The anticancer effect of probiotic Bacillus polyfermenticus on human colon cancer cells is mediated through ErbB2 and ErbB3 inhibition

Potential of Synbiotics and Probiotics as Chemopreventive Agent

Cancer remains a global problem, with millions of new cases diagnosed yearly and countless lives lost. The financial burden of cancer therapy, along with worries about the long-term safety of existing medicines, necessitates the investigation of alternative approaches to cancer prevention. Probiotics generate chemopreventive compounds such as bacteriocins, short-chain fatty acids (SCFA), and extracellular polymeric substances (EPS), which have demonstrated the ability to impede cancer cell proliferation, induce apoptosis, and bolster the expression of pro-apoptotic genes. On the other hand, prebiotics, classified as non-digestible food ingredients, promote the proliferation of probiotics within the colon, thereby ensuring sustained functionality of the gut microbiota. Consequently, the synergistic effect of combining prebiotics with probiotics, known as the synbiotic effect, in dietary interventions holds promise for potentially mitigating cancer risk and augmenting preventive measures. The utilization of gut microbiota in cancer treatment has shown promise in alleviating adverse health effects. This review explored the potential and the role of probiotics and synbiotics in enhancing health and contributing to cancer prevention efforts. In this review, the applications of functional probiotics and synbiotics, the mechanisms of action of probiotics in cancer, and the relationship of probiotics with various drugs were discussed, shedding light on the potential of probiotics and synbiotics to alleviate the burdens of cancer treatment.

Coadministration of doxorubicin with vitamin D3, Lactobacillus acidophilus, and Lactobacillus casei in the 4T1 mouse model of breast cancer: anticancer and enteroprotective effects

The use of doxorubicin (Dox) in the treatment of breast cancer negatively affects the intestines and other tissues. Many studies have proven that probiotics and vitamin D3 have antitumor and intestinal tissue-protecting properties. To achieve effectiveness and minimize side effects, the current study aims to administer Dox together with probiotics (Lactobacillus acidophilus and Lactobacillus casei) and vitamin D3. Forty-two female BALB/c inbred mice were divided into six groups: Group 1 (Control), Group 2 (Dox), Group 3 (Dox and probiotics), Group 4 (Dox and vitamin D3), Group 5 (Dox, probiotics, and vitamin D3), and Group 6 (probiotics and vitamin D3). The 4T1 mouse carcinoma cell line was injected into the mammary fat pad of each mouse. Gene expression was examined using quantitative real-time PCR. The treated groups (except group 6) showed significantly reduced tumor volume and weight compared to the control group (P < 0.05, P < 0.01). Probiotics/vitamin D3 with Dox reduced chemotherapy toxicity and a combination of supplements had a significant protective effect against Dox (P < 0.05, 0.01, 0.001). The treated groups (except 6) had significantly higher expression of Bax/Caspase 3 genes and lower expression of Bcl-2 genes than the control group (P < 0.05, 0.01). Coadministration of Dox with probiotics and vitamin D3 showed promising results in reducing tumor size, protecting intestinal tissue and influencing gene expression, suggesting a strategy to enhance the effectiveness of breast cancer treatment while reducing side effects.

Inhibitory Effects of Latilactobacillus curvatus BYB3 Cell-Free Extract on Human Melanoma B16F10 Cells and Tumorigenic Mice

Latilactobacillus curvatus BYB3 (BYB3) is a species of lactic acid bacteria, formerly named Lactobacillus curvatus, which is isolated from kimchi. In this study, the effect of BYB3, Lactobacillus rhamnosus GG, and Lactobacillus acidophilus GP1B strain extracts at various concentrations was examined on B16F10, a mouse melanoma cell line. Cell viability was examined via MTT assay, and the results indicated that compared to the other two probiotics, BYB3 significantly decreased the total percentages of viable cells. The effects of BYB3 on cell migration and proliferation in B16F10 cells were evaluated using wound healing mobility and proliferation assays, respectively; the results indicated that BYB3 inhibits cell migration and proliferation in a concentration-dependent manner. Using human dermal fibroblast cells to investigate BYB3 extract in vivo had no effect on skin-related cells. Nonetheless, the BYB3 extract inhibited tumor growth in a mouse model, as demonstrated by liver slices. Therefore, this suggests that using BYB3 extract to inhibit melanoma may be a novel approach.

Evaluation of immunomodulatory potential of probiotic conditioned medium on murine macrophages

Probiotics are a mixture of beneficial live bacteria and/or yeasts that naturally exist in our bodies. Recently, numerous studies have focused on the immunostimulatory effects of single-species or killed multi-species probiotic conditioned mediums on macrophages. This study investigates the immunostimulatory effect of commercially available active, multi-species probiotic conditioned medium (CM) on RAW264.7 murine macrophages. The probiotic CM was prepared by culturing the commercially available probiotic in a cell-culture medium overnight at 37 °C, followed by centrifugation and filter-sterilization to be tested on macrophages. The immunostimulatory effect of different dilution percentages (50%, 75%, 100%) of CM was examined using the MTT assay, proinflammatory cytokine (tumor necrosis factor TNF-alpha) production in macrophages, migration, and phagocytosis assays. For all the examined CM ratios, the percentages of cell viability were > 80%. Regarding the migration scratch, TNF-alpha and phagocytosis assays, CM demonstrated a concentration-dependent immunostimulatory effect. However, the undiluted CM (100%) showed a significant (p-value < 0.05) stimulatory effect compared to the positive and negative controls. The findings suggest that the secretions and products of probiotics, as measured in the CM, may be closely associated with their immune-boosting effects. Understanding this relationship between probiotic secretions and immune function is crucial for further exploring the potential benefits of probiotics in enhancing overall health and well-being.

Bifidobacterium longum suppresses colorectal cancer through the modulation of intestinal microbes and immune function

Colorectal cancer (CRC), one of the most common malignancies in the world, urgently requires more treatment strategies. Although there has been much research on probiotics, limited research has been done in treating cancer. The purpose of this study was to investigate the role of Bifidobacterium longum (B. longum) in the prevention and treatment of CRC. Through Cell Counting Kit-8 and Colony Formation Assays, 8 h and a B. longum count of 1 × 108 CFU/ml were chosen as the best cocultivation conditions with CRC cells. The role of B. longum in inhibiting the progression of CRC cells was verified by a series of functional and immunofluorescence assays. For instance, in vivo assays have verified that B. longum could alleviate CRC progression. In addition, according to the results of in vivo assays and clinical statistical analysis, B. longum could reduce diarrhea symptoms. Mechanistically, by 16S and RNA sequencing, it was found that B. longum could affect the development of CRC by regulating the composition of gut microbes and enhancing immune function. The B. longum might inhibit the occurrence and development of CRC and relieve diarrhea symptoms by regulating intestinal microbes and immune function.

Probiotics and their Beneficial Health Effects

Probiotics are living microorganisms that are present in cultured milk and fermented food. Fermented foods are a rich source for the isolation of probiotics. They are known as good bacteria. They have various beneficial effects on human health including antihypertensive effects, antihypercholesterolemic effects, prevention of bowel disease, and improving the immune system. Microorganisms including bacteria, yeast, and mold are used as probiotics but the major microorganisms that are used as probiotics are bacteria from the genus Lactobacillus, Lactococcus, Streptococcus, and Bifidobacterium. Probiotics are beneficial in the prevention of harmful effects. Recently, the use of probiotics for the treatment of various oral and skin diseases has also gained significant attention. Clinical studies indicate that the usage of probiotics can alter gut microbiota composition and provoke immune modulation in a host. Due to their various health benefits, probiotics are attaining more interest as a substitute for antibiotics or anti-inflammatory drugs leading to the growth of the probiotic market.

