Combining gut microbiota modulation and chemotherapy by capecitabine-loaded prebiotic nanoparticle improves colorectal cancer therapy

Layered-Responsive Multivalent Tetrahedral DNA Framework-Decorated CRISPR-Cas12a Nanocapsule Enables Precise and Enhanced Tumor Chemotherapy

The lack of selective tumor targeting and the high toxicity of conventional chemotherapy treatments remain major challenges in cancer therapy. Here, we develop a self-controlled DNA nanostructure-CRISPR-12a system, a triple-locked cascade tumor therapy nanocapsule (Tatna), for efficient and targeted tumor treatment. Tatna integrates structural DNA tetrahedrons (DTs) with high drug-loading capacity, Cas12a/crRNA ribonucleoprotein (Cas12a RNP), and doxorubicin (DOX) to enable multisite response for precise drug delivery and augmented tumor treatment. By incorporation of a nucleolin-targeting aptamer, Tatna achieves selective targeting and efficient tumor cell internalization. Encapsulation in pH-responsive poly l-lactic-co-glycolic acid (PLGA) nanocapsule ensures stable circulation and controlled release of both DOX and Cas12a until tumor-specific activation in the acidic microenvironment. The Cas12a RNP, triggered by APE1 mRNA overexpression in tumor cells, induces trans-cleavage of DTs, releasing DOX and Cas12a to transport into the nucleus and induce enhanced cell apoptosis. This self-regulating and multifunctional approach enhances the efficacy of chemotherapy while reducing off-target effects. Tatna's programmable, tumor-specific delivery system represents a powerful strategy for advancing precision medicine and personalized cancer treatment.

Gut microbiome and colorectal cancer: From pathogenesis to treatment

Colorectal cancer (CRC) continues to rank among the most prevalent cancers worldwide. A growing body of research indicates that the microbiome significantly influences the onset, development, and progression of CRC, in addition to affecting the efficacy of various systemic therapies. The composition of the microbiome, shaped by factors such as bacterial strains, geography, ethnicity, gender, and dietary habits, provides essential information for CRC screening, early diagnosis, and the prediction of treatment responses. Modulating the microbiome presents a highly promising medical strategy for improving individual health. This review aims to present a thorough overview of recent research concerning the interplay between host microbiota and CRC, along with its implications for screening and the immune response against tumors in the context of cancer treatment.

Gut Microbiota Dysbiosis: Pathogenesis, Diseases, Prevention, and Therapy

Dysbiosis refers to the disruption of the gut microbiota balance and is the pathological basis of various diseases. The main pathogenic mechanisms include impaired intestinal mucosal barrier function, inflammation activation, immune dysregulation, and metabolic abnormalities. These mechanisms involve dysfunctions in the gut-brain axis, gut-liver axis, and others to cause broader effects. Although the association between diseases caused by dysbiosis has been extensively studied, many questions remain regarding the specific pathogenic mechanisms and treatment strategies. This review begins by examining the causes of gut microbiota dysbiosis and summarizes the potential mechanisms of representative diseases caused by microbiota imbalance. It integrates clinical evidence to explore preventive and therapeutic strategies targeting gut microbiota dysregulation, emphasizing the importance of understanding gut microbiota dysbiosis. Finally, we summarized the development of artificial intelligence (AI) in the gut microbiota research and suggested that it will play a critical role in future studies on gut dysbiosis. The research combining multiomics technologies and AI will further uncover the complex mechanisms of gut microbiota dysbiosis. It will drive the development of personalized treatment strategies.

Enhancing Colorectal Cancer Treatment: The Role of Bifidobacterium in Modulating Gut Immunity and Mitigating Capecitabine-Induced Toxicity

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality globally and presents significant challenges in treatment and patient care. Capecitabine, a widely used prodrug of 5-fluorouracil (5-FU), offers targeted delivery with reduced systemic toxicity compared to traditional chemotherapies. However, capacitabine is associated with adverse effects, such as hand-foot syndrome, gastrointestinal issues, and mucositis. Emerging evidence suggests that probiotics, particularly Bifidobacterium, play a pivotal role in gut microbiota modulation, promoting anti-inflammatory cytokines and short-chain fatty acids, such as butyrate, which possess both intestinal protective and anti-cancer properties. In this review, we explored the potential of Bifidobacterium to improve chemotherapy outcomes by mitigating inflammation and enhancing mucosal immunity in CRC patients. Furthermore, we demonstrated in silico approaches, including molecular docking and protein-protein interaction analysis, for Bifidobacterium and Toll-like receptor 2 (TLR-2), a key mediator of intestinal immunity. Docking results revealed strong binding affinity, suggesting the activation of anti-inflammatory pathways. Notably, this interaction enhanced IL-10 production while reducing pro-inflammatory cytokines, such as IL-6 and TNF-α, fostering gut homeostasis and mitigating chronic inflammation, a key driver of CRC progression. Therefore, future research should focus on personalized probiotics and validating their synergy with chemotherapy and immunotherapy to improve CRC treatment outcomes.

Optimizing Cancer Treatment Through Gut Microbiome Modulation

The gut microbiome plays a pivotal role in modulating cancer therapies, including immunotherapy and chemotherapy. Emerging evidence demonstrates its influence on treatment efficacy, immune response, and resistance mechanisms. Specific microbial taxa enhance immune checkpoint inhibitor efficacy, while dysbiosis can contribute to adverse outcomes. Chemotherapy effectiveness is also influenced by microbiome composition, with engineered probiotics and prebiotics offering promising strategies to enhance drug delivery and reduce toxicity. Moreover, microbial metabolites, such as short-chain fatty acids, and engineered microbial systems have shown potential to improve therapeutic responses. These findings underscore the importance of personalized microbiome-based approaches in optimizing cancer treatments.

