The role of gut microbiota in cancer treatment: friend or foe?

Investigating the role of inflammatory cytokines in mediating the effect of gut microbiota on gastrointestinal cancers: a mendelian randomization study

PURPOSE

The purpose of this study is to explore the causal relationship between gut microbiota and gastrointestinal (GI) cancers and to investigate the potential mediating factors influencing the development of GI cancers.

METHODS

Using data from genome-wide association studies (GWAS), we employed two-sample Mendelian randomization (TSMR) to explore the relationship among gut microbiota, inflammatory cytokines and GI cancers. Subsequently, a multivariable Mendelian randomization (MVMR) analysis was meticulously conducted to perform a mediation analysis, thereby estimating the proportion of mediation effects conferred by inflammatory cytokines.

RESULTS

TSMR analysis established a causal relationship between 23 gut microbiota taxa and 11 inflammatory cytokines with GI cancers. Specifically, 7 gut microbiota taxa were associated with an increased risk of gastric cancer (GC), 6 with small intestine cancer, and 10 with colorectal cancer (CRC). Among the inflammatory cytokines, 4 were linked to GC risk, 3 to small intestine cancer, and to CRC. Mediation analysis further indicatedthat tumor necrosis factor ligand superfamily member 12 (TNFSF12) mediated 9.703% (95% CI 0.108%~15.891%) of the total effect of genus Ruminiclostridium9 on GC.

CONCLUSION

Our findings support a causal relationship between gut microbiota, inflammatory cytokines, and GI cancers. These biomarkers provide new insights into the mechanisms underlying GI cancers and have the potential to improve strategies forprevention, diagnosis, and treatment.

Therapeutic potential of microbiome modulation in reproductive cancers

The human microbiome, a complex ecosystem of microbial communities, plays a crucial role in physiological processes, and emerging research indicates a potential link between it and reproductive cancers. This connection highlights the significance of understanding the microbiome's influence on cancer development and treatment. A comprehensive review of current literature was conducted, focusing on studies that investigate the relationship between microbiome composition, reproductive cancer progression, and potential therapeutic approaches to modulate the microbiome. Evidence suggests that imbalances in the microbiome, known as dysbiosis, may contribute to the development and progression of reproductive cancers. Specific microbial populations have been associated with inflammatory responses, immune modulation, and even resistance to conventional therapies. Interventions such as probiotics, dietary modifications, and fecal microbiota transplantation have shown promise in restoring healthy microbiome function and improving cancer outcomes in pre-clinical models, with pilot studies in humans indicating potential benefits. This review explores the therapeutic potential of microbiome modulation in the management of reproductive cancers, discussing the mechanisms involved and the evidence supporting microbiome-targeted therapies. Future research is warranted to unravel the complex interactions between the microbiome and reproductive cancer pathophysiology, paving the way for innovative approaches.

Significant changes in gut microbiota and SCFAs among patients with newly diagnosed acute myeloid leukemia

The purpose of this study was to identify whether the gut microbiota and metabolites of newly diagnosed acute myeloid leukemia (AML) patients displayed specific characteristic alterations and whether these changes could be used as potential biomarkers for predicting the disease. Notably, the gut microbiota and metabolites of AML patients exhibited significant structural and quantitative alterations at the time of their initial diagnosis. Beneficial bacteria, including Faecalibacterium, Collinsella, Lacticaseibacillus, and Roseburia, as well as butyric acid and acetic acid, were found to be considerably reduced in newly diagnosed AML patients. In contrast, Enterococcus and Lactobacillus, especially Enterococcus, were significantly enriched. Further investigation indicated that Enterococcus could serve as a potential intestinal marker, showing a strong negative correlation with the levels of acetic and butyric acid. Importantly, assays aimed at identifying AML demonstrated that Enterococcus, butyric acid, and acetatic acid exhibited excellent predictive effectiveness. Colonizing Enterococcus from patients were isolated for pathogen investigation, which revealed that these bacteria possess several strong virulence factors and multiple drug-resistance gene characteristics. Therefore, we speculate that the increase of Enterococcus may contribute to the development and progression of AML.

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.

Role of gut microbiota in predicting chemotherapy-induced neutropenia duration in leukemia patients

Background

Acute leukemia is an aggressive malignancy with high morbidity and mortality, and chemotherapy is the primary treatment modality. However, chemotherapy often induces neutropenia (chemotherapy-induced neutropenia, CIN), increasing the risk of infectious complications and mortality. Current research suggests that gut microbiota may play a significant role in chemotherapy's efficacy and side effects.

Objective

This study aimed to investigate whether gut microbiota can predict the duration of chemotherapy-induced neutropenia in leukemia patients.

Methods

We included 56 leukemia patients from the Hematology Department of the Second Affiliated Hospital of Nanchang University, collecting fecal samples 1 day before and 1 day after chemotherapy. The diversity and community structure of gut microbiota were analyzed using 16S rRNA gene sequencing. Patients were divided into two groups based on the duration of neutropenia post-chemotherapy: Neutropenia ≤7 Days Group (NLE7 Group) and Neutropenia > 7 Days Group (NGT7 Group). Comparative analysis identified characteristic microbiota.

Results

After chemotherapy, gut microbiota diversity significantly decreased (p < 0.05). In the NGT7 Group, the relative abundance of Enterococcus before chemotherapy was significantly higher than in the NLE7 Group (p < 0.05). ROC curve analysis showed that the relative abundance of Enterococcus had high predictive accuracy for the duration of neutropenia (AUC = 0.800, 95% CI: 0.651-0.949).

Conclusion

The abundance of Enterococcus before chemotherapy can predict the duration of chemotherapy-induced neutropenia. These findings provide new evidence for gut microbiota as a predictive biomarker for chemotherapy side effects and may guide personalized treatment for leukemia patients.

Cross-talks between osteoporosis and gut microbiome

The gut microbiome comprises a vast community of microbes inhabiting the human alimentary canal, playing a crucial role in various physiological functions. These microbes generally live in harmony with the host; however, when dysbiosis occurs, it can contribute to the pathogenesis of diseases, including osteoporosis. Osteoporosis, a systemic skeletal disease characterized by reduced bone mass and increased fracture risk, has attracted significant research attention concerning the role of gut microbes in its development. Advances in molecular biology have highlighted the influence of gut microbiota on osteoporosis through mechanisms involving immunoregulation, modulation of the gut-brain axis, and regulation of the intestinal barrier and nutrient absorption. These microbes can enhance bone mass by inhibiting osteoclast differentiation, inducing apoptosis, reducing bone resorption, and promoting osteoblast proliferation and maturation. Despite these promising findings, the therapeutic effectiveness of targeting gut microbes in osteoporosis requires further investigation. Notably, gut microbiota has been increasingly studied for their potential in early diagnosis, intervention, and as an adjunct therapy for osteoporosis, suggesting a growing utility in improving bone health. Further research is essential to fully elucidate the therapeutic potential and clinical application of gut microbiome modulation in the management of osteoporosis.

Dual Cascade-Responsive Multifunctional Nanoparticles to Overcome Bacterium-Induced Drug Inactivation and Enhanced Photodynamic and Chemo-Immunotherapy of Pancreatic Cancer

The harsh biological barriers and bacteria within tumor microenvironment not only hinder drug penetration and induce drug inactivation, but also inhibit antitumor immune responses. Here a tumor microenvironment dual cascade-responsive multifunctional nanoparticle, Gem/Emo@NP@GHA is reported, which is engineered from a hyaluronidase (HAase)-responsive guanidine group functionalized hyaluronic acid (GHA) shell and a glutathione (GSH)-responsive biopolymer core (Gem/Emo@NP), that encapsulates anticancer drug gemcitabine (Gem) and two-photon-excited photosensitizer emodin (Emo). The constructed Gem/Emo@NP@GHA can specifically target the tumor and subsequently be degraded by HAase-abundant in the extracellular matrix. Thus, the resulting Gem/Emo@NP achieved size reduction and charge reversal, strengthening deep tumor penetration. Upon internalization, the positively charged Gem/Emo@NP effectively kills intratumor bacteria by inducing membrane depolarization. Furthermore, the high levels of GSH within tumor cells disrupt the disulfide bonds of Gem/Emo@NP, triggering drug release. Thereby, the undecomposed Gem successfully induces tumor cell apoptosis and necrosis. Under laser irradiation, photosensitizer Emo generates high singlet oxygen (1O2), further eliminating tumors and intracellular bacteria. More importantly, Gem/Emo@NP@GHA can activate T cell-mediated immune response, further enhancing antitumor activity. These findings provide a promising approach to treating bacterially infected tumors through the synergistic application of chem-immunotherapy and two-photon-excited photodynamic therapy.

