Emerging roles of lactic acid bacteria in protection against colorectal cancer

The probiotic supplementation role in improving the immune system among people with ulcerative colitis: a narrative review

OBJECTIVES

The purpose of this paper is to summarize the current evidence on probiotics' uses as an adjuvant for ulcerative colitis (UC) and provide an understanding of the effect of probiotics supplement on the immune system and inflammatory responses among UC patients and subsequent therapeutic benefits.

CONTENT

A narrative review of all the relevant published papers known to the author was conducted.

SUMMARY

UC is a chronic inflammatory bowel disease (IBD) that results in inflammation and ulceration of the colon and rectum. The primary symptoms of active disease are diarrhea, abdominal pain, and rectal bleeding. About 70% of the human immune system (mucosal-associated lymphoid tissue) originates in the intestine. Probiotics are live microorganisms that help in stabilizing the gut microbiota (nonimmunologic gut defense), restores normal flora, and enhance the humoral immune system. Probiotics especially Bifidobacterium, Saccharomyces boulardii, and lactic acid-producing bacteria have been used as an adjunct therapy for treating UC to ameliorate disease-related symptoms and reduce relapse rate. Probiotics, in general, modulate the immune system through their ability to enhance the mucosal barrier function, or through their interaction with the local immune system to enhance regulatory T cell responses, decrease the pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin 1 beta and increase anti-inflammatory factor interleukin 10.

OUTLOOK

More studies are needed to explore the properties of the various probiotic bacterial strains, their different uses, as well as the dosage of probiotics and duration for treating different disorders. Further clinical investigations on mechanisms of action and how probiotics modulate the immune system may lead to further advances in managing IBD.

The probiotic supplementation role in improving the immune system among people with ulcerative colitis: a narrative review

OBJECTIVES

The purpose of this paper is to summarize the current evidence on probiotics' uses as an adjuvant for ulcerative colitis (UC) and provide an understanding of the effect of probiotics supplement on the immune system and inflammatory responses among UC patients and subsequent therapeutic benefits.

CONTENT

A narrative review of all the relevant published papers known to the author was conducted.

SUMMARY

UC is a chronic inflammatory bowel disease (IBD) that results in inflammation and ulceration of the colon and rectum. The primary symptoms of active disease are diarrhea, abdominal pain, and rectal bleeding. About 70% of the human immune system (mucosal-associated lymphoid tissue) originates in the intestine. Probiotics are live microorganisms that help in stabilizing the gut microbiota (nonimmunologic gut defense), restores normal flora, and enhance the humoral immune system. Probiotics especially Bifidobacterium, Saccharomyces boulardii, and lactic acid-producing bacteria have been used as an adjunct therapy for treating UC to ameliorate disease-related symptoms and reduce relapse rate. Probiotics, in general, modulate the immune system through their ability to enhance the mucosal barrier function, or through their interaction with the local immune system to enhance regulatory T cell responses, decrease the pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin 1 beta and increase anti-inflammatory factor interleukin 10.

OUTLOOK

More studies are needed to explore the properties of the various probiotic bacterial strains, their different uses, as well as the dosage of probiotics and duration for treating different disorders. Further clinical investigations on mechanisms of action and how probiotics modulate the immune system may lead to further advances in managing IBD.

Cell-Free Lactobacillus casei 21L10 Modulates Nitric Oxide Release and Cell Proliferation/Cell Death in Lipopolysaccharide-Challenged HT-29 Cells

Lactobacillus casei (L. casei) is one of the probiotic strains that may influence intestinal injury and inflammation in nonspecific intestinal diseases. We aimed to evaluate the effect of cell-free Lactobacillus casei 21L10 supernatant (LC) on the cell line HT-29 challenged with lipopolysaccharide (LPS) in order to modulate production of NO, cell proliferation, and apoptosis. Cell line HT-29 was stimulated with LPS in the presence or absence of LC. Our results showed that LC from L. casei 21L10 did not affect the viability of unstimulated HT-29 cells line. HT-29 cell line treatment with LC caused significant decrease of LPS induced NO production after 3 h, and 24 h, but not after 48 h. Proliferation activity of LPS stimulated HT-29 cell line analysed with MTT assay significantly decreased after 24 h and 48 h, but not after 3 h. The majority of LPS stimulated HT-29 cell line treated with LC showed annexin V/PI positivity at 48 h survival, which corresponded to late apoptotic/necrotic cell features. The observed differences suggest that cell-free L. casei 21L10 supernatant could participate in attenuation of LPS-induced inflammation, and may exhibit anti-proliferative and pro-apoptotic/necrotic effects. This study provides pilot data for the further development of L. casei exoproducts as an anti-inflammatory or anti-proliferative agent for the treatment of inflammatory and cancer diseases in gut. However, more data is needed before final conclusions of L. casei cell-free supernatant's efficacy can be drawn.

The Microbiome as a Potential Target for Therapeutic Manipulation in Pancreatic Cancer

Simple Summary

Pancreatic cancer is one of the most lethal cancers. It is a difficult cancer to treat, and the complexity surrounding the pancreatic tumour is one of the contributing factors. The microbiome is the collection of microorganisms within an environment and its genetic material. They reside on body surfaces and most abundantly within the human gut in symbiotic balance with their human host. Disturbance in the balance can lead to many diseases, including cancers. Significant advances have been made in cancer treatment since the introduction of immunotherapy, and the microbiome may play a part in the outcome and survival of patients with cancer, especially those treated with immunotherapy. Immunotherapy use in pancreatic cancer remains challenging. This review will focus on the potential interaction of the microbiome with pancreas cancer and how this could be manipulated.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and is projected to be the second most common cause of cancer-related death by 2030, with an overall 5-year survival rate between 7% and 9%. Despite recent advances in surgical, chemotherapy, and radiotherapy techniques, the outcome for patients with PDAC remains poor. Poor prognosis is multifactorial, including the likelihood of sub-clinical metastatic disease at presentation, late-stage at presentation, absence of early and reliable diagnostic biomarkers, and complex biology surrounding the extensive desmoplastic PDAC tumour micro-environment. Microbiota refers to all the microorganisms found in an environment, whereas microbiome is the collection of microbiota and their genome within an environment. These organisms reside on body surfaces and within mucosal layers, but are most abundantly found within the gut. The commensal microbiome resides in symbiosis in healthy individuals and contributes to nutritive, metabolic and immune-modulation to maintain normal health. Dysbiosis is the perturbation of the microbiome that can lead to a diseased state, including inflammatory bowel conditions and aetiology of cancer, such as colorectal and PDAC. Microbes have been linked to approximately 10% to 20% of human cancers, and they can induce carcinogenesis by affecting a number of the cancer hallmarks, such as promoting inflammation, avoiding immune destruction, and microbial metabolites can deregulate host genome stability preceding cancer development. Significant advances have been made in cancer treatment since the advent of immunotherapy. The microbiome signature has been linked to response to immunotherapy and survival in many solid tumours. However, progress with immunotherapy in PDAC has been challenging. Therefore, this review will focus on the available published evidence of the microbiome association with PDAC and explore its potential as a target for therapeutic manipulation.

Prophylactic effects of secretion metabolites of dairy lactobacilli through downregulation of ErbB-2 and ErbB-3 genes on colon cancer cells

Colon cancer is one of the most prevalent cancers, and intestinal microbial community plays a pivotal role in colorectal tumor genesis. Probiotics as live microorganisms may be able to exert an anticancer effect in colon cancer. The aim of this study was to isolate and identify Lactobacillus spp. from traditional dairy products with probiotic properties and to investigate their anticancer effects through ErbB-2 and ErbB-3 gene expression in colon cancer cells. The isolated lactobacilli from yogurt and cheese samples were molecularly identified by blasting of 16-23s rDNA region PCR sequenced products. The probiotic properties, including acid and bile tolerance, antimicrobial activity, and antibiotic susceptibility, were assayed. The proliferation inhibition effects of lactobacilli secretion metabolites with probiotic potential on colon cancer cell lines (HT-29 and caco-2) were analyzed using MTT assay. The real-time PCR was used for assessment of ErbB-2 and ErbB-3 gene expression after being treated with probiotics. Four species of bacteria with the most probiotic properties, including Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Lactobacillus plantarum, were characterized and their effects on different human cell lines were taken into consideration. Total bacterial secretions significantly reduced the viability of HT-29 and caco-2 cancer cells compared with untreated controls. The metabolites secreted by bacteria downregulated the expression of ErbB-2 and ErbB-3 genes in colon cancer cells. The present study indicated that probiotic bacteria isolated from traditional dairy products exert anticancer effect on colon cancer cells through the downregulation of ErbB-2 and ErbB-3 gene expression.

