the prevention of colorectal cancer.

Microbiota-associated mechanisms in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, ranking third in terms of incidence and second as a cause of cancer-related death. There is growing scientific evidence that the gut microbiota plays a key role in the initiation and development of CRC. Specific bacterial species and complex microbial communities contribute directly to CRC pathogenesis by promoting the neoplastic transformation of intestinal epithelial cells or indirectly through their interaction with the host immune system. As a result, a protumoural and immunosuppressive environment is created conducive to CRC development. On the other hand, certain bacteria in the gut microbiota contribute to protection against CRC. In this chapter, we analysed the relationship of the gut microbiota to CRC and the associations identified with specific bacteria. Microbiota plays a key role in CRC through various mechanisms, such as increased intestinal permeability, inflammation and immune system dysregulation, biofilm formation, genotoxin production, virulence factors and oxidative stress. Exploring the interaction between gut microbiota and tumourigenesis is essential for developing innovative therapeutic approaches in the fight against CRC.

Microbiota composition effect on immunotherapy outcomes in colorectal cancer patients: A systematic review

BACKGROUND

Immune checkpoint inhibitors (ICIs) have emerged as an effective treatment for colorectal cancer (CRC). Studies indicate that the composition of gut microbiota could potentially serve as a biomarker for predicting the clinical effectiveness of immune checkpoint inhibitors.

METHODS

Following PRISMA guidelines, the review was conducted after registering the protocol with PROSPERO. A comprehensive literature search was carried out across five databases: PubMed, Scopus, Web of Science, Embase, and Cochrane Library. Assessment tools from the National Institutes of Health (NIH) were used to gauge the quality of the studies.

RESULTS

A total of 5,132 papers were identified, and three studies and one conference abstract published between 2017-2022 met the inclusion criteria and were summarized in a descriptive synthesis table. These four studies were in accord with the following findings, four main phyla, Firmicutes, Bacteroidata, Actinobacteria, and Verrucomicrobiota were associated with CRC patients' clinical response toward ICIs treatment. Ruminococcaceae was predominantly related to CRC patients responding to therapy, while the Micrococcaceae family was more common among the non-responders. Bacterial taxa such as Faecalibacterium and Prevotellaceae were associated with better responses to ICIs and could be predictive biomarkers. The signature of fecal microbiota with Akkermansia muciniphila and Eubacterium rectale enrichment, and Rothia mucilaginosa depletion could independently predict better response to ICIs in patients with CRC.

CONCLUSION

The findings have brought attention to the notable differences in terms of richness and composition of microbiota between patients who responded positively to the treatment and those who did not. Bacterial species and families, such as Faecalibacterium, Bifidobacterium, Lachnospiraceae, Akkermansia sp., Ruminococcaceae, and Prevotellaceae, have consistently surfaced as potential indicators of immunotherapeutic responses. Furthermore, this review also emphasizes the need for additional comprehensive, multi-center studies with larger sample sizes to validate reported microbiota and expand our understanding of the role of gut microbiota in CRC ICIs therapy. PROSPERO ID: CRD42021277691.

Opioid Use and Gut Dysbiosis in Cancer Pain Patients

Opioids are commonly used for the management of severe chronic cancer pain. Their well-known pharmacological effects on the gastrointestinal system, particularly opioid-induced constipation (OIC), are the most common limiting factors in the optimization of analgesia, and have led to the wide use of laxatives and/or peripherally acting mu-opioid receptor antagonists (PAMORAs). A growing interest has been recently recorded in the possible effects of opioid treatment on the gut microbiota. Preclinical and clinical data, as presented in this review, showed that alterations of the gut microbiota play a role in modulating opioid-mediated analgesia and tolerability, including constipation. Moreover, due to the bidirectional crosstalk between gut bacteria and the central nervous system, gut dysbiosis may be crucial in modulating opioid reward and addictive behavior. The microbiota may also modulate pain regulation and tolerance, by activating microglial cells and inducing the release of inflammatory cytokines and chemokines, which sustain neuroinflammation. In the subset of cancer patients, the clinical meaning of opioid-induced gut dysbiosis, particularly its possible interference with the efficacy of chemotherapy and immunotherapy, is still unclear. Gut dysbiosis could be a new target for treatment in cancer patients. Restoring the physiological amount of specific gut bacteria may represent a promising therapeutic option for managing gastrointestinal symptoms and optimizing analgesia for cancer patients using opioids.

