Probiotic Strain Lactobacillus casei BL23 Prevents Colitis-Associated Colorectal Cancer

Human colitis-associated colorectal carcinoma progression is accompanied by dysbiosis with enriched pathobionts

Dysbiosis and pathobionts contribute to inflammation and the risk of colitis-associated carcinoma (CAC) in animal models, but their roles in humans with this uncommon disease are unknown. We identified microbiome differences in human CAC compared with longstanding inflammatory bowel disease (IBD) and sporadic colorectal carcinoma (CRC). Twenty-four CAC resections were matched with CRC and IBD controls. Methods included histopathology, 16S rDNA metagenomics, and pathobiont-specific qPCR. Beta diversity differed by diagnosis (PERMANOVA p = 0.007). The distinguishing taxa included Akkermansia enriched in CRC, and Bacteroides spp. enriched in IBD. The non-neoplastic mucosae presented distinct beta diversity (p = 0.005), but the CAC/CRC tumor microbiomes were similar (p = 0.7). Within metastases and margins, Enterobacteriaceae were enriched in CAC, and Bacteroidales in CRC. Pathobiont-specific qPCR confirmed a greater frequency of pks+ E. coli and enterotoxigenic Bacteroides fragilis in CAC than IBD. High alpha diversity was associated with active inflammation, advanced cancer stage, and shorter overall survival (log-rank p = 0.008). Mucosal microbiomes distinguish CAC from longstanding IBD, implicating pathobionts as markers for disease progression. Integrating our findings with prior animal model research, pathobionts promote carcinogenesis in IBD patients through genotoxicity and host cell signaling.

The impact of gut microbial short-chain fatty acids on colorectal cancer development and prevention

Cancer is a long-term illness that involves an imbalance in cellular and immune functions. It can be caused by a range of factors, including exposure to environmental carcinogens, poor diet, infections, and genetic alterations. Maintaining a healthy gut microbiome is crucial for overall health, and short-chain fatty acids (SCFAs) produced by gut microbiota play a vital role in this process. Recent research has established that alterations in the gut microbiome led to decreased production of SCFA's in lumen of the colon, which associated with changes in the intestinal epithelial barrier function, and immunity, are closely linked to colorectal cancer (CRC) development and its progression. SCFAs influence cancer progression by modifying epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNA functions thereby affecting tumor initiation and metastasis. This suggests that restoring SCFA levels in colon through microbiota modulation could serve as an innovative strategy for CRC prevention and treatment. This review highlights the critical relationship between gut microbiota and CRC, emphasizing the potential of targeting SCFAs to enhance gut health and reduce CRC risk.

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

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

Gerobiotics: Exploring the Potential and Limitations of Repurposing Probiotics in Addressing Aging Hallmarks and Chronic Diseases

As unhealthy aging continues to rise globally, there is a pressing need for effective strategies to promote healthy aging, extend health span, and address aging-related complications. Gerobiotics, an emerging concept in geroscience, offers a novel approach to repurposing selective probiotics, postbiotics, and parabiotics to modulate key aging processes and enhance systemic health. This review explores recent advancements in gerobiotics research, focusing on their role in targeting aging hallmarks, regulating longevity-associated pathways, and reducing risks of multiple age-related chronic conditions. Despite their promise, significant challenges remain, including optimizing formulations, ensuring safety and efficacy across diverse populations, and achieving successful clinical translation. Addressing these gaps through rigorous research, well-designed clinical trials, and advanced biotechnologies can establish gerobiotics as a transformative intervention for healthy aging and chronic disease prevention.

Innovative strategies for the rapid restoration of intestinal function in patients undergoing abdominal surgery: use of probiotics. Pilot study of 15 patients

BACKGROUND

The clinical value of probiotics in patients undergoing abdominal surgery, particularly colorectal surgery, remains uncertain despite their well-documented health benefits. This pilot randomized controlled trial aimed to assess the effects of perioperative and postoperative oral administration of two probiotics, Clostridium butyricum CBM588® and Bifidobacterium longum ES1, on immune function, systemic inflammatory response, postoperative infections, and recovery after colorectal surgery.

METHODS

Fifteen adult patients underwent colorectal resection, with two groups receiving probiotics and one acting as a control. Blood and fecal samples were collected, and clinical parameters were assessed.

RESULTS

Results showed the safety of probiotics, resistance to antibiotics and gastric acid, and potential benefits in reducing postoperative infections and intestinal inflammation.

CONCLUSIONS

Future trials should provide more conclusive evidence on the efficacy and safety of perioperative probiotic administration in colorectal surgery, aiming for improved patient outcomes and reduced healthcare costs.

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

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

Evaluation of Risk Factors Causing Diagnostic Delay in Non-steroidal Anti-inflammatory Drug-exacerbated Respiratory Disease

OBJECTIVE

Non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) can be difficult to diagnose due to the heterogeneity of phenotypes and a lack of validated in vitro tests. This study aimed to provide a better understanding of the course of N-ERD disease, analyze whether there was a delay in clinical diagnosis, and explore the factors that might cause diagnostic delay.

MATERIAL AND METHODS

This observational, cross-sectional, study included patients aged over 18. The time taken by clinicians to diagnose N-ERD was recorded as the clinician diagnosis time, while the time taken by patients to complete the N-ERD triad was recorded as the actual diagnosis time. A difference of six months or longer between actual diagnosis and clinician diagnosis times was accepted as diagnostic delay. Statistical analyses were performed to ascertain the parameters that could cause this delay.

RESULTS

The study included a total of 107 patients diagnosed with N-ERD. The patients had been diagnosed with chronic rhinosinusitis with nasal polyps, asthma, and NSAID hypersensitivity for an average duration of 14.9±9.6, 14.3±9.9, and 11.7±9.3 years, respectively. Thirty-nine (36.4%) of the patients had a delayed diagnosis. The mean delay in the diagnosis of N-ERD was 7.4±6.6 (2.0-12.0) years. Delayed diagnosis showed a correlation with thyroid dysfunction (P = 0.021), while it did not have a significant relationship with the remaining factors.

CONCLUSION

The results of this study have indicated delays in diagnosing N-ERD patients and emphasized the need for adequately recognizing the disease to initiate timely, appropriate treatment.

Research progress on anti-inflammatory drugs for preventing colitis-associated colorectal cancer

Colorectal cancer (CRC) is the third most prevalent malignancy worldwide. Inflammatory bowel diseases (IBD) encompass a group of chronic intestinal inflammatory disorders, including ulcerative colitis (UC) and Crohn's disease (CD). As a chronic inflammatory bowel disease, UC may persist and elevate the risk of malignancy, thereby contributing to the development of colorectal cancer, known as colitis-associated colorectal cancer (CAC). Chronic intestinal inflammation is a significant risk factor for colorectal cancer, and the incidence of colitis-associated colorectal cancer continues to rise. Current studies indicate that therapeutic agents targeting inflammation and key molecules or signaling pathways involved in the inflammatory process may effectively prevent and treat CAC. Mechanistically, drugs with anti-inflammatory or modulatory effects on inflammation-related pathways may exert preventive or therapeutic roles in CAC through multiple molecules or signaling pathways implicated in tumor development. Moreover, the development or discovery of novel drugs with anti-inflammatory properties to prevent or delay CAC progression is becoming an emerging field in fighting against CRC. Therefore, this review aims to summarize drugs that prevent or delay CAC through modulating anti-inflammatory pathways. First, we categorize the published studies exploring the role of anti-inflammatory in CAC prevention. Second, we highlight the specific molecular mechanisms underlying the anti-inflammatory effect of the above-mentioned drugs. Finally, we discuss the potential and challenges associated with clinical application of these drugs. It is hoped that this review offers new insights for further drug development and mechanism exploration.