Low Abundance of Lactococcus lactis in Human Colorectal Cancer Is Associated with Decreased Natural Killer Cells

A limited number of studies have demonstrated the role of Lactococcus lactis (L. lactis) in human colorectal cancers (CRCs). The association of L. lactis abundance with the density of natural killer (NK) cells has not been investigated before. In this study, the L. lactis abundance in 60 CRC specimens, 20 adenoma (AD) specimens, and 29 normal colorectal tissues (NCs) specimens was investigated using the fluorescence in situ hybridization of 16S ribosomal RNA. The density of NK cells was detected using immunofluorescence in 28 CRC specimens, 12 AD specimens, and 22 NC specimens. The presence of L. lactis in NCs (48.28%) was detected significantly higher than that in the AD (20.00%, P = .044) and CRC (23.33%, P = .018) specimens. The abundance of L. lactis in NCs (32.73 ± 7.24) was also found to be significantly higher than that in AD (8.91 ± 5.89, P = .029) and CRC (5.63 ± 1.67, P = .003) specimens. In addition, the density of NKp30⁺ NK cells in NCs (51.14 ± 4.84) was significantly higher than that in the AD (6.10 ± 1.31) and CRC (1.72 ± 0.40) specimens (P < .001). Moreover, a positive association of L. lactis abundance with NKp30⁺ NK cells density in the colorectal samples (P < .001) was observed. The low abundance of L. lactis in the CRC tissues was associated with the decreased NK cells, which suggested that this might contribute to the progression of CRC by decreasing the number of NK cells.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1944649.

A Comprehensive Overview of Colon Cancer- A Grim Reaper of the 21st Century

A few decades ago, the incidence of colorectal cancer (CRC) was low and is now the fourth in the list of deadly cancers producing nearly a million deaths annually. A population that is aging along with risk factors such as smoking, obesity, sedentary lifestyle with little or no physical activity, and non-healthy food habits of developed countries can increase the risk of colorectal cancer. The balance in gut microbiota and the metabolites produced during bacterial fermentation within the host plays a significant role in regulating intestinal diseases as well as colorectal cancer development. Recent progress in the understanding of illness resulted in multiple treatment options such as surgery, radiation, and chemotherapy, including targeted therapy and multitherapies. The treatment plan for CRC depends on the location, stage and grade of cancer as well as genomic biomarker tests. Despite all the advancements made in the genetic and molecular aspects of the disease, the knowledge seems inadequate as the drug action as well as the wide variation in drug response did not appear strongly correlated with the individual molecular and genetic characteristics, which suggests the requirement of comprehensive molecular understanding of this complex heterogeneous disease. Furthermore, multitherapies or a broad spectrum approach, which is an amalgamation of the various promising as well as effective therapeutic strategies that can tackle heterogeneity and act on several targets of the disease, need to be validated in clinical studies. The latest treatment options have significantly increased the survival of up to three years in the case of advanced disease. The fact that colorectal cancer is developed from a polypoid precursor, as well as the symptoms of the disease that occur at an advanced stage, underlines how screening programs can help early detection and decrease mortality as well as morbidity from CRC.

Apoptotic Effect of Saccharomyces cerevisiae on Human Colon Cancer SW480 Cells by Regulation of Akt/NF-ĸB Signaling Pathway

Drug resistance is one of the major problems, which causes recurrence of cancers. Therefore, complementary treatments are needed to improve the impacts of chemotherapy agents. The effect of probiotics as cancer-preventing agents through involvement in the activation of apoptotic pathways has been established. The present study sought to investigate how the heat-killed form of Saccharomyces cerevisiae (as a probiotic) could affect the Akt/NF-kB-induced apoptosis in colon cancer cells, the SW480 cell line. The cytotoxic effects of heat-killed yeast (HKY) and 5-fluorouracil (5-FU, as a positive control drug) were assayed using the MTT method. Morphological changes followed by apoptosis were examined using DAPI staining. The transcription and translation level of apoptosis genes were explored with qRT-PCR and western blotting. The data were analyzed using GraphPad Prism V6.0 Software. The results showed that HKY could induce apoptosis in colon cancer cell line through downregulation of p-Akt1, Rel A, Bcl-XL, pro-caspase 3, and pro-caspase 9 expressions, and upregulation of BAX, cleaved caspase-3, and cleaved caspase-9. Besides, Akt protein expression was not affected. It is noticeable that HKY had a better modulating effect on BAX expression compared with 5-FU. It was able to modulate Akt/NF-kB signaling pathway followed by the apoptotic cascade.

Microbiome analysis combined with targeted metabolomics reveal immunological anti-tumor activity of icariside I in a melanoma mouse model

Recent studies report that the gut microbiome can enhance systemic and antitumor immunity by modulating responses to antibody immunotherapy in melanoma patients. In this study, we found that icariside I, a novel anti-cancer agent isolated from Epimedium, significantly inhibited B16F10 melanoma growth in vivo through regulation of gut microbiota and host immunity. Oral administration of icariside I improved the microbiota community structure with marked restoration of Lactobacillus spp. and Bifidobacterium spp. abundance in the cecal contents of tumor-bearing mice. We also found that icariside I improves the levels of microbiota-derived metabolites such as short-chain fatty acids (SCFAs) and indole derivatives, consequently promoting repair of the intestinal barrier and reducing systemic inflammation of tumor-bearing mice. Icariside I exhibited strong immunological anti-tumor activity, directly manifested by up-regulation of multiple lymphocyte subsets including CD4+ and CD8+ T cells or NK and NKT cells in peripheral blood of tumor-bearing mice. Collectively, these results suggest that icariside I, via its microbiome remodeling and host immune regulation properties, may be developed as an anticancer drug.

A synthetic probiotic engineered for colorectal cancer therapy modulates gut microbiota

BACKGROUND

Successful chemoprevention or chemotherapy is achieved through targeted delivery of prophylactic agents during initial phases of carcinogenesis or therapeutic agents to malignant tumors. Bacteria can be used as anticancer agents, but efforts to utilize attenuated pathogenic bacteria suffer from the risk of toxicity or infection. Lactic acid bacteria are safe to eat and often confer health benefits, making them ideal candidates for live vehicles engineered to deliver anticancer drugs.

RESULTS

In this study, we developed an effective bacterial drug delivery system for colorectal cancer (CRC) therapy using the lactic acid bacterium Pediococcus pentosaceus. It is equipped with dual gene cassettes driven by a strong inducible promoter that encode the therapeutic protein P8 fused to a secretion signal peptide and a complementation system. In an inducible CRC cell-derived xenograft mouse model, our synthetic probiotic significantly reduced tumor volume and inhibited tumor growth relative to the control. Mice with colitis-associated CRC induced by azoxymethane and dextran sodium sulfate exhibited polyp regression and recovered taxonomic diversity when the engineered bacterium was orally administered. Further, the synthetic probiotic modulated gut microbiota and alleviated the chemically induced dysbiosis. Correlation analysis demonstrated that specific bacterial taxa potentially associated with eubiosis or dysbiosis, such as Akkermansia or Turicibacter, have positive or negative relationships with other microbial members.