Gut microbiota as a new target for anticancer therapy: from mechanism to means of regulation

In order to decipher the relationship between gut microbiota imbalance and cancer, this paper reviewed the role of intestinal microbiota in anticancer therapy and related mechanisms, discussed the current research status of gut microbiota as a biomarker of cancer, and finally summarized the reasonable means of regulating gut microbiota to assist cancer therapy. Overall, our study reveals that the gut microbiota can serve as a potential target for improving cancer management.

Microbial dysbiosis with tryptophan metabolites alteration in lower respiratory tract is associated with clinical responses to anti-PD-1 immunotherapy in advanced non-small cell lung cancer

Lower respiratory tract microbiome constitutes a unique immune microenvironment for advanced non-small cell lung cancer as one of dominant localized microbial components. However, there exists little knowledge on the associations between this regional microbiome and clinical responses to anti-PD-1 immunotherapy from clinical perspectives. Here, we equivalently collected bronchoalveolar lavage fluids from 56 advanced NSCLC participants treated with none (untreated, n = 28) or anti-PD-1 immunotherapy (treated, n = 28), which was further divided into responder (n = 17) and non-responder (n = 11) subgroups according to clinical responses, aiming to compare their microbial discrepancy by performing metagenomic sequencing and targeted metabolic alterations by tryptophan sequencing. Correspondingly, microbial diversities transformed significantly after receiving immunotherapeutic agents, where Gammaproteobacteria and Campylobacter enriched, but Escherichia, Streptococcus, Chlamydia, and Staphylococcus reduced at the genus level, differences of which failed to be achieved among subgroups with various clinical responses (responder or non-responder; LDA > 2, P < 0.05*). And the relative abundance of Staphylococcus and Streptomyces was escalated in response subgroup to anti-PD-1 immunotherapy by microbial compositional analysis (as relative abundance ≥ 3%, P < 0.05*), no significance of which was achieved among treated and untreated groups. In addition, relative abundances of bacterial tryptophan metabolites and its derivatives were also higher in the responder subgroup, distinctively being associated with divergent genera (VIP > 1, P < 0.05*). Our study revealed predictive performance of lower respiratory tract microbiome to antitumoral immunotherapy and further suggested that anti-PD-1 immunotherapy may alter lower respiratory tract microbiome composition and interact with its tryptophan metabolites to regulate therapeutic efficacy in advanced NSCLC, performing as potential biomarkers to prognosis and interventional strategies.

Exploring the Impact of Chemotherapy on the Emergence of Antibiotic Resistance in the Gut Microbiota of Colorectal Cancer Patients

With nearly half of colorectal cancer (CRC) patients diagnosed at advanced stages where surgery alone is insufficient, chemotherapy remains a cornerstone for this cancer treatment. To prevent infections and improve outcomes, antibiotics are often co-administered. However, chemotherapeutic interactions with the gut microbiota cause significant non-selective toxicity, affecting not only tumor and normal epithelial cells but also the gut microbiota. This toxicity triggers the bacterial SOS response and loss of microbial diversity, leading to bacterial mutations and dysbiosis. Consequently, pathogenic overgrowth and systemic infections increase, necessitating broad-spectrum antibiotics intervention. This review underscores how prolonged antibiotic use during chemotherapy, combined with chemotherapy-induced bacterial mutations, creates selective pressures that drive de novo antimicrobial resistance (AMR), allowing resistant bacteria to dominate the gut. This compromises the treatment efficacy and elevates the mortality risk. Restoring gut microbial diversity may mitigate chemotherapy-induced toxicity and improve therapeutic outcomes, and emerging strategies, such as fecal microbiota transplantation (FMT), probiotics, and prebiotics, show considerable promise. Given the global threat posed by antibiotic resistance to cancer treatment, prioritizing antimicrobial stewardship is essential for optimizing antibiotic use and preventing resistance in CRC patients undergoing chemotherapy. Future research should aim to minimize chemotherapy's impact on the gut microbiota and develop targeted interventions to restore microbial diversity affected during chemotherapy.

Comparative Analysis of Microbiological Profiles and Antibiotic Resistance Genes in Subjects with Colorectal Cancer and Healthy Individuals

Alteration of the gut microbiota (GM) is associated with various diseases, including colorectal cancer (CRC). With the development of next-generation sequencing techniques, metagenomic sequencing, along with metabolic function and antibiotic-resistant gene analyses, has been used to investigate differences in GM between CRC patients and healthy controls. Fecal samples were obtained from seven CRC patients and six healthy subjects, and the sequencing data were analyzed for similarity, a-diversity, principal component analysis (PCA), and linear discriminant analyses (LDA). Regarding Actinobacteria, 3 orders, 5 families, 9 genera, and 19 species were identified with no differences between the CRC and control groups, while the levels of Bifidobacterium bifidum and Bifidobacterium dentium were higher, and the level of Bifidobacterium breve was lower in the CRC group compared to the healthy controls (p = 0.053). Otherwise, 2 genera (Leuco-nostoc and Salmonella) and 7 species of bacteria (Parabacteroides merdae, Alistipes shahii, Alistipes finegoldii, Clostridium nexile, Salmonella enterica, unclassified Salmonella, Enterobacter cloacae) were found to be significantly differently distributed between CRC patients and healthy controls. PCA-LDA successfully classified these 2 groups with satisfactory accuracy (84.52% for metabolic function and 77.38% for resistant genes). These findings underscore the potential of GM as a diagnostic tool for CRC, offering a promising avenue for non-invasive screening and risk assessment. The identification of specific microbial signatures, particularly those linked to metabolic functions and resistance traits, could open new doors for understanding the role of the microbiome in CRC progression and treatment resistance.

Concomitant medications in patients with metastatic urothelial carcinoma receiving enfortumab vedotin: real-world data from the ARON-2EV study

Patients with metastatic urothelial carcinoma (mUC) are typically elderly and often have other comorbidities that require the use of concomitant medications. In our study we evaluated the association of concomitant use of antibiotics (ATBs), proton pump inhibitors (PPIs), corticosteroids, statins, metformin and insulin with patient outcomes and we validated the prognostic role of a concomitant drug score in mUC patients treated with enfortumab vedotin (EV) monotherapy. Data from 436 patients enrolled in the ARON-2EV retrospective study were analyzed according to the concomitant medications used at baseline. Finally, the patients were stratified into three risk groups according to the concomitant drug score based on ATBs, corticosteroids and PPIs. Statistical analysis involved Fisher exact test, Kaplan-Meier method, log-rank test, and univariate/multivariate Cox proportional hazard regression models. Inferior survival outcomes were observed in ATB users compared to non-users (OS: 7.3 months, 95%CI 5.0 - 12.3 vs 13.7 months, 95%CI 12.2 - 47.3, p = 0.001; PFS: 5.1 months 95%CI 3.3 - 17.7 vs 8.3 months, 95%CI 7.1 - 47.3, p = 0.001) and also in corticosteroid users compared to non-users (OS: 8.4 months, 95%CI 6.6 - 10.0 vs 14.2 months, 95%CI 12.7 - 47.3, p < 0.001; PFS: 6.0 months 95%CI 4.6 - 7.9 vs 8.9 months, 95%CI 7.2 - 47.3, p = 0.004). In the Cox multivariate analysis, the concomitant drug score was a significant factor predicting both OS (HR = 1.32 [95% CI 1.03 - 1.68], p = 0.026) and PFS (HR = 1.23 [95% CI 1.01 - 1.51], p = 0.044). Our findings suggest detrimental impact of concomitant use of ATBs and corticosteroids on survival outcomes and the prognostic utility of the concomitant drug score in previously treated mUC patients receiving EV.

Modulation of Intestinal Flora: a Novel Immunotherapeutic Approach for Enhancing Thyroid Cancer Treatment

Over the past 3 years, there has been a growing interest in clinical research regarding the potential involvement of intestinal flora in thyroid cancer (TC). This review delves into the intricate connection between intestinal flora and TC, focusing on the particular intestinal flora that is directly linked to the disease and identifying which may be able to predict potential microbial markers of TC. In order to shed light on the inflammatory pathways connected to the onset of TC, we investigated the impact of intestinal flora on immune modulation and the connection between chronic inflammation when investigating the role of intestinal flora in the pathogenesis of TC. Furthermore, the potential role of intestinal flora metabolites in the regulation of thyroid function was clarified by exploring the effects of short-chain fatty acids and lipopolysaccharide on thyroid hormone synthesis and metabolism. Based on these findings, we further explore the effects of probiotics, prebiotics, postbiotics, vitamins, and trace elements.