Microbiota in cancer: molecular mechanisms and therapeutic interventions

The diverse bacterial populations within the symbiotic microbiota play a pivotal role in both health and disease. Microbiota modulates critical aspects of tumor biology including cell proliferation, invasion, and metastasis. This regulation occurs through mechanisms like enhancing genomic damage, hindering gene repair, activating aberrant cell signaling pathways, influencing tumor cell metabolism, promoting revascularization, and remodeling the tumor immune microenvironment. These microbiota-mediated effects significantly impact overall survival and the recurrence of tumors after surgery by affecting the efficacy of chemoradiotherapy. Moreover, leveraging the microbiota for the development of biovectors, probiotics, prebiotics, and synbiotics, in addition to utilizing antibiotics, dietary adjustments, defensins, oncolytic virotherapy, and fecal microbiota transplantation, offers promising alternatives for cancer treatment. Nonetheless, due to the extensive and diverse nature of the microbiota, along with tumor heterogeneity, the molecular mechanisms underlying the role of microbiota in cancer remain a subject of intense debate. In this context, we refocus on various cancers, delving into the molecular signaling pathways associated with the microbiota and its derivatives, the reshaping of the tumor microenvironmental matrix, and the impact on tolerance to tumor treatments such as chemotherapy and radiotherapy. This exploration aims to shed light on novel perspectives and potential applications in the field.

Probiotic potentials of lactic acid bacteria isolated from Egyptian fermented food

Lactic acid bacteria (LAB) are of major concern due to their health benefits. Fermented food products comprise variable LAB demonstrating probiotic properties. Discovering and evaluating new probiotics in fermented food products poses a global economic and health importance. Therefore, the present work aimed to investigate and evaluate the probiotic potentials of LAB strains isolated from Egyptian fermented food. In this study, we isolated and functionally characterized 100 bacterial strains isolated from different Egyptian fermented food sources as probiotics. Only four LAB strains amongst the isolated LAB showed probiotic attributes and are considered to be safe for their implementation as feed or dietary supplements. Additionally, they were shown to exert antimicrobial activities against pathogenic bacteria and anticancer effects against the colon cancer cell line Caco-2. The Enterococcus massiliensis IS06 strain was exclusively reported in this study as a probiotic strain with high antimicrobial, antioxidant, and anti-colon cancer activity. Hitherto, few studies have focused on elucidating the impact of probiotic supplementation in vivo. Therefore, in the current study, the safety of the four strains was tested in vivo through the supplementation of rats with potential probiotic strains for 21 days. The results revealed that probiotic bacterial supplementation in rats did not adversely affect the general health of rats. The Lactiplantibacillus plantarum IS07 strain significantly increased the growth performance of rats. Furthermore, the four strains exhibited increased levels of antioxidants such as superoxide dismutase and glutathione in vivo. Consistently, all strains also showed high antioxidant activity of the superoxide dismutase enzyme in vitro. Overall, these findings demonstrated that these isolated potential probiotics harbor desirable characteristics and can be applied widely as feed additives for animals or as dietary supplements for humans to exert their health benefits and combat serious diseases.

The efficacy of prevention for colon cancer based on the microbiota therapy and the antitumor mechanisms with intervention of dietary Lactobacillus

Gut microbiota and their secreted metabolites have an influence on the initiation and progression of colon cancer. Probiotics are extensively perceived as a potential microbiota-modulation strategy to promote the health of the host, while the effectiveness of preventing colon cancer based on microbiota therapy has not been confirmed, and antitumor mechanisms influenced by microbiota and their metabolites with the intervention of probiotics remain to be further investigated. In vitro, Lactobacillus (JY300-8 and JMR-01) significantly inhibited the proliferation of CT26, HT29, and HCT116 cells. Moreover, we studied the prevention and therapy efficiency of Lactobacillus and its underlying antitumor mechanism through the alteration of gut microbiota and their metabolites regulated by Lactobacillus in colon cancer models in mice. We demonstrated that the pre-administration of Lactobacillus (JY300-8 and JMR-01) for 20 days before establishing tumor models resulted in an 86.21% reduction in tumor formation rate compared to tumor control group. Subsequently, continuous oral administration of living Lactobacillus significantly suppresses tumor growth, and tumor volumes decrease by 65.2%. Microbiome and metabolome analyses reveal that Lactobacillus suppresses colonic tumorigenesis and progression through the modulation of gut microbiota homeostasis and metabolites, including the down-regulation of secondary bile acids, sphingosine 1-phosphate (S1P), and pyrimidine metabolism, as well as the production of anticarcinogenic compounds in tumor-bearing mice. Additionally, metabolome analyses of Lactobacillus (JY300-8 and JMR-01) indicate that living Lactobacillus could reduce the relative abundance of alanine and L-serine to suppress tumor progression by regulating the tumor microenvironment, including down-regulation of pyrimidine metabolism and S1P signaling in cancer. These findings provide a potential prevention strategy and therapeutic target for colon cancer through the intervention of dietary Lactobacillus. IMPORTANCE The modulation of gut microbiota and metabolites has a significant influence on the progression of colon cancer. Our research indicated that the intervention of probiotics is a potentially feasible strategy for preventing colon cancer. We have also revealed the underlying antitumor mechanism through the alteration of gut microbiota and their metabolites, which could lead to broader biomedical impacts on the prevention and therapy of colon cancer with microbiota-based therapy regulated by probiotics.

Apoptosis induction in cancer cell lines and anti-inflammatory and anti-pathogenic properties of proteinaceous metabolites secreted from potential probiotic Enterococcus faecalis KUMS-T48

Potential probiotic Enterococcus faecalis KUMS-T48, isolated from a kind of Iranian traditional dairy product (Tarkhineh), was assessed for its anti-pathogenic, anti-inflammatory and anti-proliferative properties against HT-29 and AGS cancer cell lines. This strain showed strong effects on Bacillus subtilis and Listeria monocytogenes and moderate effect on Yersinia enterocolitica, while indicated weak effect on Klebsiella pneumoniae and Escherichia coli. Also, neutralizing the cell-free supernatant and treating it with catalase and proteinase K enzymes reduced the antibacterial effects. Similar to Taxol, the cell-free supernatant of E. faecalis KUMS-T48 inhibited the in vitro proliferation of both cancer cells in a dose-dependent manner, but unlike Taxol, they had no activity against normal cell line (FHs-74). Pronase-treatment of the CFS of E. faecalis KUMS-T48 abrogated its anti-proliferative capacity, thereby showing the proteinaceous nature of the cell-free supernatant. Further, induction of apoptosis-based cytotoxic mechanism by E. faecalis KUMS-T48 cell-free supernatant is related to anti-apoptotic genes ErbB-2 and ErbB-3, which is different from Taxol's apoptosis induction (intrinsic mitochondria apoptosis pathway). Also, as evidenced by a decline in interleukin 1β inflammation-promoting gene expression and a rise in the anti-inflammatory interleukin-10 gene expression in the HT-29 cell line, probiotic E. faecalis KUMS-T48 cell-free supernatant demonstrated a significant anti-inflammatory impact.

Gut Microbiota Eubacterium callanderi Exerts Anti-Colorectal Cancer Activity

The gut microbiota (GM) is associated with colorectal cancer (CRC) development. However, studies demonstrating the role of GM in CRC are limited to metagenomic analyses. These studies lack direct evidence proving that the candidate strains are involved in CRC, and isolated probiotics for bacteriotherapy. Therefore, to identify novel GM with anti-CRC activity, we previously isolated gut bacteria from the feces of healthy individuals, screened the isolated GM's anti-CRC activity, and discovered that cell-free supernatants of GM isolates demonstrated antiproliferative activity against CRC cells. Here, our study identified one of them as Eubacterium callanderi and chose it for further study because the genus Eubacterium has been suggested to contribute to various aspects of gut health; however, the functions are unknown. First, we confirmed that E. callanderi cell-free supernatant (EcCFS) exerted antiproliferative activity-by inducing apoptosis and cell cycle arrest-that was dose-dependent and specific to cancer cell lines. Next, we discovered that EcCFS active molecules were heat stable and protease insensitive. High-performance liquid chromatography analysis revealed that EcCFS contained high butyrate concentrations possessing anticancer activity. Additionally, gas chromatography-mass spectrometry analysis of the aqueous phase of ethyl acetate-extracted EcCFS and an antiproliferation assay of the aqueous phase and 4-aminobutanoic acid (GABA) suggested that GABA is a possible anti-CRC agent. Finally, in the CT26 allograft mouse model, E. callanderi oral administration and EcCFS peri-tumoral injection inhibited tumor growth in vivo. Therefore, our study reveals that E. callanderi has an anti-CRC effect and suggests that it may be a potential candidate for developing probiotics to control CRC. IMPORTANCE The gut microbiota has been reported to be involved in colorectal cancer, as suggested by metagenomic analysis. However, metagenomic analysis has limitations, such as bias in the analysis and the absence of bacterial resources for follow-up studies. Therefore, we attempted to discover gut microorganisms that are related to colorectal cancer using the culturomics method. In this study, we discovered that Eubacterium callanderi possesses anti-colorectal cancer activity in vitro and in vivo, suggesting that E. callanderi could be used in bacteriotherapy for colorectal cancer treatment.

