Dual Anti-Metastatic and Anti-Proliferative Activity Assessment of Two Probiotics on HeLa and HT-29 Cell Lines

Glycated nisin enhances nisin's cytotoxic effects on breast cancer cells

Antimicrobial peptides, such as nisin, are proposed as promising agents for cancer treatment. While glycation has been recognized as an effective method for enhancing various physicochemical properties of nisin, its anticancer effects remain unexplored. Therefore, we aimed to assess the anticancer potential of glycated nisin against MDA-MB-231 cells. The MDA-MB cells were treated with increasing concentrations of nisin and glycated nisin for 24, 48, and 72 h. The IC50 values for nisin were higher than those for glycated nisin. Glycated nisin at concentrations of 20 and 40 µg/mL decreased cell viability more than nisin at the same concentrations. The rate of apoptosis in the group treated with 20 µg/mL of nisin was lower compared to other treatment groups, and no significant difference in apoptosis rates was observed at different time points (p > 0.05). However, in the glycated nisin groups with concentrations of 10, 20, and 40 µg/mL, the level of apoptosis was very high after 24 h (73-81% of cells undergoing apoptosis). Overall, our study suggests that glycated nisin exhibits stronger cytotoxic effects on MDA-MB-231 cells, primarily involving the induction of apoptosis. This indicates its potential utilization as an alternative approach to address the issue of drug resistance in cancer cells.

Usage of ectoine as a cryoprotectant for cryopreservation of lactic acid bacteria

Streptococcus thermophilus, the only Streptococcus species considered "Generally Recognized Safe", has been used widely in the food industry. This bacterium is one of the most valuable industrial lactic acid bacterial species. Due to the importance of this bacterium in industrial applications, it should be stored for a long time without losing its metabolic properties. The present study aimed to investigate the cryoprotectant effect of three compatible solutes (ectoine, trehalose, and sucrose) on bacterial cells stored at different temperatures (frozen at -80 °C or freeze-dried and subsequently stored at +4, -20, and -80 °C) for three months. The bacterial cells were tested for cell viability, bile salt tolerance, and lactic acid production before and after processing. The highest cell viability, bile salt tolerance, and lactic acid production were obtained with ectoine and under frozen (storage at -80 °C) conditions. In freeze-dried and subsequently stored at various temperatures, the best preservation was obtained at -80 °C, followed by -20 °C and +4 °C. Moreover, when ectoine's preservation potential was compared to other cryoprotectants, ectoine showed the highest preservation, followed by trehalose and sucrose. Although ectoine has a variety of qualities that have been proven, in the current work, we have shown for the first time that ectoine has cryoprotectant potential in yogurt starter cultures (S. thermophilus).

Analyzing of colorectal cancerrelated genes and microRNAs expression profiles in response to probiotics Lactobacillus acidophilus and Saccharomyces cerevisiae in colon cancer cell lines

BACKGROUND

Colorectal cancer is the world's third most frequent cancer and the fourth cause of mortality. Probiotics play an important function in preventing metastasis as well as the growth and proliferation of malignant cancer cells.

METHODS AND RESULTS

The study investigated the anticancer effect of Lactobacillus acidophilus supernatant and Saccharomyces cerevisiae yeast on colorectal cell lines, including HT29 and SW480 as a colorectal cancer model. The extract from the Lactobacillus acidophilus and Saccharomyces cerevisiae standard probiotics were prepared, and probiotics characterization was confirmed by morphological and Biochemical tests. The viability of HT29 and SW480 colon cancer cell lines on effecting probiotic supernatant was evaluated by measuring the MTT colorimetric method. Comparison of the expression profile of several genes involved in apoptosis, cell cycle, and metastatic pathway in HT29 and SW480 cell lines with the treatment of probiotics extract showed an upregulation in the BAX, CASP3, and CASP9 and down regulation BCl-2, MMP2, and MMP9 genes. Also, a comparison of microRNA expression profiles indicated an increase of miR 34, 135, 25, 16, 195, 27, 98, let7 and a decrease of miR 9, 106b, 17, 21, 155, 221.