Exploiting omic-based approaches to decipher Traditional Chinese Medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicine (TCM), an ancient health system, faces significant research challenges due to the complexity of its active components and targets, as well as a historical lack of detailed annotation. However, recent advances in omics technologies have begun to unravel these complexities, providing a more informed and nuanced understanding of TCM's therapeutic potential in contemporary healthcare.

AIM OF THE REVIEW

This review summarizes the application of omics technologies in TCM modernization, emphasizing components analysis, quality control, biomarker discovery, target identification, and treatment optimization. In addition, future perspectives on using omics for precision TCM treatment are also discussed.

MATERIALS AND METHODS

We have explored several databases (including PubMed, ClinicalTrials, Google Scholar, and Web of Science) to review related articles, focusing on Traditional Chinese Medicine, Omics Strategy, Precision Medicine, Biomarkers, Quality Control, and Molecular Mechanisms. Paper selection criteria involved English grammar, publication date, high citations, and broad applicability, exclusion criteria included low credibility, non-English publications, and those full-text inaccessible ones.

RESULTS

TCM and the popularity of Chinese herbal medicines (CHMs) are gaining increasing attention worldwide. This is driven, in part, by a large number of technologies, especially omics strategy, which are aiding the modernization of TCM. They contribute to the quality control of CHMs, the identification of cellular targets, discovery of new drugs and, most importantly, the understanding of their mechanisms of action.

CONCLUSION

To fully integrate TCM into modern medicine, further development of robust omics strategies is essential. This vision includes personalized medicine, backed by advanced computational power and secure data infrastructure, to facilitate global acceptance and seamless integration of TCM practices.

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.

The influence of microbiota on the efficacy and toxicity of immunotherapy in cancer treatment

Immunotherapy, which uses the body's immune system to fight cancer cells, has gained attention recently as a breakthrough in cancer treatment. Although significant progress has been made, obstacles still exist since cancers are skilled at avoiding immune monitoring. The gut microbiota is being looked at more and more in modern research as a critical component in improving the results of immunotherapy. Through modulating both innate and adaptive immune responses, the gut microbiome has a significant impact on cancer immunotherapy. The effectiveness of treatment and the way the immune system responds are significantly influenced by some microorganisms and the metabolites they produce, especially short-chain fatty acids. On the other hand, dysbiosis and persistent inflammation in the gut environment might unintentionally accelerate the growth of tumors, which makes the complex relationship between the makeup of the microbiota and cancer treatment more challenging. Gut microbiota plays a crucial role in immunotherapy effectiveness. Improved microbial diversity leads to better treatment responses, with some taxa like Bacteroides and Ruminococcaceae being linked to better responses to immune checkpoint inhibitors. Dysbiotic conditions can worsen immune-related side effects and reduce treatment effectiveness. Strategies manipulating gut microbiota, such as fecal microbiota transplantation, antibiotic therapies, and dietary interventions, could optimize immunotherapy response and prognosis. However, standardizing these interventions for different cancer types and patient populations is challenging due to individual microbiome differences. Future research should combine microbiome research with AI and rigorous clinical trials for individualized cancer treatments.

Crosstalk between gut microbiota and cancer chemotherapy: current status and trends

BACKGROUND

Chemotherapy is crucial in the management of tumors, but challenges such as chemoresistance and adverse reactions frequently lead to therapeutic delays or even premature cessation. A growing body of research underscores a profound connection between the gut microbiota (GM) and cancer chemotherapy (CC). This paper aims to pinpoint highly influential publications and monitor the current landscape and evolving trends within the realm of GM/CC research.

METHODS

On October 1st, 2024, a comprehensive search for GM/CC publications spanning the past 20 years from 2004 to 2023 was conducted utilizing the Web of Science Core Collection (WoSCC). The scope encompassed both articles and reviews, and the data was subsequently extracted. To gain insights into the evolution and dynamics of this research field, we employed bibliometric analysis tools such as the Bibliometrix R package, VOSviewer, and Microsoft Excel to visualize and analyze various dimensions, including prominent journals, leading authors, esteemed institutions, contributing countries/regions, highly cited papers, and frequently occurring keywords.

RESULTS

A total of 888 papers were obtained. The number of publications about GM/CC studies has increased gradually. China and the United States published the largest number of papers. The INSERM was in the leading position in publishers. The most productive authors were Zitvogel L from France. Cancers had the largest number of papers. Citation analysis explained the historical evolution and breakthroughs in GM/CC research. Highly cited papers and common keywords illustrated the status and trends of GM/CC research. Four clusters were identified, and the hot topics included the role of the GM in the efficacy and toxicity of CC, the targeting of the GM to improve the outcome of CC, the mechanism by which the GM affects CC, and the correlation of the GM with carcinogenesis and cancer therapy. Metabolism, GM-derived metabolites, tumor microenvironment, immunity, intestinal barrier, tumor microbiota and Fusobacterium nucleatum may become the new hotspots and trends of GM/CC research.

CONCLUSION

This study analyzed global publications and bibliometric characteristics of the links between GM and CC, identified highly cited papers in GM/CC, provided insight into the status, hotspots, and trends of global GM/CC research, and showed that the GM can be used to predict the efficacy and toxicity of CC and modifying the GM can improve the outcomes of chemotherapeutics, which may inform clinical researchers of future directions.

Progress of Immune Checkpoint Inhibitors Therapy for pMMR/MSS Metastatic Colorectal Cancer

Immunotherapy is one of the research hotspots in colorectal cancer field in recent years. The colorectal cancer patients with mismatch repair-deficient (dMMR) or high microsatellite instability (MSI-H) are the primary beneficiaries of immunotherapy. However, the vast majority of colorectal cancers are mismatch repair proficient (pMMR) or microsatellite stability (MSS), and their immune microenvironment is characterized by "cold tumors" that are generally insensitive to single immunotherapy based on immune checkpoint inhibitors (ICIs). Studies have shown that some pMMR/MSS colorectal cancer patients regulate the immune microenvironment by combining other treatments, such as multi-target tyrosine kinase inhibitors, anti-vascular endothelial growth factor (VEGF) monoclonal antibodies, chemotherapy, radiotherapy, anti-epithelial growth factor receptor (EGFR) monoclonal antibodies, and mitogen-activated protein kinase (MAPK) signaling pathway inhibitors and oncolytic viruses, etc. to transform "cold tumor" into "hot tumor", thereby improving the response to immunotherapy. In addition, screening for potential prognostic biomarkers can also enrich the population benefiting from immunotherapy for microsatellite stable colorectal cancer. Therefore, in pMMR or MSS metastatic colorectal cancer (mCRC), the optimization of immunotherapy regimens and the search for effective efficacy prediction biomarkers are currently important research directions. In this paper, we review the progress of efficacy of immunotherapy (mainly ICIs) in pMMR /MSS mCRC, challenges and potential markers, in order to provide research ideas for the development of immunotherapy for mCRC.

Plasma Levels of Organic Acids Associated with the Gut Microbiome Display Significant Alterations in Neuroendocrine Tumor Patients

INTRODUCTION

The gut microbiome, allegedly involved in both healthy homeostasis and development of disease, is found to be associated with several types of cancer. Short-chain fatty acids (SCFAs), important metabolites derived from the gut microbiota, are described to carry both protective and promoting features in cancer development. Limited research exists on neuroendocrine tumors (NETs) and their association with microbiota-derived SCFAs. The aim of this study was to investigate possible alterations in plasma SCFAs/organic acids in NET patients compared to healthy controls.

METHODS

We quantified 11 organic acids, including SCFAs, in plasma from 109 NET patients (49 curatively operated patients and 60 patients with distant metastasis) as well as 20 healthy controls. Acids were quantified using liquid chromatography tandem mass spectrometry.

RESULTS

We found that levels of 3OH-propionic acid, 3OH-butyric acid, lactic acid, formic acid, acetic acid, glyoxylic acid, and glycolic acid were significantly altered in NET patients with metastatic disease, as well as curatively operated NET patients, compared to healthy controls (p < 0.05). In addition, a trend displaying increased acid level alterations from healthy controls in curatively operated patients with future recurrence, compared to patients with no documented recurrent disease, was detected.