Bacteriocin Production by Bacillus Species: Isolation, Characterization, and Application

Antibiotic resistance is a problem that has been increasing lately; therefore, it is important to find new alternatives to treat infections induced by pathogens that cannot be eliminated with available products. Small antimicrobial peptides (AMPs) known as bacteriocin could be an alternative to antibiotics because they have shown to be effective against a great number of multidrug-resistant microbes. In addition to its high specificity against microbial pathogens and its low cytotoxicity against human cells, most bacteriocin present tolerance to enzyme degradation and stability to temperature and pH alterations. Bacteriocins are small peptides with a great diversity of structures and functions; however, their mechanisms of action are still not well understood. In this review, bacteriocin produced by Bacillus species will be described, especially its mechanisms of action, culture conditions used to improve its production and state-of-the-art methodologies applied to identify them. Bacteriocin utilization as food preservatives and as new molecules to treat cancer also will be discussed.

Anti-cancer activity of human gastrointestinal bacteria

Malignant neoplasm is one of the most incurable diseases among inflammatory diseases. Researchers have been studying for decades to win over this lethal disease and provide the light of hope to humankind. The gastrointestinal bacteria of human hold a complex ecosystem and maintain homeostasis. One hundred trillion microbes are residing in the gastrointestinal tract of human. Disturbances in the microbiota of human's gastrointestinal tract can create immune response against inflammation and also can develop diseases, including cancer. The bacteria of the gastrointestinal tract of human can secrete a variety of metabolites and bioproducts which aid in the preservation of homeostasis in the host and gut. During pathogenic dysbiosis, on the other hand, numerous microbiota subpopulations may increase and create excessive levels of toxins, which can cause inflammation and cancer. Furthermore, the immune system of host and the epithelium cell can be influenced by gut microbiota. Probiotics, which are bacteria that live in the gut, have been protected against tumor formation. Probiotics are now studied to see if they can help fight dysbiosis in cancer patients undergoing chemotherapy or radiotherapy because of their capacity to maintain gut homeostasis. Countless numbers of gut bacteria have demonstrated anti-cancer efficiency in cancer treatment, prevention, and boosting the efficiency of immunotherapy. The review article has briefly explained the anti-cancer immunity of gut microbes and their application in treating a variety of cancer. This review paper also highlights the pre-clinical studies of probiotics against cancer and the completed and ongoing clinical trials on cancers with the two most common and highly effective probiotics Lactobacillus and Bacillus spp.

A Combination of Two Probiotics, Lactobacillus sporogenes and Clostridium butyricum, Inhibits Colon Cancer Development: An In Vitro Study

Cancer remains a leading cause of death worldwide and, even though several advances have been made in terms of specific treatment, the late-stage detection and the associated side effects of the conventional drugs sustain the search for better treatment alternatives. Probiotics are live microorganisms that have been proven to possess numerous health benefits for human hosts, including anticancer effects. In the present study, the in vitro effect of the association of two probiotic strains (PBT), Lactobacillus sporogenes and Clostridium butyricum, were tested against colon (HT-29 and HCT 116), lung (A549), and liver (HepG2) cancer cell lines, alone or in combination with 5-fluorouracil (5FU). Moreover, the underlying mechanism of PBT and PBT-5FU against the HT-29 cell line was evaluated using the Hoechst 33342 staining, revealing characteristic apoptotic modifications, such as chromatin condensation, nuclear fragmentation, and membrane blebbing. Furthermore, the increase in the expression of pro-apoptotic Bax, Bid, Bad, and Bak proteins and the inhibition of the anti-apoptotic Bcl-2 and Bcl-XL proteins were recorded. Collectively, these findings suggest that the two strains of probiotic bacteria, alone or in association with 5FU, induce apoptosis in colon cancer cells and may serve as a potential anticancer treatment.

Gut microbiota: Role and Association with Tumorigenesis in Different Malignancies

The microbiota has been associated with different cancer and may vary from patient to patient. A specific microbial strain can alter the progression of cancer and therapeutic outcome in response to anti-cancer therapy. The variations in microbiota contributed due to the individual microbiome of the microorganism are responsible for diverse clinical outcomes. The expansion of microbiota subpopulation during dysbiosis can lead to toxin production, inducing inflammation and cancer. The microbiota can be a dual-edged sword because it can be tumor-suppressive or oncogenic in the case of the gut. The transition of cancer cells from early to late-stage also impacts the composition of the microbiota, and this alteration could change the behavior of cancer. Multi-omics platforms derived data from an individual's multi-dimensional data (DNA, mRNA, microRNA, protein, metabolite, microbiota, and microbiome), i.e., individualome, to exploit it for personalized tailored treatment for different cancers in a precise manner. A number of studies suggest the importance of microbiota and its add-in suitability to existing treatment options for different malignancies. Furthermore, in vitro, and in vivo studies and cancer clinical trials suggest that probiotics have driven modulation of gut microbiota and other sites discourage the aggressive behavior and progression of different cancers.

Effects of Probiotics at the Interface of Metabolism and Immunity to Prevent Colorectal Cancer-Associated Gut Inflammation: A Systematic Network and Meta-Analysis With Molecular Docking Studies

Background

Dysbiosis/imbalance in the gut microbial composition triggers chronic inflammation and promotes colorectal cancer (CRC). Modulation of the gut microbiome by the administration of probiotics is a promising strategy to reduce carcinogenic inflammation. However, the mechanism remains unclear.

Methods

In this study, we presented a systematic network, meta-analysis, and molecular docking studies to determine the plausible mechanism of probiotic intervention in diminishing CRC-causing inflammations.

Results

We selected 77 clinical, preclinical, in vitro, and in vivo articles (PRISMA guidelines) and identified 36 probiotics and 135 training genes connected to patients with CRC with probiotic application. The meta-analysis rationalizes the application of probiotics in the prevention and treatment of CRC. An association network is generated with 540 nodes and 1,423 edges. MCODE cluster analysis identifies 43 densely interconnected modules from the network. Gene ontology (GO) and pathway enrichment analysis of the top scoring and functionally significant modules reveal stress-induced metabolic pathways (JNK, MAPK), immunomodulatory pathways, intrinsic apoptotic pathways, and autophagy as contributors for CRC where probiotics could offer major benefits. Based on the enrichment analyses, 23 CRC-associated proteins and 7 probiotic-derived bacteriocins were selected for molecular docking studies. Results indicate that the key CRC-associated proteins (e.g., COX-2, CASP9, PI3K, and IL18R) significantly interact with the probiotic-derived bacteriocins (e.g., plantaricin JLA-9, lactococcin A, and lactococcin mmfii). Finally, a model for probiotic intervention to reduce CRC-associated inflammation has been proposed.

Conclusion

Probiotics and/or probiotic-derived bacteriocins could directly interact with CRC-promoting COX2. They could modulate inflammatory NLRP3 and NFkB pathways to reduce CRC-associated inflammation. Probiotics could also activate autophagy and apoptosis by regulating PI3K/AKT and caspase pathways in CRC. In summary, the potential mechanisms of probiotic-mediated CRC prevention include multiple signaling cascades, yet pathways related to metabolism and immunity are the crucial ones.

The gut microbiota can orchestrate the signaling pathways in colorectal cancer

Current evidence suggests that bacteria contribute to the development of certain cancers, such as colorectal cancer (CRC), partly by stimulating chronic inflammation. However, little is known about the bacterial impact on molecular pathways in CRC. Recent studies have demonstrated how specific bacteria can influence the major CRC-related pathways, i.e., Wnt, PI3K-Akt, MAPK, TGF-β, EGFR, mTOR, and p53. In order to advance the current understanding and facilitate the choice of pathways to investigate, we have systematically collected and summarized the current knowledge within bacterial altered major pathways in CRC. Several pro-tumorigenic and anti-tumorigenic bacterial species and their respective metabolites interfere with the major signaling pathways addressed in this review. Not surprisingly, some of these studies investigated known CRC drivers, such as Escherichia coli, Fusobacterium nucleatum, and Bacteroides fragilis. Interestingly, some metabolites produced by bacterial species typically considered pathogenic, e.g., Vibrio cholera, displayed anti-tumorigenic activities, emphasizing the caution needed when classifying healthy and unhealthy microorganisms. The results collectively emphasize the complexity of the relationship between the microbiota and the tumorigenesis of CRC, and future studies should verify these findings in more realistic models, such as organoids, which constitute a promising platform. Moreover, future trials should investigate the clinical potential of preventive modulation of the gut microbiota regarding CRC development.