Research progress on the correlation between intestinal flora and colorectal cancer

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies in the world. With the rapid pace of life and changes in diet structure, the incidence and mortality of CRC increase year by year posing a serious threat to human health. As the most complex and largest microecosystem in the human body, intestinal microecology is closely related to CRC. It is an important factor that affects and participates in the occurrence and development of CRC. Advances in next-generation sequencing technology and metagenomics have provided new insights into the ecology of gut microbes. It also helps to link intestinal flora with CRC, and the relationship between intestinal flora and CRC can be continuously understood from different levels. This paper summarizes the relationship between intestinal flora and CRC and its potential role in the diagnosis of CRC providing evidence for early screening and treatment of CRC.

Exploring the Role of the Gut Microbiota in Colorectal Cancer Development

Colorectal cancer is currently a public health concern due to its high incidence, morbidity, and mortality rates. Researchers have identified the intestinal microbiome as a crucial factor in the development of this disease. Currently, specialized literature data support the role of the microbiota in both the development of colorectal cancer and resistance to oncological therapies. Therefore, studying the composition of the gut microbiome can aid in creating risk assessment tools to identify specific populations that would benefit from tailored screening approaches. Also, manipulation of the intestinal microbiome can be useful in improving the response to chemotherapy or immunotherapy. Identifying the pathogenic mechanisms responsible for this causal link can aid in the discovery of novel treatment targets. This article will provide the latest information regarding the influence of the intestinal microbiota on the development and progression of colorectal cancer.

Colorectal cancer: a comprehensive review of carcinogenesis, diagnosis, and novel strategies for classified treatments

Colorectal cancer is the third most common and the second deadliest cancer worldwide. To date, colorectal cancer becomes one of the most important challenges of the health system in many countries. Since the clinical symptoms of this cancer appear in the final stages of the disease and there is a significant golden time between the formation of polyps and the onset of cancer, early diagnosis can play a significant role in reducing mortality. Today, in addition to colonoscopy, minimally invasive methods such as liquid biopsy have received much attention. The treatment of this complex disease has been mostly based on traditional treatments including surgery, radiotherapy, and chemotherapy; the high mortality rate indicates a lack of success for current treatment methods. Moreover, disease recurrence is another problem of traditional treatments. Recently, new approaches such as targeted therapy, immunotherapy, and nanomedicine have opened new doors for cancer treatment, some of which have already entered the market, and many methods have shown promising results in clinical trials. The success of immunotherapy in the treatment of refractory disease, the introduction of these methods into neoadjuvant therapy, and the successful results in tumor shrinkage without surgery have made immunotherapy a tough competitor for conventional treatments. It seems that the combination of those methods with such targeted therapies will go through promising changes in the future of colorectal cancer treatment.

The Crucial Roles of Diet, Microbiota, and Postbiotics in Colorectal Cancer

PURPOSE OF REVIEW

Colorectal cancer is the second deadliest cancer in the world, and its prevalence has been increasing alarmingly in recent years. After researchers discovered the existence of dysbiosis in colorectal cancer, they considered the use of probiotics in the treatment of colorectal cancer. However, for various reasons, including the low safety profile of probiotics in susceptible and immunocompromised patient5s, and the risk of developing antibiotic resistance, researchers have shifted their focus to non-living cells, their components, and metabolites. This review aims to comprehensively evaluate the literature on the effects of diet, microbiota, and postbiotics on colorectal cancer and the future of postbiotics.