Ameliorative effects of insoluble dietary fiber and its bound polyphenols from adzuki bean seed coat on acute murine colitis induced by DSS: The inflammatory response, intestinal barrier and gut microbiota

The incidence of ulcerative colitis (UC) is closely associated with dietary fiber (DF) intake. This study aims to evaluate the ameliorative effects of insoluble dietary fiber from adzuki bean seed coat (AIDF) on dextran sulfate sodium (DSS)-induced UC in mice, both with and without bound polyphenols (BPs). We employed a model based on the "remove/backfill" of components. Compared to dephenolized dietary fiber (AIDF-DF) and AIDF-DF with replaced BPs (AIDF-BP), AIDF was found to effectively reduce the splenic index, alleviate colonic histopathological damage, lower serum levels of inflammatory mediators (TNF-α, IL-1β, IFN-γ, IL-6), decrease activities of LPS, DAO, MPO, and iNOS, regulate intestinal tight junction (TJ) mRNA and protein expression, and restore the integrity of the colonic epithelial cell barrier. AIDF mitigated the inflammatory response in UC by inhibiting the TLR4/NF-κB inflammatory signaling pathway. It increased the abundance of beneficial gut microbiota (e.g., Akkermansia, Verrucomicrobiota) while reducing the abundance of harmful bacteria (e.g., Proteobacteria), thereby alleviating intestinal disturbances in DSS-induced colitis in mice. In conclusion, the presence of BPs in AIDF plays a critical role in attenuating DSS-induced UC in mice.

Gut microbiota in cancer initiation, development and therapy

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

Health-Promoting and Functional Properties of Fermented Milk Beverages with Probiotic Bacteria in the Prevention of Civilization Diseases

BACKGROUND/OBJECTIVES

There is scattered information in the scientific literature regarding the characterization of probiotic bacteria found in fermented milk beverages and the beneficial effects of probiotic bacteria on human health. Our objective was to gather the available information on the use of probiotic bacteria in the prevention of civilization diseases, with a special focus on the prevention of obesity, diabetes, and cancer.

METHODS

We carried out a literature review including the following keywords, either individually or collectively: lactic acid bacteria; probiotic bacteria; obesity; lactose intolerance; diabetes; cancer protection; civilization diseases; intestinal microbiota; intestinal pathogens.

RESULTS

This review summarizes the current state of knowledge on the use of probiotic bacteria in the prevention of civilization diseases. Probiotic bacteria are a set of living microorganisms that, when administered in adequate amounts, exert a beneficial effect on the health of the host and allow for the renewal of the correct quantitative and qualitative composition of the microbiota. Probiotic bacteria favorably modify the composition of the intestinal microbiota, inhibit the development of intestinal pathogens, prevent constipation, strengthen the immune system, and reduce symptoms of lactose intolerance. As fermented milk beverages are an excellent source of probiotic bacteria, their regular consumption can be a strong point in the prevention of various types of civilization diseases.

CONCLUSIONS

The presence of lactic acid bacteria, including probiotic bacteria in fermented milk beverages, reduces the incidence of obesity and diabetes and serves as a tool in the prevention of cancer diseases.

Microbiome in urologic neoplasms: focusing on tumor immunity

Urological tumors are an important disease affecting global human health, and their pathogenesis and treatment have been the focus of medical research. With the in - depth study of microbiomics, the role of the microbiome in urological tumors has gradually attracted attention. However, the current research on tumor - associated microorganisms mostly focuses on one type or one site, and currently, there is a lack of attention to the microbiome in the immunity and immunotherapy of urological tumors. Therefore, in this paper, we systematically review the distribution characteristics of the microbiome (including microorganisms in the gut, urine, and tumor tissues) in urologic tumors, the relationship with disease prognosis, and the potential mechanisms of microbial roles in immunotherapy. In particular, we focus on the molecular mechanisms by which the microbiome at different sites influences tumor immunity through multiple "messengers" and pathways. We aim to further deepen the understanding of microbiome mechanisms in urologic tumors, and also point out the direction for the future development of immunotherapy for urologic tumors.

Significant difference in gut microbiota Bifidobacterium species but not Lactobacillus species in colorectal cancer patients in comparison with healthy volunteers using quantitative real-time PCR

BACKGROUND

Colorectal cancer (CRC), with a growing incidence trend, is one of the most diagnosed cancers and the second cause of cancer-related deaths worldwide. The literature has frequently focused attention on the correlation between the gut microbiota imbalance and CRC. The genera Lactobacillus and Bifidobacterium have recently received increasing attention because of their potential in restoring alterations in the gut microflora. Therefore, this study aimed to quantitatively evaluate the presence of lactobacilli and bifidobacterial strains in the fecal samples of CRC patients compared to healthy volunteers.

METHODS

From 2018 to 2019, 25 confirmed CRC patients and 25 age- and gender-matched control subjects were enrolled in the study. Bacterial DNA was extracted from the fecal samples and the presence of lactobacilli and bifidobacterial strains were quantitatively determined using quantitative real-time PCR using genus-specific 16S rDNA primers.

RESULTS

A significant decline in the abundance of bifidobacteria in CRC patients compared to healthy individuals (p value<0.003) was observed; however, no significant difference was observed between the two groups regarding the abundance of lactobacilli (p value<0.163). Correlation analysis showed a positive association between the lack of genetic history of CRC and the numbers of gut bifidobacteria and lactobacilli.

CONCLUSION

As a putative gut probiotic, depletion of bifidobacteria showed significant correlation to the development and progression of CRC; therefore, therapeutic use of these probiotic bacteria could be considered a possible adjuvant approach in disease management through modulation of the microbiota.

Immunomodulation aspects of gut microbiome-related interventional strategies in colorectal cancer

Colorectal cancer (CRC), the third most common cancer worldwide, develops mainly due to the accumulation of genetic and epigenetic changes over many years. Substantial evidence suggests that gut microbiota plays a significant role in the initiation, progression, and control of CRC, depending on the balance between beneficial and pathogenic microorganisms. Nonetheless, gut microbiota composition by regulating the host immune response may either promote or inhibit CRC. Thus, modification of gut microbiota potentially impacts clinical outcomes of immunotherapy. Previous studies have indicated that therapeutic strategies such as probiotics, prebiotics, and postbiotics enhance the intestinal immune system and improve the efficacy of immunotherapeutic agents, potentially serving as a complementary strategy in cancer immunotherapy. This review discusses the role of the gut microbiota in the onset and development of CRC in relation to the immune response. Additionally, we focus on the effect of strategies manipulating gut microbiome on the immune response and efficacy of immunotherapy against CRC. We demonstrate that manipulation of gut microbiome can enhance immune response and outcomes of immunotherapy through downregulating Treg cells and other immunosuppressive cells while improving the function of T cells within the tumor; however, further research, especially clinical trials, are needed to evaluate its efficacy in cancer treatment.