CONCLUSION

Our results demonstrating significantly altered levels of multiple organic acids in NET patients represents a novel finding implicating further research on their role in NET pathophysiology.

Probiotic Mixture Attenuates Colorectal Tumorigenesis in Murine AOM/DSS Model by Suppressing STAT3, Inducing Apoptotic p53 and Modulating Gut Microbiota

Colorectal cancer (CRC) is one of the most common cancers worldwide. The standard CRC chemo drug, 5-Fluorouracil (5-FU), has a poor response rate and chemoresistance, prompting the need for a more effective and affordable treatment. In this study, we aimed to evaluate whether Prohep, a novel probiotic mixture, would alleviate azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colorectal tumorigenesis and enhance 5-FU efficacy and its mechanism. Our results suggested that Prohep showed stronger anti-tumorigenesis effects than 5-FU alone or when combined in the AOM/DSS model. Prohep significantly reduced the total tumor count, total tumor size, caecum weight, colonic crypt depth, colonic inflammation, and collagen fibrosis. Prohep downregulated pro-inflammatory TNF-α and proliferative p-STAT3 and upregulated apoptotic p53. Metagenomics analysis indicated that Prohep-enriched Helicobacter ganmani, Desulfovibrio porci, Helicobacter hepaticus, and Candidatus Borkfalkia ceftriaxoniphila were inversely correlated to the total tumor count. In addition, Prohep-enriched Prevotella sp. PTAC and Desulfovibrio porci were negatively correlated to AOM/DSS enriched bacteria, while forming a co-existing community with other beneficial bacteria. From KEGG analysis, Prohep downregulated CRC-related pathways and enhanced pathways related to metabolites suppressing CRC like menaquinone, tetrapyrrole, aminolevulinic acid, and tetrahydrofolate. From Metacyc analysis, Prohep downregulated CRC-related peptidoglycan, LPS, and uric acid biosynthesis, and conversion. Prohep elevated the biosynthesis of the beneficial L-lysine, lipoic acid, pyrimidine, and palmitate. Prohep also elevated metabolic pathways related to energy utilization of lactic acid-producing bacteria (LAB) and acetate producers. Similarly, fecal acetate concentration was upregulated by Prohep. To sum up, Prohep demonstrated exceptional anti-tumorigenesis effects in the AOM/DSS model, which revealed its potential to develop into a novel CRC therapeutic in the future.

Emerging Role of Gut Microbiota in Breast Cancer Development and Its Implications in Treatment

Background: The human digestive system contains approximately 100 trillion bacteria. The gut microbiota is an emerging field of research that is associated with specific biological processes in many diseases, including cardiovascular disease, obesity, diabetes, brain disease, rheumatoid arthritis, and cancer. Emerging evidence indicates that the gut microbiota affects the response to anticancer therapies by modulating the host immune system. Recent studies have explained a high correlation between the gut microbiota and breast cancer: dysbiosis in breast cancer may regulate the systemic inflammatory response, hormone metabolism, immune response, and the tumor microenvironment. Some of the gut bacteria are related to estrogen metabolism, which may increase or decrease the risk of breast cancer by changing the number of hormones. Further, the gut microbiota has been seen to modulate the immune system in respect of its ability to protect against and treat cancers, with a specific focus on hormone receptor-positive breast cancer. Probiotics and other therapies claiming to control the gut microbiome by bacterial means might be useful in the prevention, or even in the treatment, of breast cancer. Conclusions: The present review underlines the various aspects of gut microbiota in breast cancer risk and its clinical application, warranting research on individualized microbiome-modulated therapeutic approaches to breast cancer treatment.

Causal Relationship Between Gut Microbiota and Leukemia: Future Perspectives

The gut microbiota plays a crucial role in maintaining homeostasis in the human gastrointestinal tract. Numerous studies have shown a strong association between the gut microbiota and the emergence and progression of various diseases. Leukemia is one of the most common hematologic malignancies. Although standardized protocols and expert consensus have been developed for routine diagnosis and treatment, limitations remain due to individual differences. Nevertheless, a large number of studies have established a link between the gut microbiota and leukemia, with disturbances in the gut microbiota directly or indirectly affecting the development of leukemia. However, the causal relationship between the two remains unclear, and studying and exploring the causal relationship may open up entirely new avenues and protocols for use in the prevention and/or treatment of leukemia, offering new insights into diagnosis and treatment. In this review, the intricate relationship between the gut microbiota and leukemia is explored in depth, including causal associations, metabolite effects, therapeutic applications, and complications. Based on the characteristics of the gut microbiota, the future applications and prospects of gut microbiota are discussed to provide useful information for clinical treatment of leukemia.

Prevotellaceae Modulates Colorectal Cancer Immune Microenvironment to Assist Anti-PD-L1 Immunotherapy

Background/Aims

Colorectal cancer (CRC) stands as the third most prevalent cancer on a global scale. In recent years, immunotherapy, such as anti-PD-L1 treatment, has demonstrated promising therapeutic outcomes in CRC. However, studies have suggested that intestinal microbiota may influence the efficacy of anti-PD-L1 immunotherapy. This study aimed to investigate the linkage between intestinal bacteria and anti-PD-L1 therapy.

Materials and Methods

Bioinformatics analysis was employed to study the correlation between the intestinal microbiota of CRC patients and immune infiltration. The study delved into the relationship between Prevotellaceae and immune-related genes in CRC. Mouse experiments were conducted to validate the association between Prevotellaceae abundance and the efficacy of anti-PD-L1 tumor treatment. Prevotellaceae abundance in mouse feces was assayed by 16S sequencing. Flow cytometry was utilized to assay immune cell infiltration in patient tumor tissues, while western blot and quantitative polymerase chain reaction (qPCR) assays measured IFN-γ, IL-2, and PD-L1 levels in tumor tissues.

Results

The high immune cell infiltration group demonstrated reduced tumor purity when compared with the group displaying low immune cell infiltration. Substantial variances were discerned in the Stromal Score, Immune Score, ESTIMATE Score, and Tumor Purity among the 3 distinct subtypes. The community evenness in the gut microbiota of CRC patients from cluster 2 and cluster 3 subtypes displayed significant differences. Members of the Prevotellaceae family were significantly enriched in the gut microbiota of cluster 3 subtype patients. In vivo experiments ascertained the supportive role of Prevotellaceae in anti-PD-L1 immunotherapy.

Conclusion

The facilitating effect of Prevotellaceae on anti-PD-L1 treatment was demonstrated in CRC. The findings suggest that elevating Prevotellaceae abundance may offer a new direction for assisting in CRC immunotherapy and provide a foundation for devising more effective CRC immunotherapeutic strategies.

[Cancer prevention recommendations: Update 2024]

Cancer is one of the main causes of morbidity and mortality. Environmental factors along with lifestyle: tobacco and alcohol consumption, unhealthy diet and sedentary lifestyle and lack of physical activity, are some of the risk factors that have caused an increase in cancer. This article updates the evidence and recommendations for cancer prevention strategies through screening in asymptomatic patients, as well as early detection of signs and symptoms in medium-risk and high-risk populations.

