Probiotic supplementation attenuates the aggressiveness of chemically induced colorectal tumor in rats

Comprehensive pulmonary metabolic responses to silica nanoparticles exposure in Fisher 344 rats

Silica nanoparticles (SiNPs) could induce adverse pulmonary effects, but the mechanism was not clear enough. Metabolomics is a sensitive and high-throughput approach that could investigate the intrinsic causes of adverse health effects caused by SiNPs. The current investigation represented the first in vivo metabolomics study examining the chronic pulmonary toxicity of SiNPs at a low dosage, mimicking real human exposure situation. The recovery process after the cessation of exposure was also taken into consideration. Fisher 344 rats were treated with either saline or SiNPs for 6 months. Half of the animals in each group received an additional six-month period for recovery. The findings indicated that chronic low-level exposure to SiNPs resulted in notable alterations in pulmonary metabolism of amino acids, lipids, carbohydrates, and nucleotides. SiNPs exerted an impact on various metabolites and metabolic pathways which are linked to oxidative stress, inflammation and tumorigenesis. These included but were not limited to L-carnitine, spermidine, taurine, xanthine, and glutathione metabolism. The metabolic alterations caused by SiNPs exhibited a degree of reversibility. However, the interference of SiNPs on two metabolic pathways related to tumorigenesis was observed to persist after a recovery period. The two metabolic pathways are glycerophospholipid metabolism as well as phenylalanine, tyrosine and tryptophan biosynthesis. This study elucidated the metabolic alterations induced by chronic low-level exposure to SiNPs and presented novel evidence of the chronic pulmonary toxicity and carcinogenicity of SiNPs, from a metabolomic perspective.

Exploring the Potential of Humoral Immune Response to Commensal Bifidobacterium as a Biomarker for Human Health, including Both Malignant and Non-Malignant Diseases: A Perspective on Detection Strategies and Future Directions

In this comprehensive review, we explore the pivotal role of commensal Bifidobacterium (c-BIF) as potent non-self-antigens through antigenic mimicry, along with exploring the potential of humoral immune responses for both malignant and non-malignant disease. c-BIF, a predominant component of the human gut microbiome encompassing around 90% of the human genome, has emerged as a pivotal player in human biology. Over recent decades, there has been extensive research elucidating the intricate connections between c-BIF and various facets of human health, with particular emphasis on their groundbreaking impact on anti-cancer effects and the management of non-malignant diseases. The multifaceted role of c-BIF is explored, ranging from enhancing anti-tumor immunity to improving the efficacy of anti-cancer and anti-infectious disease strategies, and serving as predictive biomarkers for various diseases. Recent studies highlight not only c-BIF's promotion of anti-tumor immunity but also their role in enhancing the efficacy of immune checkpoint inhibitors. The review emphasizes the promising avenue of manipulating the gut microbiota, particularly c-BIF, for modulating cancer immunotherapy with targeted effects on tumor cells while minimizing harm to normal tissue. In the context of infectious and inflammatory diseases, the crucial role of c-BIFs in the management of COVID-19 symptoms is examined, emphasizing their impact on the severity of and immune response to COVID-19. Furthermore, c-BIF exhibits preventive and therapeutic effects on Human Papillomaviruses (HPV) and shows promise in improving inflammatory bowel diseases. The potential application of c-BIF as a biomarker for immunotherapy is explored, with a specific emphasis on its predictive and prognostic value in cancer. Suggestions are made regarding the use of humoral immune responses to cytotoxic T lymphocyte (CTL) epitope peptides that share motifs with c-BIF, proposing them as potential markers for predicting overall survival in diverse cancer patients. In conclusion, c-BIF emerges as a crucial and multifaceted determinant of human health, across anti-tumor immunity to infectious and inflammatory disease management. The manipulation of c-BIF and gut microbiota presents a promising avenue for advancing therapeutic strategies, particularly in the realm of cancer immunotherapy. Additionally, this review highlights the significance of c-BIF as potent non-self-antigens via antigenic mimicry, emphasizing the importance of robust humoral immune responses against c-BIF for preventing various diseases, including inflammatory conditions. Elevated levels of circulating antibodies against c-BIF in healthy individuals may serve as potential indicators of lower risks for malignant and non-malignant diseases.