Biotechnological Applications of Probiotics: A Multifarious Weapon to Disease and Metabolic Abnormality

Consumption of live microorganisms "Probiotics" for health benefits and well-being is increasing worldwide. Their use as a therapeutic approach to confer health benefits has fascinated humans for centuries; however, its conceptuality gradually evolved with methodological advancement, thereby improving our understanding of probiotics-host interaction. However, the emerging concern regarding safety aspects of live microbial is enhancing the interest in non-viable or microbial cell extracts, as they could reduce the risks of microbial translocation and infection. Due to technical limitations in the production and formulation of traditionally used probiotics, the scientific community has been focusing on discovering new microbes to be used as probiotics. In many scientific studies, probiotics have been shown as potential tools to treat metabolic disorders such as obesity, type-2 diabetes, non-alcoholic fatty liver disease, digestive disorders (e.g., acute and antibiotic-associated diarrhea), and allergic disorders (e.g., eczema) in infants. However, the mechanistic insight of strain-specific probiotic action is still unknown. In the present review, we analyzed the scientific state-of-the-art regarding the mechanisms of probiotic action, its physiological and immuno-modulation on the host, and new direction regarding the development of next-generation probiotics. We discuss the use of recently discovered genetic tools and their applications for engineering the probiotic bacteria for various applications including food, biomedical applications, and other health benefits. Finally, the review addresses the future development of biological techniques in combination with clinical and preclinical studies to explain the molecular mechanism of action, and discover an ideal multifunctional probiotic bacterium.

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.

Cell-Free Supernatant of Odoribacter splanchnicus Isolated From Human Feces Exhibits Anti-colorectal Cancer Activity

The gut microbiota (GM) has been shown to be closely associated with the development of colorectal cancer (CRC). However, the involvement of GM is CRC has mainly been demonstrated by metagenomic profiling studies showing the compositional difference between the GM of healthy individuals and that of CRC patients and not by directly studying isolated gut microbes. Thus, to discover novel gut microbes involved in CRC, we isolated the GM from the feces of healthy individuals and evaluated its anti-CRC activity in vitro and in vivo. After GM isolation, cell-free supernatants (CFSs) were prepared from the isolated gut microorganisms to efficiently screen a large amount of the GM for anti-proliferative ability in vitro. Our results showed that the CFSs of 21 GM isolates had anti-proliferative activity against human colon cancer HCT 116 cells. Of these 21 GM isolates, GM07 was chosen for additional study because it had the highest anti-cancer activity against mouse colon cancer CT 26 cells in vitro and was further evaluated in a CT 26 allograft mouse model in vivo. GM07 was identified as Odoribacter splanchnicus through phylogenetic analysis based on 16S rRNA gene sequencing. Further investigation determined that the CFS of O. splanchnicus (OsCFS) induced anti-proliferative activity via apoptosis, but not cell cycle arrest. Moreover, GC/MS analysis suggested that the putative active molecule in OsCFS is malic acid. Finally, in the CRC mouse model, peri-tumoral injection of OsCFS significantly decreased CRC formation, compared to the control group. Altogether, these findings will provide valuable information for the discovery of potential probiotic candidates that inhibit CRC.

Cell cycle arrest and anti-cancer potential of probiotic Lactobacillus rhamnosus against HT-29 cancer cells

Introduction: Nowadays, probiotic bacteria have been considered as a factor in the prevention and treatment of cancer, especially by induction of apoptosis. This study aimed to evaluate the cytotoxic, anti-proliferative, and apoptotic effects of the supernatant of probiotic Lactobacillus rhamnosus on HT-29 cell line.

Methods : Molecular identification of probiotic L. rhamnosus was carried out using specific primers of 16S rRNA gene and sequencing. HT-29 cells were treated with different concentrations of bacterial supernatants at 24, 48, and 72 hours. MTT assay, Annexin V-FITC, real-time PCR, cell cycle analysis, and DAPI staining tests were conducted to evaluate the induction of apoptosis. The level of cyclin D1 protein was measured by immunocytochemistry method.

Results: The supernatant of L. rhamnosus inhibited the growth of HT-29 cancer cells in a dose- and time-dependent manner. The results of flow cytometry confirmed apoptotic cell death. Probiotic bacterial supernatant caused up-regulation of pro-apoptotic genes including caspase-3, caspase-9, and Bax. In addition, they resulted in down-regulation of Bcl2 and a decrease in expression levels of cyclin D1, cyclin E, and ERBB2 genes. Cancer cells were arrested in the G0/G1 phase of the cell cycle. The results of immunocytochemistry showed significant down-regulation of cyclin D1 protein during the 48 hours treatment with bacterial supernatant compared to the untreated cells.

Conclusion: The supernatant of probiotic L. rhamnosus has a great potential to inhibit the proliferation of HT-29 cells and the induction of apoptosis. L. rhamnosus might be used as a biological anti-cancer factor in the prevention and treatment of colon cancer.

Functional Genomic Insights into Probiotic Bacillus siamensis Strain B28 from Traditional Korean Fermented Kimchi

Bacillus siamensis strain B28 was previously isolated from traditional Korean fermented kimchi and inhibited expression of the microphthalmia-associated transcription factor and β-catenin in human embryonic kidney 293 cells. Here, we determined the complete genome sequence of strain B28 and compared it with other strains to elucidate its potential probiotic properties. Strain B28 does not contain antibiotic resistance-, hemolysin- or enterotoxin-encoding genes. The genome includes genes related to survival in extreme conditions, adhesion in the gut, and synthesis of the bacteriocin. Considering the potential for enhancement of human health, the strain B28 genome encodes genes related to production of eight essential amino acids, γ-aminobutyric acid, branched-chain fatty acids, γ-glutamyltransferase, and subtilisin. There are genes for the synthesis of uracil, lipoteichoic acid, glutathione, and several reactive oxygen species-scavenging enzymes. Experimentally, strain B28 exhibited sensitivity to eight antibiotics and antibacterial activity against seven foodborne pathogens. B. siamensis B28 is a safe strain with potential for development as a probiotic.

The Impact of Long-Term Antibiotic Therapy of Cutaneous Adverse Reactions to EGFR Inhibitors in Colorectal Cancer Patients

Colorectal cancer (CRC) is an important public health issue, in terms of incidence and mortality, with approximately 1.8 million new cases reported worldwide in 2018. Advancements in understanding pathophysiological key steps in CRC tumorigenesis have led to the development of new targeted therapies such as those based on epidermal growth factor receptor inhibitors (EGFR inhibitors). The cutaneous adverse reactions induced by EGFR inhibitors, particularly papulopustular rash, often require long-term antibiotic treatment with tetracycline agents (mostly minocycline and doxycycline). However, this raises several issues of concern: possible occurrence of gut dysbiosis in already vulnerable CRC patients, selection of highly antibiotic resistant and/or virulent clones, development of adverse reactions related to tetracyclines, interference of antibiotics with the response to oncologic therapy, with a negative impact on disease prognosis etc. In the context of scarce information regarding these issues and controversial opinions regarding the role of tetracyclines in patients under EGFR inhibitors, our aim was to perform a thorough literature review and discuss the main challenges raised by long-term use of tetracyclines in advanced CRC patients receiving this targeted therapy.