CONCLUSIONS

Taken together, our work illustrates that an effective and stable synthetic probiotic composed of P. pentosaceus and the P8 therapeutic protein can reduce CRC and contribute to rebiosis, and the validity and feasibility of cell-based designer biopharmaceuticals for both treating CRC and ameliorating impaired microbiota. Video abstract.

Anticancer effects of bifidobacteria on colon cancer cell lines

Background

Colorectal cancer (CRC), with a growing incidence trend worldwide, is resistant to apoptosis and has uncontrolled proliferation. It is recently reported that probiotic microorganisms exert anticancer effects. The genus Bifidobacterium, one of the dominant bacterial populations in the gastrointestinal tract, has received increasing attention because of widespread interest in using it as health-promoting microorganisms. Therefore, the present study aimed to assess the apoptotic effects of some bifidobacteria species on colon cancer cell lines.

Methods

The cytotoxicity evaluations performed using MTT assay and FACS-flow cytometry tests. Also, the effects of five species of bifidobacteria secretion metabolites on the expression level of anti- or pro-apoptotic genes including BAD, Bcl-2, Caspase-3, Caspase-8, Caspase-9, and Fas-R studied by real-time polymerase chain reaction (RT-PCR) method.

Results

The cell-free supernatant of all studied bifidobacteria significantly decreased the survival rates of colon cancer cells compared with control groups. Flow cytometric and RT-PCR results indicated that apoptosis is induced by bifidobacteria secretion metabolites and the mechanism for the action of bifidobacteria species in CRC prevention could be down-regulation and up-regulation of anti-apoptotic and, pro-apoptotic genes.

Conclusions

In the present study, different bifidobacteria species showed anticancer activity on colorectal cancer cells through down-regulation and up-regulation of anti-apoptotic and pro-apoptotic genes. However, further studies are required to clarify the exact mechanism of apoptosis induction by bifidobacteria species.

Biogenic selenium nanoparticles produced by Lactobacillus casei ATCC 393 inhibit colon cancer cell growth in vitro and in vivo

Selenium compounds exhibit excellent anticancer properties but have a narrow therapeutic window. Selenium nanoparticles, however, are less toxic compared to other selenium forms, and their biogenic production leads to improved bioavailability. Herein, we used the probiotic strain Lactobacillus casei ATCC 393, previously shown to inhibit colon cancer cell growth, to synthesize biogenic selenium nanoparticles. We examined the anticancer activity of orally administered L. casei, L. casei-derived selenium nanoparticles and selenium nanoparticle-enriched L. casei, and investigated their antitumor potential in the CT26 syngeneic colorectal cancer model in BALB/c mice. Our results indicate that L. casei-derived selenium nanoparticles and selenium nanoparticle-enriched L. casei exert cancer-specific antiproliferative activity in vitro. Moreover, the nanoparticles were found to induce apoptosis and elevate reactive oxygen species levels in cancer cells. It is noteworthy that, when administered orally, selenium nanoparticle-enriched L. casei attenuated the growth of colon carcinoma in mice more effectively than the isolated nanoparticles or L. casei, suggesting a potential additive effect of the nanoparticles and the probiotic. To the best of our knowledge this is the first comparative study examining the anticancer effects of selenium nanoparticles synthesized by a microorganism, the selenium nanoparticle-enriched microorganism and the sole microorganism.

Probiotic potential and anticancer properties of Pediococcus sp. isolated from traditional dairy products

Herein, 18 lactic acid bacteria isolated from 30 samples of traditional dairy products were identified, and their probiotic potential was evaluated. According to the results, almost all strains showed the probiotic properties sufficiently, though M1 had better characterise. 16S rRNA gene sequencing revealed that this strain belongs to the Pediococcus sp. (<95 % similarity). This strain had substantial antipathogenic activity and did not show any worrying antibiotic resistance. Also, the strain was resistant to high concentrations of bile salt (1 %), NaCl (6.5 %), and low pH (2). Furthermore, it was revealed that cell-free supernatant (CFS), heat-killed cells and live cells derived from M1 significantly decreased the viability of MCF-7 cells so that the CFS resulted in 85 % cell death. Flow cytometry and western blot analysis determined that this compound induced apoptosis in the cancerous cells through increasing the BAX protein expression and decreasing the Bcl-2 protein expression.

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.

Lactobacillus bulgaricus inhibits colitis-associated cancer via a negative regulation of intestinal inflammation in azoxymethane/dextran sodium sulfate model

BACKGROUND

Colitis-associated cancer (CAC) accounts for 2%-3% of colorectal cancer (CRC) cases preceded by inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis. Intestinal microbiota has been reported to play a central role in the pathogenesis of IBD and CAC. Recently, numerous prebiotics and probiotics have being investigated as antitumor agents due to their capacity to modulate inflammatory responses. Previous studies have indicated that lactic acid bacteria could be successfully used in managing sporadic CRC, however little is known about their role in CAC.

AIM

To investigate the effect of the probiotic Lactobacillus bulgaricus (L. bulgaricus) during the development of an experimental model of colitis associated colon cancer (CAC).

METHODS

C57BL/6 mice received an intraperitoneal injection of azoxymethane (10 mg/kg), followed by three cycles of sodium dextran sulphate diluted in water (5% w/v). Probiotic group received daily L. bulgaricus. Intestinal inflammation was determined by scoring clinical signs. Cytokines levels were determined from colon and/or tumor samples by ELISA BD OptEIATM kits. The level of significance was set at P < 0.05. Graphs were generated and statistical analysis performed using the software GraphPad Prism 6.0.

RESULTS

L. bulgaricus treatment inhibited of total tumor volume and mean size of tumors. In addition, the probiotic also attenuated the clinical signs of intestinal inflammation inducing a decrease in intestinal and tumor levels of IL-6, TNF-α, IL-17, IL-23 and IL-1β.

CONCLUSION

Our results suggest a potential chemopreventive effect of probiotic on CAC. L. bulgaricus regulates the inflammatory response and preventing CAC.

Postbiotics as Promising Tools for Cancer Adjuvant Therapy

As many investigations have reported, there is a complicated relation between fermented foods, lactic acid bacteria (LAB), and human health. It seems that bioactive components such as prebiotics, probiotics, and postbiotics are key mediators of the complex and direct association between these factors. LAB activity in the matrix of fermented foods and improving their growth by prebiotic compounds ultimately results in the production of bioactive molecules (postbiotics), which possess specific biological and physiological properties. The term "postbiotics" refers to a complex of biological micro- and macromolecules, if consumed in adequate amounts, provides the host with different health-promoting effects. Different reports have suggested that postbiotics possess the ability to moderate the effectiveness of cancer treatment and reduce the side-effects of conventional therapies in cancer patients due to their anti-proliferative, anti-inflammatory and anti-cancer properties. Consequently, postbiotics, for their unique characteristics, have gained great scientific attention and are considered as a novel approach for adjuvant therapy in patients with cancer.

The Role of the Microbiome in Oral Squamous Cell Carcinoma with Insight into the Microbiome-Treatment Axis

Oral squamous cell carcinoma (OSCC) is one of the leading presentations of head and neck cancer (HNC). The first part of this review will describe the highlights of the oral microbiome in health and normal development while demonstrating how both the oral and gut microbiome can map OSCC development, progression, treatment and the potential side effects associated with its management. We then scope the dynamics of the various microorganisms of the oral cavity, including bacteria, mycoplasma, fungi, archaea and viruses, and describe the characteristic roles they may play in OSCC development. We also highlight how the human immunodeficiency viruses (HIV) may impinge on the host microbiome and increase the burden of oral premalignant lesions and OSCC in patients with HIV. Finally, we summarise current insights into the microbiome–treatment axis pertaining to OSCC, and show how the microbiome is affected by radiotherapy, chemotherapy, immunotherapy and also how these therapies are affected by the state of the microbiome, potentially determining the success or failure of some of these treatments.

