Intake of Bifidobacterium longum and Fructo-oligosaccharides prevents Colorectal Carcinogenesis

Metformin alleviates colitis-associated colorectal cancer via inhibition of the TLR4/MyD88/NFκB/MAPK pathway and macrophage M2 polarization

BACKGROUND

Colon inflammation plays an essential role in the development and progression of colorectal cancer. Emerging evidence from clinical and animal studies indicates that metformin may reduce the risk of colorectal cancer through its anti-inflammatory effects.

AIMS

To investigate the efficacy of metformin in reducing the risk of colorectal cancer and the possible pathways and mechanisms.

METHODS

The Enterotoxigenic Bacteroides Fragilis (ETBF)/azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model was established and low-dose metformin (125 mg/kg) or high-dose metformin (250 mg/kg) was administered daily by gavage. Colon tumors were counted, and colon tissue was stained with hematoxylin and eosin (HE) and Periodic Acid-Schiff's and Alcian Blue (PAS-AB). Colon Ki67, ZO-1 Muc2, Claudin-1, Occludin, MPO, reactive oxygen species (ROS), E-cadherin, CD206 and Arg-1 expression were detected by immunohistochemistry or immunofluorescence staining. NF-κB pathway-related protein expression was assessed by Western blot. Fecal short-chain fatty acid (SCFA) levels were also examined.

RESULTS

Our results showed that low- or high-dose metformin ameliorates colonic mucosal damage, reduces colonic inflammation, and eventually inhibits colorectal tumorigenesis in the ETBF/AOM/DSS mouse model. Our further research found that metformin suppresses the expression of TLR4/MyD88/NFκB/MAPK pathway-related proteins, modulates macrophage M2 polarization and increases SCFA levels in colon contents, which may be the mechanisms by which metformin exerts a protective effect against colon carcinogenesis.

CONCLUSION

Metformin inhibited colorectal tumorigenesis by suppressing the TLR4/MyD88/NFκB/MAPK pathway, modulating macrophage M2 polarization and increasing SCFA levels. It holds promise as a potentially effective treatment for colorectal cancer.

Black Soybean Seed Coat Extract Suppresses Gut Tumorigenesis by Augmenting the Production of Gut Microbiota-Derived Short-Chain Fatty Acids

BACKGROUND

Proanthocyanidins (PACs) from black soybean seed coat have antioxidant and anti-tumorigenic properties. We investigated the anti-tumor properties and mechanisms of action of PACs on colorectal cancer (CRC).

METHODS

We fed the APCmin/+ mice, which are highly susceptible to spontaneous intestinal adenoma formation, diets supplemented with or without PACs for 7 weeks and assessed adverse effects, the number and size of intestinal polyps, and the expression of pro- and anti-proliferative proteins in the intestine. The mouse gut microbiome composition was analyzed, and the concentrations of gut short-chain fatty acids (SCFAs) were quantified. We also compared CRC incidence in Tamba in Japan, where black soybean is consumed frequently, with that in the rest of Japan.

RESULTS

The number and size of intestinal polyps notably decreased in the PAC-fed mice. Compared with control mice, the PAC-fed mice showed lower expression of proliferation markers proliferating cell nuclear antigen and β catenin and a higher expression of the anti-inflammatory protein oligomeric mucus gel-forming. PAC supplementation increased the prevalence and concentrations of beneficial gut microbes and SCFAs, respectively.

CONCLUSIONS

Diet supplemented with black soybean-derived PACs could prevent CRC development in mice through gut microbiome remodeling. Regions consuming black soybeans have low CRC incidence. Notably, the incidence of CRC, breast cancer, and liver cancer was significantly lower in Tamba than in the rest of Hyogo Prefecture or Japan. Future studies should delineate the mechanisms underlying the CRC-protective effects of PACs. Nevertheless, our results demonstrate the potential of including PACs in dietary recommendations for cancer prevention.