Mechanism of probiotics in the intervention of colorectal cancer: a review

The human microbiome interacts with the host mainly in the intestinal lumen, where putrefactive bacteria are suggested to promote colorectal cancer (CRC). In contrast, probiotics and their isolated components and secreted substances, display anti-tumor properties due to their ability to modulate gut microbiota composition, promote apoptosis, enhance immunity, resist oxidation and alter metabolism. Probiotics help to form a solid intestinal barrier against damaging agents via altering the gut microbiota and preventing harmful microbes from colonization. Probiotic strains that specifically target essential proteins involved in the process of apoptosis can overcome CRC resistance to apoptosis. They can increase the production of anti-inflammatory cytokines, essential in preventing carcinogenesis, and eliminate cancer cells by activating T cell-mediated immune responses. There is a clear indication that probiotics optimize the antioxidant system, decrease radical generation, and detect and degrade potential carcinogens. In this review, the pathogenic mechanisms of pathogens in CRC and the recent insights into the mechanism of probiotics in CRC prevention and therapy are discussed to provide a reference for the actual application of probiotics in CRC.

Crosstalk between COVID-19 and the gut-brain axis: a gut feeling

The microbes in the gut are crucial for maintaining the body's immune system and overall gut health. However, it is not fully understood how an unstable gut environment can lead to more severe cases of SARS-CoV-2 infection. The gut microbiota also plays a role in the gut-brain axis and interacts with the central nervous system through metabolic and neuroendocrine pathways. The interaction between the microbiota and the host's body involves hormonal, immune, and neural pathways, and any disruption in the balance of gut bacteria can lead to dysbiosis, which contributes to pathogen growth. In this context, we discuss how dysbiosis could contribute to comorbidities that increase susceptibility to SARS-CoV-2. Probiotics and fecal microbiota transplantation have successfully treated infectious and non-infectious inflammatory-related diseases, the most common comorbidities. These treatments could be adjuvant therapies for COVID-19 infection by restoring gut homeostasis and balancing the gut microbiota.

Harnessing the power of probiotic strains in functional foods: nutritive, therapeutic, and next-generation challenges

Functional foods have become an essential element of the diet in developed nations, due to their health benefits and nutritive values. Such food products are only called functional if they, "In addition to basic nutrition, have valuable effects on one or multiple functions of the human body, thereby enhancing general and physical conditions and/or reducing the risk of disease progression". Functional foods are currently one of the most extensively researched areas in the food and nutrition sciences. They are fortified and improved food products. Presently, probiotics are regarded as the most significant and commonly used functional food product. Diverse probiotic food products and supplements are used according to the evidence that supports their strength, functionality, and recommended dosage. This review provides an overview of the current functional food market, with a particular focus on probiotic microorganisms as pivotal functional ingredients. It offers insights into current research endeavors and outlines potential future directions in the field.

Exploring the Relationship Between Diet, Lifestyle and Gut Microbiome in Colorectal Cancer Development: A Recent Update

Colorectal cancer (CRC) is one of the major causes of cancer-related mortality worldwide. Despite advances in treatment modalities, its prevalence continues to rise, notably among younger populations. Unhealthy dietary habits, sedentary routines, and obesity have been identified as one of the key contributors to the development of colorectal cancer, apart from genetic and epigenetic modifications. Recognizing the profound impact of diet and lifestyle on the intricate gut microbiota ecosystem offers a promising avenue for understanding CRC development and its treatment. Gut dysbiosis, characterized by imbalances favoring harmful microbes over beneficial ones, has emerged as a defining feature of CRC. Changes in diet and lifestyle can profoundly alter the composition of gut microbes and the metabolites they produce, potentially contributing to CRC onset. Focusing on recent evidence, this review discussed various dietary factors, such as high consumption of red and processed meats and low fiber intake, and lifestyle factors, including obesity, lack of physical activity, smoking, and excessive alcohol consumption, that influence the gut microbiome composition and elevate CRC risk.

Milk and Lacticaseibacillus paracasei BL23 effects on intestinal responses in a murine model of colitis

Probiotic-containing fermented dairy foods have the potential to benefit human health, but the importance of the dairy matrix for efficacy remains unclear. We investigated the capacity of Lacticaseibacillus paracasei BL23 in phosphate-buffered saline (BL23-PBS), BL23-fermented milk (BL23-milk), and milk to modify intestinal and behavioral responses in a dextran sodium sulfate (DSS, 3% wt/vol) mouse model of colitis. Significant sex-dependent differences were found such that female mice exhibited more severe colitis, greater weight loss, and higher mortality rates. Sex differences were also found for ion transport ex vivo, colonic cytokine and tight junction gene expression, and fecal microbiota composition. Measurements of milk and BL23 effects showed BL23-PBS consumption improved weight recovery in females, whereas milk resulted in better body weight recovery in males. Occludin and Claudin-2 gene transcript levels indicated barrier function was impaired in males, but BL23-milk was still found to improve colonic ion transport in those mice. Proinflammatory and anti-inflammatory gene expression levels were increased in both male and female mice fed BL23, and to a more variable extent, milk, compared with controls. The female mouse fecal microbiota contained high proportions of Akkermansia (average of 18.1%) at baseline, and females exhibited more changes in gut microbiota composition following BL23 and milk intake. Male fecal microbiota harbored significantly more Parasutterella and less Blautia and Roseburia after DSS treatment, independent of BL23 or milk consumption. These findings show the complex interplay between dietary components and sex-dependent responses in mitigating inflammation in the digestive tract.NEW & NOTEWORTHY Sex-dependent responses to probiotic Lacticaseibacillus paracasei and milk and the potential of the dairy matrix to enhance probiotic protection against colitis in this context have not been previously explored. Female mice were more sensitive than males to colonic injury, and neither treatment effectively alleviated inflammation in both sexes. These sex-dependent responses may result from differences in the higher baseline proportions of Akkermansia in the gut microbiome of female mice.

Critical role of the gut microbiota in immune responses and cancer immunotherapy

The gut microbiota plays a critical role in the progression of human diseases, especially cancer. In recent decades, there has been accumulating evidence of the connections between the gut microbiota and cancer immunotherapy. Therefore, understanding the functional role of the gut microbiota in regulating immune responses to cancer immunotherapy is crucial for developing precision medicine. In this review, we extract insights from state-of-the-art research to decipher the complicated crosstalk among the gut microbiota, the systemic immune system, and immunotherapy in the context of cancer. Additionally, as the gut microbiota can account for immune-related adverse events, we discuss potential interventions to minimize these adverse effects and discuss the clinical application of five microbiota-targeted strategies that precisely increase the efficacy of cancer immunotherapy. Finally, as the gut microbiota holds promising potential as a target for precision cancer immunotherapeutics, we summarize current challenges and provide a general outlook on future directions in this field.