CONCLUSIONS AND DISCUSSION

The findings of this study indicate that probiotics can effectively suppress the proliferation of colorectal cancer cells and even reverse their development. Additionally, the study of cellular genes and miRNA profiles associated with colorectal cancer have demonstrated that our probiotics play a crucial role in CRC prevention by increasing the expression of tumor suppressor microRNAs and their target genes while decreasing oncogenes.

Living Gut Bacteria Functionalized with Gold Nanoclusters and Drug for Facile Cancer Theranostics

Bacbots are potent self-propelling vehicles for targeted therapy that can be guided by chemical and biochemical stimuli of the host. In addition, they can be guided externally by the use of magnetic field or other physical forces. The challenge is to incorporate drugs and diagnostic tools in living bacteria with retention of theranostic activity until reaching the targets and easy clearance of the remainder following the treatment. We report that living Lactobacillus rhamnosus, when functionalized with photoluminescent Au nanoclusters and the anticancer drug methotrexate, was cytotoxic to monolayer and spheroids of cancer cells (HeLa and HT29) even at a low dose of bacteria used (10⁷ cfu/mL). The observed cell death was nearly 90% in HeLa spheroids and 70% in HT29 spheroids. Further, functionalization of the bacterial surface with the nanoclusters helped incorporate the drug onto their cell surfaces. The drug and nanocluster-loaded bacteria annihilated the cells and the spheroids in a rather short time (6 h) that revealed the specificity and effectiveness of the bacbots. The bacbots exhibited synergistic toxicity on the cells as their effect was more than the drug and the bacteria individually. This higher toxicity could be associated with elevated levels of reactive oxygen species generated in the bacbot-treated cells. The multifunctional bacbots reported here provide an option for guided therapy with the natural variant of the human gut-friendly living bacteria without the need for attenuation or genetic modification.

Impact of intestinal dysbiosis on breast cancer metastasis and progression

Breast cancer has a high mortality rate among malignant tumors, with metastases identified as the main cause of the high mortality. Dysbiosis of the gut microbiota has become a key factor in the development, treatment, and prognosis of breast cancer. The many microorganisms that make up the gut flora have a symbiotic relationship with their host and, through the regulation of host immune responses and metabolic pathways, are involved in important physiologic activities in the human body, posing a significant risk to health. In this review, we build on the interactions between breast tissue (including tumor tissue, tissue adjacent to the tumor, and samples from healthy women) and the microbiota, then explore factors associated with metastatic breast cancer and dysbiosis of the gut flora from multiple perspectives, including enterotoxigenic Bacteroides fragilis, antibiotic use, changes in gut microbial metabolites, changes in the balance of the probiotic environment and diet. These factors highlight the existence of a complex relationship between host-breast cancer progression-gut flora. Suggesting that gut flora dysbiosis may be a host-intrinsic factor affecting breast cancer metastasis and progression not only informs our understanding of the role of microbiota dysbiosis in breast cancer development and metastasis, but also the importance of balancing gut flora dysbiosis and clinical practice.

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

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

The role of probiotics in vaginal health

Probiotics have been widely used in the treatment of intestinal diseases, but the effect of probiotics on female reproductive tract health is still controversial. Lactobacillus is the most abundant microorganism in the vagina, which is related to the vaginal mucosal barrier. Lactobacillus adheres to the vaginal epithelium and can competitively antagonize the colonization of pathogens. The factors produced by Lactobacillus, such as bacteriocin and hydrogen peroxide (H₂O₂), can inhibit the growth of pathogenic microorganisms and maintain the low pH environment of the vagina. Probiotics play an important role in maintaining the stability of vaginal microenvironment, improving immune defense and blocking the progression of cervical cancer. We review the research progress of probiotics represented by Lactobacillus in gynecological diseases such as human papilloma virus (HPV) infection, bacterial vaginosis (BV) and Genitourinary Syndrome of Menopause (GSM), so as to provide basis for further exerting the role of probiotics in women’s health.