The Gut Connection: Exploring the Possibility of Implementing Gut Microbial Metabolites in Lymphoma Treatment

Recent research has implicated the gut microbiota in the development of lymphoma. Dysbiosis of the gut microbial community can disrupt the production of gut microbial metabolites, thereby impacting host physiology and potentially contributing to lymphoma. Dysbiosis-driven release of gut microbial metabolites such as lipopolysaccharides can promote chronic inflammation, potentially elevating the risk of lymphoma. In contrast, gut microbial metabolites, such as short-chain fatty acids, have shown promise in preclinical studies by promoting regulatory T-cell function, suppressing inflammation, and potentially preventing lymphoma. Another metabolite, urolithin A, exhibited immunomodulatory and antiproliferative properties against lymphoma cell lines in vitro. While research on the role of gut microbial metabolites in lymphoma is limited, this article emphasizes the need to comprehend their significance, including therapeutic applications, molecular mechanisms of action, and interactions with standard chemotherapies. The article also suggests promising directions for future research in this emerging field of connection between lymphoma and gut microbiome.

The postbiotic sodium butyrate synergizes the antiproliferative effects of dexamethasone against the AGS gastric adenocarcinoma cells

A growing body of literature underlines the fundamental role of gut microbiota in the occurrence, treatment, and prognosis of cancer. In particular, the activity of gut microbial metabolites (also known as postbiotics) against different cancer types has been recently reported in several studies. However, their in-depth molecular mechanisms of action and potential interactions with standard chemotherapeutic drugs remain to be fully understood. This research investigates the antiproliferative activities of postbiotics- short-chain fatty acid (SCFA) salts, specifically magnesium acetate (MgA), sodium propionate (NaP), and sodium butyrate (NaB), against the AGS gastric adenocarcinoma cells. Furthermore, the potential synergistic interactions between the most active SCFA salt-NaB and the standard drug dexamethasone (Dex) were explored using the combination index model. The molecular mechanisms of the synergy were investigated using reactive oxygen species (ROS), flow cytometry and biochemometric and liquid chromatography-mass spectrometry (LC-MS)-driven proteomics analyses. NaB exhibited the most significant inhibitory effect (p < 0.05) among the tested SCFA salts against the AGS gastric cancer cells. Additionally, Dex and NaB exhibited strong synergy at a 2:8 ratio (40 μg/mL Dex + 2,400 μg/mL NaB) with significantly greater inhibitory activity (p < 0.05) compared to the mono treatments against the AGS gastric cancer cells. MgA and NaP reduced ROS production, while NaB exhibited pro-oxidative properties. Dex displayed antioxidative effects, and the combination of Dex and NaB (2,8) demonstrated a unique pattern, potentially counteracting the pro-oxidative effects of NaB, highlighting an interaction. Dex and NaB individually and in combination (Dex:NaB 40:2400 μg/mL) induced significant changes in cell populations, suggesting a shift toward apoptosis (p < 0.0001). Analysis of dysregulated proteins in the AGS cells treated with the synergistic combination revealed notable downregulation of the oncogene TNS4, suggesting a potential mechanism for the observed antiproliferative effects. These findings propose the potential implementation of NaB as an adjuvant therapy with Dex. Further investigations into additional combination therapies, in-depth studies of the molecular mechanisms, and in vivo research will provide deeper insights into the use of these postbiotics in cancer, particularly in gastric malignancies.

An Update on Prebiotics and on Their Health Effects

Prebiotic compounds were originally defined as "a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health"; however, a significant modulation of the definition was carried out in the consensus panel of The International Scientific Association for Probiotics and Prebiotics (ISAPP), and the last definition states that "prebiotics are substrates that are selectively utilized by host microorganisms conferring a health benefit". Health effects of prebiotics compounds attracted the interest of researchers, food companies and Regulatory Agencies, as inferred by the number of articles on Scopus for the keywords "prebiotic" and "health effects", that is ca. 2000, for the period January 2021-January 2024. Therefore, the aim of this paper is to contribute to the debate on these topics by offering an overview of existing knowledge and advances in this field. A literature search was performed for the period 2012-2023 and after the selection of the most relevant items, the attention was focused on seven conditions for which at least 8-10 different studies were found, namely colorectal cancer, neurological or psychiatric conditions, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. In addition, the analysis of the most recent articles through the software VosViewer version 1.6.20 pointed out the existence of five clusters or macro-categories, namely: (i) pathologies; (ii) metabolic condvitions; (iii) structure and use in food; (iv) immunomodulation; (v) effect on gut microbiota.