Oral microbiota in colorectal cancer: Unraveling mechanisms and application potential

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

Exploring the role of gut microbiota in colorectal liver metastasis through the gut-liver axis

Colorectal liver metastasis (CRLM) represents a major therapeutic challenge in colorectal cancer (CRC), with complex interactions between the gut microbiota and the liver tumor microenvironment (TME) playing a crucial role in disease progression via the gut-liver axis. The gut barrier serves as a gatekeeper, regulating microbial translocation, which influences liver colonization and metastasis. Through the gut-liver axis, the microbiota actively shapes the TME, where specific microbial species and their metabolites exert dual roles in immune modulation. The immunologically "cold" nature of the liver, combined with the influence of the gut microbiota on liver immunity, complicates effective immunotherapy. However, microbiota-targeted interventions present promising strategies to enhance immunotherapy outcomes by modulating the gut-liver axis. Overall, this review highlights the emerging evidence on the role of the gut microbiota in CRLM and provides insights into the molecular mechanisms driving the dynamic interactions within the gut-liver axis.

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.

Magnetically triggered thermoelectric heterojunctions with an efficient magnetic-thermo-electric energy cascade conversion for synergistic cancer therapy

Thermoelectric therapy has been emerging as a promising and versatile strategy for targeting malignant tumors treatment. However, the lack of effective time-space controlled triggering of thermoelectric effect in vivo limits the application of thermoelectric therapy. Here a magnetically triggered thermoelectric heterojunction (CuFe2O4/SrTiO3, CFO/STO) for synergistic thermoelectric/chemodynamic/immuno-therapy is developed. The efficient magnetothermal nanoagent (CFO) is synthesized using the hydrothermal method, and thermoelectric nanomaterials (STO) are grown on its surface to create the heterojunction. To enhance oral delivery efficiency, a fusion membrane (M) of Staphylococcus aureus and macrophage cell membranes are coated the CFO/STO heterojunction, enabling effective targeting of orthotopic colorectal cancer. Once the CFO/STO@M reaches the tumor region, in vitro alternating magnetic field (AMF) stimulation activates the catalytic treatment through a magnetic-thermo-electric energy cascade conversion effect. Additionally, the immunogenic death of tumor cells, down-regulating vascular endothelial growth factor and heat shock protein HSP70, increasing expression of endothelial cell adhesion molecule (ICAM-1/VCAM-1), and M1 polarization of macrophages contribute to tumor immunotherapy. Overall, the magnetically triggered thermoelectric heterojunction based on CFO/STO@M shows remarkable antitumor capability in female mice, offering a promising approach to broaden both the scope of application and the effectiveness of catalytic therapy.

Gut microbiota in colorectal cancer: a review of its influence on tumor immune surveillance and therapeutic response

Colorectal cancer (CRC) poses a significant global health burden, with gut microbiota emerging as a crucial modulator of CRC pathogenesis and therapeutic outcomes. This review synthesizes current evidence on the influence of gut microbiota on tumor immune surveillance and responses to immunotherapies and chemotherapy in CRC. We highlight the role of specific microbial taxa in promoting or inhibiting tumor growth and the potential of microbiota-based biomarkers for predicting treatment efficacy. The review also discusses the implications of microbiota modulation strategies, including diet, probiotics, and fecal microbiota transplantation, for personalized CRC management. By critically evaluating the literature, we aim to provide a comprehensive understanding of the gut microbiota's dual role in CRC and to inform future research directions in this field.

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.

Nanoscale Liposomes Co-Loaded with Irinotecan Hydrochloride and Thalidomide for Colorectal Cancer Synergistic Therapy

Irinotecan hydrochloride (CPT-11) is one of the first-line drugs used in the clinical treatment of colorectal cancer (CRC). However, the concomitant adverse effect of delayed diarrhea has hindered its clinical use. CPT-11 combined with Thalidomide (THA) therapy is considered a palliative strategy. To optimize the synergistic treatment of CPT-11 and THA, co-loaded liposomes are constructed using cholesterol, lecithin, and 1, 2-Distearoyl-sn-glycero-3-phosphoethanolamine-Poly(ethylene glycol) (DSPE-PEG) as the "immune and gut microbiota regulator." The co-loaded liposomes, which possess good stability, are prepared by the solvent injection method. After the treatment with the co-loaded liposomes, tumor growth in CRC-bearing mice is significantly inhibited. In particular, the co-loaded liposomes demonstrate favorable diarrhea-relieving effects through the modulation of inflammatory cytokines and gut microbiota. These findings suggest that the co-loaded liposomes have great potential as a combined drug-delivery platform for CRC therapy.

5-Fluorouracil Loaded Prebiotic-Probiotic Liposomes Modulating Gut Microbiota for Improving Colorectal Cancer Chemotherapy

The gut microbiota exerts inhibitory effects on the occurrence and progression of colorectal cancer (CRC) through various mechanisms. Compared to traditional microbiota regulation methods, prebiotics and probiotics demonstrate significant advantages in terms of safety and patient adaptability. Their synergy not only improves the intestinal environment but also enhances the host's anti-tumor immune response. 5-Fluorouracil (5-FU) is a first-line chemotherapy drug that has a short half-life and low bioavailability. However, if administered in an untargeted manner, 5-FU also causes adverse reactions. Liposomes can improve the pharmacokinetic profile of drugs and provide targeted delivery to the tumor site, thereby reducing side effects. In this work, a 5-FU-loaded liposome is modified with the prebiotic xylan derivative Sxy and the probiotic Akkermansia muciniphila active phospholipid homolog 1,2-dipalmitoylphosphatidy-lethanolamine (DPPE) to construct FLSK. The latter effectively prolongs the intestinal transport and release of 5-FU, maintaining high drug concentrations at the tumor site. FLSK is found to inhibit tumor growth and significantly extends the survival period of mice. In addition, FLSK promotes anti-tumor immunity and regulation of the gut microbiota. Combining the merits of prebiotics and probiotics, FLSK provides a potential strategy for integrating chemotherapy with gut microbiota regulation therapy for the treatment of CRC.