Effects of probiotic supplementation on chronic inflammatory process modulation in colorectal carcinogenesis

The current study investigated the potential effects of probiotic supplementation on colorectal carcinogenesis chemically induced with 1,2-dimethylhydrazine (DMH) and treated with 5-fluorouracil (5FU)-based chemotherapy in mice. Animals were randomly allocated in five different groups: Control: which not receive any treatment throughout the experimental course; Colitis model group (DMH): treated with DMH; DMH+ 5FU: animals received I.P. (intraperitoneal) dose of chemotherapy on a weekly basis; DMH+PROB: animals received daily administrations (via gavage) of probiotics (Lactobacillus: acidophilus and paracasei, Bifidobacterium lactis and bifidum); and DMH+ PROB+ 5FU: animals received the same treatment as the previous groups. After ten-week treatment, mice's large intestine was collected and subjected to colon length, histopathological, periodic acid-schiff (PAS) staining and immunohistochemistry (TLR2, MyD88, NF-κB, IL-6, TLR4, TRIF, IRF-3, IFN-γ, Ki-67, KRAS, p53, IL-10, and TGF-β) analyzes. Variance (ANOVA) and Kruskal-Wallis tests were used for statistical analysis, at significance level p 0.05. Probiotics' supplementation has increased the production of Ki-67 cell-proliferation marker, reduced body weight, and colon shortening, as well as modulated the chronic inflammatory process in colorectal carcinogenesis by inhibiting NF-κB expression and mitigating mucin depletion. Thus, these findings lay a basis for guide future studies focused on probiotics' action mechanisms in tumor microenvironment which might have implications in clinical practice.

Protective effect of synbiotic combination of Lactobacillus plantarum SC-5 and olive oil extract tyrosol in a murine model of ulcerative colitis

BACKGROUND

Ulcerative colitisis (UC) classified as a form of inflammatory bowel diseases (IBD) characterized by chronic, nonspecific, and recurrent symptoms with a poor prognosis. Common clinical manifestations of UC include diarrhea, fecal bleeding, and abdominal pain. Even though anti-inflammatory drugs can help alleviate symptoms of IBD, their long-term use is limited due to potential side effects. Therefore, alternative approaches for the treatment and prevention of inflammation in UC are crucial.

METHODS

This study investigated the synergistic mechanism of Lactobacillus plantarum SC-5 (SC-5) and tyrosol (TY) combination (TS) in murine colitis, specifically exploring their regulatory activity on the dextran sulfate sodium (DSS)-induced inflammatory pathways (NF-κB and MAPK) and key molecular targets (tight junction protein). The effectiveness of 1 week of treatment with SC-5, TY, or TS was evaluated in a DSS-induced colitis mice model by assessing colitis morbidity and colonic mucosal injury (n = 9). To validate these findings, fecal microbiota transplantation (FMT) was performed by inoculating DSS-treated mice with the microbiota of TS-administered mice (n = 9).

RESULTS

The results demonstrated that all three treatments effectively reduced colitis morbidity and protected against DSS-induced UC. The combination treatment, TS, exhibited inhibitory effects on the DSS-induced activation of mitogen-activated protein kinase (MAPK) and negatively regulated NF-κB. Furthermore, TS maintained the integrity of the tight junction (TJ) structure by regulating the expression of zona-occludin-1 (ZO-1), Occludin, and Claudin-3 (p < 0.05). Analysis of the intestinal microbiota revealed significant differences, including a decrease in Proteus and an increase in Lactobacillus, Bifidobacterium, and Akkermansia, which supported the protective effect of TS (p < 0.05). An increase in the number of Aspergillus bacteria can cause inflammation in the intestines and lead to the formation of ulcers. Bifidobacterium and Lactobacillus can regulate the micro-ecological balance of the intestinal tract, replenish normal physiological bacteria and inhibit harmful intestinal bacteria, which can alleviate the symptoms of UC. The relative abundance of Akkermansia has been shown to be negatively associated with IBD. The FMT group exhibited alleviated colitis, excellent anti-inflammatory effects, improved colonic barrier integrity, and enrichment of bacteria such as Akkermansia (p < 0.05). These results further supported the gut microbiota-dependent mechanism of TS in ameliorating colonic inflammation.

CONCLUSION

In conclusion, the TS demonstrated a remission of colitis and amelioration of colonic inflammation in a gut microbiota-dependent manner. The findings suggest that TS could be a potential natural medicine for the protection of UC health. The above results suggest that TS can be used as a potential therapeutic agent for the clinical regulation of UC.

The Impact of the Gut Microbiome, Environment, and Diet in Early-Onset Colorectal Cancer Development

Traditionally considered a disease common in the older population, colorectal cancer is increasing in incidence among younger demographics. Evidence suggests that populational- and generational-level shifts in the composition of the human gut microbiome may be tied to the recent trends in gastrointestinal carcinogenesis. This review provides an overview of current research and putative mechanisms behind the rising incidence of colorectal cancer in the younger population, with insight into future interventions that may prevent or reverse the rate of early-onset colorectal carcinoma.