RECENT FINDINGS

The link between diet, gut microbiota, and colorectal cancer has been established primarily as a relationship rather than a cause-effect relationship. The gut microbiota can convert gastrointestinal tract and dietary factors into either onco-metabolites or tumor suppressor metabolites. There is serious dysbiosis in the microbiota in colorectal cancer. Postbiotics appear to be promising agents in the prevention and treatment of colorectal cancer. It has been shown that various postbiotics can selectively induce apoptosis in CRC, inhibit cell proliferation, growth, invasion, and migration, modulate the immune system, suppress carcinogenic signaling pathways, maintain intestinal epithelial integrity, and have a synergistic effect with chemotherapy drugs. However, it is also reported that some postbiotics are ineffective and may be risky in terms of safety profile in some patients. Many issues need to be researched about postbiotics. Large-scale, randomized, double-blind clinical studies are needed.

Dandelion root extracts and taraxasterol inhibit LPS‑induced colorectal cancer cell viability by blocking TLR4‑NFκB‑driven ACE2 and TMPRSS2 pathways

Colorectal cancer is the fourth leading cause of cancer-related death worldwide. Notably, abnormalities in intestinal bacteria may contribute to the initiation or progression of colorectal cancer. Lipopolysaccharide (LPS), a bacterial endotoxin, is elevated in patients with colorectal cancer. The present study investigated the protective effects of dandelion root extracts and taraxasterol (TS; a major pharmacologically active compound in dandelion root extracts) on LPS-induced colorectal cancer cell viability, as well as the underlying mechanisms. Cell viability was assessed by MTT assay, and protein and gene expression levels were determined by western blotting and quantitative PCR. It was revealed that LPS at a low dose (0.5 µg/ml) significantly promoted the viability of human colorectal cancer cells but did not affect normal colon epithelial cells. The addition of dandelion root extracts (0.1-1 mg/ml) or TS (0.05-1 µg/ml) was able to reverse the LPS-induced increase in colorectal cancer cell viability and colony formation. Mechanistically, dandelion root extracts or TS may inhibit the LPS-promoted toll-like receptor 4 (TLR4)/NFκB-p65 pathway and transcription levels of pro-inflammatory genes (TNFα, IL4 and IL6). Compared with normal colon epithelial cells, human colorectal cancer cells had higher expression levels of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), which could be further enhanced by LPS treatment but this was reversed by co-incubation with dandelion root extracts or TS. In addition, suppression of the TLR4/NFκB-p65 pathway with CLI095 significantly reversed the stimulatory effect of LPS on the expression levels of ACE2 and TMPRSS2, whereas TNFα (10 ng/ml) markedly induced the expression levels of ACE2 and TMPRSS2. In conclusion, the present study suggested that dandelion root extracts and TS could be used as prevention strategies for reversing bacteria-driven colorectal cancer cell viability.

The impact of pre-, pro- and synbiotics supplementation in colorectal cancer treatment: a systematic review

Introduction

The effectiveness of the supplementation of prebiotics, probiotics and synbiotics as a therapeutic approach in colorectal cancer (CRC) remains unclear. The aim of this systematic review is to critically examine the current scientific evidence on the impact of modulating the microbiota, through the use of prebiotics, probiotics and synbiotics, in patients diagnosed with CRC undergoing treatment, to determine the potential therapeutic use of this approach.

Methods

This systematic review was made according to the PRISMA 2020 guidelines. Inclusion criteria were randomized controlled trials (RCT) comparing the impact of pre-, pro-, or synbiotic supplementation with placebo or standard care in patients with CRC undergoing treatment. Exclusion criteria were non-human studies, non-RCTs, and studies in languages other than English or Portuguese. Six databases were consulted, namely, Cochrane Library, Pubmed, Scopus, Cinahl, MedicLatina and Web of Science until May of 2023. RAYYAN software was used to manage the search results and risk of bias was assessed according to the guidelines of the Cochrane Collaboration using the Rob 2.0 tool.

Results

Twenty-four RCTs met the inclusion criteria and were included in this review. Administration of pre-, pro-, or synbiotics improved surgical outcomes such as the incidence of infectious and non-infectious postoperative complications, return to normal gut function, hospital length of stay, and antibiotic usage. The supplementation of these microorganisms also alleviated some symptoms from chemotherapy and radiotherapy, mainly diarrhea. Evidence on the best approach in terms of types of strains, dosage and duration of intervention is still scarce.