Probiotics: A Promising Candidate for Management of Colorectal Cancer

Colorectal cancer (CRC) is the World's third most frequently diagnosed cancer type. It accounted for about 9.4% mortality out of the total incidences of cancer in the year 2020. According to estimated facts by World Health Organization (WHO), by 2030, 27 million new CRC cases, 17 million deaths, and around 75 million people living with the disease will appear. The facts and evidence that establish a link between the intestinal microflora and the occurrence of CRC are quite intuitive. Current shortcomings of chemo- and radiotherapies and the unavailability of appropriate treatment strategies for CRC are becoming the driving force to search for an alternative approach for the prevention, therapy, and management of CRC. Probiotics have been used for a long time due to their beneficial health effects, and now, it has become a popular candidate for the preventive and therapeutic treatment of CRC. The probiotics adopt different strategies such as the improvement of the intestinal barrier function, balancing of natural gut microflora, secretion of anticancer compounds, and degradation of carcinogenic compounds, which are useful in the prophylactic treatment of CRC. The pro-apoptotic ability of probiotics against cancerous cells makes them a potential therapeutic candidate against cancer diseases. Moreover, the immunomodulatory properties of probiotics have created interest among researchers to explore the therapeutic strategy by activating the immune system against cancerous cells. The present review discusses in detail different strategies and mechanisms of probiotics towards the prevention and treatment of CRC.

In vivo murine breast cancer targeting by magnetic iron nanoparticles involving L. GG cytoplasmic fraction

OBJECTIVES

Use of chemical anti-cancer drugs frequently creates serious side effects. However, probiotics are natural and treat different kinds of cancer without undesired effects.

MATERIALS AND METHODS

In this study, a nano delivery system was planned to transport the Lactobacillus rhamnosus GG (L. GG) cytoplasmic fraction (Cf) to cancerous tissue in a mouse model. Magnetic iron nanoparticles (MINPs) were synthesized and loaded with L. GG-Cf(0, 0.312, 0.625, 1.25, and 2.5 mg/ml) and were administrated for three weeks to treat experimentally induced murine breast cancer in a constant magnetic field. At the end of the trial, the treating efficacy of this complex molecule was evaluated via western blotting, immunohistochemistry, and qPCR.

RESULTS

Results showed that MINPS can deliver and accumulate L. GG-Cf in cancer tissue, and reduce the size and volume of the tumors. Additionally, in cancer tissues of treated mice with 2.5 mg/ml of Cf-MINPs, significantly induced apoptosis was seen compared with untreated mice (control), and our data proved that this induction may be due to the caspase-3 pathway.

CONCLUSION

L. GG-Cf could treat murine breast cancer, and MINPs are a suitable candidate for drug delivery because of their safety, uniformity, and magnetic properties.

Exploring the Role of Gut Microbiome in Colon Cancer

Dysbiosis of the gut microbiome has been associated with the development of colorectal cancer (CRC). Gut microbiota is involved in the metabolic transformations of dietary components into oncometabolites and tumor-suppressive metabolites that in turn affect CRC development. In a healthy colon, the major of microbial metabolism is saccharolytic fermentation pathways. The alpha-bug hypothesis suggested that oncogenic bacteria such as enterotoxigenic Bacteroides fragilis (ETBF) induce the development of CRC through direct interactions with colonic epithelial cells and alterations of microbiota composition at the colorectal site. Escherichia coli, E. faecalis, F. nucleatum, and Streptococcus gallolyticus showed higher abundance whereas Bifidobacterium, Clostridium, Faecalibacterium, and Roseburia showed reduced abundance in CRC patients. The alterations of gut microbiota may be used as potential therapeutic approaches to prevent or treat CRC. Probiotics such as Lactobacillus and Bifidobacterium inhibit the growth of CRC through inhibiting inflammation and angiogenesis and enhancing the function of the intestinal barrier through the secretion of short-chain fatty acids (SCFAs). Crosstalk between lifestyle, host genetics, and gut microbiota is well documented in the prevention and treatment of CRC. Future studies are required to understand the interaction between gut microbiota and host to the influence and prevention of CRC. However, a better understanding of bacterial dysbiosis in the heterogeneity of CRC tumors should also be considered. Metatranscriptomic and metaproteomic studies are considered a powerful omic tool to understand the anti-cancer properties of certain bacterial strains. The clinical benefits of probiotics in the CRC context remain to be determined. Metagenomic approaches along with metabolomics and immunology will open a new avenue for the treatment of CRC shortly. Dietary interventions may be suitable to modulate the growth of beneficial microbiota in the gut.

The Role of Probiotics in Cancer Prevention

Simple Summary

Cancer is considered one of the leading causes of human mortality in the world and is the subject of much research. The risk of developing cancer depends on genetic factors, as well as the body’s immune status. The intestinal microbiome plays very important role in maintaining homeostasis in the human body. Probiotics have gained increasing medical significance due to the beneficial effect on the human body associated with the prevention and support of the treatment of many chronic diseases, including cancer in the absence of side effects. The aim of this review was to summarize the knowledge about the effect of probiotic microorganisms in the prevention of cancer. There is a lot of evidence that the use of probiotics can play an important role in cancer prevention and support anti-cancer therapies.

Abstract

The gut microbiome can play important role in maintaining homeostasis in the human body. An imbalance in the gut microbiome can lead to pro-inflammatory immune responses and the initiation of disease processes, including cancer. The research results prove some strains of probiotics by modulating intestinal microbiota and immune response can be used for cancer prevention or/and as adjuvant treatment during anticancer chemotherapy. This review presents the latest advances in research into the effectiveness of probiotics in the prevention and treatment support of cancer. The described issues concern to the anticancer activity of probiotic microorganisms and their metabolites. In addition, we described the potential mechanisms of probiotic chemoprevention and the advisability of using probiotics.

The Protective Role of Probiotics against Colorectal Cancer

Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide and a major global public health problem. With the rapid development of the economy, the incidence of CRC has increased linearly. Accumulating evidence indicates that changes in the gut microenvironment, such as undesirable changes in the microbiota composition, provide favorable conditions for intestinal inflammation and shaping the tumor growth environment, whereas administration of certain probiotics can reverse this situation to a certain extent. This review summarizes the roles of probiotics in the regulation of CRC, such as enhancing the immune barrier, regulating the intestinal immune state, inhibiting pathogenic enzyme activity, regulating CRC cell proliferation and apoptosis, regulating redox homeostasis, and reprograming intestinal microbial composition. Abundant studies have provided a theoretical foundation for the roles of probiotics in CRC prevention and treatment, but their mechanisms of action remain to be investigated, and further clinical trials are warranted for the application of probiotics in the target population.

Probiotics in Medicine: A Long Debate

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called “microbiota-gut-liver axis” as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the “microbiota-gut-brain axis.” Moreover, recently the “gut-lung axis” in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.

Molecular mechanisms of postbiotics in colorectal cancer prevention and treatment

The occurrence of colorectal cancer (CRC) has been rising expeditiously and anticipated that 2.4 million new occasions of CRC will be detected yearly around the world until the year 2035. Due to some side-effects and complications of conventional CRC therapies, bioactive components such as microbial-derived biomolecules (postbiotics) have been attaining great significance by researchers for adjuvant therapy in CRC patients. The term 'postbiotics' encompasses an extensive range of complex micro- and macro-molecules (<50, 50-100, and 100< kDa) such as inactivated microbial cells, cell fractions or metabolites, which confer various physiological health benefits to the host when administered in adequate amounts. Postbiotics modulate the composition of the gut microbiota and the functionality of the immune system, as well as promote the CRC treatment effectiveness and reduces its side-effects in CRC patients due to possessing anti-oxidant, anti-proliferative, anti-inflammatory, and anti-cancer activities. Presently scientific literature confirms that postbiotics with their unique characteristics in terms of clinical (safe origin), technological (stability), and economic (low production costs) aspects can be used as promising tools for both prevent and adjuvant treat strategies in CRC patients without any serious undesirable side-effects. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the prevention and treatment of CRC.

Anti-cancer effects of Bifidobacterium species in colon cancer cells and a mouse model of carcinogenesis

INTRODUCTION

Probiotics are suggested to prevent colorectal cancer (CRC). This study aimed to investigate the anticancer properties of some potential probiotics in vitro and in vivo.