Bifidobacterium longum SX-1326 ameliorates gastrointestinal toxicity after irinotecan chemotherapy via modulating the P53 signaling pathway and brain-gut axis

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignant malignancy affecting the gastrointestinal tract that is usually treated clinically with chemotherapeutic agents, whereas chemotherapeutic agents can cause severe gastrointestinal toxicity, which brings great pain to patients. Therefore, finding effective adjuvant agents for chemotherapy is crucial.

METHODS

In this study, a CRC mouse model was successfully constructed using AOM/DSS, and the treatment was carried out by probiotic Bifidobacterium longum SX-1326 (B. longum SX-1326) in combination with irinotecan. Combining with various techniques of modern biomedical research, such as Hematoxylin and Eosin (H&E), Immunohistochemistry (IHC), Western blotting and 16S rDNA sequencing, we intend to elucidate the effect and mechanism of B. longum SX-1326 in improving the anticancer efficacy and reducing the side effects on the different levels of molecules, animals, and bacteria.

RESULTS

Our results showed that B. longum SX-1326 enhanced the expression of Cleaved Caspase-3 (M vs. U = p < 0.01) and down-regulated the expression level of B-cell lymphoma-2 (Bcl-2) through up-regulation of the p53 signaling pathway in CRC mice, which resulted in an adjuvant effect on the treatment of CRC with irinotecan. Moreover, B. longum SX-1326 was also able to regulate the gut-brain-axis (GBA) by restoring damaged enterochromaffin cells, reducing the release of 5-hydroxytryptamine (5-HT) in brain tissue (I vs. U = 89.26 vs. 75.03, p < 0.05), and further alleviating the adverse effects of nausea and vomiting. In addition, B. longum SX-1326 reversed dysbiosis in CRC model mice by increasing the levels of Dehalobacterium, Ruminnococcus, and Mucispirillum. And further alleviated colorectal inflammation by downregulating the TLR4/MyD88/NF-κB signaling pathway.

CONCLUSIONS

In conclusion, our work reveals that B. longum SX-1326 has a favorable effect in adjuvant irinotecan for CRC and amelioration of post-chemotherapy side effects, and also provides the theoretical basis and data for finding a safe and efficient chemotherapeutic adjuvant.

Traditional Chinese medicine as a novel therapy for colorectal cancer by modulating intestinal flora

Colorectal cancer is a common clinical malignant tumor of the digestive tract, and intestinal flora has played an important role in the development of colorectal cancer. Bifidobacteria, as one of the main dominant florae in intestinal tract, can inhibit the occurrence and development of colorectal cancer through various mechanisms. Recent studies have shown that traditional Chinese medicine can regulate the abundance of bifidobacteria in intestinal tract and exhibit anti-tumor effects on colorectal cancer. Detailed investigations have revealed that the mechanisms of bifidobacteria in the treatment of colorectal cancer involve three aspects: the production of short-chain fatty acids, the regulation of the body's immunity, and the regulation of cell apoptosis and differentiation. In this review, we provide an updated summary of recent advances in our understanding of the mechanisms by which traditional Chinese medicine regulate intestinal flora to inhibit colorectal cancer development and metastasis.

A Current Review on the Role of Prebiotics in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of death in the United States and worldwide. Recent evidence has corroborated a strong correlation between poor diet and the development of CRC, and further research is being conducted to investigate the association between intestinal microbiome and the development of cancer. New studies have established links with certain foods and synthetic food compounds that may be effective in reducing the risk for carcinogenesis by providing protection against cancer cell proliferation and antagonizing oncogenic pathways. Prebiotics are gaining popularity as studies have demonstrated chemo-preventive as well as anticancer potential of prebiotics. This paper aims to discuss the wide definition and scope of prebiotics by reviewing the studies that provide insights into their effects on human health in the context of colorectal cancer.