The role of gut microbiota and probiotics in preventing, treating, and boosting the immune system in colorectal cancer

The gut microbiome plays a significant role in developing colorectal cancer (CRC). The gut microbiome usually acts as a protective barrier against harmful pathogens and infections in the intestine, while also regulating inflammation by affecting the human immune system. The gut microbiota and probiotics play a role not only in intestinal inflammation associated with tumor formation but also in regulating anti-cancer immune response. As a result, they associated with tumor progression and the effectiveness of anti-cancer therapies. Research indicates that gut microbiota and probiotics can be used as biomarkers to predict the impact of immunotherapy and enhance its efficacy in treating CRC by regulating it. This review examines the importance of gut microbiota and probiotics in the development and progression of CRC, as well as their synergistic impact on anti-cancer treatments.

Influence of Microbiota on Tumor Immunotherapy

The role of the microbiome in immunotherapy has recently garnered substantial attention, with molecular studies and clinical trials providing emerging evidence on the pivotal influence of the microbiota in enhancing therapeutic outcomes via immune response modulation. However, the impact of microbial communities can considerably vary across individuals and different immunotherapeutic approaches, posing prominent challenges in harnessing their potential. In this comprehensive review, we outline the current research applications in tumor immunotherapy and delve into the possible mechanisms through which immune function is influenced by microbial communities in various body sites, encompassing those in the gut, extraintestinal barrier, and intratumoral environment. Furthermore, we discuss the effects of diverse microbiome-based strategies, including probiotics, prebiotics, fecal microbiota transplantation, and the targeted modulation of specific microbial taxa, and antibiotic treatments on cancer immunotherapy. All these strategies potentially have a profound impact on immunotherapy and pave the way for personalized therapeutic approaches and predictive biomarkers.

Intestinal Dysbiosis: Microbial Imbalance Impacts on Colorectal Cancer Initiation, Progression and Disease Mitigation

The human gastrointestinal tract houses a diverse range of microbial species that play an integral part in many biological functions. Several preclinical studies using germ-free mice models have demonstrated that the gut microbiome profoundly influences carcinogenesis and progression. Colorectal cancer appears to be associated with microbial dysbiosis involving certain bacterial species, including F. nucleatum, pks+ E. coli, and B. fragilis, with virome commensals also disrupted in patients. A dysbiosis toward these pro-carcinogenic species increases significantly in CRC patients, with reduced numbers of the preventative species Clostridium butyicum, Roseburia, and Bifidobacterium evident. There is also a correlation between Clostridium infection and CRC. F. nucleatum, in particular, is strongly associated with CRC where it is associated with therapeutic resistance and poor outcomes in patients. The carcinogenic mode of action of pathogenic bacteria in CRC is a result of genotoxicity, epigenetic alterations, ROS generation, and pro-inflammatory activity. The aim of this review is to discuss the microbial species and their impact on colorectal cancer in terms of disease initiation, progression, and metastasis. The potential of anticancer peptides as anticancer agents or adjuvants is also discussed, as novel treatment options are required to combat the high levels of resistance to current pharmaceutical options.

Colorectal cancer and microbiota: systematic review

Introduction

The gut microbiome maintains the mucus membrane barrier's integrity, and it is modulated by the host's immune system.

Aim

To detect the effect of microbiota modulation using probiotics, prebiotics, symbiotics, and natural changes on colorectal cancers (CRCs).

Methods

A PubMed search was conducted to retrieve the original and in vivo articles published in English language from 2010 until 2021 containing the following keywords: 1) CRCs, 2) CRCs treatment (i.e. surgical, chemotherapy, radiotherapy and/or immunotherapy), and 3) microbiota probiotic(s), prebiotic(s), symbiotic(s), dysbiosis and/or nutritional treatment. A total of 198 PubMed records/articles were initially identified. 108 articles were excluded at the initial screening, and another 29 articles were excluded after reviewing the abstracts, and finally 61 studies were analysed for this systematic review.

Results

The gut microbiota metabolites and (SCFAs) short-chain fatty acids (i.e. acetate and butyrate) have a protective effect against CRCs. SCFAs reduce the inflammatory cytokines, inhibit colonocyte proliferation, and promote malignant cell apoptosis. Butyrate maintains the integrity of the mucus membrane barrier and reduces intestinal mucosal inflammation. Reduced butyric acid level and increased inflammatory cytokines were observed after reduced Bacteroides fragilis and Bacteroides vulgatus species in the colon. Akkermansia muciniphila bacterium decreased in patients with CRCs.

Conclusions

Prebiotics (i.e. inulin and resistant starch, SCFAs producers) and consumption of unprocessed plant products are useful for developing and maintaining healthy gut microbiota. The pro-, pre- and/or symbiotics may be useful when carefully selected for CRC patients, to restore beneficial gut microbiota and support treatment efficacy.

Gut Microbiome-Colorectal Cancer Relationship

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

The Microbiome Modulates the Immune System to Influence Cancer Therapy

The gut microbiota composition can affect the tumor microenvironment and its interaction with the immune system, thereby having implications for treatment predictions. This article reviews the studies available to better understand how the gut microbiome helps the immune system fight cancer. To describe this fact, different mechanisms and approaches utilizing probiotics to improve advancements in cancer treatment will be discussed. Moreover, not only calorie intake but also the variety and quality of diet can influence cancer patients' immunotherapy treatment because dietary patterns can impair immunological activities either by stimulating or suppressing innate and adaptive immunity. Therefore, it is interesting and critical to understand gut microbiome composition as a biomarker to predict cancer immunotherapy outcomes and responses. Here, more emphasis will be given to the recent development in immunotherapies utilizing microbiota to improve cancer therapies, which is beneficial for cancer patients.

Gut microbiota reshapes cancer immunotherapy efficacy: Mechanisms and therapeutic strategies

Gut microbiota is essential for maintaining local and systemic immune homeostasis in the presence of bacterial challenges. It has been demonstrated that microbiota play contrasting roles in cancer development as well as anticancer immunity. Cancer immunotherapy, a novel anticancer therapy that relies on the stimulation of host immunity, has suffered from a low responding rate and incidence of severe immune-related adverse events (irAEs). Previous studies have demonstrated that the diversity and composition of gut microbiota were associated with the heterogeneity of therapeutic effects. Therefore, alteration in microbiota taxa can lead to improved clinical outcomes in immunotherapy. In this review, we determine whether microbiota composition or microbiota-derived metabolites are linked to responses to immunotherapy and irAEs. Moreover, we discuss various approaches to improve immunotherapy efficacy or reduce toxicities by modulating microbiota composition.

Role of the intestinal microbiome and its therapeutic intervention in cardiovascular disorder

The gut microbiome is a heterogeneous population of microbes comprising viruses, bacteria, fungi, and protozoa. Such a microbiome is essential for sustaining host equilibrium, and its impact on human health can be altered by a variety of factors such as external variables, social behavior, age, nutrition, and genetics. Gut microbes' imbalances are related to a variety of chronic diseases including cancer, obesity, and digestive disorders. Globally, recent findings show that intestinal microbes have a significant role in the formation of cardiovascular disease (CVD), which is still the primary cause of fatalities. Atherosclerosis, hypertension, diabetes, inflammation, and some inherited variables are all cardiovascular risk variables. However, studies found correlations between metabolism, intestinal flora, and dietary intake. Variations in the diversity of gut microbes and changes in their activity are thought to influence CVD etiology. Furthermore, the gut microbiota acts as an endocrine organ, producing bioactive metabolites such as TMA (trimethylamine)/TMAO (trimethylamine N-oxide), SCFA (short-chain fatty acids), and bile acids, which have a substantial impact on host wellness and disease by multiple mechanisms. The purpose of this overview is to compile current evidence highlighting the intricate links between gut microbiota, metabolites, and the development of CVD. It focuses on how intestinal dysbiosis promotes CVD risk factors such as heart failure, hypertension, and atherosclerosis. This review explores the normal physiology of intestinal microbes and potential techniques for targeting gut bacteria for CVD treatment using various microbial metabolites. It also examines the significance of gut bacteria in disease treatment, including supplements, prebiotics, probiotics, antibiotic therapies, and fecal transplantation, which is an innovative approach to the management of CVD. As a result, gut bacteria and metabolic pathways become increasingly attractive as potential targets for CVD intervention.