MATERIALS AND METHODS

Anticancer effects of the following potential probiotic groups were investigated in LS174T cancer cells compared to IEC-18 normal cells. 1. a single strain of Bifidobacterium. breve, 2. a single strain of Lactobacillus. reuteri, 3. a cocktail of 5 strains of Lactobacilli (LC), 4. a cocktail of 5 strains of Bifidobacteria (BC), 5. a cocktail of 10 strains from Lactobacillus and Bifidobacterium (L+B). Apoptosis rate, EGFR, HER-2 and PTGS-2 (COX-2 protein) expression levels were assessed as metrics of evaluating anticancer properties. Effect of BC, as the most effective group in vitro, was further assessed in mice models.

RESULTS

BC induced ~21% and only ~3% apoptosis among LS174T and IEC-18 cells respectively. BC decreased the expression of EGFR by 4.4 folds, HER-2 by 6.7 folds, and PTGS-2 by 20 folds among the LS174T cells. In all these cases, BC did not interfere significantly with the expression of the genes in IEC-18 cells. This cocktail has caused only 1.1 folds decrease, 1.8 folds increase and 1.7 folds decrease in EGFR, HER-2 and PTGS-2 expression, respectively. Western blot analysis confirmed these results in the protein level. BC significantly ameliorated the disease activity index, restored colon length, inhibited the increase in incidence and progress of tumors to higher stages and grades.

CONCLUSIONS

BC was the most efficient treatment in this study. It had considerable "protective" anti-cancer properties and concomitantly down regulated EGFR, HER-2 and PTGS-2 (COX-2), while having significant anti-CRC effects on CRC mice models. In general, this potential probiotic could be considered as a suitable nutritional supplement to treat and prevent CRC.

Effects of an orally supplemented probiotic on the autophagy protein LC3 and Beclin1 in placentas undergoing spontaneous delivery during normal pregnancy

BACKGROUND

Probiotic supplementation has been shown to be beneficial and is now widely promoted as an auxiliary medicine for maternal health, but the underlying mechanism is still unclear. Thus, this study aimed to explore the effects of probiotic supplementation on the placental autophagy-related proteins LC3 and Beclin1.

METHOD

A population-based cohort of specimens was collected under sterile conditions from 37 healthy nulliparous pregnant women who underwent systemic examination and delivered at the First Affiliated Hospital of Jinan University (Guangzhou, China). At 32 weeks of gestation, the pregnant women in the probiotic group were orally supplemented with golden bifid, and the pregnant women in the control group received no probiotic. Pregnant women with pregnancy-associated complications were excluded in the follow-up period, and 25 pregnant women undergoing spontaneous delivery were enrolled. The placental tissue specimens were collected at term. Western blotting was used to detect the protein expression, and qRT-PCR was used to detect the mRNA expression of the placental autophagy-related proteins LC3 and Beclin1.

RESULTS

①There was no significant difference in the expression levels of either LC3 or Beclin1 protein between the two groups (P > 0.05). ②Probiotic supplementation induced a modest but not significant decrease in the content of LC3-mRNA with a significant decrease in the content of Beclin1-mRNA (P < 0.05).

CONCLUSION

Our study indicates that probiotic supplementation may reduce Beclin1-mRNA levels.

Diet influences the functions of the human intestinal microbiome

Gut microbes programme their metabolism to suit intestinal conditions and convert dietary components into a panel of small molecules that ultimately affect host physiology. To unveil what is behind the effects of key dietary components on microbial functions and the way they modulate host-microbe interaction, we used for the first time a multi-omic approach that goes behind the mere gut phylogenetic composition and provides an overall picture of the functional repertoire in 27 fecal samples from omnivorous, vegan and vegetarian volunteers. Based on our data, vegan and vegetarian diets were associated to the highest abundance of microbial genes/proteins responsible for cell motility, carbohydrate- and protein-hydrolyzing enzymes, transport systems and the synthesis of essential amino acids and vitamins. A positive correlation was observed when intake of fiber and the relative fecal abundance of flagellin were compared. Microbial cells and flagellin extracted from fecal samples of 61 healthy donors modulated the viability of the human (HT29) colon carcinoma cells and the host response through the stimulation of the expression of Toll-like receptor 5, lectin RegIIIα and three interleukins (IL-8, IL-22 and IL-23). Our findings concretize a further and relevant milestone on how the diet may prevent/mitigate disease risk.

Association of oral dysbiosis with oral cancer development

Oral squamous cell carcinoma (OSCC) is the leading cause of mortality for oral cancer. Numerous risk factors mainly related to unhealthy habits and responsible for chronic inflammation and infections have been recognized as predisposing factors for oral carcinogenesis. Recently, even microbiota alterations have been associated with the development of human cancers. In particular, some specific bacterial strains have been recognized and strongly associated with oral cancer development (Capnocytophaga gingivalis, Fusobacterium spp., Streptococcus spp., Peptostreptococcus spp., Porphyromonas gingivalis and Prevotella spp.). Several hypotheses have been proposed to explain how the oral microbiota could be involved in cancer pathogenesis by mainly paying attention to chronic inflammation, microbial synthesis of cancerogenic substances, and alteration of epithelial barrier integrity. Based on knowledge of the carcinogenic effects of dysbiosis, it was recently suggested that probiotics may have anti-tumoral activity. Nevertheless, few data exist with regard to probiotic effects on oral cancer. On this basis, the association between the development of oral cancer and oral dysbiosis is discussed focusing attention on the potential benefits of probiotics administration in cancer prevention.

Long Non-Coding RNA Cancer Susceptibility 9 (CASC9) Up-Regulates the Expression of ERBB2 by Inhibiting miR-193a-5p in Colorectal Cancer

Background

Emerging studies have reported that long non-coding RNAs (lncRNAs) were crucial regulators in the progression of colorectal cancer (CRC). LncRNA susceptibility 9 (CASC9) was involved in several cancers; however, its role in CRC remains unknown.

Methods

RT-PCR was done to probe the expression of CASC9 and miR-193a-5p in CRC samples. CRC cell lines (HCT116 and SW480) were used as cell models. The biological influence of CASC9 on cancer cells was studied using CCK-8 assay, Transwell assay and TUNEL assay in vitro, and subcutaneous xenotransplanted tumor model in vivo. Interaction between CASC9 and miR-193a-5p was investigated by bioinformatics analysis, RT-PCR, and luciferase reporter assay. The expression level of the downstream gene of miR-193a-5p, erb-b2 receptor tyrosine kinase 2 (ERBB2), was tested by Western blot.

Results

CASC9 was significantly up-regulated in CRC samples, while miR-193a-5p was markedly down-regulated. Overexpression of CASC9 promoted viability, migration and invasion of CRC cells, while overexpression of miR-193a-5p had the opposite effect. CASC9 could down-regulate miR-193a-5p via sponging it, and there was a negative relevancy between CASC9 and miR-193a-5p in CRC samples. CASC9 also enhanced the expression levels of ERBB2, while this effect could be reversed by co-transfection with miR-193a-5p.

Conclusion

CASC9, an oncogenic lncRNA, was abnormally up-regulated in CRC tissues, and it could indirectly modulate the expression of ERBB2 via reducing the expression level of miR-193a-5p.

Bacillus strains as human probiotics: characterization, safety, microbiome, and probiotic carrier

Both spore and vegetative forms of Bacillus species have been used as probiotics, and they have high stability to the surrounding atmospheric conditions such as heat, gastric conditions, and moisture. The commercial Bacillus probiotic strains in use are B. cereus, B. clausii, B. coagulans, B. licheniformis, B. polyfermenticus, B. pumilus, and B. subtilis. These strains have antimicrobial, anticancer, antioxidant, and vitamin production properties. However, Bacillus probiotics can also produce toxins and biogenic amines and transfer antibiotic resistance genes; therefore, their safety is a concern. Studies on the microbiome using probiotic Bacillus strains are limited in humans. Most microbiome research has been conducted in chicken, mouse, and pig. Some Bacillus probiotics are used as fermentation starters in plant and soybean and dietary supplement of baking foods as a probiotic carrier. This review summarizes the characterization of Bacillus species as probiotics for human use and their safety, microbiome, and probiotic carrier.