Anti-inflammatory pathways of kefir in murine model: a systematic review

CONTEXT

Kefir consumption has been associated with immune response modulation, antioxidant, and anti-inflammatory effects.

OBJECTIVE

The objective of this systematic review was to investigate the role of kefir against inflammation and the main response mechanisms involved in this process in a murine model.

DATA SOURCES

The searches were searched in the PubMed, Science Direct, and LILACS databases. Only murine model studies, according to PRISMA guidelines, published in the past 10 years were included.

STUDY SELECTION

Only articles about original and placebo-controlled experiments in murine models used to investigate the anti-inflammatory mechanisms of kefir were considered. Of the articles found, 349 were excluded according to the following criteria: duplicate articles (n = 99), off-topic title and abstract (n = 157), reviews (n = 47), studies in vitro (n = 29), and studies with humans (n = 17). In total, 23 studies were included in this review.

DATA EXTRACTION

Two independently working authors assessed the risk of bias and extracted data from the included studies.

RESULTS

Kefir consumption had positive effects on inflammation modulation. The main mechanisms involved were the reduction of pro-inflammatory and molecular markers; reduction in inflammatory infiltrate in tissues, serum biomarkers, risk factors for chronic diseases, and parasitic infection; composition and metabolic activity change of intestinal microbiota and mycobiota; activation of humoral and cellular immunity; and modulation of oxidative stress.

CONCLUSIONS

Kefir modulates the immune system in different experimental models, among other secondary outcomes, to improve overall health. The beverage reduces inflammation through the alternation between innate, Th1, and Th2 responses, reducing levels of pro-inflammatory cytokines while increasing those of anti-inflammatory ones. In addition, it also mediates immunomodulatory and protective effects through the numerous molecular biomarkers and organic acids produced and secreted by kefir in the intestinal microbiota. The health-promoting effects attributed to kefir may help in the different treatments of inflammatory, chronic, and infectious diseases in the population.

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.

Combination of vitamin D and probiotics inhibits chemically induced colorectal carcinogenesis in Wistar rats

The modulation of inflammatory elements, cell differentiation and proliferation by vitamin D and the role of probiotics in the intestinal microbiota and immunogenic response have sparked interest in the application of both in chemotherapeutics and chemoprevention of colorectal tumors.

AIMS

The present study aimed to investigate the effects of isolated and/or combined treatment of vitamin D3 and probiotics on colorectal carcinogenesis.

MAIN METHODS

Pre-neoplastic lesions were induced with 1,2-dimethylhydrazine in the colon of Wistar rats, which were treated with probiotics and/or vitamin D in three different approaches (simultaneous, pre-, and post-treatment). We investigated the frequency of aberrant crypt foci (ACF) and aberrant crypt (AC) in the distal colon, fecal microbiome composition, gene and protein expression through immunohistochemical and RT-PCR assays, and general toxicity through water consumption and weight gain monitoring.

KEY FINDINGS

Results confirm the systemic safety of treatments, and show a protective effect of vitamin D and probiotics in all approaches studied, as well as in combined treatments, with predominance of different bacterial phyla compared to controls. Treated groups show different levels of Nrf2, GST, COX2, iNOS, β-catenin and PCNA expression.

SIGNIFICANCE

These experimental conditions explore the combination of vitamin D and probiotics supplementation at low doses over pathways involved in distinct stages of colorectal carcinogenesis, with results supporting its application in prevention and long-term strategies.

Global research on the crosstalk between intestinal microbiome and colorectal cancer: A visualization analysis

Background

Increasing evidence has shown that the intestinal microbiome (IM) is highly linked to colorectal cancer (CRC). To investigate scientific output, identify highly cited papers, and explore research hotspots and trends in the field of IM/CRC, we conducted a bibliometric and visualized analysis.

Methods

A bibliographic search regarding IM/CRC research (2012-2021) was implemented on October 17, 2022. The terms attached to IM and CRC were searched for in the titles (TI), abstracts (AB), and author keywords (AK). The main information was extracted from the Web of Science Core Collection (WoSCC). Biblioshiny from R packages and VOSviewer were used for data visualization.

Results

A total of 1725 papers related to IM/CRC were retrieved. Publications on IM/CRC have grown rapidly from 2012 to 2021. China and the United States were in the leading position for publications in this field and made the most significant contributions to IM/CRC research. Shanghai Jiao Tong University and Harvard University were the most productive institutions. The high-yield authors were Yu Jun and Fang Jing Yuan. The International Journal of Molecular Sciences published the most papers, whereas Gut had the most citations. Historical citation analysis showed the evolution of IM/CRC research. Current status and hotspots were highlighted using keyword cluster analysis. The hot topics include the effect of IM on tumorigenesis, the effect of IM on CRC treatment, the role of IM in CRC screening, the mechanisms of IM involvement in CRC, and IM modulation for CRC management. Some topics, such as chemotherapy, immunotherapy, Fusobacterium nucleatum and short-chain fatty acids could be the focus of IM/CRC research in the coming years.