Conclusions

Pre-, pro-, and synbiotics supplementation appears to be a beneficial therapeutic approach in CRC treatment to improve surgical outcomes and to alleviate side-effects such as treatment toxicity. More RCTs with larger sample sizes and less heterogeneity are needed to confirm these potential benefits and to determine the best strains, dosage, and duration of administration in each situation.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023413958.

Circulating microbiome DNA as biomarkers for early diagnosis and recurrence of lung cancer

Lung cancer mortality is exacerbated by late-stage diagnosis. Emerging evidence indicates the potential clinical significance of distinct microbial signatures as diagnostic and prognostic biomarkers across various cancers. However, circulating microbiome DNA (cmDNA) profiles are underexplored in lung cancer (LC). Here, whole-genome sequencing is performed on plasma of LC patients and healthy controls (HCs). Differentially enriched microbial species are identified between LC and HC. A diagnostic model is developed, which has a high sensitivity of 87.7% and achieves an AUC of 93.2% in the independent validation dataset. Crucially, this model demonstrates the capability to detect early-stage LC, achieving a sensitivity of 86.5% for stage I and 87.1% for tumors <1 cm. In addition, we construct a cmDNA model for recurrence, which precisely predicts LC recurrence after surgery. Overall, this study highlights the significant alterations of cmDNA profiles in LC, indicating its potential as biomarkers for early diagnosis and recurrence.

Unlocking the secrets: exploring the influence of the aryl hydrocarbon receptor and microbiome on cancer development

Gut microbiota regulates various aspects of human physiology by producing metabolites, metabolizing enzymes, and toxins. Many studies have linked microbiota with human health and altered microbiome configurations with the occurrence of several diseases, including cancer. Accumulating evidence suggests that the microbiome can influence the initiation and progression of several cancers. Moreover, some microbiotas of the gut and oral cavity have been reported to infect tumors, initiate metastasis, and promote the spread of cancer to distant organs, thereby influencing the clinical outcome of cancer patients. The gut microbiome has recently been reported to interact with environmental factors such as diet and exposure to environmental toxicants. Exposure to environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) induces a shift in the gut microbiome metabolic pathways, favoring a proinflammatory microenvironment. In addition, other studies have also correlated cancer incidence with exposure to PAHs. PAHs are known to induce organ carcinogenesis through activating a ligand-activated transcriptional factor termed the aryl hydrocarbon receptor (AhR), which metabolizes PAHs to highly reactive carcinogenic intermediates. However, the crosstalk between AhR and the microbiome in mediating carcinogenesis is poorly reviewed. This review aims to discuss the role of exposure to environmental pollutants and activation of AhR on microbiome-associated cancer progression and explore the underlying molecular mechanisms involved in cancer development.

Gut Microbiome-Colorectal Cancer Relationship

Traditionally, the role of gut dysbiosis was thought to be limited to pathologies like Clostridioides difficile infection, but studies have shown its role in other intestinal and extraintestinal pathologies. Similarly, recent studies have surfaced showing the strong potential role of the gut microbiome in colorectal cancer, which was traditionally attributed mainly to sporadic or germline mutations. Given that it is the third most common cancer and the second most common cause of cancer-related mortality, 78 grants totaling more than USD 28 million have been granted to improve colon cancer management since 2019. Concerted efforts by several of these studies have identified specific bacterial consortia inducing a proinflammatory environment and promoting genotoxin production, causing the induction or progression of colorectal cancer. In addition, changes in the gut microbiome have also been shown to alter the response to cancer chemotherapy and immunotherapy, thus changing cancer prognosis. Certain bacteria have been identified as biomarkers to predict the efficacy of antineoplastic medications. Given these discoveries, efforts have been made to alter the gut microbiome to promote a favorable diversity to improve cancer progression and the response to therapy. In this review, we expand on the gut microbiome, its association with colorectal cancer, and antineoplastic medications. We also discuss the evolving paradigm of fecal microbiota transplantation in the context of colorectal cancer management.