Bacterial Lysate-Based Bifunctional mRNA Nanoformulation for Efficient Colon Cancer Immunogene Therapy

mRNA-based nonviral gene therapy has played an important role in cancer therapy, however, the limited delivery efficiency and therapeutic capacity still require further exploration and enhancement. Immunogene therapy provides a strategy for cancer treatment. Bacteria are tiny single-celled living organisms, many of which can be found in and on the human body and are beneficial to humans. Lactobacillus reuteri is a bacterial member of the gut flora, and recent research has shown that it can reduce intestinal inflammation by stimulating an immunomodulatory response. L. reuteri lysate represents an ideal resource for constructing advanced mRNA delivery systems with immune stimulation potential. Here, we prepared a bifunctional mRNA delivery system DMP-Lac (DOTAP-mPEG-PCL-L. reuteri lysate), which successfully codelivered L. reuteri lysate and IL-23A mRNA, exhibited a high mRNA delivery efficiency of 75.56% ± 0.85%, and strongly promoted the maturation and activation of the immune system in vivo. Both the CT26 abdominal metastasis model and the lung metastasis model also exhibited a good therapeutic effect, and the tumor inhibition rate of DMP-Lac/IL-23A group reached 97.92%. Protein chip technology verified that DMP acted as an immune adjuvant, demonstrating that the L. reuteri lysate could regulate the related immune cells, while IL-23 mRNA caused changes in downstream factors, thus producing the corresponding tumor treatment effect. The DMP-Lac/IL-23A complex exhibited strong anticancer immunotherapeutic effects. Our results demonstrated that this bifunctional mRNA formulation served as a tumor-specific nanomedicine, providing an advanced strategy for colon cancer immunogene therapy.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Targeting the gut microbiota: a new strategy for colorectal cancer treatment

BACKGROUND

How to reduce the high incidence rate and mortality of colorectal cancer (CRC) effectively is the focus of current research. Endoscopic treatment of early-stage CRC and colorectal adenomas (CAC) has a high success rate, but although several treatments are available for advanced CRC, such as surgery, radiotherapy, chemotherapy, and immunotherapy, the 5-year survival rate remains low. In view of the high incidence rate and mortality of CRC, early rational drug prevention for high-risk groups and exploration of alternative treatment modalities are particularly warranted. Gut microbiota is the target of and interacts with probiotics, prebiotics, aspirin, metformin, and various Chinese herbal medicines (CHMs) for the prevention of CRC. In addition, the anti-cancer mechanisms of probiotics differ widely among bacterial strains, and both bacterial strains and their derivatives and metabolites have been found to have anti-cancer effects. Gut microbiota plays a significant role in early drug prevention of CRC and treatment of CRC in its middle and late stages, targeting gut microbiota may be a new strategy for colorectal cancer treatment.

A new strategy for immunotherapy of microsatellite-stable (MSS)-type advanced colorectal cancer: Multi-pathway combination therapy with PD-1/PD-L1 inhibitors

Colorectal cancer (CRC) is a frequent gastrointestinal malignancy with high rates of morbidity and mortality; 85% of these tumours are proficient mismatch repair (pMMR)-microsatellite instability-low (MSI-L)/microsatellite stable (MSS) CRC known as 'cold' tumours that are resistant to immunosuppressive drugs. Monotherapy with programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors is ineffective for treating MSS CRC, making immunotherapy for MSS CRC a bottleneck. Recent studies have found that the multi-pathway regimens combined with PD-1/PD-L1 inhibitors can enhance the efficacy of anti-PD-1/PD-L1 in MSS CRC by increasing the number of CD8+ T cells, upregulating PD-L1 expression and improving the tumour microenvironment. This paper reviews the research progress of PD-1/PD-L1 inhibitors in combination with cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors, oncolytic virus, intestinal flora, antiangiogenic agents, chemotherapy, radiotherapy and epigenetic drugs for the treatment of pMMR-MSI-L/MSS CRC.

Interconnected influences of tumour and host microbiota on treatment response and side effects in nasopharyngeal cancer

This study elucidates the intricate relationship between nasopharyngeal carcinoma (NPC), a significant malignancy predominant in Asia with notable global incidence and mortality rates, and the host microbiota, including those of tumour, nasal, nasopharyngeal, oral, oropharyngeal, and gut communities. It underscores how the composition and diversity of microbiota are altered in NPC, delving into their implications for disease pathogenesis, treatment response, and the side effects of therapies. A consistent reduction in alpha diversity across oral, nasal, and gut microbiomes in NPC patients compared to healthy individuals signals a distinct microbial signature indicative of the diseased state. The study also shows unique microbial changes tied to different NPC stages, indicating a dynamic interplay between disease progression and microbiota composition. Patients with specific microbial profiles exhibit varied responses to chemotherapy and immunotherapy, underscoring the potential for treatment personalisation based on microbiota analysis. Furthermore, the side effects of NPC treatments, such as oral mucositis, are intensified by shifts in microbial communities, suggesting a direct link between microbiota composition and treatment tolerance. This nexus offers opportunities for interventions aimed at modulating the microbiota to alleviate side effects, improve quality of life, and potentially enhance treatment efficacy. Highlighting the dual potential of microbiota as both a therapeutic target and a biomarker for NPC, this review emphasises its significance in influencing treatment outcomes and side effects, heralding a new era in NPC management through personalised treatment strategies and innovative approaches.

The gut microbiota is altered significantly in primary diffuse large b-cell lymphoma patients and relapse refractory diffuse large b-cell lymphoma patients

PURPOSE

Studies have shown that the gut microbiota may affect anti-tumor immunity by regulating the host immune system and tumor microenvironment. To date, little is known about whether the gut microbiota underlies the occurrence of diffuse large B-cell lymphoma (DLBCL) and drug resistance.

METHODS

In the present study, we compared the gut microbiota structure of fecal samples from 26 patients with primary DLBCL, 28 patients with relapsed and refractory (RR) DLBCL, and 30 healthy people.

RESULTS

Notably, Fusobacteria (from phylum to species) was enriched in the primary group. A decrease of Fusobacterium and an increase of Enterococcus were found in the RR group. PICRUSt analysis found that genes related to cytochrome P450 were upregulated in the RR group compared to the primary group, which likely contributes to the occurrence of DLBCL and the formation of drug resistance.

CONCLUSIONS

Our study provides further evidence for the relationship between gut microbiota and DLBCL and the formation of drug resistance, highlighting the potential significance of the bacterial variations may be used as new biomarkers of DLBCL.

The role of the gut microbiome in neuroinflammation and chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most debilitating adverse effects caused by chemotherapy drugs such as paclitaxel, oxaliplatin and vincristine. It is untreatable and often leads to the discontinuation of cancer therapy and a decrease in the quality of life of cancer patients. It is well-established that neuroinflammation and the activation of immune and glial cells are among the major drivers of CIPN. However, these processes are still poorly understood, and while many chemotherapy drugs alone can drive the activation of these cells and consequent neuroinflammation, it remains elusive to what extent the gut microbiome influences these processes. In this review, we focus on the peripheral mechanisms driving CIPN, and we address the bidirectional pathways by which the gut microbiome communicates with the immune and nervous systems. Additionally, we critically evaluate literature addressing how chemotherapy-induced dysbiosis and the consequent imbalance in bacterial products may contribute to the activation of immune and glial cells, both of which drive neuroinflammation and possibly CIPN development, and how we could use this knowledge for the development of effective treatment strategies.

Application of omics technologies in studies on antitumor effects of Traditional Chinese Medicine

Traditional Chinese medicine (TCM) is considered to be one of the most comprehensive and influential form of traditional medicine. It plays an important role in clinical treatment and adjuvant therapy for cancer. However, the complex composition of TCM presents challenges to the comprehensive and systematic understanding of its antitumor mechanisms, which hinders further development of TCM with antitumor effects. Omics technologies can immensely help in elucidating the mechanism of action of drugs. They utilize high-throughput sequencing and detection techniques to provide deeper insights into biological systems, revealing the intricate mechanisms through which TCM combats tumors. Multi-omics approaches can be used to elucidate the interrelationships among different omics layers by integrating data from various omics disciplines. By analyzing a large amount of data, these approaches further unravel the complex network of mechanisms underlying the antitumor effects of TCM and explain the mutual regulations across different molecular levels. In this study, we presented a comprehensive overview of the recent progress in single-omics and multi-omics research focused on elucidating the mechanisms underlying the antitumor effects of TCM. We discussed the significance of omics technologies in advancing research on the antitumor properties of TCM and also provided novel research perspectives and methodologies for further advancing this research field.