Role of microbes in colorectal cancer therapy: Cross-talk between the microbiome and tumor microenvironment

The human gut microbiota is associated with the development and progression of colorectal cancer, and manipulation of the gut microbiota is a novel strategy for the prevention and treatment of colorectal cancer. Some bacteria have antitumor activity against colorectal cancer, where specific bacteria can improve the tumor microenvironment, activate immune cells including dendritic cells, helper T cells, natural killer cells, and cytotoxic T cells, and upregulate the secretion of pro-tumor immune cytokines such as interleukin-2 and interferon. In this paper, we summarize some bacteria with potential benefits in colorectal cancer and describe their roles in the tumor microenvironment, demonstrate the application of gut microbes in combination with immunosuppressive agents, and provide suggestions for further experimental studies and clinical practice applications.

The potential role of prebiotics, probiotics, and synbiotics in adjuvant cancer therapy especially colorectal cancer

Cancer is a global health issue that is rising swiftly with younger people and an increased number of patients. The role of human microbiota in the pathophysiology of tumors has been paid more and more attention. Microecologics including prebiotics, probiotics, and synbiotics are among the best validated/proven resources for the application of microbiological prophylaxis and therapy. There is strong evidence that microecologics have anti-cancer activity and their potential association with cancer is significant. In this review, we will focus on the role of prebiotics, probiotics, and synbiotics in tumor suppression in maintaining the colon barrier, metabolism, immune regulation, inhibition of host tumor cell proliferation, and epidemiological-based recommendations. Besides, other signs illuminate the role of microecological agents to adjunct the cancer treatment and counter the toxic side effects of cancer drugs. In addition, we will explore their role in chemotherapy, where these probiotics can be used as an adjunct to chemotherapy, counteracting the toxic side effects of chemotherapy drugs to minimize or optimize the therapeutic effect. In the treatment of cancer, we can see the role of prebiotics, probiotics, synbiotics, and their application in cancer patients, and the effectiveness effect can be considered as a clinical benefit. PRACTICAL APPLICATIONS: A large number of studies have shown that microecologics including prebiotics, probiotics, and synbiotics play an important role in regulating intestinal microecology and contribute to the prevention and treatment of cancer, indicating that prebiotics, probiotics, and synbiotics have the potential to be used as microecological modulators in the adjuvant therapy of cancer. However, it is not clear what is the anti-tumor mechanism of these microecologics and how they antagonize the side effects of cancer chemotherapy and protect normal cells. This paper reviews the role of prebiotics, probiotics, and synbiotics in tumor suppression in maintaining the colon barrier, metabolism, immune regulation, and prevention of rapid growth of host cells, as well as their potential role in cancer chemotherapy. This review helps to better understand the relationship between prebiotics, probiotics, and synbiotics with immune regulation, intestinal microecology, metabolic regulation, and cell proliferation and provides strong evidence for their potential application as microecologics in cancer adjuvant therapy.

Biodetoxification and Protective Properties of Probiotics

Probiotic consumption is recognized as being generally safe and correlates with multiple and valuable health benefits. However, the mechanism by which it helps detoxify the body and its anti-carcinogenic and antimutagenic potential is less discussed. A widely known fact is that globalization and mass food production/cultivation make it impossible to keep all possible risks under control. Scientists associate the multitude of diseases in the days when we live with these risks that threaten the population’s safety in terms of food. This review aims to explore whether the use of probiotics may be a safe, economically viable, and versatile tool in biodetoxification despite the numerous risks associated with food and the limited possibility to evaluate the contaminants. Based on scientific data, this paper focuses on the aspects mentioned above and demonstrates the probiotics’ possible risks, as well as their anti-carcinogenic and antimutagenic potential. After reviewing the probiotic capacity to react with pathogens, fungi infection, mycotoxins, acrylamide toxicity, benzopyrene, and heavy metals, we can conclude that the specific probiotic strain and probiotic combinations bring significant health outcomes. Furthermore, the biodetoxification maximization process can be performed using probiotic-bioactive compound association.