Ursolic acid in colorectal cancer: mechanisms, current status, challenges, and future research directions

Colorectal cancer (CRC) ranks as the third most prevalent cancer globally, contributing to approximately 10% of all cancer cases and representing the second leading cause of cancer-related mortality worldwide. Ursolic acid (UA), a widely studied pentacyclic triterpenoid, has attracted substantial attention from researchers and clinicians due to its potential therapeutic effects against malignant tumors. Multiple studies have confirmed that UA inhibits tumor cell proliferation, induces differentiation and apoptosis, suppresses invasion, and impedes tumor angiogenesis via diverse mechanisms. However, research specifically addressing UA's anti-CRC effects remains limited, and systematic reviews of its underlying mechanisms in CRC are scarce. This study seeks to provide a comprehensive review of UA's mechanisms of action against CRC, offering valuable insights and references for researchers and clinicians.

Global research trends on nanotechnology and colorectal cancer: a two-decade analysis

INTRODUCTION

Colorectal cancer (CRC) remains a serious threat to humans worldwide. In this study, we used bibliometric analysis of the scientific literature to assess the trends and prospects of nanotechnology applications in CRC.

MATERIALS AND METHODS

We used the Web of Science Core Collection database to screen relevant publications on nanotechnology and CRC from 2004 to 2023 based on the inclusion criteria. Bibliometric analyses were performed on all selected publication and citation data. Visual analysis using VOSviewer and CiteSpace intuitively reflected the hotspots in this field.

RESULTS

In total, 2040 publications on nanotechnology in CRC were identified for this two-decade analysis. China (443, 29.14%) and the USA (199, 13.09%) were the top two most productive countries, and Sichuan University was the most prolific institution. The most influential journal was the International Journal of Nanomedicine. The author with the most papers was Li L. "Nanoparticles," "drug delivery," and "CRC" were the most common keywords. Green synthesis and gold nanoparticles were peripheral, incompletely developed topics.

CONCLUSION

This study provides a comprehensive overview of nanomaterials in CRC as clinical medicine, enriching the body of evidence in this field.

An Oral H2S Responsive Cu5.4O Nanozyme Platform with Strong ROS/H2S Scavenging Capacity for the Treatment of Colitis

Inflammatory bowel disease involves excess reactive oxygen species (ROS) and hydrogen sulfide (H2S) at inflammatory sites. Nanozyme-mediated ROS and H2S scavenging therapy is promising for colitis treatment. Here, we synthesized a multiple ROS scavenging Cu5.4O nanoparticle and first explored its H2S scavenging capacity. Chitosan oligosaccharide modified with alpha-lipoic acid was coated on the nanoparticles to further enhance the H2S scavenging capacity. Furthermore, calcium alginate was coated on the surface to develop an oral nanoplatform (Cu5.4O@SAG) possessing dual-pH/H2S-responsive release characteristics. Importantly, Cu5.4O@SAG exhibited enrichment at the colonic inflammation site and relieved the inflammatory index, containing the recovery of colon length, spleen index, liver index, and body weight, as well as inflammatory cell infiltration. In vivo and in vitro experiments revealed the dual ROS and H2S scavenging capacities of the nanoplatform. Additionally, Cu5.4O@SAG regulated tight junctions, mucus layers, and gut microbiota, which was accompanied by the downregulation of inflammatory cytokines. Notably, Cu5.4O@SAG also had excellent biocompatibility. In conclusion, this oral multiple-scavenging nanozyme platform provides a new and safe paradigm for the development of nanozymes for colitis treatment.

A glutenin protein corona ameliorated TiO2 nanoparticle-induced gut barrier dysfunction and altered the gut microbiota composition

Previously, we found that glutenin proteins formed a protein corona around food-grade titanium dioxide (TiO2) nanoparticles. The protein corona would alter the gastrointestinal behavior and biological activity of the nanoparticles. Here, in this study, the influence of protein corona formation on the adverse effects of TiO2 nanoparticles on gut barrier function using in vitro and in vivo assays and the potential mechanism were investigated and elucidated. Our findings showed that the presence of the protein corona mitigated gut barrier injury caused by TiO2 nanoparticles while increasing gene expression for tight junction proteins; for example, in vitro gastrointestinal digestion and fermentation experiments showed that the glutenin-TiO2 protein corona was relatively stable to digestion and influenced the composition of the gut microbiota. Specifically, the glutenin-TiO2 protein corona increased the relative abundance of beneficial bacteria such as Bifidobacterium, Parasutterella, and Bacillus while reducing the relative abundance of harmful bacteria like Streptococcus. Moreover, the formation of the protein corona reduced the cytotoxicity of the TiO2 nanoparticles to Caco-2 and RAW264.7 cells. Mechanistically, we found that the presence of the glutenin-TiO2 protein corona decreased the production of reactive oxygen species and increased the mitochondrial membrane potential in both Caco-2 and RAW264.7 cells compared to TiO2 nanoparticles alone. This study provides valuable mechanistic insights into the potential biological effects of protein corona formation around food inorganic nanoparticles in the food industry.

Biotransformation characteristics of urate-lowering probiotic fermented apple juice and potential regulatory mechanisms for ameliorating hyperuricemia via mediating gut microbiota and metabolic pathways

Hyperuricemia has evolved into a global public health concern, and applying probiotics fermented apple juice holds promise for alleviating this condition. This study aimed to investigate the biotransformation and metabolic features of urate-lowering probiotics sequentially fermented dealcoholized apple juice (PSFA), and assess its ameliorative effects and potential mechanisms on hyperuricemia mice. Results showed that CICC 6074 and 20,292 possessed excellent purine, nucleotide and nucleoside degradation and acid and bile salt resistance; sequential fermentation decreased the fructose in apple juice, and viable counts reached 3.76 × 108 CFU/mL. Histopathological analysis showed that PSFA ameliorated kidney damage in hyperuricemia mice. Furthermore, PSFA significantly reduced Urea, Creatinine and Uric acid levels in hyperuricemia mice; and inhibited xanthine oxidase activity and the expression of pro-inflammatory factors. Importantly, PSFA reversed gut microbiota dysbiosis and raised the abundance of beneficial bacteria (Lactobacillush, Faecalibaculum and Lachnospiraceae_NK4A136_group). KEGG and COG functional prediction results revealed that the potential mechanism of PSFA to ameliorate hyperuricemia may be lipid metabolism and glycolysis pathways.