Antibacterial tellurium-containing polycarbonate drug carriers to eliminate intratumor bacteria for synergetic chemotherapy against colorectal cancer

Intratumor microbes have attracted great attention in cancer research due to its influence on the tumorigenesis, progression and metastasis of cancer. However, the therapeutic strategies targeting intratumoral microbes are still in their infancy. Specific microorganisms, such as Fusobacterium nucleatum (F. nucleatum), are abundant in various cancer and always result in the CRC progression and chemotherapy resistance. Here, a combined anticancer and antibacterial therapeutic strategy is proposed to deliver antitumor drug to the tumors containing intratumor microbiota by the antibacerial polymeric drug carriers. We construct oral tellurium-containing drug carriers using a complex of tellurium-containing polycarbonate with cisplatin (PTE@CDDP). The results show that the particle size of the prepared nanoparticles could be maintained at about 105 nm in the digestive system environment, which is in line with the optimal particle size of oral nanomedicine. In vitro mechanism study indicates that the tellurium-containing polymers are highly effective in killing F.nucleatum through a membrane disruption mechanism. The pharmacokinetic experiments confirmed that PTE@CDDP has the potential function of enhancing the oral bioavailability of cisplatin. Both in vitro and in vivo studies show that PTE@CDDP could inhibit intratumor F.nucleatum and lead to a reduction in cell proliferation and inflammation in the tumor site. Together, the study identifies that the CDDP-loaded tellurium-containing nanoparticles have great potential for treating the F.nucleatum-promoted colorectal cancer (CRC) by combining intratumor microbiota modulation and chemotherapy. The synergistic therapeutic strategy provide new insight into treating various cancers combined with bacterial infection. STATEMENT OF SIGNIFICANCE: The synthesized antibacterial polymer was first employed to remodel the intratumor microbes in tumor microenvironment (TME). Moreover, it was the first report of tellurium-containing polymers against F.nucleatum and employed for treatment of the CRC. A convenient oral dosage form of cisplatin (CDDP)-loaded tellurium-containing nanoparticles (PTE@CDDP) was adopted here, and the synergistic antibacterial/chemotherapy effect occurred. The PTE@CDDP could quickly and completely eliminate F.nucleatum in a safe dose. In the CRC model, PTE@CDDP effectively reversed the inflammation level and even restored the intestinal barrier damaged by F.nucleatum. The ultrasensitive ROS-responsiveness of PTE@CDDP triggered the fast oxidation and efficient drug release of CDDP and thus a highly efficient apoptosis of the tumors. Therefore, the tellurium-containing polymers are expected to serve as novel antibacterial agents in vivo and have great potential in the F.nucleatum-associated cancers. The achievements provided new insight into treating CRC and other cancers combined with bacterial infection.

From Crypts to Cancer: A Holistic Perspective on Colorectal Carcinogenesis and Therapeutic Strategies

Colorectal cancer (CRC) represents a significant global health burden, with high incidence and mortality rates worldwide. Recent progress in research highlights the distinct clinical and molecular characteristics of colon versus rectal cancers, underscoring tumor location's importance in treatment approaches. This article provides a comprehensive review of our current understanding of CRC epidemiology, risk factors, molecular pathogenesis, and management strategies. We also present the intricate cellular architecture of colonic crypts and their roles in intestinal homeostasis. Colorectal carcinogenesis multistep processes are also described, covering the conventional adenoma-carcinoma sequence, alternative serrated pathways, and the influential Vogelstein model, which proposes sequential APC, KRAS, and TP53 alterations as drivers. The consensus molecular CRC subtypes (CMS1-CMS4) are examined, shedding light on disease heterogeneity and personalized therapy implications.

Unraveling the association between gut microbiota and chemotherapy efficacy: a two-sample Mendelian randomization study

Emerging evidence has underscored the complex link between gut microbiota and chemotherapy efficacy; however, establishing causality remains elusive due to confounding factors. This study, leveraging bidirectional two-sample Mendelian randomization (MR) analyses, explores the casual relationship between gut microbiota and chemotherapy efficacy. Utilizing genome-wide association study (GWAS) data from the MiBioGen consortium for gut microbiota and IEU Open GWAS for chemotherapy efficacy, we employed genetic variants as instrumental variables (IVs). The inverse variance weighted (IVW) method, weighted median estimator (WME), and MR-Egger regression method were applied, with sensitivity analyses ensuring robustness. Furthermore, we conducted reverse MR analyses between chemotherapy efficacy and identified significant gut microbial taxa. The results indicated that genus Butyricicoccus (OR = 3.7908, 95% CI: 1.4464-9.9350, P = 0.01), Dorea (OR = 3.3295, 95% CI: 1.2794-8.6643, P = 0.01), Hungatella (OR = 2.6284, 95% CI: 1.0548-6.5498, P = 0.04), and Turicibacter (OR = 2.5694, 95% CI: 1.0392-6.3526, P = 0.04) were positively associated with chemotherapy efficacy using the IVW method. Conversely, family Porphyromonadaceae (OR = 0.2283, 95% CI: 0.0699-0.7461, P = 0.01) and genus Eggerthella (OR = 0.4953, 95% CI: 0.2443-1.0043, P = 0.05) exhibited negative associations. WME demonstrated consistent results with IVW method only for genus Eggerthella (OR = 0.3343, 95% CI: 0.1298-0.8610, P = 0.02). No significant heterogeneity or horizontal pleiotropy was observed. Reverse MR analyses revealed no significant causal effect of chemotherapy on identified gut microbiota. This study sheds light on the intricate relationship between gut microbiota, with a particular emphasis on the genus Eggerthella, and chemotherapy efficacy, offering valuable insights for refining cancer treatment strategies.IMPORTANCEGlobal advancements in cancer treatment, particularly in chemotherapy, have notably decreased mortality rates in recent years. However, the correlation between gut microbiota and chemotherapy efficacy remains elusive. Our study, emphasizing the role of genus Eggerthella, represented a crucial advance in elucidating this intricate interplay. The identified associations offer potential therapeutic targets, contributing to global efforts for enhanced treatment precision and improved patient outcomes. Furthermore, our findings hold promise for personalized therapeutic interventions, shaping improved strategies in the ever-evolving landscape of cancer treatment.

Label-Free Monitoring of Coculture System Dynamics: Probing Probiotic and Cancer Cell Interactions via Infrared Spectroscopic Imaging

Evaluating the dynamic interaction of microorganisms and mammalian cells is challenging due to the lack of suitable platforms for examining interspecies interactions in biologically relevant coculture conditions. In this work, we demonstrate the interaction between probiotic bacteria (Lactococcus lactis and Escherichia coli) and A498 human cancer cells in vitro, utilizing a hydrogel-based platform in a label-free manner by infrared spectroscopy. The L. lactis strain recapitulated in the compartment system secretes polypeptide molecules such as nisin, which has been reported to trigger cell apoptosis. We propose a mid-infrared (IR) spectroscopic imaging approach to monitor the variation of biological components utilizing kidney cells (A498) as a model system cocultured with bacteria. We characterized the biochemical composition (i.e., nucleic acids, protein secondary structures, and lipid conformations) label-free using an unbiased measurement. Several IR spectral features, including unsaturated fatty acids, β-turns in protein, and nucleic acids, were utilized to predict cellular response. These features were then applied to establish a quantitative relationship through a multivariate regression model to predict cellular dynamics in the coculture system to assess the effect of nisin on A498 kidney cancer cells cocultured with bacteria. Overall, our study sheds light on the potential of using IR spectroscopic imaging as a label-free tool to monitor complex microbe-host cell interactions in biological systems. This integration will enable mechanistic studies of interspecies interactions with insights into their underlying physiological processes.

The Tumor Microbiome Reacts to Hypoxia and Can Influence Response to Radiation Treatment in Colorectal Cancer

Tumor hypoxia has been shown to predict poor patient outcomes in several cancer types, partially because it reduces radiation's ability to kill cells. We hypothesized that some of the clinical effects of hypoxia could also be due to its impact on the tumor microbiome. Therefore, we examined the RNA sequencing data from the Oncology Research Information Exchange Network database of patients with colorectal cancer treated with radiotherapy. We identified microbial RNAs for each tumor and related them to the hypoxic gene expression scores calculated from host mRNA. Our analysis showed that the hypoxia expression score predicted poor patient outcomes and identified tumors enriched with certain microbes such as Fusobacterium nucleatum. The presence of other microbes, such as Fusobacterium canifelinum, predicted poor patient outcomes, suggesting a potential interaction between hypoxia, the microbiome, and radiation response. To experimentally investigate this concept, we implanted CT26 colorectal cancer cells into immune-competent BALB/c and immune-deficient athymic nude mice. After growth, in which tumors passively acquired microbes from the gastrointestinal tract, we harvested tumors, extracted nucleic acids, and sequenced host and microbial RNAs. We stratified tumors based on their hypoxia score and performed a metatranscriptomic analysis of microbial gene expression. In addition to hypoxia-tropic and -phobic microbial populations, analysis of microbial gene expression at the strain level showed expression differences based on the hypoxia score. Thus, hypoxia gene expression scores seem to associate with different microbial populations and elicit an adaptive transcriptional response in intratumoral microbes, potentially influencing clinical outcomes.

SIGNIFICANCE

Tumor hypoxia reduces radiotherapy efficacy. In this study, we explored whether some of the clinical effects of hypoxia could be due to interaction with the tumor microbiome. Hypoxic gene expression scores associated with certain microbes and elicited an adaptive transcriptional response in others that could contribute to poor clinical outcomes.