Conclusion

This research evaluated the global scientific output of IM/CRC research and its quantitative features, identified some significant papers, and gathered information on the status and trends of IM/CRC research, which may shape future paths for academics and practitioners.

Gut Microbiome in Colorectal Cancer: Clinical Diagnosis and Treatment

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers and the leading cause of cancer-associated deaths. Epidemiological studies have shown that both genetic and environmental risk factors contribute to the development of CRC. Several metagenomic studies of CRC have identified gut dysbiosis as a fundamental risk factor in the evolution of colorectal malignancy. Although enormous efforts and substantial progresses have been made in understanding the relationship between the human gut microbiome and CRC, the precise mechanisms involved remain elusive. Recent data have shown a direct causative role of the gut microbiome in DNA damage, inflammation, and drug resistance in CRC, suggesting that modulation of the gut microbiome can act as a powerful tool in CRC prevention and therapy. Here, we provide an overview of the relationship between the gut microbiome and CRC, and explore relevant mechanisms of colorectal tumorigenesis. We next highlight the potential of bacterial species as clinical biomarkers, as well as their roles in therapeutic response. Factors limiting the clinical translation of the gut microbiome and strategies for resolving the current challenges are further discussed.

Role of a mixed probiotic product, VSL#3, in the prevention and treatment of colorectal cancer

Colorectal cancer (CRC) is a multifactorial disease. The incidence of this type of cancer in younger patients has increased in recent years, and more strategies are needed to prevent and delay the progression of CRC. Probiotics play an adjunctive role in the prevention and treatment of CRC and can not only prevent the onset and delay the progression of disease but also reduce the side effects after the application of anti-cancer drugs. The anti-cancer effect of individual probiotics has been extensively studied, and the exact curative effect of various probiotics has been found, but the anti-cancer effect of mixed probiotics is still not well summarized. In this review, we discuss the positive effects of mixed probiotics on CRC and the related mechanisms of action, especially VSL#3 (VSL Pharmaceuticals, Inc., Gaithersburg, MD, USA), thus providing new ideas for the treatment of CRC. Moreover, we suggest the need to search for more therapeutic possibilities, especially via the research and application of synbiotics and postbiotics.

Bidirectional effects of intestinal microbiota and antibiotics: a new strategy for colorectal cancer treatment and prevention

PURPOSE

Colorectal cancer (CRC) is the third most common cancer worldwide, and its incidence and mortality rates are increasing every year. The intestinal microbiota has been called the "neglected organ" and there is growing evidence that the intestinal microbiota and its metabolites can be used in combination with immunotherapy, radiotherapy and chemotherapy to greatly enhance the treatment of colorectal cancer and to address some of the side effects and adverse effects of these therapies. Antibiotics have great potential to eliminate harmful microbiota, control infection, and reduce colorectal cancer side effects. However, the use of antibiotics has been a highly controversial issue, and numerous retrospective studies have shown that the use of antibiotics affects the effectiveness of treatment (especially immunotherapy). Understanding the bi-directional role of the gut microbiota and antibiotics will further enhance our research into the diagnosis and treatment of cancer.

METHODS

We searched the "PubMed" database and selected the following keywords "intestinal microbiota, antibiotics, treatment, prevention, colorectal cancer". In this review, we discuss the role of the intestinal microbiota in immunotherapy, radiotherapy, chemotherapy, diagnosis, and prevention of CRC. We also conclude that the intestinal microbiota and antibiotics work together to promote the treatment of CRC through a bidirectional effect.

RESULTS

We found that the intestinal microbiota plays a key role in promoting immunotherapy, chemotherapy, radiotherapy, diagnosis and prevention of CRC. In addition, gut microbiota and antibiotic interactions could be a new strategy for CRC treatment.

CONCLUSION

The bi-directional role of the intestinal microbiota and antibiotics plays a key role in the prevention, diagnosis, and treatment of colorectal cancer.