A cell-free, biomimetic hydrogel based on probiotic membrane vesicles ameliorates wound healing

Probiotic bacteria, such as Lactobacilli, have been shown to elicit beneficial effects in various tissue regeneration applications. However, their formulation as living bacteria is challenging, and their therapeutic use as proliferating microorganisms is especially limited in immunocompromised patients. Here, we propose a new therapeutic avenue to circumvent these shortcomings by developing a bacteriomimetic hydrogel based on membrane vesicles (MVs) produced by Lactobacilli. We coupled MVs from Lactobacillus plantarum and Lactobacillus casei, respectively, to the surface of synthetic microparticles, and embedded those bacteriomimetics into a pharmaceutically applicable hydrogel matrix. The wound microenvironment changes during the wound healing process, including adaptions of the pH and changes of the oxygen supply. We thus performed proteomic characterization of the MVs harvested under different culture conditions and identified characteristic proteins related to the biological effect of the probiotics in every culture state. In addition, we highlight a number of unique proteins expressed and sorted into the MVs for every culture condition. Using different in vitro models, we demonstrated that increased cell migration and anti-inflammatory effects of the bacteriomimetic microparticles were dependent on the culture condition of the secreting bacteria. Finally, we demonstrated the bacteriomimetic hydrogel's ability to improve healing in an in vivo mouse full-thickness wound model. Our results create a solid basis for the future application of probiotic-derived vesicles in the treatment of inflammatory dispositions and stimulates the initiation of further preclinical trials.

Lactobacillus casei combined with Lactobacillus reuteri alleviate pancreatic cancer by inhibiting TLR4 to promote macrophage M1 polarization and regulate gut microbial homeostasis

BACKGROUND

Pancreatic cancer is a highly lethal disease with no effective treatments. Lactobacillus casei (L. casei) and Lactobacillus reuteri (L. reuteri) exhibited therapeutic effects on several cancers, but their roles in pancreatic cancer are unknown. This study aims to explore how L. casei & L. reuteri influence pancreatic cancer and the underlying mechanisms.

METHODS

Pancreatic cancer cells were treated with L. casei & L. reuteri and co-cultured with macrophages in a transwell system in vitro. Pancreatic cancer xenograft model was established and L. casei & L. reuteri was used to treat mice in vivo. MTT, CCK-8 assay or immunohistochemical staining were used to determine the proliferation of pancreatic cancer cells or tumor tissues. Transwell assay was applied to test the migration and invasion of pancreatic cells. RT-qPCR was utilized to assess TLR4 and MyD88 expressions in pancreatic cells or tumor tissues. WB, immunofluorescence staining, or flow cytometry was used to evaluate the M1/M2 polarization of macrophages. Besides, the composition of gut microbiota of tumor-bearing mice was determined by 16 S rRNA sequencing, and ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) untargeted metabolomics was used to evaluate the metabolic profiles of feces.

RESULTS

L. casei & L. reuteri inhibited the proliferation, migration, invasion of pancreatic cancer cells and pancreatic cancer cell-induced M2 polarization of macrophages by suppressing TLR4. Meanwhile, L. casei & L. reuteri repressed pancreatic cancer growth and promoted M1 macrophage polarization. Besides, L. casei & L. reuteri reduced fecal Alloprevotella and increased fecal azelate and glutamate in nude mice, while TLR4 inhibitor TAK-242 increased Clostridia UCG-014, azelate, uridine, methionine sulfoxide, oxypurinol, and decreased glyceryl monoester in the feces of pancreatic tumor-bearing mice. Fecal oxypurinol and glyceryl monoester levels were positively or negatively associated with gut Clostridia UCG-014 abundance, respectively.

CONCLUSION

L. casei & L. reuteri alleviate pancreatic cancer by inhibiting TLR4 to promote macrophage M1 polarization and regulate gut microbial homeostasis.

Colitis-associated carcinogenesis: crosstalk between tumors, immune cells and gut microbiota

Colorectal cancer (CRC) is the third most common cancer worldwide. One of the main causes of colorectal cancer is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). Intestinal epithelial cells (IECs), intestinal mesenchymal cells (IMCs), immune cells, and gut microbiota construct the main body of the colon and maintain colon homeostasis. In the development of colitis and colitis-associated carcinogenesis, the damage, disorder or excessive recruitment of different cells such as IECs, IMCs, immune cells and intestinal microbiota play different roles during these processes. This review aims to discuss the various roles of different cells and the crosstalk of these cells in transforming intestinal inflammation to cancer, which provides new therapeutic methods for chemotherapy, targeted therapy, immunotherapy and microbial therapy.

Potential effects of gut microbiota on host cancers: focus on immunity, DNA damage, cellular pathways, and anticancer therapy

The symbiotic bacteria that live in the human gut and the metabolites they produce have long influenced local and systemic physiological and pathological processes of the host. The gut microbiota are increasingly being recognized for its impact on a range of human diseases, including cancer, it may play a key role in the occurrence, progression, treatment, and prognosis of many types of cancer. Understanding the functional role of the gut microbiota in cancer is crucial for the development of the era of personalized medicine. Here, we review recent advances in research and summarize the important associations and clear experimental evidence for the role of the gut microbiota in a variety of human cancers, focus on the application and possible challenges associated with the gut microbiota in antitumor therapy. In conclusion, our research demonstrated the multifaceted mechanisms of gut microbiota affecting human cancer and provides directions and ideas for future clinical research.

Impact of Oral Administration of Lactiplantibacillus plantarum Strain CNCM I-4459 on Obesity Induced by High-Fat Diet in Mice

Recent evidence suggests that some lactobacilli strains, particularly Lactiplantibacillus plantarum, have a beneficial effect on obesity-associated syndromes. Several studies have investigated probiotic challenges in models of high-fat diet (HFD)-induced obesity, specifically with respect to its impact on hepatic and/or adipocyte metabolism, gut inflammation and epithelial barrier integrity, and microbiota composition. However, only a few studies have combined these aspects to generate a global understanding of how probiotics exert their protective effects. Here, we used the probiotic strain L. plantarum CNCM I-4459 and explored its impact on a mouse model of HFD-induced obesity. Briefly, mice were administered 1 × 109 CFUs/day and fed HFD for 12 weeks. Treatment with this strain improved insulin sensitivity by lowering serum levels of fasting glucose and fructosamine. Administration of the probiotic also affected the transport and metabolism of glucose, resulting in the downregulation of the hepatic Glut-4 and G6pase genes. Additionally, L. plantarum CNCM I-4459 promoted a decreased concentration of LDL-c and modulated hepatic lipid metabolism (downregulation of Fasn, Plin, and Cpt1α genes). Probiotic treatment also restored HFD-disrupted intestinal microbial composition by increasing microbial diversity and lowering the ratio of Firmicutes to Bacteroidetes. In conclusion, this probiotic strain represents a potential approach for at least partial restoration of the glucose sensitivity and lipid disruption that is associated with obesity.