An Update on the Effects of Probiotics on Gastrointestinal Cancers

Because of their increasing prevalence, gastrointestinal (GI) cancers are regarded as an important global health challenge. Microorganisms residing in the human GI tract, termed gut microbiota, encompass a large number of living organisms. The role of the gut in the regulation of the gut-mediated immune responses, metabolism, absorption of micro- and macro-nutrients and essential vitamins, and short-chain fatty acid production, and resistance to pathogens has been extensively investigated. In the past few decades, it has been shown that microbiota imbalance is associated with the susceptibility to various chronic disorders, such as obesity, irritable bowel syndrome, inflammatory bowel disease, asthma, rheumatoid arthritis, psychiatric disorders, and various types of cancer. Emerging evidence has shown that oral administration of various strains of probiotics can protect against cancer development. Furthermore, clinical investigations suggest that probiotic administration in cancer patients decreases the incidence of postoperative inflammation. The present review addresses the efficacy and underlying mechanisms of action of probiotics against GI cancers. The safety of the most commercial probiotic strains has been confirmed, and therefore these strains can be used as adjuvant or neo-adjuvant treatments for cancer prevention and improving the efficacy of therapeutic strategies. Nevertheless, well-designed clinical studies are still needed for a better understanding of the properties and mechanisms of action of probiotic strains in mitigating GI cancer development.

Relationships of Gut Microbiota Composition, Short-Chain Fatty Acids and Polyamines with the Pathological Response to Neoadjuvant Radiochemotherapy in Colorectal Cancer Patients

Emerging evidence has suggested that dysbiosis of the gut microbiota may influence the drug efficacy of colorectal cancer (CRC) patients during cancer treatment by modulating drug metabolism and the host immune response. Moreover, gut microbiota can produce metabolites that may influence tumor proliferation and therapy responsiveness. In this study we have investigated the potential contribution of the gut microbiota and microbial-derived metabolites such as short chain fatty acids and polyamines to neoadjuvant radiochemotherapy (RCT) outcome in CRC patients. First, we established a profile for healthy gut microbiota by comparing the microbial diversity and composition between CRC patients and healthy controls. Second, our metagenomic analysis revealed that the gut microbiota composition of CRC patients was relatively stable over treatment time with neoadjuvant RCT. Nevertheless, treated patients who achieved clinical benefits from RTC (responders, R) had significantly higher microbial diversity and richness compared to non-responder patients (NR). Importantly, the fecal microbiota of the R was enriched in butyrate-producing bacteria and had significantly higher levels of acetic, butyric, isobutyric, and hexanoic acids than NR. In addition, NR patients exhibited higher serum levels of spermine and acetyl polyamines (oncometabolites related to CRC) as well as zonulin (gut permeability marker), and their gut microbiota was abundant in pro-inflammatory species. Finally, we identified a baseline consortium of five bacterial species that could potentially predict CRC treatment outcome. Overall, our results suggest that the gut microbiota may have an important role in the response to cancer therapies in CRC patients.

Preventing Colorectal Cancer through Prebiotics

Colorectal cancer (CRC), the third most common cancer in the world, has been recently rising in emerging countries due to environmental and lifestyle factors. Many of these factors are brought up by industrialization, which includes lack of physical activity, poor diet, circadian rhythm disruption, and increase in alcohol consumption. They can increase the risk of CRC by changing the colonic environment and by altering gut microbiota composition, a state referred to as gut dysbiosis. Prebiotics, which are nutrients that can help maintain intestinal microbial homeostasis and mitigate dysbiosis, could be beneficial in preventing inflammation and CRC. These nutrients can hinder the effects of dysbiosis by encouraging the growth of beneficial bacteria involved in short-chain fatty acids (SCFA) production, anti-inflammatory immunity, maintenance of the intestinal epithelial barrier, pro-apoptotic mechanisms, and other cellular mechanisms. This review aims to summarize recent reports about the implication of prebiotics, and probable mechanisms, in the prevention and treatment of CRC. Various experimental studies, specifically in gut microbiome, have effectively demonstrated the protective effect of prebiotics in the progress of CRC. Hence, comprehensive knowledge is urgent to understand the clinical applications of prebiotics in the prevention or treatment of CRC.