Nourishing the gut: the impact of diet on host-gut microbiota interaction

PURPOSE OF REVIEW

Understanding the spectrum of drivers that influence the gut microbiome (GM) remains a crucial field of investigation. Among these factors, diet has received particular attention, as it could explain up to 20% of the variability in GM composition between individuals. This review focuses on the complex relationships between different dietary patterns and GM in humans, based on recent findings.

RECENT FINDINGS

Current evidence underscores the multifaceted impact of diet on GM richness, diversity, and overall composition. Key contributing factors encompass dietary habits, nutritional interventions, food quality and variety, macronutrient distribution, timing of feeding, and selective exclusion of certain foods.

SUMMARY

The intricate interplay between diet and GM is of fundamental importance in shaping the interaction between the host and the environment. Further understanding the causal impact of diet on GM has promising potential for the advancement of strategies to promote health and mitigate cardio-metabolic disease risks through dietary interventions.

GRAPHICAL ABSTRACT

http://links.lww.com/COCN/A21.

Organoids in gastrointestinal diseases: from bench to clinic

The etiology of gastrointestinal (GI) diseases is intricate and multifactorial, encompassing complex interactions between genetic predisposition and gut microbiota. The cell fate change, immune function regulation, and microenvironment composition in diseased tissues are governed by microorganisms and mutated genes either independently or through synergistic interactions. A comprehensive understanding of GI disease etiology is imperative for developing precise prevention and treatment strategies. However, the existing models used for studying the microenvironment in GI diseases-whether cancer cell lines or mouse models-exhibit significant limitations, which leads to the prosperity of organoids models. This review first describes the development history of organoids models, followed by a detailed demonstration of organoids application from bench to clinic. As for bench utilization, we present a layer-by-layer elucidation of organoid simulation on host-microbial interactions, as well as the application in molecular mechanism analysis. As for clinical adhibition, we provide a generalized interpretation of organoid application in GI disease simulation from inflammatory disorders to malignancy diseases, as well as in GI disease treatment including drug screening, immunotherapy, and microbial-targeting and screening treatment. This review draws a comprehensive and systematical depiction of organoids models, providing a novel insight into the utilization of organoids models from bench to clinic.

Interleukin-2 mediated associations between gut microbiota and acute myeloid leukemia: A population-based mediation Mendelian randomization study

The relationship between the gut microbiota and acute myeloid leukemia (AML) has been established, but the exact role of interleukin (IL) in mediating this relationship has remained unclear. This study aimed to utilize whether interleukins mediate the relationships between gut microbiota and AML, thereby identifying potential novel targets for future AML treatment. Mendelian randomization (MR) is a method for finding the causality of exposure and outcome. Final instrumental variables were selected based on MR assumptions, and used to judge validity of the results. Our study identified risk and protective factors for AML, and interleukin-related gut microbiota. Finally, mediation MR analyses resulted in Interleukin-2 (IL-2) mediated associations between Clostridiaceae 1, Clostridium sensu stricto 1 and AML, with IL-2 respectively explaining 13.96 % and 12.11 % of the total effect of the aforementioned gut microbiota on AML. Our results successfully identified causal effects between specific gut microbiota, AML, and interleukins, while also elucidating the mediating role of IL-2 in these associations using MR analysis. These findings provide valuable insights into potential therapeutic targets for AML treatment.

Refining the relationship between gut microbiota and common hematologic malignancies: insights from a bidirectional Mendelian randomization study

Background

The relationship between gut microbiota and hematologic malignancies has attracted considerable attention. As research progresses, it has become increasingly clear that the composition of gut microbiota may influence the onset and progression of hematologic malignancies. However, our understanding of this association remains limited.

Methods

In our study, we classified gut microbiota into five groups based on information at the phylum, class, order, family, and genus levels. Subsequently, we obtained data related to common hematologic malignancies from the IEU Open GWAS project. We then employed a bidirectional Mendelian Randomization (MR) approach to determine whether there is a causal relationship between gut microbiota and hematologic malignancies. Additionally, we conducted bidirectional MR analyses to ascertain the directionality of this causal relationship.

Results

Through forward and reverse MR analyses, we found the risk of lymphoid leukemia was significantly associated with the abundance of phylum Cyanobacteria, order Methanobacteriales, class Methanobacteria, family Peptococcaceae, family Methanobacteriaceae, and genera Lachnospiraceae UCG010, Methanobrevibacter, Eubacterium brachy group, and Butyrivibrio. The risk of myeloid leukemia was significantly associated with the abundance of phylum Actinobacteria, phylum Firmicutes, order Bifidobacteriales, order Clostridiales, class Actinobacteria, class Gammaproteobacteria, class Clostridia, family Bifidobacteriaceae, and genera Fusicatenibacter, Eubacterium hallii group, Blautia, Collinsella, Ruminococcus gauvreauii group, and Bifidobacterium. The risk of Hodgkin lymphoma was significantly associated with the abundance of family Clostridiales vadinBB60 group, genus Peptococcus, and genus Ruminococcaceae UCG010. The risk of malignant plasma cell tumor was significantly associated with the abundance of genera Romboutsia and Eubacterium rectale group. The risk of diffuse large B-cell lymphoma was significantly associated with the abundance of genera Erysipelatoclostridium and Eubacterium coprostanoligenes group. The risk of mature T/NK cell lymphomas was significantly associated with the abundance of phylum Verrucomicrobia, genus Ruminococcaceae UCG013, genus Lachnoclostridium, and genus Eubacterium rectale group. Lastly, the risk of myeloproliferative neoplasms was significantly associated with the abundance of genus Coprococcus 3 and Eubacterium hallii group.

Conclusion

Our study provided new evidence for the causal relationship between gut microbiota and hematologic malignancies, offering novel insights and approaches for the prevention and treatment of these tumors.

Role of mucositis in predicting gut microbiota composition in people with cancer

PURPOSE OF REVIEW

Disruption of the precious ecosystem of micro-organisms that reside in the gut - the gut microbiota - is rapidly emerging as a key driver of the adverse side effects/toxicities caused by numerous anti-cancer agents. Although the contribution of the gut microbiota to these toxicities is understood with ever increasing precision, the cause of microbial disruption (dysbiosis) remains poorly understood. Here, we discuss current evidence on the cause(s) of dysbiosis after cancer therapy, positioning breakdown of the intestinal mucosa (mucositis) as a central cause.

RECENT FINDINGS

Dysbiosis in people with cancer has historically been attributed to extensive antibiotic use. However, evidence now suggests that certain antibiotics have minimal impacts on the microbiota. Indeed, recent evidence shows that the type of cancer therapy predicts microbiota composition independently of antibiotics. Given most anti-cancer drugs have modest effects on microbes directly, this suggests that their impact on the gut microenvironment, in particular the mucosa, which is highly vulnerable to cytotoxicity, is a likely cause of dysbiosis. Here, we outline evidence that support this hypothesis, and discuss the associated clinical implications/opportunities.

SUMMARY

The concept that mucositis dictates microbiota compositions provides two important implications for clinical practice. Firstly, it reiterates the importance of prioritising the development of novel mucoprotectants that preserve mucosal integrity, and indirectly support microbial stability. Secondly, it provides an opportunity to identify dysbiotic events and associated consequences using readily accessible, minimally invasive biomarkers of mucositis such as plasma citrulline.

From microbes to medicine: harnessing the gut microbiota to combat prostate cancer

The gut microbiome (GM) has been identified as a crucial factor in the development and progression of various diseases, including cancer. In the case of prostate cancer, commensal bacteria and other microbes are found to be associated with its development. Recent studies have demonstrated that the human GM, including Bacteroides, Streptococcus, Bacteroides massiliensis, Faecalibacterium prausnitzii, Eubacterium rectale, and Mycoplasma genitalium, are involved in prostate cancer development through both direct and indirect interactions. However, the pathogenic mechanisms of these interactions are yet to be fully understood. Moreover, the microbiota influences systemic hormone levels and contributes to prostate cancer pathogenesis. Currently, it has been shown that supplementation of prebiotics or probiotics can modify the composition of GM and prevent the onset of prostate cancer. The microbiota can also affect drug metabolism and toxicity, which may improve the response to cancer treatment. The composition of the microbiome is crucial for therapeutic efficacy and a potential target for modulating treatment response. However, their clinical application is still limited. Additionally, GM-based cancer therapies face limitations due to the complexity and diversity of microbial composition, and the lack of standardized protocols for manipulating gut microbiota, such as optimal probiotic selection, treatment duration, and administration timing, hindering widespread use. Therefore, this review provides a comprehensive exploration of the GM's involvement in prostate cancer pathogenesis. We delve into the underlying mechanisms and discuss their potential implications for both therapeutic and diagnostic approaches in managing prostate cancer. Through this analysis, we offer valuable insights into the pivotal role of the microbiome in prostate cancer and its promising application in future clinical settings.