Oral administration of Manuka honey induces IFNγ-dependent resistance to tumor growth that correlates with beneficial modulation of gut microbiota composition

Background

To investigate the potential of Manuka honey (MH) as an immunomodulatory agent in colorectal cancer (CRC) and dissect the underlying molecular and cellular mechanisms.

Methods

MH was administered orally over a 4 week-period. The effect of MH treatment on microbiota composition was studied using 16S rRNA sequencing of fecal pellets collected before and after treatment. Pretreated mice were implanted with CRC cells and followed for tumor growth. Tumors and lymphoid organs were analyzed by flow cytometry (FACS), immunohistochemistry and qRT-PCR. Efficacy of MH was also assessed in a therapeutic setting, with oral treatment initiated after tumor implantation. We utilized IFNγ-deficient mice to determine the importance of interferon signaling in MH-induced immunomodulation.

Results

Pretreatment with MH enhanced anti-tumor responses leading to suppression of tumor growth. Evidence for enhanced tumor immunogenicity included upregulated MHC class-II on intratumoral macrophages, enhanced MHC class-I expression on tumor cells and increased infiltration of effector T cells into the tumor microenvironment. Importantly, oral MH was also effective in retarding tumor growth when given therapeutically. Transcriptomic analysis of tumor tissue highlighted changes in the expression of various chemokines and inflammatory cytokines that drive the observed changes in tumor immunogenicity. The immunomodulatory capacity of MH was abrogated in IFNγ-deficient mice. Finally, bacterial 16S rRNA sequencing demonstrated that oral MH treatment induced unique changes in gut microbiota that may well underlie the IFN-dependent enhancement in tumor immunogenicity.

Conclusion

Our findings highlight the immunostimulatory properties of MH and demonstrate its potential utilization in cancer prevention and treatment.

Investigating the therapeutic potential of Bifidobacterium breve and Lactobacillus rhamnosus postbiotics through apoptosis induction in colorectal HT-29 cancer cells

Background and Objectives

Colorectal cancer (CRC) is a prevalent form of cancer worldwide. Recent studies suggest that postbiotics derived from probiotic bacteria have the potential as an adjunct therapy for CRC. This study investigates the anti-cancer effects of Bifidobacterium breve (B. breve) and Lactobacillus rhamnosus (L. rhamnosus) postbiotics on the HT-29 cell line.

Materials and Methods

Through MTT and scratch assay, we investigated the anti-proliferation and anti-migration effects of B. breve and L. rhamnosus postbiotics on HT-29 cells. Furthermore, postbiotic-mediated apoptosis was assessed by analyzing the expression of Bax, Bcl-2, and caspase-3. We also investigated the effects of B. breve postbiotics on the expression of three important genes involved in metastasis, including RSPO2, NGF, and MMP7. Consequently, we validated the expression of selected genes in twelve adenocarcinoma tissues.

Results

The results demonstrated the significant impact of postbiotics on HT-29 cells, highlighting their ability to induce anti-proliferation, anti-migration, and apoptosis-related effects. Notably, these effects were more pronounced using B. breve postbiotics than L. rhamnosus. Additionally, B. breve postbiotics could inhibit metastasis through upregulation of RSPO2 while downregulating NGF and MMP7 expression in HT-29 cells.

Conclusion

Our research suggests that postbiotic metabolites may be effective biological products for the prevention and treatment of cancer.

The Networked Interaction between Probiotics and Intestine in Health and Disease: A Promising Success Story

Probiotics are known to promote human health either precautionary in healthy individuals or therapeutically in patients suffering from certain ailments. Although this knowledge was empirical in past tomes, modern science has already verified it and expanded it to new limits. These microorganisms can be found in nature in various foods such as dairy products or in supplements formulated for clinical or preventive use. The current review examines the different mechanisms of action of the probiotic strains and how they interact with the organism of the host. Emphasis is put on the clinical therapeutic use of these beneficial microorganisms in various clinical conditions of the human gastrointestinal tract. Diseases of the gastrointestinal tract and particularly any malfunction and inflammation of the intestines seriously compromise the health of the whole organism. The interaction between the probiotic strains and the host's microbiota can alleviate the clinical signs and symptoms while in some cases, in due course, it can intervene in the underlying pathology. Various safety issues of the use of probiotics are also discussed.