Modulation of Gut Microbiota Combined with Upregulation of Intestinal Tight Junction Explains Anti-Inflammatory Effect of Corylin on Colitis-Associated Cancer in Mice

Inflammatory bowel disease (IBD) involves chronic inflammation, loss of epithelial integrity, and gastrointestinal microbiota dysbiosis, resulting in the development of a colon cancer known as colitis-associated colorectal cancer (CAC). In this study, we evaluated the effects of corylin in a mouse model of dextran sodium sulfate (DSS)-induced colitis. The results showed corylin could improved the survival rate and colon length, maintained body weight, and ameliorated the inflammatory response in the colon. Then, we further identified the possible antitumor effects after 30-day treatment of corylin on an azoxymethane (AOM)/DSS-induced CAC mouse model. Biomarkers associated with inflammation, the colon tissue barrier, macrophage polarization (CD11c, CCR7, CD163, and CD206), and microbiota dysbiosis were monitored in the AOM/DSS group versus corylin groups. Corylin downregulated pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, and IL-6) mRNA expression and inflammatory signaling-associated markers (TLR4, MyD88, AP-1, CD11b, and F4/80). In addition, a colon barrier experiment revealed that epithelial cell proliferation of the mucus layer (Lgr5, Cyclin D1, and Olfm4) was downregulated and tight junction proteins (claudin-1 and ZO-1) were upregulated. Furthermore, the Firmicutes/Bacteroidetes ratio changed with corylin intervention, and the microbial diversity and community richness of the AOM/DSS mice were improved by corylin. The comparative analysis of gut microbiota revealed that Bacteroidetes, Patescibacteria, Candidatus Saccharimonas, Erysipelatoclostridium, and Enterorhabdus were significantly increased but Firmicutes, Turicibacter, Romboutsia, and Blautia decreased after corylin treatment. Altogether, corylin administration showed cancer-ameliorating effects by reducing the risk of colitis-associated colon cancer via regulation of inflammation, carcinogenesis, and compositional change of gut microbiota. Therefore, corylin could be a novel, potential health-protective, natural agent against CAC.

Survival effect of probiotics in a rat model of colorectal cancer treated with capecitabine

BACKGROUND

Probiotics are used to manage a number of gastrointestinal disorders due to their beneficial properties. Clinical reports showed that probiotics also improve the life quality of patients with colorectal cancer (CRC) subjected to oncologic treatment. In a CRC animal model, probiotics supplementation has the potential to decrease the formation of aberrant crypts and ameliorate tumor malignancy, enhancing the antitumor effect of 5-fluorouracil (5-FU) chemotherapy. Based on these data, we hypothesize that the administration of probiotics impact positively in the overall survival and life quality of rats with CRC under the treatment of capecitabine, which is the pro drug of 5-FU.

AIM

To evaluate the probiotics effects in a rat CRC model treated with capecitabine and followed until the end of life.

METHODS

1,2-Dimethylhidrazine dihydrochloride (1,2-DMH) was employed as carcinogen inductor of CRC. Fifty male Wistar-Lewis rats were randomly assigned to one of five following groups: Control (n = 5), Control + probiotics (Control-P group, n = 5), 1,2-DMH alone (DMH group, n = 10), 1,2-DMH + capecitabine (DMH-C group, n = 10), 1,2-DMH + probiotics (DMH-P group, n = 10) and 1,2-DMH + capecitabine + probiotics (DMH-C-P group, n = 10). All parametric data were expressed as the mean ± SD. The statistical significance of differences was analyzed using one-way ANOVA. Data were analyzed with InfoStat software. The results were considered statistically significant at P < 0.05. Overall survival was evaluated with the Kaplan-Meier estimator with the log-rank test.

RESULTS

The data of mean overall survival for DMH, DMH-P, DMH-C, DMH-C-P, Control and Control-P groups were 250 d [95% confidence interval (CI): 242.5-253.1], 268 d (95%CI: 246.3-271.4), 380 d (95%CI: 337.8-421.9), 480 d (95%CI: 436.9-530.7), 588 d (95%CI: 565.8-609.3) and 590 d (95%CI: 564.3-612.9), respectively, with a significant difference between DMH-C and DMH-C-P groups (P = 0.001). Comparing all groups by Kaplan-Meier estimator, we found a significantly different in the overall survival of DMH and DMH-P groups respect to DMH-C (P = 0.001) and DMH-C-P (P = 0.001) groups; interestingly, there were no meaningful differences between Control, Control-P and DMH-C-P groups (P = 0.012). The tendency of change in body weight gain of the rats at 90 d of finishing DMH administration was similar in Control group compared with DMH-C and DMH-C-P groups; however, and of relevance, DMH-C-P group has experienced a higher body weight gain at the end of animal’s life than DMH-C group (P = 0.001). In DMH-C-P group we found a positive effect of probiotics in clinical manifestations since diarrhea, constipation and blood stool were absenting. Also, the tumor burden was lower in DMH-C-P than DMH-C, DMH-P or DMH groups (1.25 vs 1.81 vs 3.9 vs 4.8 cm², respectively). DMH-C and DMH-C-P groups showed only mucinous carcinoma type while in other DMH groups the tumor types were variable. However, mucinous carcinoma from DMH-C-P group showed invasion until muscularis propria layer. Interestingly, metastatic lymph node was observed in DMH, DMH-C and DMH-P groups but not in DMH-C-P. All animals in Control group died from natural causes without objective injuries. All animals of DMH and DMH-P groups died from tumor complications (i.e., obstruction or intestinal perforation); however, this cause was seen only in 44.5% of DMH-C and DMH-C-P groups

CONCLUSION

Probiotics administration improves life quality of rats with CRC under capecitabine treatment and also has a positive effect in the overall survival of these animals treated with this drug.