Gut Microbiota Are a Novel Source of Biomarkers for Immunotherapy in Non-Small-Cell Lung Cancer (NSCLC)

Despite the recent availability of immune checkpoint inhibitors, not all patients affected by Non-Small-Cell Lung Cancer (NSCLC) benefit from immunotherapy. The reason for this variability relies on a variety of factors which may allow for the identification of novel biomarkers. Presently, a variety of biomarkers are under investigation, including the PD1/PDL1 axis, the tumor mutational burden, and the microbiota. The latter is made by all the bacteria and other microorganisms hosted in our body. The gut microbiota is the most represented and has been involved in different physiological and pathological events, including cancer. In this light, it appears that all conditions modifying the gut microbiota can influence cancer, its treatment, and its treatment-related toxicities. The aim of this review is to analyze all the conditions influencing the gut microbiota and, therefore, affecting the response to immunotherapy, iRAEs, and their management in NSCLC patients. The investigation of the landscape of these biological events can allow for novel insights into the optimal management of NSCLC immunotherapy.

Microbiome and cancer: from mechanistic implications in disease progression and treatment to development of novel antitumoral strategies

Cancer is a very aggressive disease and one of mankind's most important health problems, causing numerous deaths each year. Its etiology is complex, including genetic, gender-related, infectious diseases, dysbiosis, immunological imbalances, lifestyle, including dietary factors, pollution etc. Cancer patients also become immunosuppressed, frequently as side effects of chemotherapy and radiotherapy, and prone to infections, which further promote the proliferation of tumor cells. In recent decades, the role and importance of the microbiota in cancer has become a hot spot in human biology research, bringing together oncology and human microbiology. In addition to their roles in the etiology of different cancers, microorganisms interact with tumor cells and may be involved in modulating their response to treatment and in the toxicity of anti-tumor therapies. In this review, we present an update on the roles of microbiota in cancer with a focus on interference with anticancer treatments and anticancer potential.

CPX-351 exploits the gut microbiota to promote mucosal barrier function, colonization resistance, and immune homeostasis

ABSTRACT

CPX-351, a liposomal combination of cytarabine plus daunorubicin, has been approved for the treatment of adults with newly diagnosed, therapy-related acute myeloid leukemia (AML) or AML with myelodysplasia-related changes, because it improves survival and outcome of patients who received hematopoietic stem cell transplant compared with the continuous infusion of cytarabine plus daunorubicin (referred to as "7 + 3" combination). Because gut dysbiosis occurring in patients with AML during induction chemotherapy heavily affects the subsequent phases of therapy, we have assessed whether the superior activity of CPX-351 vs "7 + 3" combination in the real-life setting implicates an action on and by the intestinal microbiota. To this purpose, we have evaluated the impact of CPX-351 and "7 + 3" combination on mucosal barrier function, gut microbial composition and function, and antifungal colonization resistance in preclinical models of intestinal damage in vitro and in vivo and fecal microbiota transplantation. We found that CPX-351, at variance with "7 + 3" combination, protected from gut dysbiosis, mucosal damage, and gut morbidity while increasing antifungal resistance. Mechanistically, the protective effect of CPX-351 occurred through pathways involving both the host and the intestinal microbiota, namely via the activation of the aryl hydrocarbon receptor-interleukin-22 (IL-22)-IL-10 host pathway and the production of immunomodulatory metabolites by anaerobes. This study reveals how the gut microbiota may contribute to the good safety profile, with a low infection-related mortality, of CPX-351 and highlights how a better understanding of the host-microbiota dialogue may contribute to pave the way for precision medicine in AML.

In vitro co-culture of Clostridium scindens with primary human colonic epithelium protects the epithelium against Staphylococcus aureus

A complex and dynamic network of interactions exists between human gastrointestinal epithelium and intestinal microbiota. Therefore, comprehending intestinal microbe-epithelial cell interactions is critical for the understanding and treatment of intestinal diseases. Primary human colonic epithelial cells derived from a healthy human donor were co-cultured with Clostridium scindens (C. scindens), a probiotic obligate anaerobe; Staphylococcus aureus (S. aureus), a facultative anaerobe and intestinal pathogen; or both bacterial species in tandem. The co-culture hanging basket platform used for these experiments possessed walls of controlled oxygen (O2) permeability to support the formation of an O2 gradient across the intestinal epithelium using cellular O2 consumption, resulting in an anaerobic luminal and aerobic basal compartment. Both the colonic epithelial cells and C. scindens remained viable over 48 h during co-culture. In contrast, co-culture with S. aureus elicited significant damage to colonic epithelial cells within 24 h. To explore the influence of the intestinal pathogen on the epithelium in the presence of the probiotic bacteria, colonic epithelial cells were inoculated sequentially with the two bacterial species. Under these conditions, C. scindens was capable of repressing the production of S. aureus enterotoxin. Surprisingly, although C. scindens converted cholic acid to secondary bile acids in the luminal medium, the growth of S. aureus was not significantly inhibited. Nevertheless, this combination of probiotic and pathogenic bacteria was found to benefit the survival of the colonic epithelial cells compared with co-culture of the epithelial cells with S. aureus alone. This platform thus provides an easy-to-use and low-cost tool to study the interaction between intestinal bacteria and colonic cells in vitro to better understand the interplay of intestinal microbiota with human colonic epithelium.

Polyphenolic Compounds: Orchestrating Intestinal Microbiota Harmony during Aging

In the aging process, physiological decline occurs, posing a substantial threat to the physical and mental well-being of the elderly and contributing to the onset of age-related diseases. While traditional perspectives considered the maintenance of life as influenced by a myriad of factors, including environmental, genetic, epigenetic, and lifestyle elements such as exercise and diet, the pivotal role of symbiotic microorganisms had been understated. Presently, it is acknowledged that the intestinal microbiota plays a profound role in overall health by signaling to both the central and peripheral nervous systems, as well as other distant organs. Disruption in this bidirectional communication between bacteria and the host results in dysbiosis, fostering the development of various diseases, including neurological disorders, cardiovascular diseases, and cancer. This review aims to delve into the intricate biological mechanisms underpinning dysbiosis associated with aging and the clinical ramifications of such dysregulation. Furthermore, we aspire to explore bioactive compounds endowed with functional properties capable of modulating and restoring balance in this aging-related dysbiotic process through epigenetics alterations.

The role of Akkermansia muciniphila in colorectal cancer: A double-edged sword of treatment or disease progression?

Colorectal cancer (CRC) is the second most cancer-related death worldwide. In recent years, probiotics have been used to reduce the potential risks of CRC and tumors with various mechanisms. Different bacteria have been suggested to play different roles in the progression, prevention, or treatment of CRC. Akkermansia muciniphila is considered a next-generation probiotic for preventing and treating some diseases. Therefore, in this review article, we aimed to describe and discuss different mechanisms of A. muciniphila as an intestinal microbiota or probiotic in CRC. Some studies suggested that the abundance of A. muciniphila was higher or increased in CRC patients compared to healthy individuals. However, the decreased abundance of A. muciniphila was associated with severe symptoms of CRC, indicating that A. muciniphila did not play a role in the development of CRC. In addition, A. muciniphila administration elevates gene expression of proliferation-associated molecules such as S100A9, Dbf4, and Snrpd1, or markers for cell proliferation. Some other studies suggested that inflammation and tumorigenesis in the intestine might promoted by A. muciniphila. Overall, the role of A. muciniphila in CRC development or inhibition is still unclear and controversial. Various methods of bacterial supplementation, such as viability, bacterial number, and abundance, could all influence the colonization effect of A. muciniphila administration and CRC progression. Overall, A. mucinipila has been revealed to modulate the therapeutic potential of immune checkpoint inhibitors. Preliminary human data propose that oral consumption of A. muciniphila is safe, but its efficacy needs to be confirmed in more human clinical studies.