Role of Gut Microbiota and Probiotics in Colorectal Cancer: Onset and Progression

The gut microbiota plays an important role in maintaining homeostasis in the human body, and the disruption of these communities can lead to compromised host health and the onset of disease. Current research on probiotics is quite promising and, in particular, these microorganisms have demonstrated their potential for use as adjuvants for the treatment of colorectal cancer. This review addresses the possible applications of probiotics, postbiotics, synbiotics, and next-generation probiotics in colorectal cancer research.

Gastrointestinal cancers: the role of microbiota in carcinogenesis and the role of probiotics and microbiota in anti-cancer therapy efficacy

The gut epithelium is a habitat of a variety of microorganisms, including bacteria, fungi, viruses and Archaea. With the advent of sophisticated molecular techniques and bioinformatics tools, more information on the composition and thus function of gut microbiota was revealed. The gut microbiota as an integral part of the intestinal barrier has been shown to be involved in shaping the mucosal innate and adaptive immune response and to provide protection against pathogens. Consequently, a set of biochemical signals exchanged within microbes and communication between the microbiota and the host have opened a new way of thinking about cancer biology. Probiotics are living organisms which administered in adequate amounts may bring health benefits and have the potential to be an integral part of the prevention/treatment strategies in clinical approaches. Here we provide a comprehensive review of data linking gut microbiota to cancer pathogenesis and its clinical course. We focus on gastrointestinal cancers, such as gastric, colorectal, pancreatic and liver cancer.

Nutritional combinatorial impact on the gut microbiota and plasma short-chain fatty acids levels in the prevention of mammary cancer in Her2/neu estrogen receptor-negative transgenic mice

Breast cancer is the second leading cause of cancer-related mortality in women. Various nutritional compounds possess anti-carcinogenic properties which may be mediated through their effects on the gut microbiota and its production of short-chain fatty acids (SCFAs) for the prevention of breast cancer. We evaluated the impact of broccoli sprouts (BSp), green tea polyphenols (GTPs) and their combination on the gut microbiota and SCFAs metabolism from the microbiota in Her2/neu transgenic mice that spontaneously develop estrogen receptor-negative [ER(-)] mammary tumors. The mice were grouped based on the dietary treatment: control, BSp, GTPs or their combination from beginning in early life (BE) or life-long from conception (LC). We found that the combination group showed the strongest inhibiting effect on tumor growth volume and a significant increase in tumor latency. BSp treatment was integrally more efficacious than the GTPs group when compared to the control group. There was similar clustering of microbiota of BSp-fed mice with combination-fed mice, and GTPs-fed mice with control-fed mice at pre-tumor in the BE group and at pre-tumor and post-tumor in the LC group. The mice on all dietary treatment groups incurred a significant increase of Adlercreutzia, Lactobacillus genus and Lachnospiraceae, S24-7 family in the both BE and LC groups. We found no change in SCFAs levels in the plasma of BSp-fed, GTPs-fed and combination-fed mice of the BE group. Marked changes were observed in the mice of the LC group consisting of significant increases in propionate and isobutyrate in GTPs-fed and combination-fed mice. These studies indicate that nutrients such as BSp and GTPs differentially affect the gut microbial composition in both the BE and LC groups and the key metabolites (SCFAs) levels in the LC group. The findings also suggest that temporal factors related to different time windows of consumption during the life-span can have a promising influence on the gut microbial composition, SCFAs profiles and ER(-) breast cancer prevention.