Omics-Enhanced Nanomedicine for Cancer Therapy

Cancer nanomedicine has emerged as a promising approach to overcome the limitations of conventional cancer therapies, offering enhanced efficacy and safety in cancer management. However, the inherent heterogeneity of tumors presents increasing challenges for the application of cancer nanomedicine in both diagnosis and treatment. This heterogeneity necessitates the integration of advanced and high-throughput analytical techniques to tailor nanomedicine strategies to individual tumor profiles. Omics technologies, encompassing genomics, epigenomics, transcriptomics, proteomics, metabolomics, and more, provide unparalleled insights into the molecular and cellular mechanisms underlying cancer. By dissecting tumor heterogeneity across multiple levels, these technologies offer robust support for the development of personalized and precise cancer nanomedicine strategies. In this review, the principles, techniques, and applications of key omics technologies are summarized. Especially, the synergistic integration of omics and nanomedicine in cancer therapy is explored, focusing on enhanced diagnostic accuracy, optimized therapeutic strategies and the assessment of nanomedicine-mediated biological responses. Moreover, this review addresses current challenges and outlines future directions in the field of omics-enhanced nanomedicine. By offering valuable insights and guidance, this review aims to advance the integration of omics with nanomedicine, ultimately driving improved diagnostic and therapeutic strategies for cancer.

Capecitabine mitigates cardiac allograft rejection via inhibition of TYMS-Mediated Th1 differentiation in mice

OBJECTIVES

Previous studies elucidated that capecitabine (CAP) works as an anti-tumor agent with putative immunosuppressive effects. However, the intricate mechanisms underpinning these effects remain to be elucidated. In this study, we aimed to unravel the molecular pathways by which CAP exerts its immunosuppressive effects to reduce allograft rejection.

METHODS

Hearts were transplanted from male BALB/c donors to male C57BL/6 recipients and treated with CAP for seven days. The rejection of these heart transplants was assessed using a range of techniques, including H&E staining, immunohistochemistry, RNA sequencing, LS-MS/MS, and flow cytometry. In vitro, naïve CD4+ T cells were isolated and cultured under Th1 condition medium with varying treatments, flow cytometry, LS-MS/MS were employed to delineate the role of thymidine synthase (TYMS) during Th1 differentiation.

RESULTS

CAP treatment significantly mitigated acute allograft rejection and enhanced graft survival by reducing graft damage, T cell infiltration, and levels of circulating pro-inflammatory cytokines. Additionally, it curtailed CD4+ T cell proliferation and the presence of Th1 cells in the spleen. RNA-seq showed that TYMS, the target of CAP, was robustly increased post-transplantation in splenocytes. In vitro, TYMS and its metabolic product dTMP were differentially expressed in Th0 and Th1, and were required after activation of CD4+ T cell and Th1 differentiation. TYMS-specific inhibitor, raltitrexed, and the metabolite of capecitabine, 5-fluorouracil, could inhibit the proliferation and differentiation of Th1. Finally, the combined use of CAP and the commonly used immunosuppressant rapamycin can induce long-term survival of allograft.

CONCLUSION

CAP undergoes metabolism conversion to interfere pyrimidine metabolism, which targets TYMS-mediated differentiation of Th1, thereby playing a significant role in mitigating acute cardiac allograft rejection in murine models.

Microbial Therapeutics in Oncology: A Comprehensive Review of Bacterial Role in Cancer Treatment

Conventional cancer therapies, including chemotherapy, radiotherapy, and immunotherapy, have significantly advanced cancer treatment. However, these modalities often face limitations such as systemic toxicity, lack of specificity, and the emergence of resistance. Recent advancements in genetic engineering and synthetic biology have rekindled interest in using bacteria as a novel therapeutic approach in oncology. This comprehensive review explores the potential of microbial therapeutics, particularly bacterial therapies, in the treatment of cancer. Bacterial therapies offer several unique advantages, such as the ability to selectively target and colonize hypoxic and necrotic regions of tumors, areas typically resistant to conventional treatments. The review delves into the mechanisms through which bacteria exert antitumor effects, including direct tumor cell lysis, modulation of the immune response, and delivery of therapeutic agents like cytotoxins and enzymes. Various bacterial species, such as Salmonella, Clostridium, Lactobacillus, and Listeria, have shown promise in preclinical and clinical studies, demonstrating diverse mechanisms of action and therapeutic potential. Moreover, the review discusses the challenges associated with bacterial therapies, such as safety concerns, immune evasion, and the need for precise targeting, and how recent advances in genetic engineering are being used to overcome these hurdles. Current clinical trials and combination strategies with conventional therapies are also highlighted to provide a comprehensive overview of the ongoing developments in this field. In conclusion, while bacterial therapeutics present a novel and promising avenue in cancer treatment, further research and clinical validation is required to fully realize their potential. This review aims to inspire further exploration into microbial oncology, paving the way for innovative and more effective cancer therapies.

Gut bacteria, host immunity, and colorectal cancer: From pathogenesis to therapy

The emergence of 16S rRNA and metagenomic sequencing has gradually revealed the close relationship between dysbiosis and colorectal cancer (CRC). Recent studies have confirmed that intestinal dysbiosis plays various roles in the occurrence, development, and therapeutic response of CRC. Perturbation of host immunity is one of the key mechanisms involved. The intestinal microbiota, or specific bacteria and their metabolites, can modulate the progression of CRC through pathogen recognition receptor signaling or via the recruitment, polarization, and activation of both innate and adaptive immune cells to reshape the protumor/antitumor microenvironment. Therefore, the administration of gut bacteria to enhance immune homeostasis represents a new strategy for the treatment of CRC. In this review, we cover recent studies that illuminate the role of gut bacteria in the progression and treatment of CRC through orchestrating the immune response, which potentially offers insights for subsequent transformative research.