Gut Fecal Microbiota Transplant in a Mouse Model of Orthotopic Rectal Cancer

The gut microbiota is reported to play an important role in carcinogenesis and the treatment of CRC. SW480 and SW620 colon cancer cells integrated with infrared fluorescent proteins were injected into the rectal submucosa of nude mice. In the subsequent 30 days, we observed tumor growth weekly using an in vivo imaging system. The bacterial solution was infused anally into the mice to perform bacterial transplant. Phosphate-buffered saline, Acinetobacter lwoffii, and Bifidobacterium longum solutions were infused individually. The 16S ribosomal DNA (rDNA) and polymerase chain reaction of murine feces were investigated to confirm the colonization of target bacteria. In the SW620 orthotopic xenograft rectal cancer model, 4 of 5 mice developed rectal cancer by 30 days after submucosal injection. In the SW480 orthotopic xenograft rectal cancer model, 2 of 6 mice developed rectal cancer by 30 days after submucosal injection. For the 16S rDNA analysis, the mice receiving the bacterial solution infusion demonstrated positive findings for A. lwoffii and B. longum. With the successful establishment of a mouse model of orthotopic rectal cancer and transplant of target bacteria, we can further explore the relationship between gut microbiota and CRC. The role of fecal microbiota transplant in the treatment and alleviation of adverse events of chemotherapy in CRC could be clarified in subsequent studies.

Bacterial Natural Compounds with Anti-Inflammatory and Immunomodulatory Properties (Mini Review)

Inflammation is part of the body's complex biological response to harmful stimuli such as damaged cells, pathogens, or irritants. It is a protective response involving blood cells, immune cells, and molecular mediators. The inflammation not only can eliminate the primary cause of cell injury but also clears out necrotic cells, tissue damaged from the original insults and inflammatory process. Furthermore, it can initiate tissue repair. Pro-inflammatory cytokines are produced predominantly by activated macrophages and are involved in the up-regulation of inflammatory reactions. They are involved in further regulating inflammatory reactions. There is ample evidence that some pro-inflammatory cytokines, such as interleukin 1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α), are involved in the pathological pain process. Some of the natural compounds promote cytokines production and inhibit inflammatory responses. The natural compounds which are produced from microorganisms such as omega-3 fatty acid, cyclic peptide, antimicrobial peptide, oligosaccharides, and polysaccharides can reduce inflammation and could be easily incorporated into the diet without any adverse effects. For example, SCFA (short-chain fatty acids), peptide bacteriocin, and polycyclic peptide bacteriocin (nisin) could be used in the treatment of atherosclerosis, orthopedic postoperative infections, and mycobacterium tuberculosis infection, respectively. Also, fatty acids (saturated and unsaturated fatty acids) can be introduced as anti-inflammatory drugs. This review article summarizes bacterial natural compounds with modulating effects on cytokines that are surveyed which may have potential anti-inflammatory drug-like activity.

Roles of the Polyphenol-Gut Microbiota Interaction in Alleviating Colitis and Preventing Colitis-Associated Colorectal Cancer

Accumulating evidence indicates that the gut microbiota can promote or inhibit colonic inflammation and carcinogenesis. Promotion of beneficial gut bacteria is considered a promising strategy to alleviate colonic diseases including colitis and colorectal cancer. Interestingly, dietary polyphenols, which have been shown to attenuate colitis and inhibit colorectal cancer in animal models and some human studies, appear to reach relatively high concentrations in the large intestine and to interact with the gut microbial community. This review summarizes the modulatory effects of polyphenols on the gut microbiota in humans and animals under healthy and diseased conditions including colitis and colitis-associated colorectal cancer (CAC). Existing human and animal studies indicate that polyphenols and polyphenol-rich whole foods are capable of elevating butyrate producers and probiotics that alleviate colitis and inhibit CAC, such as Lactobacillus and Bifidobacterium. Studies in colitis and CAC models indicate that polyphenols decrease opportunistic pathogenic or proinflammatory microbes and counteract disease-induced dysbiosis. Consistently, polyphenols also change microbial functions, including increasing butyrate formation. Moreover, polyphenol metabolites produced by the gut microbiota appear to have anticancer and anti-inflammatory activities, protect gut barrier integrity, and mitigate inflammatory conditions in cells and animal models. Based on these results, we conclude that polyphenol-mediated alteration of microbial composition and functions, together with polyphenol metabolites produced by the gut microbiota, likely contribute to the protective effects of polyphenols on colitis and CAC. Future research is needed to validate the causal role of the polyphenol-gut microbiota interaction in polyphenols' anti-colitis and anti-CAC effects, and to further elucidate mechanisms underlying such interaction.

Impact of a Gastrointestinal Stable Probiotic Supplement Bacillus coagulans LBSC on Human Gut Microbiome Modulation

Bacillus coagulans LBSC showed stability in acidic pH, bile and simulated human gastrointenstinal juices. Under static gut model, when passed through oral, gastric and intestinal phases, B. coagulans LBSC was found to be stable as free viable spores and also with various foods such as milk and baby foods, as well as American and European diets. In human studies, modulation of gut microbiota by B. coagulans LBSC was comprehended by whole genome metagenome analysis of fecal samples obtained from pre- and post-treatment of irritable bowel syndrome (IBS) patients. B. coagulans LBSC treatment showed positive modulation in gut microbiota, especially up regulation of phyla such as Actinobacteria and Firmicutes, whereas down regulation of Bacteroids, Proteobacteria, Streptophyta and Verrucomicrobia. Simultaneously, it has altered various microbiota associated metabolic pathways to create the normalcy of gut microenvironment.

Bryndza cheese of Slovak origin as potential resources of probiotic bacteria

Bryndza cheese includes several predominant lactic acid bacteria. The aim of our study was the antagonistic effect of lactic acid bacteria supernatant isolated from ewes´ cheese bryndza against ten Gram-positive and Gram-negative bacteria. Isolated strains of bacteria were obtained from bryndza which were produced in five different regions of Slovakia. Isolated strains of lactic acid bacteria were identified with mass spectrometry MALDI-TOF MS Biotyper. A total of one hundred and thirty lactic bacteria include Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Lactobacillus brevis, Lactobacillus harbinensis, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus paracasei ssp. paracasei, Lactobacillus paraplantarum, Lactobacillus suebicus, Lactococcus lactis ssp. lactis, Lactococcus lactis, and Pediococcus acidilactici were tested in this study against Gram-negative bacteria: Escherichia coli CCM 3988, Klebsiella pneumoniae CCM 2318, Salmonella enterica subsp. enterica CCM 3807, Shigella sonnei CCM 1373, Yersinia enterocolitica CCM 5671 and Gram-positive bacteria: Bacillus thuringiensis CCM 19, Enterococcus faecalis CCM 4224, Listeria monocytogenes CCM 4699, Staphylococcus aureus subsp. aureus CCM 2461, Streptococcus pneumonia CCM 4501 with agar diffusion method. Lactic acid bacteria showed activity 92% against Yersinia enterocolitica, 91% against Klebsiella pneumoniae, 88% against Escherichia coli, 84% against Listeria monocytogenes. The most effective bacteria against Gram-positive and Gram-negative bacteria tested was Lactobacillus paracasei ssp. paracasei.

Caenorhabditis elegans, a Host to Investigate the Probiotic Properties of Beneficial Microorganisms

Caenorhabditis elegans, a non-parasitic nematode emerges as a relevant and powerful candidate as an in vivo model for microorganisms-microorganisms and microorganisms-host interactions studies. Experiments have demonstrated the probiotic potential of bacteria since they can provide to the worm a longer lifespan, an increased resistance to pathogens and to oxidative or heat stresses. Probiotics are used to prevent or treat microbiota dysbiosis and associated pathologies but the molecular mechanisms underlying their capacities are still unknown. Beyond safety and healthy aspects of probiotics, C. elegans represents a powerful way to design large-scale studies to explore transkingdom interactions and to solve questioning about the molecular aspect of these interactions. Future challenges and opportunities would be to validate C. elegans as an in vivo tool for high-throughput screening of microorganisms for their potential probiotic use on human health and to enlarge the panels of microorganisms studied as well as the human diseases investigated.