A Reasonable Diet Promotes Balance of Intestinal Microbiota: Prevention of Precolorectal Cancer

Colorectal cancer (CRC) is a multifactorial disease and the second leading cause of cancer death worldwide. The pathogenesis of colorectal cancer includes genetics, age, chronic inflammation, and lifestyle. Increasing attention has recently been paid to dietary factors. Evidence from epidemiological studies and clinical research suggests that high-fibre diets can significantly reduce the incidence of CRC, whilst the consumption of high-fat diets, high-protein diets, red meat, and processed meat is high-risk factors for tumorigenesis. Fibre is a regulator of intestinal microflora and metabolism and is thus a key dietary component for maintaining intestinal health. Intestinal microbes are closely linked to CRC, with the growth of certain microbiota (such as Fusobacterium nucleatum, Escherichia coli, or Bacteroides fragilis) favouring carcinogenesis, whilst the dominant microbiota population of the intestine, such as Bacteroidetes, Firmicutes, Actinobacteria, and Proteobacteria, have multiple mechanisms of antitumour activity. Various dietary components have direct effects on the types of intestinal microflora: in the Western diet mode (high-fat, high-protein, and red meat), the proportion of conditional pathogens in the intestinal flora increases, the proportion of commensal bacteria decreases, and the occurrence of colorectal cancer is promoted. Conversely, a high-fibre diet can increase the abundance of Firmicutes and reduce the abundance of Bacteroides and consequently increase the concentration of short-chain fatty acids (SCFAs) in the intestine, inhibiting the development of CRC. This article reviews the study of the relationship between diet, intestinal microbes, and the promotion or inhibition of CRC and analyses the relevant molecular mechanisms to provide ideas for the prevention and treatment of CRC.

Lactobacillus plantarum induces apoptosis in gastric cancer cells via modulation of signaling pathways in Helicobacter pylori

Introduction: Gastric cancer is considered the second prevalent cause of death around the world. This type of cancer is generally induced by Helicobacter pylori which could colonize within the gastric mucosa of the infected cases. To date, triple antibiotic therapy has routinely been utilized for controlling the H. pylori- induced infection. However, this strategy has been unsuccessful, in large part because of issues such as occurring point mutations in the H. pylori genome that can induce resistance to the antibiotics administered. Recently, it has been shown that different probiotics may have strong anti-cancer effects, in which they are capable of inhibiting H. pylori by both immunological and non-immunological mechanisms. Here, we aimed at finding possible anti-cancer impacts of the probiotic bacterium Lactobacillus plantarum on gastric cancer, AGS cells. Methods: The anti-cancer effects of the conditioned media of the locally isolated L. plantarum on the AGS cells were evaluated by different analyses such as flow cytometry, DNA ladder assay, DAPI staining, and RT-PCR. Results: Our findings showed that the conditioned media of L. plantarum can inhibit both H. pylori and AGS cells through up-/down-regulation of PTEN, Bax, TLR4, and AKT genes. The exudates of the probiotic L. plantarum bacteria can increase the expression of PTEN, Bax, and TLR4, and also decrease the expression of AKT gene. Conclusion: In agreement with different reports, our results proved the anti-cancer effects of the locally isolated L. plantarum through some immunological cell signaling pathways. Accordingly, it seems the probiotics could be considered as at least a complementary treatment for different types of malignancies.

Identification of a bacteriocin-like compound from Lactobacillus plantarum with antimicrobial activity and effects on normal and cancerogenic human intestinal cells

In this paper, we demonstrate that the antimicrobial activity of L. plantarum PBS067 strain against antagonist microorganisms was mediated by the production of a bacteriocin-like compound secreted at the stationary phase of the growth. The novel bacteriocin-like compound, designed plantaricin P1053, was identified by using sorption–desorption method, butanol extraction and SEC-HPLC. The molecular mass of plantaricin P1053 was shown to be 1053 Da by ESI-MS analysis. Plantaricin P1053 exhibited a broad-spectrum antimicrobial activity against Gram-positive bacteria as S. aureus and Gram-negative bacteria as E. coli. In addition to the antimicrobial activity, the isolated bacteriocin-like compound showed effects on normal and cancerogenic epithelial intestinal cell lines through an enhancing of viability of healthy cells and a proliferation reduction of cancer cells. Moreover, in this paper we demonstrate that the isolated bacteriocin-like compound acts on healthy cells through the epidermal growth factor receptor (EGFR) pathways. In conclusion, plantaricin P1053 isolated from L. plantarum PBS067 strain could represent one of the first multifunctional bacteriocin-like compound acting on human epithelial intestinal cells.

Probiotic Bacteria: A Promising Tool in Cancer Prevention and Therapy

Gut microbiota is widely considered to be one of the most important components to maintain balanced homeostasis. Looking forward, probiotic bacteria have been shown to play a significant role in immunomodulation and display antitumour properties. Bacterial strains could be responsible for detection and degradation of potential carcinogens and production of short-chain fatty acids, which affect cell death and proliferation and are known as signaling molecules in the immune system. Lactic acid bacteria present in the gut has been shown to have a role in regression of carcinogenesis due to their influence on immunomodulation, which can stand as a proof of interaction between bacterial metabolites and immune and epithelial cells. Probiotic bacteria have the ability to both increase and decrease the production of anti-inflammatory cytokines which play an important role in prevention of carcinogenesis. They are also capable of activating phagocytes in order to eliminate early-stage cancer cells. Application of heat-killed probiotic bacteria coupled with radiation had a positive influence on enhancing immunological recognition of cancer cells. In the absence of active microbiota, murine immunity to carcinogens has been decreased. There are numerous cohort studies showing the correlation between ingestion of dairy products and the risk of colon and colorectal cancer. An idea of using probiotic bacteria as vectors to administer drugs has emerged lately as several papers presenting successful results have been revealed. Within the next few years, probiotic bacteria as well as gut microbiota are likely to become an important component in cancer prevention and treatment.

The Protective Role of Bacteroides fragilis in a Murine Model of Colitis-Associated Colorectal Cancer

The incidence of colorectal cancer (CRC) is rapidly growing worldwide, and there is therefore a greater emphasis on studies of the treatment or prevention of CRC pathogenesis. Recent studies suggested that consideration of the microbiota is unavoidable to understand inflammation and tumorigenesis in the gastrointestinal tract. We demonstrate, using a mouse model of colitis-associated CRC, that human commensal B. fragilis protects against colon tumorigenesis. The protective role against tumor formation provided by B. fragilis is associated with inhibition of expression of the chemokine receptor CCR5 in the colon. The molecular mechanism for protection against CRC provided by B. fragilis is dependent on polysaccharide A production and is mediated by TLR2 signaling. Our results suggest that the commensal microorganism B. fragilis can be used to prevent inflammation-associated CRC development and may provide an effective therapeutic strategy for CRC.

Many patients with chronic inflammation of the gut, such as that observed in inflammatory bowel disease (IBD), develop colorectal cancer (CRC). Recent studies have reported that the development of IBD and CRC partly results from an imbalanced composition of intestinal microbiota and that intestinal inflammation in these diseases can be modulated by the microbiota. The human commensal Bacteroides fragilis is best exemplified playing a protective role against the development of experimental colitis in several animal disease models. In this study, we found that gut inflammation caused by dextran sulfate sodium (DSS) treatment was inhibited by B. fragilis colonization in mice. Further, we reveal a protective role of B. fragilis treatment against colon tumorigenesis using an azoxymethane (AOM)/DSS-induced model of colitis-associated colon cancer in mice and demonstrate that the decreased tumorigenesis by B. fragilis administration is accompanied by inhibited expression of C-C chemokine receptor 5 (CCR5) in the gut. We show direct evidence that the inhibition of tumor formation provided by B. fragilis in colitis-associated CRC animals was dependent on the production of polysaccharide A (PSA) from B. fragilis and that Toll-like receptor 2 (TLR2) signaling was responsible for the protective function of B. fragilis.

IMPORTANCE The incidence of colorectal cancer (CRC) is rapidly growing worldwide, and there is therefore a greater emphasis on studies of the treatment or prevention of CRC pathogenesis. Recent studies suggested that consideration of the microbiota is unavoidable to understand inflammation and tumorigenesis in the gastrointestinal tract. We demonstrate, using a mouse model of colitis-associated CRC, that human commensal B. fragilis protects against colon tumorigenesis. The protective role against tumor formation provided by B. fragilis is associated with inhibition of expression of the chemokine receptor CCR5 in the colon. The molecular mechanism for protection against CRC provided by B. fragilis is dependent on polysaccharide A production and is mediated by TLR2 signaling. Our results suggest that the commensal microorganism B. fragilis can be used to prevent inflammation-associated CRC development and may provide an effective therapeutic strategy for CRC.