A comprehensive view on the fisetin impact on colorectal cancer in animal models: Focusing on cellular and molecular mechanisms

Flavonoids, including fisetin, have been linked to a reduced risk of colorectal cancer (CRC) and have potential therapeutic applications for the condition. Fisetin, a natural flavonoid found in various fruits and vegetables, has shown promise in managing CRC due to its diverse biological activities. It has been found to influence key cell signaling pathways related to inflammation, angiogenesis, apoptosis, and transcription factors. The results of this study demonstrate that fisetin induces colon cancer cell apoptosis through multiple mechanisms. It impacts the p53 pathway, leading to increased levels of p53 and decreased levels of murine double minute 2, contributing to apoptosis induction. Fisetin also triggers the release of important components in the apoptotic process, such as second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI and cytochrome c. Furthermore, fisetin inhibits the cyclooxygenase-2 and wingless-related integration site (Wnt)/epidermal growth factor receptor/nuclear factor kappa B signaling pathways, reducing Wnt target gene expression and hindering colony formation. It achieves this by regulating the activities of cyclin-dependent kinase 2 and cyclin-dependent kinase 4, reducing retinoblastoma protein phosphorylation, decreasing cyclin E levels, and increasing p21 levels, ultimately influencing E2 promoter binding factor 1 and cell division cycle 2 (CDC2) protein levels. Additionally, fisetin exhibits various effects on CRC cells, including inhibiting the phosphorylation of Y-box binding protein 1 and ribosomal S6 kinase, promoting the phosphorylation of extracellular signal-regulated kinase 1/2, and disrupting the repair process of DNA double-strand breaks. Moreover, fisetin serves as an adjunct therapy for the prevention and treatment of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA)-mutant CRC, resulting in a reduction in phosphatidylinositol-3 kinase (PI3K) expression, Ak strain transforming phosphorylation, mTOR activity, and downstream target proteins in CRC cells with a PIK3CA mutation. These findings highlight the multifaceted potential of fisetin in managing CRC and position it as a promising candidate for future therapy development.

Extracellular Vesicles from Nanomedicine-Trained Intestinal Microbiota Substitute for Fecal Microbiota Transplant in Treating Ulcerative Colitis

The biosafety concerns associated with fecal microbiota transplant (FMT) limit their clinical application in treating ulcerative colitis (UC). Gut microbiota secrete abundant extracellular vesicles (Gm-EVs), which play a critical role in bacteria-to-bacteria and bacteria-to-host communications. Herein, intestinal microbiota are trained using tea leaf lipid/pluronic F127-coated curcumin nanocrystals (CN@Lp127s), which can maintain stability during transit through the gastrointestinal tract. Compared with FMT, Gm-EVs derived from healthy mice significantly improve treatment outcomes against UC by reducing colonic inflammatory responses, restoring colonic barrier function, and rebalancing intestinal microbiota. Strikingly, Gm-EVs obtained from CN@Lp127-trained healthy mice exhibit a superior therapeutic effect on UC compared to groups receiving FMT from healthy mice, Gm-EVs from healthy mice, and FMT from CN@Lp127-trained healthy mice. Oral administration of Gm-EVs from CN@Lp127-trained healthy mice not only alleviates colonic inflammation, promotes mucosal repair, and regulates gut microbiota but also regulates purine metabolism to decrease the uric acid level, resulting in a robust improvement in the UC. This study demonstrates the UC therapeutic efficacy of Gm-EVs derived from nanomedicine-trained gut microbiota in regulating the immune microenvironment, microbiota, and purine metabolism of the colon. These EVs provide an alternative platform to replace FMT as a treatment for UC.

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.

Obesity-Associated Colorectal Cancer

Colorectal cancer (CRC) affects approximately 2 million people worldwide. Obesity is the major risk factor for CRC. In addition, obesity contributes to a chronic inflammatory stage that enhances tumor progression through the secretion of proinflammatory cytokines. In addition to an increased inflammatory response, obesity-associated cancer presents accrued molecular factors related to cancer characteristics, such as genome instability, sustained cell proliferation, telomere dysfunctions, angiogenesis, and microbial alteration, among others. Despite the evidence accumulated over the last few years, the treatments for obesity-associated CRC do not differ from the CRC treatments in normal-weight individuals. In this review, we summarize the current knowledge on obesity-associated cancer, including its epidemiology, risk factors, molecular factors, and current treatments. Finally, we enumerate possible new therapeutic targets that may improve the conditions of obese CRC patients. Obesity is key for the development of CRC, and treatments resulting in the reversal of obesity should be considered as a strategy for improving antineoplastic CRC therapies.

Biopolymeric nanocarriers in cancer therapy: unleashing the potency of bioactive anticancer compounds for enhancing drug delivery

Effective cancer treatment is becoming a global concern, and recent developments in nanomedicine are essential for its treatment. Cancer is a severe metabolic syndrome that affects the human population and is a significant contributing factor to deaths globally. In science, nanotechnology offers rapidly developing delivery methods for natural bioactive compounds that are becoming increasingly prominent and can be used to treat diseases in a site-specific way. Chemotherapy and radiotherapy are conventional approaches for preventing cancer progression and have adverse effects on the human body. Many chemically synthesized drugs are used as anticancer agents, but they have several side effects; hence, they are less preferred. Medicinal plants and marine microorganisms represent a vast, mostly untapped reservoir of bioactive compounds for cancer treatment. However, they have several limitations, including nonspecific targeting, weak water solubility and limited therapeutic potential. An alternative option is the use of biopolymeric nanocarriers, which can generate effective targeted treatment therapies when conjugated with natural anticancer compounds. The present review focuses on biopolymeric nanocarriers utilizing natural sources as anticancer drugs with improved tumor-targeting efficiency. This review also covers various natural anticancer compounds, the advantages and disadvantages of natural and synthetic anticancer compounds, the problems associated with natural anticancer drugs and the advantages of biopolymeric nanocarriers over synthetic nanocarriers as drug delivery agents. This review also discusses various biopolymeric nanocarriers for enhancing the controlled delivery of anticancer compounds and the future development of nanomedicines for treating cancer.

Leveraging the intratumoral microbiota to treat human cancer: are engineered exosomes an effective strategy?