Cancer Microbiome; Opportunities and Challenges

BACKGROUND

Microbe-host association has emerged as a modulator in modern medicine. Cancer and its associated host microbes are collectively referred to as the cancer microbiome. The cancer microbiome is complex, and many aspects remain unclear including metabolic plasticity, microenvironment remodeling, cellular communications, and unique signatures within the host, all of which have a vital role in homeostasis and pathogenesis of host physiology. However, the role of the microbiome in cancer initiation, progression, and therapy is still poorly understood and remains to be explored.

OBJECTIVE

The objective of this review is to elucidate the role of the microbiome in cancer metabolism and the tumor microenvironment. It also focuses on the importance of therapeutic opportunities and challenges in the manipulation of the cancer microbiome.

METHODS

A literature search was conducted on the role of the microbiome in cancer initiation, progression, and therapy.

CONCLUSION

The tumor microenvironment and cancer metabolism are significant in host-microbiome interactions. The microbiome can modulate standard cancer therapies like chemotherapy and immunotherapy. Microbiome transplantation has also been demonstrated as an effective therapy against cancer. Furthermore, the modulation of the microbiome also has potential clinical outcomes in modern medicine.

Functional probiotics of lactic acid bacteria from Hu sheep milk

Background

Probiotics are being considered as valuable microorganisms related to human health. Hu sheep is referred as one of the important sheep breeds in China. Goat milk produced by Hu sheep is characterized with high nutritional value and hypoallergenic in nature. Particularly, this milk contains plenty of milk prebiotic and probiotic bacteria. This study was aimed to scrutinize more bacterial strains from Hu sheep milk with potential probiotic activity.

Results

Based on 16S rRNA sequence analysis, pool of forty bacterial strains were identified and evaluated their antimicrobial activities against Staphylococcus aureus, enterohemorrhagic Escherichia coli (EHEC), Salmonella typhimurium, Listeria monocytogenes enterotoxigenic E. coli (ETEC) and Aeromonas caviae. Four out of these isolated strains demonstrated their efficient bacteriostatic ability and potential healthy properties. We also examined the safety aspects of these bacterial candidates including three Lactococcus lactis strains (named as HSM-1, HSM-10, and HSM-18) and one Leuconostoc lactis strain (HSM-14), and were further evaluated via in vitro tests, including antimicrobial activity, cell surface characteristics (hydrophobicity, co-aggregation, and self-aggregation), heat treatment, antibiotic susceptibility, simulated transport tolerance in the gastrointestinal tract, and acid/bile tolerance. The obtained results revealed that HSM-1, HSM-10, HSM-14, and HSM-18 showed high survival rate at different conditions for example low pH, presence of bovine bile and demonstrated high hydrophobicity. Moreover, HSM-14 had an advantage over other strains in terms of gastrointestinal tract tolerance, antimicrobial activities against pathogens, and these results were significantly better than other bacterial candidates.

Conclusion

Hu sheep milk as a source of exploration of potential lactic acid bacteria (LAB) probiotics open the new horizon of probiotics usage from unconventional milk sources. The selected LAB strains are excellent probiotic candidates which can be used for animal husbandry in the future. Rationale of the study was to utilize Hu sheep milk as a source of potential probiotic LABs. The study has contributed to the establishment of a complete bacterial resource pool by exploring the Hu sheep milk microflora.

An Aqueous Extract of a Bifidobacterium Species Induces Apoptosis and Inhibits Invasiveness of Non-Small Cell Lung Cancer Cells

Chemotherapy regimens for non?small cell lung cancer (NSCLC) have various adverse effects on the human body. For this reason, probiotics have received attention regarding their potential value as a safe and natural complementary strategy for cancer prevention. This study analyzed the anticancer effects of aqueous extracts of probiotic bacteria Bifidobacterium bifidum (BB), Bifidobacterium longum (BL), Bifidobacterium lactis (BLA), Bifidobacterium infantis 1 (BI1), and Bifidobacterium infantis 2 (BI2) on NSCLC cell lines. When the aqueous extracts of probiotic Bifidobacterium species were applied to the NSCLC cell lines A549, H1299, and HCC827, cell death increased considerably; in particular, the aqueous extracts from BB and BLA markedly reduced cell proliferation. p38 phosphorylation induced by BB aqueous extract increased the expression of cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase (PARP), consequently inducing the apoptosis of A549 and H1299 cells. When the p38 inhibitor SB203580 was applied, phosphorylation of p38 decreased, and the expression of cleaved caspase 3 and cleaved PARP was also inhibited, resulting in a reduction of cell death. In addition, BB aqueous extracts reduced the secretion of MMP-9, leading to inhibition of cancer cell invasion. By contrast, after transfection of short hairpin RNA shMMP-9 (for a knockdown of MMP-9) int°Cancer cells, BB aqueous extracts treatment failed to suppress the cancer cell invasiveness. According to our results about their anticancer effects on NSCLC, probiotics consisting of Bifidobacterium species may be useful as adjunctive anticancer treatment in the future.

Probiotics for cancer alternative prevention and treatment

Cancer is a fatal malignancy with high clinical significance and remains one of the major causes of illness and death. It has no suitable cure existing till now. The safety and stability of the standard chemotherapeutics drugs and synthetic agents used to manage cancer are doubtful. These agents are affecting the quality of life or contributing for development of drug resistance and are not affordable to the majority of the patients. Therefore, scientists are looking into clinical management of the cancer with high efficiency. This review focuses on the role of probiotics as alternative prevention and treatment of cancer. In this regard, we discuss the alternative cancer biotherapeutic drugs including live or dead probiotics and their metabolites, such as short chain fatty acids, inhibitory compounds of protein, polysaccharide, nucleic acid and ferrichrome in in vitro, in vivo and clinical studies. We also discuss the effectiveness of these biotherapeutics in prevention and treatment of various types of cancer linked with probiotic bacterial or fungal strains, probiotic dose, and time of exposure. More in vivo mainly clinical trials are necessary to further reveal and approve the significant role of live and dead probiotics as well as their metabolic products in cancer prevention and treatment. Finally, the majority of the positive results provided by probiotic treatments are limited to experimental settings. To minimize side effects associated with probiotics, short and long term effect studies in the direction of methodology standardization are required.

Pharmabiotic beads with improved encapsulation and gut survival for management of colonic inflammation associated gut derangements

Encapsulation techniques and materials, explored for addressing compromised probiotic gut survival, report significant production losses resulting in <10% entrapment. Presently, we report three-time enhanced entrapment (30 ± 1.2%) of Lactobacillus acidophilus (LAB) in calcium-alginate beads, by modifying process parameters and employing polyethylene glycol (PEG). Water-loving, viscolysing and osmotic-building effects of PEG create numerous, fine voids in the alginate gel allowing efficient diffusion of crosslinking calcium ions, resulting in less leaky beads. Eudragit S100 overcoat improved LAB survival by 690 times in simulated GIT stresses.In DMH-DSS induced colitis and precancerous lesions in rats, while free LAB failed to show any protection, pharmabiotic beads significantly (p < .05) reduced lipid peroxidation, increased antioxidant levels; decreased serum inflammatory burden; downregulated COX-2, iNOS, and c-Myc expression; elevated levels of the selected gut bacteria and SCFAs especially butyrate, all of which add up to antioxidant, anti-inflammatory, balanced gut biota, and ultimately anticancer effects.

Colorectal Cancer and Probiotics: Are Bugs Really Drugs?

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

Multi-omic profiling reveals associations between the gut mucosal microbiome, the metabolome, and host DNA methylation associated gene expression in patients with colorectal cancer

Background

The human gut microbiome plays a critical role in the carcinogenesis of colorectal cancer (CRC). However, a comprehensive analysis of the interaction between the host and microbiome is still lacking.