Oral Microbiota: The Influences and Interactions of Saliva, IgA, and Dietary Factors in Health and Disease

Recent advances in metagenomic analyses have made it easier to analyze microbiota. The microbiota, a symbiotic community of microorganisms including bacteria, archaea, fungi, and viruses within a specific environment in tissues such as the digestive tract and skin, has a complex relationship with the host. Recent studies have revealed that microbiota composition and balance particularly affect the health of the host and the onset of disease. Influences such as diet, food preferences, and sanitation play crucial roles in microbiota composition. The oral cavity is where the digestive tract directly communicates with the outside. Stable temperature and humidity provide optimal growth environments for many bacteria. However, the oral cavity is a unique environment that is susceptible to pH changes, salinity, food nutrients, and external pathogens. Recent studies have emphasized the importance of the oral microbiota, as changes in bacterial composition and balance could contribute to the development of systemic diseases. This review focuses on saliva, IgA, and fermented foods because they play critical roles in maintaining the oral bacterial environment by regulating its composition and balance. More attention should be paid to the oral microbiota and its regulatory factors in oral and systemic health.

Association between Probiotics and Modulation of Gut Microbial Community Composition in Colorectal Cancer Animal Models: A Systematic Review (2010-2021)

Background

Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies and is considered the third major cause of mortality globally. Probiotics have been shown to protect against the CRC cascade in numerous studies.

Aims

The goal of this systematic review was to gather the preclinical studies that examined the impact of probiotics on the alteration of gut microbiota profiles (bacterial communities) and their link to colorectal carcinogenesis as well as the potential processes involved.

Methods

The search was performed using Scopus, Web of Science, and PubMed databases. Five parameters were used to develop search filters: "probiotics," "prebiotics," "synbiotics," "colorectal cancer," and "animal model."

Results

Of the 399 full texts that were screened, 33 original articles met the inclusion criteria. According to the current findings, probiotics/synbiotics could significantly attenuate aberrant crypt foci (ACF) formation, restore beneficial bacteria in the microbiota population, increase short-chain fatty acids (SCFAs), and change inflammatory marker expression.

Conclusions

The present systematic review results indicate that probiotics could modulate the gut microbial composition and immune regulation to combat/inhibit CRC in preclinical models. However, where the evidence is more limited, it is critical to transfer preclinical research into clinical data.

Relevance of tumor microbiome in cancer incidence, prognosis, and its clinical implications in therapeutics

The microbiota is garnering progressively greater consideration as an essential facet of the tumor microenvironment that regulates tumor proliferation and affects cancer prognosis. Microbial populations that inhabit different body locations are involved in the carcinogenesis and tumor progression of their corresponding malignancies. It has been learned that the microbial populations primarily thriving within tumors are tumor-type specific. Mechanistic studies have revealed that the tumor-associated microbiota contributes to playing a pivotal role in the establishment of the tumor microenvironment, regulation of local immunity, modulation of tumor cell biology, and directly influences the therapeutic efficacy of drug treatment for tumors. This review article incorporates the pertinent studies on recent advancements in tumor microbiome studies, the interplay between the intratumor microbiota and cancer, and, discusses their role and mechanism of action in the emergence and treatment of cancer, and their relationship to clinical characteristics.

Potential Ability of Probiotics in the Prevention and Treatment of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer in the world, and its incidence rate and mortality are on the rise in many countries. In recent years, with the improvement of economic conditions, people's living habits have changed, including lack of physical activity, poor diet patterns and circadian rhythm disorder. These risk factors can change the colon environment and the composition of intestinal microbiota. This state is called intestinal imbalance, which increases the risk of cancer. Probiotics, a class of microorganisms that help maintain gut microbial homeostasis and alleviate dysbiosis, may help prevent inflammation and colorectal cancer. These probiotics inhibit or ameliorate the effects of dysbiosis through the production of short-chain fatty acids (SCFAs), modulation of immunity, maintenance of the intestinal epithelial barrier, pro-apoptotic mechanisms, and other mechanisms. This review aims to explain the interaction between probiotics, the gut microenvironment and the gut microbiota, and summarize reports on the possibility of probiotics in the prevention and treatment of colorectal cancer.

Herbal medicine and its impact on the gut microbiota in colorectal cancer

It is well-established that there are trillions of gut microbiota (GM) in the human gut. GM and its metabolites can reportedly cause cancer by causing abnormal immune responses. With the development of sequencing technology and the application of germ-free models in recent years, significant inroads have been achieved in research on GM and microbiota-related metabolites. Accordingly, the role and mechanism of GM in colorectal cancer (CRC) development have been gradually revealed. Traditional Chinese medicine (TCM) represents an important source of natural medicines and herbal products, with huge potential as anti-CRC agents. The potential application of TCM to target gut microbes for the treatment of colorectal cancer represents an exciting area of investigation.

Cell-Free Supernatant Derived from a Lactobacillus casei BL23 Culture Modifies the Antiviral and Immunomodulatory Capacity of Mesenchymal Stromal Cells

Immune responses are highly complex and intricately regulated processes involving immune and non-immune cells in close direct and indirect contact with each other. These cells are highly sensitive to environmental signals, including factors derived from microbiota. Here, we demonstrate that the human microbiota member Lactobacillus casei (L. casei)-derived cell-free supernatant (CFS) enhances the sensitivity of mesenchymal-stromal-cell-like (MSCI) cells to viral stimuli and induces the development of dendritic cells (DCs) with anti-inflammatory and antiviral properties via pretreated MSCl cells. Our results showed that the production of INFβ and CXCL10 by MSCl cells upon viral stimulation was dependent on the presence of L. casei-derived extracellular vesicles in CFS during pretreatment. Moreover, L. casei CFS and/or poly (I:C)-conditioned MSCI cells altered the differentiation process of freshly isolated monocytes, as well as the developing DCs' phenotype and functional activities, such as cytokine and chemokine secretion. Taken together, L. casei CFS contains factors which contribute to the pronounced antiviral response of MSCI cells, avoiding the development of inflammation via the induction of differentiation of anti-inflammatory DCs that retain their antiviral properties.