Microbiome Dysbiosis, Dietary Intake and Lifestyle-Associated Factors Involve in Epigenetic Modulations in Colorectal Cancer: A Narrative Review

Background: Colorectal cancer is the second cause of cancer mortality and the third most commonly diagnosed cancer worldwide. Current data available implicate epigenetic modulations in colorectal cancer development. The health of the large bowel is impacted by gut microbiome dysbiosis, which may lead to colon and rectum cancers. The release of microbial metabolites and toxins by these microbiotas has been shown to activate epigenetic processes leading to colorectal cancer development. Increased consumption of a 'Westernized diet' and certain lifestyle factors such as excessive consumption of alcohol have been associated with colorectal cancer.Purpose: In this review, we seek to examine current knowledge on the involvement of gut microbiota, dietary factors, and alcohol consumption in colorectal cancer development through epigenetic modulations.Methods: A review of several published articles focusing on the mechanism of how changes in the gut microbiome, diet, and excessive alcohol consumption contribute to colorectal cancer development and the potential of using these factors as biomarkers for colorectal cancer diagnosis.Conclusions: This review presents scientific findings that provide a hopeful future for manipulating gut microbiome, diet, and alcohol consumption in colorectal cancer patients' management and care.

A perspective on emerging therapies in metastatic colorectal cancer: Focusing on molecular medicine and drug resistance

The majority of cancer cases are colorectal cancer, which is also the second largest cause of cancer-related deaths worldwide. Metastasis is the leading cause of death for patients with colorectal cancer. Metastatic colorectal cancer incidence are on the rise due to a tiny percentage of tumors developing resistant to medicines despite advances in treatment tactics. Cutting-edge targeted medications are now the go-to option for customized and all-encompassing CRC care. Specifically, multitarget kinase inhibitors, antivascular endothelial growth factors, and epidermal growth factor receptors are widely used in clinical practice for CRC-targeted treatments. Rare targets in metastatic colorectal cancer are becoming more well-known due to developments in precision diagnostics and the extensive use of second-generation sequencing technology. These targets include the KRAS mutation, the BRAF V600E mutation, the HER2 overexpression/amplification, and the MSI-H/dMMR. Incorporating certain medications into clinical trials has significantly increased patient survival rates, opening new avenues and bringing fresh viewpoints for treating metastatic colorectal cancer. These focused therapies change how cancer is treated, giving patients new hope and better results. These markers can significantly transform and individualize therapy regimens. They could open the door to precisely customized and more effective medicines, improving patient outcomes and quality of life. The fast-growing body of knowledge regarding the molecular biology of colorectal cancer and the latest developments in gene sequencing and molecular diagnostics are directly responsible for this advancement.

Gut microbiota in pathophysiology, diagnosis, and therapeutics of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a multifactorial disease, which is thought to be an interplay between genetic, environment, microbiota, and immune-mediated factors. Dysbiosis in the gut microbial composition, caused by antibiotics and diet, is closely related to the initiation and progression of IBD. Differences in gut microbiota composition between IBD patients and healthy individuals have been found, with reduced biodiversity of commensal microbes and colonization of opportunistic microbes in IBD patients. Gut microbiota can, therefore, potentially be used for diagnosing and prognosticating IBD, and predicting its treatment response. Currently, there are no curative therapies for IBD. Microbiota-based interventions, including probiotics, prebiotics, synbiotics, and fecal microbiota transplantation, have been recognized as promising therapeutic strategies. Clinical studies and studies done in animal models have provided sufficient evidence that microbiota-based interventions may improve inflammation, the remission rate, and microscopic aspects of IBD. Further studies are required to better understand the mechanisms of action of such interventions. This will help in enhancing their effectiveness and developing personalized therapies. The present review summarizes the relationship between gut microbiota and IBD immunopathogenesis. It also discusses the use of gut microbiota as a noninvasive biomarker and potential therapeutic option.