Results

We found correlations between the change in abundance of microbial taxa, butyrate-related colonic metabolites, and methylation-associated host gene expression in colonic tumour mucosa tissues compared with the adjacent normal mucosa tissues. The increase of genus Fusobacterium abundance was correlated with a decrease in the level of 4-hydroxybutyric acid (4-HB) and expression of immune-related peptidase inhibitor 16 (PI16), Fc Receptor Like A (FCRLA) and Lymphocyte Specific Protein 1 (LSP1). The decrease in the abundance of another potentially 4-HB-associated genus, Prevotella 2, was also found to be correlated with the down-regulated expression of metallothionein 1 M (MT1M). Additionally, the increase of glutamic acid-related family Halomonadaceae was correlated with the decreased expression of reelin (RELN). The decreased abundance of genus Paeniclostridium and genus Enterococcus were correlated with increased lactic acid level, and were also linked to the expression change of Phospholipase C Beta 1 (PLCB1) and Immunoglobulin Superfamily Member 9 (IGSF9) respectively. Interestingly, 4-HB, glutamic acid and lactic acid are all butyrate precursors, which may modify gene expression by epigenetic regulation such as DNA methylation.

Conclusions

Our study identified associations between previously reported CRC-related microbial taxa, butyrate-related metabolites and DNA methylation-associated gene expression in tumour and normal colonic mucosa tissues from CRC patients, which uncovered a possible mechanism of the role of microbiome in the carcinogenesis of CRC. In addition, these findings offer insight into potential new biomarkers, therapeutic and/or prevention strategies for CRC.

Alterations of the Predominant Fecal Microbiota and Disruption of the Gut Mucosal Barrier in Patients with Early-Stage Colorectal Cancer

Growing evidence indicated that the gut microbiota was the intrinsic and essential component of the cancer microenvironment, which played vital roles in the development and progression of colorectal cancer (CRC). In our present study, we investigated the alterations of fecal abundant microbiota with real-time quantitative PCR and the changes of indicators of gut mucosal barrier from 53 early-stage CRC patients and 45 matched healthy controls. We found that the traditional beneficial bacteria such as Lactobacillus and Bifidobacterium decreased significantly and the carcinogenic bacteria such as Enterobacteriaceae and Fusobacterium nucleatum were significantly increased in CRC patients. We also found gut mucosal barrier dysfunction in CRC patients with increased levels of endotoxin (LPS), D-lactate, and diamine oxidase (DAO). With Pearson's correlation analysis, D-lactate, LPS, and DAO were correlated negatively with Lactobacillus and Bifidobacterium and positively with Enterobacteriaceae and F. nucleatum. Our present study found dysbiosis of the fecal microbiota and dysfunction of the gut mucosal barrier in patients with early-stage CRC, which implicated that fecal abundant bacteria and gut mucosal barrier indicators could be used as targets to monitor the development and progression of CRC in a noninvasive and dynamic manner.

Association between dietary patterns and disease recurrence in Thai colorectal cancer patients

Beside established anti-cancer treatment, dietary modification is one of the most promising approaches for reducing the probability of colorectal cancer (CRC) recurrence. Many Western studies showed a relationship between shortened survival and increased amounts of Western diet (meat and processed meat). Given that Thai food is dissimilar to Western diet, we aimed to explore the association between dietary patterns and disease recurrence among Thai CRC patients.Early-stage CRC patients who were disease-free at the end of a 2-year period or patients with disease recurrence within 2 years were enrolled. Patients were administered a food frequency questionnaire to evaluate their dietary lifestyle. Quantitative comparison within individual food groups among patients who were disease-free and among those with recurrence was performed. Proportion of patients with recurrence and disease-free survival was compared between patients who had consumed the lowest and highest tertile of each dietary pattern.A total of 225 CRC patients were enrolled (151 disease-free and 74 recurrence). There were no significant differences in demographic or tumor parameters between patients with or without disease recurrence. From the questionnaire, 45 food items were assigned to 1 of 12 food groups according to similarity in nutritional profile. Patients who consumed high amounts of pickled fish or chili-paste had significantly lower recurrence rates compared to patients who had never eaten those foods (P < .01). From the factor analysis, meat/wheat, vegetarian, and fast-food/processed fruit patterns were identified as the major dietary patterns. There was no significant association between intakes of individual dietary patterns and CRC recurrence.Among CRC patients with Thai dietary lifestyles there was no association between meat/wheat, fast-food/processed fruit, or vegetarian dietary patterns and CRC recurrence. Greater consumption of some unique Thai foods, such as chili-paste or pickled fish, may relate to better outcomes for CRC patients.

Microbiome in Colorectal Cancer: How to Get from Meta-omics to Mechanism?

Mounting evidence from metagenomic analyses suggests that a state of pathological microbial imbalance or dysbiosis is prevalent in the gut of patients with colorectal cancer. Several bacterial taxa have been identified of which representative isolate cultures interact with human cancer cells in vitro and trigger disease pathways in animal models. However, how the complex interrelationships in dysbiotic communities may be involved in cancer pathogenesis remains a crucial question. Here, we provide a survey of current knowledge of the gut microbiome in colorectal cancer. Moving beyond observational studies, we outline new experimental approaches for gaining ecosystem-level mechanistic understanding of the gut microbiome's role in cancer pathogenesis.

Immune Responses Raised in an Experimental Colon Carcinoma Model Following Oral Administration of Lactobacillus casei

The role of dietary probiotic strains on host anticancer immune responses against experimental colon carcinoma was investigated. We have previously shown that Lactobacillus casei administration led to tumor growth suppression in an experimental colon cancer model. Here, we investigated the underlying immune mechanisms involved in this tumorgrowth inhibitory effect. BALB/c mice received daily live lactobacilli per os prior to the establishment of a syngeneic subcutaneous CT26 tumor. Tumor volume, cytokine production, T cell differentiation and migration, as well as tumor cell apoptosis were examined to outline potential immunomodulatory effects following L. casei oral intake. Probiotic administration in mice resulted in a significant increase in interferon gamma (IFNγ), Granzyme B and chemokine production in the tumor tissue as well as enhanced CD8⁺ T cell infiltration, accompanied by a suppression of tumor growth. Cytotoxic activity against cancer cells was enhanced in probioticfed compared to control mice, as evidenced by the elevation of apoptotic markers, such as cleaved caspase 3 and poly (ADPribose) polymerase 1 (PARP1), in tumor tissue. Oral administration of Lactobacillus casei induced potent Th1 immune responses and cytotoxic T cell infiltration in the tumor tissue of tumorbearing mice, resulting in tumor growth inhibition. Thus, the microorganism may hold promise as a novel dietary immunoadjuvant in raising protective anticancer immune responses.

Inhibitory effects of Lactobacilli cocktail on HT-29 colon carcinoma cells growth and modulation of the Notch and Wnt/β-catenin signaling pathways

Probiotics could be considered as attractive candidates for preventing tumor growth through maintaining homeostasis. The aim of this study was to evaluate the inhibitory effect of a cocktail of five Lactobacillus species on human colorectal carcinoma cell line HT-29. The anti-proliferative and apoptotic effects of Lactobacilli cocktail were evaluated using MTT and flow cytometry tests, respectively. Quantitative real-time polymerase chain reaction (qPCR) was used to analyze the expression of several genes in the Notch (notch, hes1, msi1, and numb) and Wnt/β-catenin (CTNNB1 and CCND1) pathways, following the treatment of HT-29 cells with Lactobacilli cocktail. The treatment by Lactobacilli cocktail induced a significant anti-proliferative effect and late stage apoptosis among the cancer cells (p < 0.05). Compared to the untreated cells, Lactobacilli cocktail induced the down-regulation of notch, hes1, and msi1 genes and up-regulation of numb gene in the Notch pathway as well as the down-regulation of CTNNB1 and CCND1 genes in the Wnt/β-catenin pathway in a time-dependent manner (p < 0.05). CONCLUSION: Lactobacilli cocktail was shown to have beneficial anti-tumor effects on HT-29 cells by modulating the Notch and Wnt/β-catenin pathways; therefore, the use of Lactobacilli probiotics as nutritional supplements may prevent the incidence of colon cancer.