BLAB2CancerKD: a knowledge graph database focusing on the association between lactic acid bacteria and cancer, but beyond

In a broad sense, lactic acid bacteria (LAB) is a general term for Gram-positive bacteria that can produce lactic acid by utilizing fermentable carbohydrates. It is widely used in essential fields such as industry, agriculture, animal husbandry and medicine. At the same time, LAB are closely related to human health. They can regulate human intestinal flora and improve gastrointestinal function and body immunity. Cancer, a disease in which some cells grow out of control and spread to other body parts, is one of the leading causes of human death worldwide. In recent years, the potential of LAB in cancer treatment has attracted attention. Mining knowledge from the scientific literature significantly accelerates its application in cancer treatment. Using 7794 literature studies of LAB cancer as source data, we have processed 16 543 biomedical concepts and 23 091 associations by using automatic text mining tools combined with manual curation of domain experts. An ontology containing 31 434 pieces of structured data is constructed. Finally, based on ontology, a knowledge graph (KG) database, which is called Beyond 'Lactic acid bacteria to Cancer Knowledge graph Database' (BLAB2CancerKD), is constructed by using KG and web technology. BLAB2CancerKD presents all the relevant knowledge intuitively and clearly in various data presentation forms, and the interactive system function also makes it more efficient. BLAB2CancerKD will be continuously updated to advance the research and application of LAB in cancer therapy. Researchers can visit BLAB2CancerKD at. Database URL http://110.40.139.2:18095/.

Mucin Binding Protein of Lactobacillus casei Inhibits HT-29 Colorectal Cancer Cell Proliferation

Many Lactobacillus casei strains are reported to exhibit anti-proliferative effects on colorectal cancer cells; however, the mechanism remains largely unknown. While there has been considerable interest in bacterial small metabolites such as short chain fatty acids, prior reports suggested that larger-sized molecules mediate the anti-proliferative effect of L. casei. Here, other possible ways of communication between gut bacteria and its host are investigated. LevH1 is a protein displayed on the surface of L. casei, and its mucin binding domain is highly conserved. Based on previous reports that the cell-free supernatant fractions decreased colorectal cell proliferation, we cloned the mucin binding domain of the LevH1 protein, expressed and purified this mucin binding protein (MucBP). It has a molecular weight of 10 kDa, is encoded by a 250 bp gene, and is composed primarily of a β-strand, β-turns, and random coils. The amino acid sequence is conserved while the 36th amino acid residue is arginine in L. casei CAUH35 and serine in L. casei IAM1045, LOCK919, 12A, and Zhang. MucBP^36R exhibited dose-dependent anti-proliferative effects against HT-29 cells while a mutation of 36S abolished this activity. Predicted structures suggest that this mutation slightly altered the protein structure, thus possibly affecting subsequent communication with HT-29 cells. Our study identified a novel mode of communication between gut bacteria and their host.

Gut microbiota in colorectal cancer development and therapy

Colorectal cancer (CRC) is one of the commonest cancers globally. A unique aspect of CRC is its intimate association with the gut microbiota, which forms an essential part of the tumour microenvironment. Research over the past decade has established that dysbiosis of gut bacteria, fungi, viruses and Archaea accompanies colorectal tumorigenesis, and these changes might be causative. Data from mechanistic studies demonstrate the ability of the gut microbiota to interact with the colonic epithelia and immune cells of the host via the release of a diverse range of metabolites, proteins and macromolecules that regulate CRC development. Preclinical and some clinical evidence also underscores the role of the gut microbiota in modifying the therapeutic responses of patients with CRC to chemotherapy and immunotherapy. Herein, we summarize our current understanding of the role of gut microbiota in CRC and outline the potential translational and clinical implications for CRC diagnosis, prevention and treatment. Emphasis is placed on how the gut microbiota could now be better harnessed by developing targeted microbial therapeutics as chemopreventive agents against colorectal tumorigenesis, as adjuvants for chemotherapy and immunotherapy to boost drug efficacy and safety, and as non-invasive biomarkers for CRC screening and patient stratification. Finally, we highlight the hurdles and potential solutions to translating our knowledge of the gut microbiota into clinical practice.

Tumor microenvironment signaling and therapeutics in cancer progression

Tumor development and metastasis are facilitated by the complex interactions between cancer cells and their microenvironment, which comprises stromal cells and extracellular matrix (ECM) components, among other factors. Stromal cells can adopt new phenotypes to promote tumor cell invasion. A deep understanding of the signaling pathways involved in cell-to-cell and cell-to-ECM interactions is needed to design effective intervention strategies that might interrupt these interactions. In this review, we describe the tumor microenvironment (TME) components and associated therapeutics. We discuss the clinical advances in the prevalent and newly discovered signaling pathways in the TME, the immune checkpoints and immunosuppressive chemokines, and currently used inhibitors targeting these pathways. These include both intrinsic and non-autonomous tumor cell signaling pathways in the TME: protein kinase C (PKC) signaling, Notch, and transforming growth factor (TGF-β) signaling, Endoplasmic Reticulum (ER) stress response, lactate signaling, Metabolic reprogramming, cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) and Siglec signaling pathways. We also discuss the recent advances in Programmed Cell Death Protein 1 (PD-1), Cytotoxic T-Lymphocyte Associated Protein 4 (CTLA4), T-cell immunoglobulin mucin-3 (TIM-3) and Lymphocyte Activating Gene 3 (LAG3) immune checkpoint inhibitors along with the C-C chemokine receptor 4 (CCR4)- C-C class chemokines 22 (CCL22)/ and 17 (CCL17), C-C chemokine receptor type 2 (CCR2)- chemokine (C-C motif) ligand 2 (CCL2), C-C chemokine receptor type 5 (CCR5)- chemokine (C-C motif) ligand 3 (CCL3) chemokine signaling axis in the TME. In addition, this review provides a holistic understanding of the TME as we discuss the three-dimensional and microfluidic models of the TME, which are believed to recapitulate the original characteristics of the patient tumor and hence may be used as a platform to study new mechanisms and screen for various anti-cancer therapies. We further discuss the systemic influences of gut microbiota in TME reprogramming and treatment response. Overall, this review provides a comprehensive analysis of the diverse and most critical signaling pathways in the TME, highlighting the associated newest and critical preclinical and clinical studies along with their underlying biology. We highlight the importance of the most recent technologies of microfluidics and lab-on-chip models for TME research and also present an overview of extrinsic factors, such as the inhabitant human microbiome, which have the potential to modulate TME biology and drug responses.

Impacts of pre-existing diabetes mellitus on colorectal cancer in a mice model

BACKGROUND

Although diabetes mellitus (DM) is regarded as a risk factor of colorectal cancer (CRC), the impacts of pre-existing DM on CRC without drug intervention remain unknown. The purpose of this study was to investigate and analyze the effects of diabetes mellitus (DM) on colorectal cancer (CRC). And, to further explore the influencing factors and the mechanisms of DM affects CRC progression.

METHODS

In this study, we investigated the effects of DM on CRC progression in a streptozotocin-induced DM mice model. Furthermore, we evaluated the change of T cells levels using flow cytometry and indirect immunofluorescence. We assessed the alternation of gut microbiome and the transcriptional response using 16s rRNA sequencing and RNA-seq.

RESULTS

Results showed that the mice survival time was significantly decreased in CRC complicated with DM group (DM-CRC), compared with only tumor bearing mice (CRC group). Furthermore, we found that DM could affect the immune response by changing the infiltration of CD4+ T cells, CD8+ T cells and mucosal-associated invariant T cell (MAIT) in the CRC progression. In addition, DM could induce gut microbiome dysbiosis and change the transcriptional response in CRC complicated with DM.