An Overview of Gut Microbiota and Colon Diseases with a Focus on Adenomatous Colon Polyps

It is known and accepted that the gut microbiota composition of an organism has an impact on its health. Many studies deal with this topic, the majority discussing gastrointestinal health. Adenomatous colon polyps have a high prevalence as colon cancer precursors, but in many cases, they are hard to diagnose in their early stages. Gut microbiota composition correlated with the presence of adenomatous colon polyps may be a noninvasive and efficient tool for diagnosis with a high impact on human wellbeing and favorable health care costs. This review is meant to analyze the gut microbiota correlated with the presence of adenomatous colon polyps as the first step for early diagnosis, prophylaxis, and treatment.

Effects of postoperative adjuvant chemotherapy and palliative chemotherapy on the gut microbiome in colorectal cancer

BACKGROUND

The gut microbiome changes are related to the colorectal cancer (CRC). Chemotherapy is one of the main treatment methods for CRC.

PURPOSE

To explore the effect of chemotherapy on the gut bacteria and fungi in CRC.

METHODS

Total of 11 advanced CRC patients treated with the FOLFIRI regimen, 15 postoperative CRC patients treated with the XELOX regimen, and corresponding CRC patients without surgery and chemotherapy were recruited. The 16S ribosomal RNA and ITS sequences were sequenced, and bioinformatics analysis was executed to screen for the distinctive gut microbiome.

RESULTS

The abundances of Veillonella, Humicola, Tremellomycetes and Malassezia were increased in postoperative CRC patients treated with the XELOX regimen. The abundances of Faecalibacterium, Clostridiales, phascolarctobacterium, Humicola and Rhodotorula were decreased, and the abundances of Candida, Magnusiomyces, Tremellomycetes, Dipodascaceae, Saccharomycetales, Malassezia and Lentinula were increased in advanced CRC patients treated with the FOLFIRI regimen. The abundances of Humicola, Rhodotorula, and Magnusiomyces were decreased, and the abundances of Candida, Tremellomycetes, Dipodascaceae, Saccharomycetales, Malassezia and Lentinula were increased in advanced CRC patients treated with the FOLFIRI regimen combined with cetuximab compared with those treated with the FOLFIRI regimen alone.

CONCLUSIONS

The community structure of gut bacteria and fungi changes in chemotherapy on CRCs.

Colorectal Cancer and Probiotics: Are Bugs Really Drugs?

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. There are many factors that predispose a patient to the disease such as age, family history, ethnicity, and lifestyle. There are different genetic factors and diseases that also increase a person’s risk for developing CRC. Studies have found associations between gut microbiome and the risk for developing versus protection against CRC. Normal gut microbiome aid in daily functions of the human body such as absorption, metabolism, detoxification, and regulation of inflammation. While some species of bacteria prevent CRC development and aid in therapeutic responses to various treatment regiments, other species seem to promote CRC pathogenesis. In this regard, many studies have been conducted to not only understand the biology behind these opposing different bacterial species; but also to determine if supplementation of these tumor opposing bacterial species as probiotics lends toward decreased risk of CRC development and improved therapeutic responses in patients with CRC. In this literature review, we aim to discuss the basics on colorectal cancer (epidemiology, risk factors, targets, treatments), discuss associations between different bacterial strains and CRC, and discuss probiotics and their roles in CRC prevention and treatment.

Anti-colon cancer activity of Bifidobacterium metabolites on colon cancer cell line SW742

BACKGROUND/AIMS

Bacteria species, which are used as probiotics, are lactic acid bacteria. The majority of them are under the genera Bifidobacterium and Lactobacillus. The aim of the present study was to isolate and identify Bifidobacterium and to evaluate the effects of their 24 h and 120 h cell-free supernatants (CFS) from both cultures on colon cancer cell line.

MATERIALS AND METHODS

In the present study, 84 samples of dairy products, infant feces, and probiotic capsule were collected, and Bifidobacterium was isolated. Gram stain, biochemical tests, and molecular identification were done for the isolation and identification of Bifidobacterium. Cytotoxicity effects of CFS derived from both cultures of isolated Bifidobacterium were assessed on colon cancer cell lines.