An overview of yeast probiotics as cancer biotherapeutics: possible clinical application in colorectal cancer

The previous reports have established a strong link between diet, lifestyle, and gut microbiota population with the onset of the colorectal cancer (CRC). Administration of probiotics has become a particular interest in prevention and treatment of CRC. As potential dietary complements, probiotics might be able to lower the risk of CRC and manage the safety of traditional cancer therapies such as surgery, radiation therapy, and chemotherapy. This review investigates the promising effects of probiotics as biotherapeutics, with due attention to possible clinical application of yeast probiotics in prevention and treatment of CRC. In addition, various underlying anti-cancer mechanisms are covered here based on scientific evidence and findings from numerous experimental studies. Application of probiotics as biotherapeutics in CRC, however, needs to be approved by human clinical trials. It is of prime concern, to find potential probiotic strains, effective doses for administrations and regimes, and molecular mechanisms involved in prevention and treatment.

Colorectal Cancer Therapy Using a Pediococcus pentosaceus SL4 Drug Delivery System Secreting Lactic Acid Bacteria-Derived Protein p8

Despite decades of research into colorectal cancer (CRC), there is an ongoing need for treatments that are more effective and safer than those currently available. Lactic acid bacteria (LAB) show beneficial effects in the context of several diseases, including CRC, and are generally regarded as safe. Here, we isolated a Lactobacillus rhamnosus (LR)-derived therapeutic protein, p8, which suppressed CRC proliferation. We found that p8 translocated specifically to the cytosol of DLD-1 cells. Moreover, p8 down-regulated expression of Cyclin B1 and Cdk1, both of which are required for cell cycle progression. We confirmed that p8 exerted strong anti-proliferative activity in a mouse CRC xenograft model. Intraperitoneal injection of recombinant p8 (r-p8) led to a significant reduction (up to 59%) in tumor mass when compared with controls. In recent years, bacterial drug delivery systems (DDSs) have proven to be effective therapeutic agents for acute colitis. Therefore, we aimed to use such systems, particularly LAB, to generate the valuable therapeutic proteins to treat CRC. To this end, we developed a gene expression cassette capable of inducing secretion of large amounts of p8 protein from Pediococcus pentosaceus SL4 (PP). We then confirmed that this protein (PP-p8) exerted anti-proliferative activity in a mouse CRC xenograft model. Oral administration of PP-p8 DDS led to a marked reduction in tumor mass (up to 64%) compared with controls. The PP-p8 DDS using LAB described herein has advantages over other therapeutics; these advantages include improved safety (the protein is a probiotic), cost-free purification, and specific targeting of CRC cells.

Bacillus subtilis, an ideal probiotic bacterium to shrimp and fish aquaculture that increase feed digestibility, prevent microbial diseases, and avoid water pollution

Beneficial microorganisms maintain the ecosystems, plants, animals and humans working in healthy conditions. In nature, around 95% of all microorganisms produce beneficial effects by increasing nutrients digestion and assimilation, preventing pathogens development and by improving environmental parameters. However, increase in human population and indiscriminate uses of antibiotics have been exerting a great pressure on agriculture, livestock, aquaculture, and also to the environment. This pressure has induced the decomposition of environmental parameters and the development of pathogenic strains resistant to most antibiotics. Therefore, all antibiotics have been restricted by corresponding authorities; hence, new and healthy alternatives to prevent or eliminate these pathogens need to be identified. Thus, probiotic bacteria utilization in aquaculture systems has emerged as a solution to prevent pathogens development, to enhance nutrients assimilation and to improve environmental parameters. In this sense, B. subtilis is an ideal multifunctional probiotic bacterium, with the capacity to solve these problems and also to increase aquaculture profitability.

Tetrabromobisphenol A (TBBPA) inhibits denitrification via regulating carbon metabolism to decrease electron donation and bacterial population

The potential risks of brominated flame retardants (BFRs) like tetrabromobisphenol A (TBBPA) have attracted much attention. However, the influence of TBBPA on functional microbes remains poorly understood, especially with regards to denitrification, which is closely related with the carbon and nitrogen cycles, eutrophication and greenhouse gas emission. Herein, we found that 1.0 mg/L of TBBPA significantly decreased the total nitrogen removal efficiency by 81.7%, but increased the accumulation of NO₂^--N (by 81.5%) and N₂O (by 172-fold). This was found to be underlie by the significant decrease in both the denitrifying capability of denitrifiers and total bacterial population. Further investigation revealed that TBBPA inhibited the pathways of glucolysis and pentose phosphate, and promoted glyoxylate bypass via regulating genes expressions of key enzymes (such as glucose-6-phosphate isomerase, pyruvate dehydrogenase, isocitrate lyase, etc.), then decreased the generation of NADH serving as electron donor for denitrification, and inhibited the denitrifying capability of denitrifiers. Moreover, insufficient NADH stimulated the accumulation of denitrifying intermediates (NO₂^--N and N₂O), which induced the increase of reactive nitrogen species (RNS), whose accumulation decreased proliferation and increased apoptosis of denitrifying bacteria. Finally, the decrease in the denitrifying capability of denitrifier and bacterial population resulted in negative denitrifying performance.

Characterization of the Anti-Cancer Activity of the Probiotic Bacterium Lactobacillus fermentum Using 2D vs. 3D Culture in Colorectal Cancer Cells

The aim of this study was to investigate the potential anti-cancer effects of probiotic cell-free supernatant (CFS) treatment using Lactobacillusfermentum for colorectal cancer (CRC) in 3D culture systems. Cell viability was assessed using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assays, whereas apoptosis was monitored through RT-qPCR analysis of Bax, Bak, Noxa, and Bid mRNA expressions in addition to flow cytometry analysis of Lactobacillus cell-free supernatant (LCFS) treatment. Our results showed that the anti-cancer effect of LCFS on cell viability was pronouncedly enhanced in 3D-cultured HCT-116 cells, which was linked to the increased level of cleaved caspase 3. Additionally, upregulation of apoptotic marker gene mRNA transcription was dramatically increased in 3D cultured cells compared to 2D systems. In conclusion, this study suggests that LCFS enhances the activation of intrinsic apoptosis in HCT-116 cells and the potential anti-cancer effects of Lactobacilli mixtures in 3D culture systems. All in all, our study highlights the benefits of 3D culture models over 2D culture modeling in studying the anti-cancer effects of probiotics.

Anti-Colorectal Cancer Effects of Probiotic-Derived p8 Protein

Recently, we reported a novel therapeutic probiotic-derived protein, p8, which has anti-colorectal cancer (anti-CRC) properties. In vitro experiments using a CRC cell line (DLD-1), anti-proliferation activity (about 20%) did not improve after increasing the dose of recombinant-p8 (r-p8) to >10 μM. Here, we show that this was due to the low penetrative efficiency of r-p8 exogenous treatment. Furthermore, we found that r-p8 entered the cytosol through endocytosis, which might be a reason for the low penetration efficiency. Therefore, to improve the therapeutic efficacy of p8, we tried to improve delivery to CRC cells. This resulted in endogenous expression of p8 and increased the anti-proliferative effects by up to 2-fold compared with the exogenous treatment (40 μM). Anti-migration activity also increased markedly. Furthermore, we found that the anti-proliferation activity of p8 was mediated by inhibition of the p53-p21-Cyclin B1/Cdk1 signal pathway, resulting in growth arrest at the G2 phase of the cell cycle. Taken together, these results suggest that p8 is toxic to cancer cells, shows stable expression within cells, and shows strong cancer suppressive activity by inducing cell cycle arrest. Therefore, p8 is a strong candidate for gene therapy if it can be loaded onto cancer-specific viruses.