The Association of Gut Microbiota and Complications in Gastrointestinal-Cancer Therapies

The therapy of gastrointestinal carcinomas includes surgery, chemo- or immunotherapy, and radiation with diverse complications such as surgical-site infection and enteritis. In recent years, the microbiome’s influence on different diseases and complications has been studied in more detail using methods such as next-generation sequencing. Due to the relatively simple collectivisation, the gut microbiome is the best-studied so far. While certain bacteria are sometimes associated with one particular complication, it is often just the loss of alpha diversity linked together. Among others, a strong influence of Fusobacterium nucleatum on the effectiveness of chemotherapies is demonstrated. External factors such as diet or specific medications can also predispose to dysbiosis and lead to complications. In addition, there are attempts to treat developed dysbiosis, such as faecal microbiota transplant or probiotics. In the future, the underlying microbiome should be investigated in more detail for a better understanding of the precipitating factors of a complication with specific therapeutic options.

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.

Intervention on gut microbiota may change the strategy for management of colorectal cancer

Dysbiosis in the gut microbiota composition due to environmental or genetic variations can disrupt the immune system and may promote several diseases such as colorectal cancer (CRC). Gut microbiota can alter the toxicity and efficiency of an extensive range of CRC treatment methods, especially surgery, chemotherapy, radiotherapy, and immunotherapy. The recent scientific evidence suggested that gut microbiota modulation exhibits an essential positive influence on inhibition and treatment of CRC. The literature survey revealed that modulating the gut microbiota composition by probiotics, prebiotics, and diets protects CRC patients from treatment-associated adverse effects. This review summarizes the recent advancements in the association between interventions on gut microbiota and CRC to provide innovative strategies for enhancing the safety and efficiency of CRC therapy.

Orange Juice and Yogurt Carrying Probiotic Bacillus coagulans GBI-30 6086: Impact of Intake on Wistar Male Rats Health Parameters and Gut Bacterial Diversity

This study aimed to investigate the impact of the food matrix (orange juice and yogurt) on the effects of the spore-forming probiotic microorganism Bacillus coagulans GBI-30 6086 in health parameters and gastrointestinal tract (gut) bacterial diversity in Wistar male rats. Rats (n = 48) were randomly distributed into six groups. The groups were the Control (which received sterile distilled water), Juice (which received orange juice), Yogurt (which received yogurt), Probiotic Bacillus (which received B. coagulans GBI-30 6086 in distilled water), Probiotic Juice (which received orange juice with B. coagulans GBI-30 6086), and Probiotic Yogurt (which received yogurt with B. coagulans GBI-30 6086). Each animal belonging to the different groups was treated for 21 days. The daily administration of probiotic juice or probiotic yogurt did not affect the rats’ food or body weight. Rats fed with Probiotic Yogurt showed lower glucose and triglycerides levels (p < 0.05) in comparison to the control group (p < 0.05), while no changes in these parameters were observed in the rats fed with Probiotic Juice. Rats fed with Probiotic Yogurt showed a higher gut bacterial diversity than the control group (p < 0.05), and higher abundance (p < 0.05) of Vibrionales, Enterobacteriales, Burkholderiales, Erysipelotrichales, and Bifidobacteriales compared to all other groups. No changes were observed in the expression levels of antioxidant enzymes or heat shock protein 70 of rats fed with probiotic yogurt or probiotic juice. Results reveal that the consumption of yogurt containing B. coagulans GBI-30 6086 decreases triglycerides and glucose levels and positively impacts the gut bacterial ecology in healthy rats. These animal model findings indicate that the matrix also impacts the functionality of foods carrying spore-forming probiotics. Besides, this research indicates that yogurt is also a suitable food carrier of Bacillus coagulans GBI-30 6086.