RESULTS

In the present study, 17 isolates of Bifidobacterium were identified. The results show that Bifidobacterium was most frequently associated with infant feces and dairy products, whereas the lowest rate was associated with local milk. After the effects of CFS on colon cancer cell line, two isolates were identified from infant feces and probiotic capsule; they had the highest ability in inhibiting the growth of cancer cells. Bifidobacterium bifidum was effective in combating cancer cells and was associated with a substantial improvement in gastrointestinal cancer.

CONCLUSION

The study has shown that the regular ingested probiotics could prevent the development of colorectal cancer. During the present study, the produced CFS could inhibit the growth of colon cancer cells. In conclusion, probiotics have good potential to be introduced as a new approach to colon cancer treatment.

The interplay between dietary factors, gut microbiome and colorectal cancer: a new era of colorectal cancer prevention

Colorectal cancer is the third most common cancer in the world and its incidence is on the rise. Dietary intervention has emerged as an attractive strategy to curtail its occurrence and progression. Diet is known to influence the gut microbiome, as dietary factors and gut bacteria can act in concert to cause or protect from colorectal cancer. Several studies have presented evidence for such interactions and have pointed out the different ways by which the diet and gut microbiome can be altered to produce beneficial effects. This review article aims to summarize the interrelationship between diet, gut flora and colorectal cancer so that a better preventive approach can be applied.

Lysates of Lactobacillus acidophilus combined with CTLA-4-blocking antibodies enhance antitumor immunity in a mouse colon cancer model

Previous reports have suggested that many gut microbiomes were associated with the development of colorectal cancer (CRC), and could modulate response to numerous forms of cancer therapy, including checkpoint blockade immunotherapy. Here we evaluated the protective efficacy of Lactobacillus acidophilus (L. acidophilus) cell lysates combined with an anti-CTL antigen-4 blocking antibody (CTLA-4 mAb) in syngeneic BALB/c mice CRC models induce by a single intraperitoneal injection of 10 mg/kg azoxymethane (AOM), followed by three cycles of 2% dextran sulfate sodium (DSS) in drinking water. In contrast to CTLA-4 mAb monotherapy, L. acidophilus lysates could attenuate the loss of body weight and the combined administration significantly protected mice against CRC development, which suggested that the lysates enhanced antitumor activity of CTLA-4 mAb in model mice. The enhanced efficacy was associated with the increased CD8 + T cell, increased effector memory T cells (CD44 + CD8 + CD62L+), decreased Treg (CD4 + CD25 + Foxp3+) and M2 macrophages (F4/80 + CD206+) in the tumor microenvironment. In addition, our results revealed that L. acidophilus lysates had an immunomodulatory effect through inhibition the M2 polarization and the IL-10 expressed levels of LPS-activated Raw264.7 macrophages. Finally, the 16S rRNA gene sequencing of fecal microbiota demonstrated that the combined administration significantly inhibited the abnormal increase in the relative abundance of proteobacteria and partly counterbalance CRC-induced dysbiosis in model mice. Overall, these data support promising clinical possibilities of L. acidophilus lysates with CTLA-4 mAb in cancer patients and the hypothesis that probiotics help shape the anticancer immune response.

Relationship between intestinal microorganisms and T lymphocytes in colorectal cancer

Colorectal cancer (CRC) is a common type of malignant cancer worldwide. Recent studies have identified the gut microbiota as the origin of CRC, and T lymphocyte-mediated immune functions have been shown to play an important role in this disease. By summarizing previous literature, we found that Fusobacterium nucleatum may protect CRC from immune cell attack by inhibiting T cells and influencing the production of many chemokines and cytokines. Some bacterial metabolites and probiotics have been shown to participate in the regulation of CRC through T cell-mediated molecular pathways. To visualize the relevant data, an association network of intestinal microorganisms and T lymphocytes associated with CRC was constructed. This work may provide direction for - and insight into - further research on the relationship between intestinal microorganisms and T lymphocytes in CRC.