Integrative analysis of gut microbiota composition, host colonic gene expression and intraluminal metabolites in aging C57BL/6J mice

The aging process is associated with diminished colonic health. In this study, we applied an integrative approach to reveal potential interactions between determinants of colonic health in aging C57BL/6J mice. Analysis of gut microbiota composition revealed an enrichment of various potential pathobionts, including Desulfovibrio spp., and a decline of the health-promoting Akkermansia spp. and Lactobacillus spp. during aging. Intraluminal concentrations of various metabolites varied between ages and we found evidence for an increased gut permeability at higher age. Colonic gene expression analysis suggested that during the early phase of aging (between 6 and 12 months), expression of genes involved in epithelial-to-mesenchymal transition and (re)organization of the extracellular matrix were increased. Differential expression of these genes was strongly correlated with Bifidobacterium spp. During the later phase of aging (between 12 and 28 months), gene expression profiles pointed towards a diminished antimicrobial defense and were correlated with an uncultured Gastranaerophilales spp. This study demonstrates that aging is associated with pronounced changes in gut microbiota composition and colonic gene expression. Furthermore, the strong correlations between specific bacterial genera and host gene expression may imply that orchestrated interactions take place in the vicinity of the colonic wall and potentially mediate colonic health during aging.

Changing our microbiome: probiotics in dermatology

BACKGROUND

Commensal bacteria are a major factor in human health and disease pathogenesis. Interest has recently expanded beyond the gastrointestinal microbiome to include the skin microbiome and its impact on various skin diseases.

OBJECTIVES

Here we present current data reviewing the role of the microbiome in dermatology, considering both the gut and skin microflora. Our objective was to evaluate whether the clinical data support the utility of oral and topical probiotics for certain dermatological diseases.

METHODS

The PubMed and ClinicalTrials.gov databases were searched for basic science, translational research and clinical studies that investigated differences in the cutaneous microbiome and the impact of probiotics in patients with atopic dermatitis, acne vulgaris, psoriasis, chronic wounds, seborrhoeic dermatitis and cutaneous neoplasms.

RESULTS

Few clinical trials exist that explore the utility of probiotics for the prevention and treatment of dermatological diseases, with the exception of atopic dermatitis. Most studies investigated oral probiotic interventions, and of those utilizing topical probiotics, few included skin commensals. In general, the available clinical trials yielded positive results with improvement of the skin conditions after probiotic intervention.

CONCLUSIONS

Oral and topical probiotics appear to be effective for the treatment of certain inflammatory skin diseases and demonstrate a promising role in wound healing and skin cancer. However, more studies are needed to confirm these results. What's already known about this topic? The microbiome plays a role in human health and disease pathogenesis. Probiotics can manipulate the host microbiome and may confer health benefits for patients. Research to date has already begun to explore the utility of oral and topical probiotics for certain dermatological diseases. What does this study add? This review presents basic science and clinical trial data to support the role of the gut and skin microbiome in dermatology. Current data are reviewed on the use of probiotics in the prevention and treatment of skin diseases, including atopic dermatitis, acne vulgaris, psoriasis, seborrhoeic dermatitis, chronic wounds and cutaneous neoplasms. Future probiotic interventions are proposed.

A randomized double-blind placebo-controlled trial of probiotics in post-surgical colorectal cancer

Background

Our study aimed to determine the effect of probiotic consumption containing six viable microorganisms of 30 × 10¹⁰ cfu Lactobacillus and Bifidobacteria strains for six months on clinical outcomes and inflammatory cytokines (TNF-α, IFN-γ, IL-6, IL-10, IL-12, IL-17A, IL-17C and IL-22) in patients with colorectal cancer.

Methods

Fifty-two patients with colorectal cancer were randomized at four weeks after surgery to receive either a placebo (n = 25) or 30 billion colony-forming unit (CFU) of a mixture of six viable strains including 107 mg of Lactobacillus acidophilus BCMC® 12,130, Lactobacillus lactis BCMC® 12,451, Lactobacillus casei subsp BCMC® 12,313, Bifidobacterium longum BCMC® 02120, Bifidobacterium bifidum BCMC® 02290 and Bifidobacterium infantis BCMC® 02129 (n = 27). Patients were instructed to take the product orally twice daily for six months. Infection status, diarrhea or hospital admission were recorded throughout the study. Blood was taken pre- and post-intervention to measure TNF-α, IFN-γ, IL-6, IL-10, IL-12, IL-17A, IL-17C and IL-22 using ELISA multiplex kit.

Results

The majority of cases (~ 70%) were in Duke’s C colorectal cancer for both groups. No surgical infection occurred and no antibiotics were required. Chemotherapy induced diarrhea was observed in both groups. Significant reduction in the level of pro-inflammatory cytokine, TNF-α, IL-6, IL-10, IL-12, IL-17A, IL-17C and IL-22 were observed in CRC patients who received probiotics as compared to pre-treatment level (P < 0.05). However, there was no significant difference in the IFN-γ in both groups.

Conclusions

We have shown that probiotics containing six viable microorganisms of Lactobacillus and Bifidobacteria strains are safe to be consumed at four weeks after surgery in colorectal cancer patients and have reduced pro-inflammatory cytokines (except for IFN-gamma). Probiotic may modify intestinal microenvironment resulting in a decline in pro-inflammatory cytokines.

Trial registration

NCT03782428; retrospectively registered on 20th December 2018.

Xenobiotics Formed during Food Processing: Their Relation with the Intestinal Microbiota and Colorectal Cancer

The colonic epithelium is exposed to a mixture of compounds through diet, among which some are procarcinogens, whereas others have a protective effect. Therefore, the net impact of these compounds on human health depends on the overall balance between all factors involved. Strong scientific evidence has demonstrated the relationship between nitrosamines (NA), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs), which are the major genotoxins derived from cooking and food processing, and cancer. The mechanisms of the relationship between dietary toxic xenobiotics and cancer risk are not yet well understood, but it has been suggested that differences in dietary habits affect the colonic environment by increasing or decreasing the exposure to mutagens directly and indirectly through changes in the composition and activity of the gut microbiota. Several changes in the proportions of specific microbial groups have been proposed as risk factors for the development of neoplastic lesions and the enrichment of enterotoxigenic microbial strains in stool. In addition, changes in the gut microbiota composition and activity promoted by diet may modify the faecal genotoxicity/cytotoxicity, which can be associated with a higher or lower risk of developing cancer. Therefore, the interaction between dietary components and intestinal bacteria may be a modifiable factor for the development of colorectal cancer in humans and deserves more attention in the near future.

TRAIL-expressing recombinant Lactococcus lactis induces apoptosis in human colon adenocarcinoma SW480 and HCT116 cells

AIMS

We investigated the ability of Lactococcus lactis, a species generally regarded as safe, to express tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) protein. The expressed protein was either cell wall anchored or secreted, and it was assessed whether this could induce apoptosis in human colon adenocarcinoma cell lines SW480 and HCT116.

METHODS AND RESULTS

Constructs were designed to produce either secreted or cell wall-anchored forms of human TRAIL cloned into pNZ7021 expression vector. The expression by L. lactis was confirmed by Western blotting and immunofluorescence. Induction of cell death was evaluated by coculturing transformants producing either form of TRAIL protein with the two cell lines followed by MTT assay. Gene expression of apoptosis genes, Bax and Bcl2, was assessed by qPCR. The viability of SW480 and HCT116 cells treated with recombinant L. lactis was significantly reduced. A significant change was observed in the ratio of Bax/Bcl2 expression in HCT116 cells only following treatment with the supernatant of recombinant L. lactis containing secreted TRAIL.

CONCLUSION

Recombinant L. lactis producing TRAIL protein can induce apoptosis in human colon adenocarcinoma cell lines SW480 and HCT116.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of recombinant probiotics that produce anticancer compounds is a promising option for combating cancer cells.