CONCLUSION

For the first time, the effects of DM on CRC were systematically characterized in a mice model. Our findings highlight the effects of pre-existing DM on CRC, and these findings should facilitate further studies in exploring and developing potentially targeted therapy for CRC in diabetic patients. Our results suggest that the effects induced by DM should be considered in the treatment for CRC complicated with DM patients.

Investigation into the Potential Role of Propionibacterium freudenreichii in Prevention of Colorectal Cancer and Its Effects on the Diversity of Gut Microbiota in Rats

Colorectal cancer (CRC) accounts for 10% of all cancer diagnoses and cancer-related deaths worldwide. Over the past two decades, several studies have demonstrated the clinical benefits of probiotic supplementation and some studies have shown that certain probiotics can modulate immunity and strengthen gut microbiota diversity. This study aims to assess the impact of the Propionibacterium freudenreichii (PF) probiotic against CRC induced by azoxymethane (AOM), and to investigate its effects on gut microbiota diversity in rats, as well as to evaluate the anti-proliferative activities of PF in HCT116 CRC cells. This experiment was performed using four groups of SD rats: normal control, AOM group, PF group (1 × 10⁹ CFU/mL), and standard drug control (5-fluorouracil, 35 mg/kg). Methylene blue staining of colon tissues showed that the administration of PF significantly reduced the formation of colonic aberrant crypt foci (ACF) compared to the AOM control group. In addition, treated rats had lower levels of malondialdehyde in their colon tissue homogenates, indicating that lipid peroxidation was suppressed by PF supplementation. Furthermore, 16S rRNA gene analysis revealed that probiotic treatment enhanced the diversity of gut microbiota in rats. In vitro study showed that the viability of HCT116 cells was inhibited by the probiotic cell-free supernatant with an IC₅₀ value of 13.3 ± 0.133. In conclusion, these results reveal that consuming PF as probiotic supplements modulates gut microbiota, inhibits the carcinogenic effects of AOM, and exerts anti-proliferative activity against CRC cells. Further studies are required to elucidate the role of PF on the immune response during the development and growth of CRC.

Current and emerging therapeutic approaches for colorectal cancer: A comprehensive review

Colorectal cancer (CRC) affects 1 in 23 males and 1 in 25 females, making it the third most common cancer. With roughly 608000 deaths worldwide, CRC accounts for 8% of all cancer-related deaths, making it the second most common cause of death due to cancer. Standard and conventional CRC treatments include surgical expurgation for resectable CRC and radiotherapy, chemotherapy, immunotherapy, and their combinational regimen for non-resectable CRC. Despite these tactics, nearly half of patients develop incurable recurring CRC. Cancer cells resist the effects of chemotherapeutic drugs in a variety of ways, including drug inactivation, drug influx and efflux modifications, and ATP-binding cassette transporter overexpression. These constraints necessitate the development of new target-specific therapeutic strategies. Emerging therapeutic approaches, such as targeted immune boosting therapies, non-coding RNA-based therapies, probiotics, natural products, oncolytic viral therapies, and biomarker-driven therapies, have shown promising results in preclinical and clinical studies. We tethered the entire evolutionary trends in the development of CRC treatments in this review and discussed the potential of new therapies and how they might be used in conjunction with conventional treatments as well as their advantages and drawbacks as future medicines.

Pterostilbene and Probiotic Complex in Chemoprevention of Putative Precursor Lesions for Colorectal Cancer in an Experimental Model of Intestinal Carcinogenesis with 1,2-Dimethylhydrazine

Dietary supplementation with pterostilbene (PS) and/or a probiotic (PRO) may ameliorate the intestinal microbiota in disease conditions. This study aims to evaluate PS and PRO for the chemoprevention of putative precursor lesions for colorectal cancer (CRC) in an experimental model of intestinal carcinogenesis with 1,2-dimethylhydrazine (1,2-DMH). Sixty male Wistar rats were equally divided into five groups: Sham, 1,2-DMH, 1,2-DMH + PS, 1,2-DMH + PRO, and 1,2-DMH + PS + PRO. PRO (5 × 107/mL) was offered in water, and PS (300 ppm) was provided in the diet ad libitum. 1,2-DMH (20 mg/kg/week) was administered for 15 consecutive weeks. In the 25th week, proctocolectomy was conducted. PRO alone and PRO combined with PS were the best intervention strategies to improve experimental 1,2-DMH-induced CRC regarding several parameters of carcinogenesis. Our findings may contribute to the development of novel preventive strategies for CRC and may help to identify novel modulators of colon carcinogenesis.

Inhibitory effects of Clostridium butyricum culture and supernatant on inflammatory colorectal cancer in mice

Clostridium butyricum (CB) is a spore-forming, gram-positive and obligate anaerobic rod bacterium. CB can modulate the composition of the gut microbiome and promote the growth of beneficial microbes in the intestine by generating short-chain fatty acids (SCFAs), which in turn protect against colitis and prevents the formation of inflammatory-associated colorectal cancer (CRC) by ameliorating colon inflammatory processes. Yet, it remains unclear whether the culture and supernatant of CB could directly influence inflammatory CRC in mice. In this study, azoxymethane (AOM)+dextran sodium sulphate (DSS) was used to induce CRC model in C57BL/6 mice. Next, the serum levels of inflammatory cytokines, including interleukin-6 (IL-6), interleukin-10 (IL-10), and cytokines TNF-α, were measured and the pathohistological examination of the large intestine was performed. Both CB culture and supernatant were found to have anti-inflammatory properties. Subsequently, Western blot and Real-Time Quantitative PCR (RT-qPCR) revealed that CB and supernatant regulate the NF-κB/p65 pathway to inhibit the development and progression of inflammatory CRC in AOM+DSS-treated mice, which could be due to the high levels of butyric acid in the supernatant.

Anti-tumor effect of infant-derived Enterococcus via the inhibition of proliferation and inflammation as well as the promotion of apoptosis

Probiotic Enterococcus hirae WEHI01 and Enterococcus faecium WEFA23 from infants were previously found to effectively inhibit the development of melanoma. In this study, their immunomodulatory and antitumor mechanisms were systemically studied. In vitro assay showed that E. hirae WEHI01 and E. faecium WEFA23 achieved biphasic immune regulation, which was revealed by the activation of resting spleen lymphocytes and RAW264.7 macrophages, as well as the anti-inflammation effect when immune cells were treated with LPS. The antitumor effects of E. hirae WEHI01 and E. faecium WEFA23 in vitro and vivo were then investigated. CCK8 and the cell scratch assay showed that the conditioned media, which were co-incubated with Enterococcus and spleen lymphocytes, significantly inhibited the proliferation and migration of B16F10, HepG-2 and HT-29 cells. The results of the tumor-bearing mice model experiment showed that E. faecium WEFA23 inhibition of the growth of tumors in mice, and the anti-tumor mechanism involved three aspects, namely tumor proliferation (decreasing expressions of LDHA, VEGF, MMP2, MMP9 and HIF-1α), inhibition of the pro-inflammation state (decreasing expressions of IL-6, TGF-β and IL-17) and the promotion of apoptosis (increasing expression of Bax/Bcl-2, caspase-3 and p53). The results suggest that the two strains of Enterococcus could be promising candidates for treating melanoma with a highly inhibitory effect.