Probiotics and Their Potential Preventive and Therapeutic Role for Cancer, High Serum Cholesterol, and Allergic and HIV Diseases

The potential health benefits of probiotics have long been elucidated since Metchnikoff and his coworkers postulated the association of probiotic consumption on human's health and longevity. Since then, many scientific findings and research have further established the correlation of probiotic and gut-associated diseases such as irritable bowel disease and chronic and antibiotic-associated diarrhea. However, the beneficial impact of probiotic is not limited to the gut-associated diseases alone, but also in different acute and chronic infectious diseases. This is due to the fact that probiotics are able to modify the intestinal microbial ecosystem, enhance the gut barrier function, provide competitive adherence to the mucosa and epithelium, produce antimicrobial substances, and modulate the immune activity by enhancing the innate and adaptive immune response. Nevertheless, the current literature with respect to the association of probiotic and cancer, high serum cholesterol, and allergic and HIV diseases are still scarce and controversial. Therefore, in the present work, we reviewed the potential preventive and therapeutic role of probiotics for cancer, high serum cholesterol, and allergic and HIV diseases as well as providing its possible mechanism of actions.

Probiotics and their role in gastrointestinal cancers prevention and treatment; an overview

Cancers of the gastrointestinal (GI) track are a serious global health problem. The human GI tract is home to trillions of microorganisms that known as gut microbiota and have established a symbiotic relationship with the host. The human intestinal microbiota plays an important role in the development of the gut immune system, metabolism, nutrition absorption, production of short-chain fatty acids and essential vitamins, resistance to pathogenic microorganisms, and modulates a normal immunological response. Microbiota imbalance has been involved in many disorders including inflammatory bowel disease, obesity, asthma, psychiatric illnesses, and cancers. Oral administration of probiotics seems to play a protective role against cancer development as a kind of functional foods. Moreover, clinical application of probiotics has shown that some probiotic strains can reduce the incidence of post-operative inflammation in cancer patients. In the present narrative review, we carried out update knowledge on probiotic effects and underlying mechanism to GI cancers. Currently, it is accept that most commercial probiotic products are generally safe and can used as a supplement for cancer prevention and treatment. Nevertheless, well-designed, randomized, double blind, placebo-controlled human studies are required to gain the acceptance of the potential probiotics as an alternative therapy for cancer control..

The prophylactic effect of Acetobacter syzygii probiotic species against squamous cell carcinoma

Background. Squamous cell carcinoma is a prevalent carcinoma of the oral cavity. Recently anti-proliferative effect of probiotics has been considered and assessed against different cancers. The aim of this study was to evaluate the cytotoxicity of Acetobacter syzygii strain supernatant on KB human oral cancer cell line and KDR human epithelial normal cell line. Methods. The cytotoxicity assessments were performed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) as well as through qualitative (4',6-diamidino-2-phenylindole staining) and quantitative (flow cytometry assessments using the BD Biosciences Annexin V-FITC Kit) evaluations of apoptosis. Results.A. syzygii secretions exhibited significant cytotoxicity against KB cancer cell lines similar to cisplatin (75.7% apoptosis) while the rate of apoptosis in KDR normal cells was only 9.36%. The prophylactic effects of Lactobacillus acidophilus (PTCC 1643), as a reference bacterium, was similar to A. syzygii, indicating beneficial effects of useful bacteria on prevention of oral diseases. Conclusion. The anticancer bioactivity of A. syzygii strain secretions depends on the induction of apoptosis in KB cancer cells. However, several investigations should be conducted to precisely determine effective compounds to be used as anticancer therapeutics in the future.

Anticancer effects of the microbiome and its products

The human gut microbiome modulates many host processes, including metabolism, inflammation, and immune and cellular responses. It is becoming increasingly apparent that the microbiome can also influence the development of cancer. In preclinical models, the host response to cancer treatment has been improved by modulating the gut microbiome; this is known to have an altered composition in many diseases, including cancer. In addition, cancer treatment with microbial agents or their products has the potential to shrink tumours. However, the microbiome could also negatively influence cancer prognosis through the production of potentially oncogenic toxins and metabolites by bacteria. Thus, future antineoplastic treatments could combine the modulation of the microbiome and its products with immunotherapeutics and more conventional approaches that directly target malignant cells.

Functional foods and their role in cancer prevention and health promotion: a comprehensive review

Following cardiovascular disease, cancer is the second leading cause of death in most affluent countries. The 13.3 million new cases of cancer in 2010 were predicted to cost US$ 290 billion, but the total costs were expected to increases to US$ 458 billion in the year 2030 on basis of World Economic Forum in 2011. More than half of all cancer cases and deaths worldwide are consider being preventable. From its inception, the disease control priorities series has focused attention on delivering efficacious health interventions that can result in dramatic reductions in mortality and disability at relatively modest cost. The approach has been multidisciplinary, and the recommendations have been evidence-based, scalable, and adaptable in multiple settings. Better and more equitable health care is the shared responsibility of governments and international agencies, public and private sectors, and societies and individuals, and all of these partners have been involved in the development of the series. Functional foods are foods and food components that supply health benefits beyond basic nutrition. It's-believed these functional foods do more than simply provide nutrients because they help to maintaining health and thereby reducing the risk of disease. There are some reported evidences showing association between functional foods and cancer. For example, S-ally cysteine of garlic and lycopene from tomatoes in combination form suppressed the development of chemically induced gastric cancer by modulation of apoptosis-associated proteins (reduced Bcl-2/Bax ratio and up-regulation of Bim and caspases 8 and 3) at considerably lower intakes than when these substances were given in isolation. Similarly, vitamin D3 with genistein in combination form precipitated a growth inhibition of prostate cancer cells at much lower concentration than when these substances were provided individually. There are very few studies conducted worldwide to see the effects of functional foods on health or cancer or related states. This review, presents the complex patterns of cancer incidence and death around the world and evidence on effective and cost-effective ways to control cancers. The evaluation of cancer will indicate where cancer treatment is ineffective and wasteful, and offer alternative cancer care packages that are cost-effective and suited to low-resource settings. In the present paper, cancer prevention by functional foods is reviewed and the possible mechanisms of action are described.

Metabiotics: One Step ahead of Probiotics; an Insight into Mechanisms Involved in Anticancerous Effect in Colorectal Cancer

Colorectal cancer is closely associated with environment, diet and lifestyle. Normally it is treated with surgery, radiotherapy or chemotherapy but increasing systemic toxicity, resistance and recurrence is prompting scientists to devise new potent and safer alternate prophylactic or therapeutic strategies. Among these, probiotics, prebiotics, synbiotics, and metabiotics are being considered as the promising candidates. Metabiotics or probiotic derived factors can optimize various physiological functions of the host and offer an additional advantage to be utilized even in immunosuppressed individuals. Interestingly, anti colon cancer potential of probiotic strains has been attributable to metabiotics that have epigenetic, antimutagenic, immunomodulatory, apoptotic, and antimetastatic effects. Thus, it's time to move one step further to utilize metabiotics more smartly by avoiding the risks associated with probiotics even in certain normal/or immuno compromised host. Here, an attempt is made to provide insight into the adverse effects associated with probiotics and beneficial aspects of metabiotics with main emphasis on the modulatory mechanisms involved in colon cancer.

Evolving Roles of Probiotics in Cancer Prophylaxis and Therapy

In nutraceutical science, the ingestible live microbes 'probiotics' are regarded for their ability to confer multiplicity of health benefits on the consumers. Wide spectrum impact of these friendly microbes on the host health has been proved very frequently. They have been confirmed to boost immunity, aid in digestion, eliminate pathogens, curb inflammatory bowel diseases, moderate side effects of antibiotic therapy, lower cholesterol and blood glycemic index and produce vitamins. This review, however, focuses on the incipient, but promising area of probiotic diet-based prevention and remedy of cancer. Researchers are in universal agreement with the critical role of probiotics in getting rid of mutagens, delaying the onset of tumors, alleviating the side effects, pepping up chemotherapy, easing the postoperative complications, foiling remission and lifting the spirit of survivors. The key findings in the emerging roles of probiotics in onco-care have been summarized; the biological pathways discussed and anticipated developments in coming times are presented.