Cancer remains a leading cause of global mortality. The tumor microbiota has increasingly been recognized as a key regulator of cancer onset and progression, in addition to shaping tumor responses to immunotherapy. Microbes, including viruses, bacteria, fungi, and other eukaryotic species can impact the internal homeostasis and health of humans. Research focused on the gut microflora and the intratumoral microbiome has revolutionized the current understanding of how tumors grow, progress, and resist therapeutic interventions. Even with this research, however, there remains relatively little that is known with respect to the abundance of microbes and their effects on tumors and the tumor microenvironment. Engineered exosomes are a class of artificial extracellular nanovesicles that can actively transport small molecule drugs and nucleic acids, which have the broad prospects of tumor cell therapy. The present review offers an overview of recent progress and challenges associated with the intratumoral microbiome and engineered exosomes in the context of cancer research. These discussions are used to inform the construction of a novel framework for engineered exosome-mediated targeted drug delivery, taking advantage of intratumoral microbiota diversity as a strategic asset and thereby providing new opportunities to more effectively treat and manage cancer in the clinic.

The challenge and opportunity of gut microbiota-targeted nanomedicine for colorectal cancer therapy

The gut microbiota is an integral component of the colorectal cancer (CRC) microenvironment and is intimately associated with CRC initiation, progression, and therapeutic outcomes. We reviewed recent advancements in utilizing nanotechnology for modulating gut microbiota, discussing strategies and the mechanisms underlying their design. For future nanomedicine design, we propose a 5I principle for individualized nanomedicine in CRC management.

Antioxidant, Antitumoral, Antimicrobial, and Prebiotic Activity of Magnetite Nanoparticles Loaded with Bee Pollen/Bee Bread Extracts and 5-Fluorouracil

The gut microbiota dysbiosis that often occurs in cancer therapy requires more efficient treatment options to be developed. In this concern, the present research approach is to develop drug delivery systems based on magnetite nanoparticles (MNPs) as nanocarriers for bioactive compounds. First, MNPs were synthesized through the spraying-assisted coprecipitation method, followed by loading bee pollen or bee bread extracts and an antitumoral drug (5-fluorouracil/5-FU). The loaded-MNPs were morphologically and structurally characterized through transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Dynamic Light Scattering (DLS), and thermogravimetric analysis. UV-Vis spectroscopy was applied to establish the release profiles and antioxidant activity. Furthermore, the antibacterial and antitumoral activity of loaded-MNPs was assessed. The results demonstrate that MNPs with antioxidant, antibacterial, antiproliferative, and prebiotic properties are obtained. Moreover, the data highlight the improvement of 5-FU antibacterial activity by loading on the MNPs' surface and the synergistic effects between the anticancer drug and phenolic compounds (PCs). In addition, the prolonged release behavior of PCs for many hours (70-75 h) after the release of 5-FU from the developed nanocarriers is an advantage, at least from the point of view of the antioxidant activity of PCs. Considering the enhancement of L. rhamnosus MF9 growth and antitumoral activity, this study developed promising drug delivery alternatives for colorectal cancer therapy.

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.

Recent Progress of Oral Functional Nanomaterials for Intestinal Microbiota Regulation

The gut microbiota is closely associated with human health, and alterations in gut microbiota can influence various physiological and pathological activities in the human body. Therefore, microbiota regulation has become an important strategy in current disease treatment, albeit facing numerous challenges. Nanomaterials, owing to their excellent protective properties, drug release capabilities, targeting abilities, and good biocompatibility, have been widely developed and utilized in pharmaceuticals and dietary fields. In recent years, significant progress has been made in research on utilizing nanomaterials to assist in regulating gut microbiota for disease intervention. This review explores the latest advancements in the application of nanomaterials for microbiota regulation and offers insights into the future development of nanomaterials in modulating gut microbiota.

Colorectal cancer and inulin supplementation: the good, the bad, and the unhelpful

The prebiotic inulin has been vaunted for its potential to reduce the risk of colorectal cancer. Inulin fermentation resulting in the production of short-chain fatty acids, primarily butyrate, has been reported to be associated with properties that are beneficial for gut health and has led to an increased consumption of inulin in the Western population through processed food and over-the-counter dietary supplements. However, in clinical trials, there is limited evidence of the efficacy of inulin in preventing colorectal cancer. Moreover, recent data suggest that improper inulin consumption may even be harmful for gastro-intestinal health under certain circumstances. The main objective of this review is to provide insight into the beneficial and potentially detrimental effects of inulin supplementation in the context of colorectal cancer prevention and enhancement of treatment efficacy.

Novel strategies for modulating the gut microbiome for cancer therapy

Recent advancements in genomics, transcriptomics, and metabolomics have significantly advanced our understanding of the human gut microbiome and its impact on the efficacy and toxicity of anti-cancer therapeutics, including chemotherapy, immunotherapy, and radiotherapy. In particular, prebiotics, probiotics, and postbiotics are recognized for their unique properties in modulating the gut microbiota, maintaining the intestinal barrier, and regulating immune cells, thus emerging as new cancer treatment modalities. However, clinical translation of microbiome-based therapy is still in its early stages, facing challenges to overcome physicochemical and biological barriers of the gastrointestinal tract, enhance target-specific delivery, and improve drug bioavailability. This review aims to highlight the impact of prebiotics, probiotics, and postbiotics on the gut microbiome and their efficacy as cancer treatment modalities. Additionally, we summarize recent innovative engineering strategies designed to overcome challenges associated with oral administration of anti-cancer treatments. Moreover, we will explore the potential benefits of engineered gut microbiome-modulating approaches in ameliorating the side effects of immunotherapy and chemotherapy.

Gut microbiota characteristics of colorectal cancer patients in Hubei, China, and differences with cohorts from other Chinese regions

The research on the correlation or causality between gut microbiota and the occurrence, development, and treatment of colorectal cancer (CRC) is receiving increasing emphasis. At the same time, the incidence and mortality of colorectal cancer vary among individuals and regions, as does the gut microbiota. In order to gain a better understanding of the characteristics of the gut microbiota in CRC patients and the differences between different regions, we initially compared the gut microbiota of 25 CRC patients and 26 healthy controls in the central region of China (Hubei Province) using 16S rRNA high-throughput sequencing technology. The results showed that Corynebacterium, Enterococcus, Lactobacillus, and Escherichia-Shigella were significantly enriched in CRC patients. In addition, we also compared the potential differences in functional pathways between the CRC group and the healthy control group using PICRUSt's functional prediction analysis. We then analyzed and compared it with five cohort studies from various regions of China, including Central, East, and Northeast China. We found that geographical factors may affect the composition of intestinal microbiota in CRC patients. The composition of intestinal microbiota is crucial information that influences colorectal cancer screening, early detection, and the prediction of CRC treatment outcomes. This emphasizes the importance of conducting research on CRC-related gut microbiota in various regions of China.