Evaluation of the efficacy of probiotic VSL#3 and synbiotic VSL#3 and yacon-based product in reducing oxidative stress and intestinal permeability in mice induced to colorectal carcinogenesis

The objective of the present study was to evaluate the effect of probiotic VSL#3 isolated or associated with a yacon-based product (synbiotic) on oxidative stress modulation and intestinal permeability in an experimental model of colorectal carcinogenesis. Forty-five C57BL/6J mice were divided into three groups: control (standard diet AIN-93 M); probiotic (standard diet AIN-93 M and multispecies probiotic VSL#3, 2.25 × 10⁹ CFU), and synbiotic (standard diet AIN-93 M with yacon-based product, 6% fructooligosaccharides and inulin, and probiotic VSL#3, 2.25 × 10⁹ CFU). The experimental diets were provided for 13 weeks. The probiotic and the yacon-based product showed antioxidant activity, with the percentage of DPPH radical scavenging equal to 69.7 ± 0.4% and 74.3 ± 0.1%, respectively. These findings contributed to reduce hepatic oxidative stress: the control group showed higher concentration of malondialdehyde (1.8-fold, p = 0.007 and 1.5-fold, p = 0.035) and carbonylated protein (2-fold, p = 0.008 and 5.6-fold, p = 0.000) compared to the probiotic and synbiotic groups, respectively. Catalase enzyme activity increased 1.43-fold (p = 0.014) in synbiotic group. The crypt depth increased 1.2-fold and 1.4-fold with the use of probiotic and synbiotic, respectively, compared to the control diet (p = 0.000). These findings corroborate the reduction in intestinal permeability in the probiotic and synbiotic groups, as measured by the percentage of urinary lactulose excretion (CON: 0.93 ± 0.62% × PRO: 0.44 ± 0.05%, p = 0.048; and CON: 0.93 ± 0.62% × SYN: 0.41 ± 0.12%, p = 0.043). In conclusion, the probiotic and synbiotic showed antioxidant activity, which contributed to the reduction of oxidative stress markers. In addition, they protected the mucosa from damage caused by chemical carcinogen and reduced intestinal permeability. PRACTICAL APPLICATION: The relationship between intestinal health and the occurrence of various organic disorders has been demonstrated in many studies. The use of probiotics and prebiotics is currently one of the main targets for modulation of intestinal health. We demonstrated that the use of a commercial mix of probiotic bacteria (VSL#3) isolated or associated with a yacon-based prebiotic, rich in fructooligosaccharides and inulin, is able to reduce the oxidative stress and intestinal permeability in a colorectal carcinogenesis model. These compounds have great potential to be used as a food supplement, or as ingredients in the development of food products.

Update on Strategies of Probiotics for the Prevention and Treatment of Colorectal Cancer

In recent years, with the further research on probiotics, probiotics may become an indispensable part in the prevention and treatment of colorectal cancer (CRC) in the future. As one of the most common cancer, the incidence of CRC is still rising in developing countries. Nowadays, there are lacking in prevention methods with low side effect. Surgery and chemotherapy, as the main treatment of CRC, bring many complications and affect the quality of life of patients. Probiotics has provided new ideas to solve these problems. Probiotics have anti-inflammatory, immune-enhancing, tumor-suppressing and other beneficial effects. Probiotics may provide some safe and effective prevention strategies for CRC. In addition, probiotics can also reduce the complications of surgery and chemotherapy, and improve the effectiveness of chemotherapy. Target administration with probiotics or probiotics cooperated with TRAIL to treat CRC. This article aims to review the mechanisms of probiotics for the prevention and treatment of CRC, as well as specific ways to use probiotics, in order to provide more new strategies for the prevention and treatment of CRC in the future, and reduce the incidence of and improve the quality of life of patients.

The inhibitory effects of probiotics on colon cancer cells: in vitro and in vivo studies

Background

Colorectal cancer (CRC) is the most common gastrointestinal malignancy. And probiotics may have the function of preventing colon cancer. The aim of this study was to investigate the inhibitory effects of a probiotic mixture on colorectal cancer and its potential mechanisms.

Methods

The effects of the probiotic mixture on proliferation and metastasis of mouse colon cancer CT26 cells were assessed by probiotics and cells co-culture assay, Cell Counting Kit-8 assay, colony formation assay, wound-healing assay, as well as migration and invasion assays. And CT26 cells were also transplanted into BALB/c mice to construct transplanted tumor animal model. The mice were randomly divided into two groups, control group and probiotic mixture intragastric administration group, after injection 21 days the tumor size and infiltration of immune cells in the tumor or spleen tissues were analyzed by hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining.

Results

The probiotic mixture significantly inhibited the proliferation, invasion, and migration ability of CT26 cells compare to the control cells (P<0.05). In the animal experiments, the tumor volume of mice that had been fed the probiotic mixture was significantly smaller than that of the control group (P<0.05). Compared with control mice, more apoptotic cells and infiltration of immune cells were showed in the tumor tissues of the mice treated with the probiotic mixture, and an increased number of CD8+ cells in the tumor and spleen tissues but no significant change in tissues.