Engineered Microorganisms for Advancing Tumor Therapy

Engineered microorganisms have attracted significant interest as a unique therapeutic platform in tumor treatment. Compared with conventional cancer treatment strategies, engineering microorganism-based systems provide various distinct advantages, such as the intrinsic capability in targeting tumors, their inherent immunogenicity, in situ production of antitumor agents, and multiple synergistic functions to fight against tumors. Herein, the design, preparation, and application of the engineered microorganisms for advanced tumor therapy are thoroughly reviewed. This review presents a comprehensive survey of innovative tumor therapeutic strategies based on a series of representative engineered microorganisms, including bacteria, viruses, microalgae, and fungi. Specifically, it offers extensive analyses of the design principles, engineering strategies, and tumor therapeutic mechanisms, as well as the advantages and limitations of different engineered microorganism-based systems. Finally, the current challenges and future research prospects in this field, which can inspire new ideas for the design of creative tumor therapy paradigms utilizing engineered microorganisms and facilitate their clinical applications, are discussed.

Doxorubicin-based ENO1 targeted drug delivery strategy enhances therapeutic efficacy against colorectal cancer

Alpha-enolase (ENO1), a multifunctional protein with carcinogenic properties, has emerged as a promising cancer biomarker because of its differential expression in cancer and normal cells. On the basis of this characteristic, we designed a cell-targeting peptide that specifically targets ENO1 and connected it with the drug doxorubicin (DOX) by aldehyde-amine condensation. A surface plasmon resonance (SPR) assay showed that the affinity for ENO1 was stronger (KD = 2.5 µM) for the resulting cell-targeting drug, DOX-P, than for DOX. Moreover, DOX-P exhibited acid-responsive capabilities, enabling precise release at the tumor site under the guidance of the homing peptide and alleviating DOX-induced cardiotoxicity. An efficacy experiment confirmed that, the targeting ability of DOX-P toward ENO1 demonstrated superior antitumor activity against colorectal cancer than that of DOX, while reducing its toxicity to cardiomyocytes. Furthermore, in vivo metabolic distribution results indicated low accumulation of DOX-P in nontumor sites, further validating its targeting ability. These results showed that the ENO1-targeted DOX-P peptide has great potential for application in targeted drug-delivery systems for colorectal cancer therapy.

Anticancer Potential of Postbiotic Derived from Lactobacillus brevis and Lactobacillus casei: In vitro Analysis of Breast Cancer Cell Line

Breast cancer has emerged as the most widespread and dangerous type of malignancy among women worldwide. Postbiotics have recently emerged as a promising novel adjunct in breast cancer therapy, due to their immunomodulatory effects and the potential to mitigate the adverse effects of conventional treatments. This study aims to investigate the therapeutic effects of postbiotics derived from Lactobacillus brevis (CSF2) and Lactobacillus casei (CFS5), specifically examining their ability to inhibit cell proliferation and induce apoptosis in MCF-7 breast cancer cells. In the current study, the anticancer activity of the cell-free supernatant of L. brevis and L. casei was investigated against MCF-7 cells using MTT assay, flow cytometry, and qRT-PCR technique. Both bacteria showed a high potential for the induction of cell death in MCF-7 cells. However, CFS2 cytotoxicity was significantly higher than CFS5. Flow cytometry results showed significant induction of early apoptosis in cells treated with both CFS2 and CFS5 within 48 h. The induction was notably higher in cells treated with CFS2 compared to CFS5. Overall, CFS2 therapy resulted in a greater increase in BAX and CASP9 gene expression, as well as an elevated BAX/BCL2 ratio within 48 h. These findings indicate that the CFS2 treatment showed a higher level of apoptotic activity than the CFS5 treatment. High biocompatibility was demonstrated following treatment with CFS2 and CFS5. These CFSs may serve as adjunctive medications for suppressing the proliferation of cancer cells. The results of the current study highlight the potential of postbiotics in cancer treatment and suggest that supernatants may serve as effective agents for suppressing cancer cell growth and viability.

Long-term relapse-free survival enabled by integrating targeted antibacteria in antitumor treatment

The role of tumor-resident intracellular microbiota (TRIM) in carcinogenesis has sparked enormous interest. Nevertheless, the impact of TRIM-targeted antibacteria on tumor inhibition and immune regulation in the tumor microenvironment (TME) remains unexplored. Herein, we report long-term relapse-free survival by coordinating antibacteria with antitumor treatment, addressing the aggravated immunosuppression and tumor overgrowth induced by TRIM using breast and prostate cancer models. Combining Ag+ release with a Fenton-like reaction and photothermal conversion, simultaneous bacteria killing and multimodal antitumor therapy are enabled by a single agent. Free of immune-stimulating drugs, the agent restores antitumor immune surveillance and activates immunological responses. Secondary inoculation and distal tumor analysis confirm lasting immunological memory and systemic immune responses. A relapse-free survival of >700 days is achieved. This work unravels the crucial role of TRIM-targeted antibacteria in tumor inhibition and unlocks an unconventional route for immune regulation in TME and a complete cure for cancer.

Biomimetic piezoelectric nanomaterial-modified oral microrobots for targeted catalytic and immunotherapy of colorectal cancer

Lactic acid (LA) accumulation in the tumor microenvironment poses notable challenges to effective tumor immunotherapy. Here, an intelligent tumor treatment microrobot based on the unique physiological structure and metabolic characteristics of Veillonella atypica (VA) is proposed by loading Staphylococcus aureus cell membrane-coating BaTiO3 nanocubes (SAM@BTO) on the surface of VA cells (VA-SAM@BTO) via click chemical reaction. Following oral administration, VA-SAM@BTO accurately targeted orthotopic colorectal cancer through inflammatory targeting of SAM and hypoxic targeting of VA. Under in vitro ultrasonic stimulation, BTO catalyzed two reduction reactions (O2 → •O2- and CO2 → CO) and three oxidation reactions (H2O → •OH, GSH → GSSG, and LA → PA) simultaneously, effectively inducing immunogenic death of tumor cells. BTO catalyzed the oxidative coupling of VA cells metabolized LA, effectively disrupting the immunosuppressive microenvironment, improving dendritic cell maturation and macrophage M1 polarization, and increasing effector T cell proportions while decreasing regulatory T cell numbers, which facilitates synergetic catalysis and immunotherapy.

Orally Administrated Hydrogel Harnessing Intratumoral Microbiome and Microbiota-Related Immune Responses for Potentiated Colorectal Cancer Treatment

The intestinal and intratumoral microbiota are closely associated with tumor progression and response to antitumor treatments. The antibacterial or tumor microenvironment (TME)-modulating approaches have been shown to markedly improve antitumor efficacy, strategies focused on normalizing the microbial environment are rarely reported. Here, we reported the development of an orally administered inulin-based hydrogel with colon-targeting and retention effects, containing hollow MnO2 nanocarrier loaded with the chemotherapeutic drug Oxa (Oxa@HMI). On the one hand, beneficial bacteria in the colon specifically metabolized Oxa@HMI, resulting in the degradation of inulin and the generation of short-chain fatty acids (SCFAs). These SCFAs play a crucial role in modulating microbiota and stimulating immune responses. On the other hand, the hydrogel matrix underwent colon microbiota-specific degradation, enabling the targeted release of Oxa and production of reactive oxygen species in the acidic TME. In this study, we have established, for the first time, a microbiota-targeted drug delivery system Oxa@HMI that exhibited high efficiency in colorectal cancer targeting and colon retention. Oxa@HMI promoted chemotherapy efficiency and activated antitumor immune responses by intervening in the microbial environment within the tumor tissue, providing a crucial clinical approach for the treatment of colorectal cancer that susceptible to microbial invasion.

Current Advances of Nanomaterial-Based Oral Drug Delivery for Colorectal Cancer Treatment

Colorectal cancer (CRC) is a common malignant tumor, and traditional treatments include surgical resection and radiotherapy. However, local recurrence, distal metastasis, and intestinal obstruction are significant problems. Oral nano-formulation is a promising treatment strategy for CRC. This study introduces physiological and environmental factors, the main challenges of CRC treatment, and the need for a novel oral colon-targeted drug delivery system (OCDDS). This study reviews the research progress of controlled-release, responsive, magnetic, targeted, and other oral nano-formulations in the direction of CRC treatment, in addition to the advantages of oral colon-targeted nano-formulations and concerns about the oral delivery of related therapeutic agents to inspire related research.

Role of the gut microbiota in tumorigenesis and treatment

The gut microbiota is a crucial component of the intricate microecosystem within the human body that engages in interactions with the host and influences various physiological processes and pathological conditions. In recent years, the association between dysbiosis of the gut microbiota and tumorigenesis has garnered increasing attention, as it is recognized as a hallmark of cancer within the scientific community. However, only a few microorganisms have been identified as potential drivers of tumorigenesis, and enhancing the molecular understanding of this process has substantial scientific importance and clinical relevance for cancer treatment. In this review, we delineate the impact of the gut microbiota on tumorigenesis and treatment in multiple types of cancer while also analyzing the associated molecular mechanisms. Moreover, we discuss the utility of gut microbiota data in cancer diagnosis and patient stratification. We further outline current research on harnessing microorganisms for cancer treatment while also analyzing the prospects and challenges associated with this approach.

Oral probiotics microgel plus Galunisertib reduced TGF-β blockade resistance and enhanced anti-tumor immune responses in colorectal cancer

Transforming growth factor β (TGF-β), a versatile immunosuppressive cytokine, has gained increasing attention as a potential target for cancer immunotherapy. However, current strategies are constrained by tumor heterogeneity and drug resistance. Therapeutic probiotics, such as Escherichia coli Nissle1917 (EcN), not only regulate the gut microbiota to increase beneficial bacteria with anti-tumor effects, but also modulate immune factors within the body, thereby enhancing immunity. In this study, we developed an oral microgel delivery system of EcN@(CS-SA)2 by electrostatic interaction between chitosan (CS) and sodium alginate (SA), aiming to enhance its bioavailability in the gastrointestinal tract (GIT). Notably, EcN@(CS-SA)2 microgel showed a synergistic enhancement of the anti-tumor efficacy of Galunisertib (Gal, a TGF-β inhibitor) by inducing apoptosis and immunogenic cell death (ICD) in tumor cells, as well as promoting increased infiltration of CD8+ T cells into the tumor microenvironment (TME).

Application of Nanoparticles in the Diagnosis and Treatment of Colorectal Cancer

Colorectal cancer is a common malignant tumor with high morbidity and mortality rates, imposing a huge burden on both patients and the healthcare system. Traditional treatments such as surgery, chemotherapy and radiotherapy have limitations, so finding more effective diagnostic and therapeutic tools is critical to improving the survival and quality of life of colorectal cancer patients. While current tumor targeting research mainly focuses on exploring the function and mechanism of molecular targets and screening for excellent drug targets, it is crucial to test the efficacy and mechanism of tumor cell therapy that targets these molecular targets. Selecting the appropriate drug carrier is a key step in effectively targeting tumor cells. In recent years, nanoparticles have gained significant interest as gene carriers in the field of colorectal cancer diagnosis and treatment due to their low toxicity and high protective properties. Nanoparticles, synthesized from natural or polymeric materials, are NM-sized particles that offer advantages such as low toxicity, slow release, and protection of target genes during delivery. By modifying nanoparticles, they can be targeted towards specific cells for efficient and safe targeting of tumor cells. Numerous studies have demonstrated the safety, efficiency, and specificity of nanoparticles in targeting tumor cells, making them a promising gene carrier for experimental and clinical studies. This paper aims to review the current application of nanoparticles in colorectal cancer diagnosis and treatment to provide insights for targeted therapy for colorectal cancer while also highlighting future prospects for nanoparticle development.