Conclusions

These results suggested that the probiotic mixture could inhibit the growth of CT26 tumors and induce an immune response in vivo. The probiotic mixture also inhibited the invasion, migration, and proliferation ability of CT26 cells in vitro.

Cancer-protective effect of a synbiotic combination between Lactobacillus gasseri 505 and a Cudrania tricuspidata leaf extract on colitis-associated colorectal cancer

Previously, a synbiotic combination of probiotic Lactobacillus gasseri 505 (LG) and a new prebiotic, Cudrania tricuspidata leaf extract (CT) in fermented milk, designated FCT, showed an in vitro immunomodulatory effect and antioxidant activity. Although synbiotic combination might have cancer-protective effects, these activities have not been fully validated in vivo. Ten-week treatment of LG, CT, or FCT to azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colitis-associated colorectal cancer (CAC) mouse model reduced both the incidence of colonic tumors and damage to the colonic mucosa effectively, suggesting a cancer-protective effect. To understand these, biomarkers associated with inflammation, colon barrier, apoptosis, and cancer cell proliferation were monitored in AOM/DSS group versus LG/CT/FCT groups. A synbiotic combination (FCT) down-regulated pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, and IL-6) and inflammation-associated enzymes (iNOS and COX-2), and up-regulated anti-inflammatory cytokines (IL-4 and IL-10). In addition, colon barrier experiment revealed that biomarkers of mucus layer (MUC-2 and TFF3) and tight junction (occludin and ZO-1) were up-regulated. Subsequent apoptosis experiment showed that pro-apoptotic factors (p53, p21, and Bax) were up-regulated and anti-apoptotic factors (Bcl-2 and Bcl-xL) were down-regulated. Furthermore, comparative metagenome analysis of gut microbiota revealed that Staphylococcus decreased but Lactobacillus, Bifidobacterium, and Akkermansia increased, supporting their protective effects, accompanied by increased short-chain fatty acids (SCFAs). Taken together, the FCT administration showed cancer-protective effects by reducing the risk of colitis-associated colon cancer via regulation of inflammation, carcinogenesis, and compositional change of gut microbiota. Consequently, the synbiotic combination (FCT) could be a novel potential health-protective natural agent against CAC.

Supplementation with L-Arginine Decreases Jejunal Lesions and Micronucleus Formation Induced by 5-Fluorouracil in Rats

The objective of this study was to evaluate the effect of L-arginine supplementation on the formation of jejunal lesions and micronuclei in Wistar rats following 5-fluorouracil (5-FU) treatment. Fifty rats were separated into five groups: CG served as the control group, G_Arg was supplemented L-arginine, G_5-FU was administered 5-FU, G_Arg+5-FU was supplemented L-arginine/day and administered 5-FU, and G_ciclo served as a positive control group for micronuclei formation. Jejunal lesions were assessed by histopathological analysis using a scoring system with a maximum of 39 points, based on the following lesions: lymph vessel dilatation, cubic enterocytes, villous flattening, villus fusion, interstitial edema, and apical necrosis of the villi. Micronuclei were counted in polychromatic erythrocytes from the femur bone marrow. The control and G_Arg rats had the lowest number of jejunal lesions (6.4 ± 2.8 and 5.3 ± 2.4, respectively) and micronuclei (1.9 ± 0.6 and 1.1 ± 0.3, respectively) while the G_5-FU rats had the highest number of jejunal lesions (24.2 ± 4.9) and micronuclei (36.0 ± 8.5). The G_Arg+5-FU rats showed significantly reduced (P < 0.05) jejunal lesions (10.2 ± 4.9) and micronuclei (15.4 ± 5.9). In conclusion L-arginine supplementation potentially reduces the jejunal lesions and DNA damage caused by 5-FU.

Microbiota Manipulation by Probiotics Administration as Emerging Tool in Cancer Prevention and Therapy

A growing body of literature indicates that microbiota plays a significant role in the development and curability of cancer, essentially due to the microbial ability to modulate immune and inflammatory responses to cancer and therapeutic treatments. Probiotics consumption, either in the form of food or supplements, is an easy and feasible way to manipulate microbiota composition and a number of recent researches have shown that it may represent a valid approach to prevent cancer onset and progression, to improve the clinical efficacy of the current anticancer treatments, and to mitigate the harmful adverse events of chemo- and radiotherapy, which often lead to scale drug doses, to delay or interrupt treatments. In this review, we gather the main in vivo studies on the current topic, focusing on the beneficial effects and underlying mechanisms provided by bacterial and yeast probiotics and their combination, in the setting of various types of cancers and different therapeutic protocols. These findings will likely open the way to consider, in future, regular probiotics intake as an adjuvant strategy in cancer prevention and management.