Anticancer Potential of Post-Fermentation Media and Cell Extracts of Probiotic Strains: An In Vitro Study

Simple Summary

Probiotics and their metabolites are very important for human health. The aim of this research was to determine probiotic strains with the strongest inhibitory properties against intestinal cancer cells. As a result of the screening, it was possible to find two strains, i.e., Lactiplantibacillus plantarum 0991 and Levilactobacillus brevis 0983, that could inhibit the proliferation of cancer cells by induction of oxidative stress and programmed cell death. Both strains exhibit interesting anticancer properties and potential as functional food ingredients; however, the results must be confirmed in further research.

Abstract

Background: Lactic acid bacteria (LAB), many of which are probiotics, can produce health-promoting metabolites (postbiotics). Purpose: To assess the mechanism of antiproliferative action of postbiotics, post-fermentation media (PFM) and cell extracts (CEs) of several strains of LAB were studied against colon (Caco-2), and cervix (HeLa) cancer cell lines, as well as normal intestine (IEC-6) cells, were used as a comparison. Methods: Postbiotics of various LAB (n = 39) were screened for their antiproliferative activity. The effect of PFM and CEs on reactive oxygen species (ROS), mitochondrial membrane potential (MMP), ATP production, phosphatidylserine (PS) externalisation, and apoptosis-related caspases 3/7 and 9 activation was assayed. Results: PFM and CEs showed strong dose-dependent antiproliferative activity against Caco-2 cells, up to 77.8 ± 0.8% and 58.4 ± 1.6% for PFM and CEs, respectively. Stronger inhibitory activity against cancerous (Caco-2 and HeLa) cells than against normal (IEC-6) cells was observed. PFM were more inhibitory than CEs, and both generated oxidative stress in Caco-2 cells. PFM of L. plantarum 0991 and L. brevis 0983 induced apoptosis in Caco-2 cells by the mitochondrial signalling pathway. Conclusions: Anticancer activity of PFM and CEs of LAB, as well as the ability of apoptosis induction, is strain-specific.

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

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

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

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

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

Lactobacillus fermentum and Lactobacillus crispatus Do Not Have Cytotoxic Effects on HN5 Oral Squamous Cell Carcinoma Cell Line

Background

The oral environment has a very complex normal flora and a wide variety of bacteria including lactobacilli. Studies have shown oral microbial flora has important influence in the development of oral cancer. Squamous cell carcinomas account for more than 90% of cancers in oral cavity. Lactobacilli are known as one of the newest methods for the prevention and treatment of cancers. Previous studies on the effects of probiotics on oral cancer cells are very limited, and only two species of Lactobacillus which are not present in the normal oral microflora have been studied. Due to the unknown effects of lactobacilli on oral cancer, this study aimed to investigate the effect of two species of lactobacilli of oral cavity on oral cancer cells.

Methods and Materials

The effects of the supernatant of two lactobacilli, namely, fermentum and crispatus were studied on HN5-cancer cells. The MTT method was used to study the effects of lactobacilli on inhibition of cancer cell growth.

Results

The results showed that these lactobacilli do not prevent the progression of oral cancer cells. Moreover, the results showed that the acidic medium had the most effect on reducing the growth of oral cancer cells.

Conclusion

Due to the different effects of lactobacilli on various cancer types, the effects of two Lactobacillus crispatus and Lactobacillus fermentum on other oral cancer cell lines may be different from what has been reported in this study.

Immune System Efficiency in Cancer and the Microbiota Influence

The immune system plays a critical role in preventing cancer development and progression. However, the complex network of cells and soluble factor that form the tumor microenvironment (TME) can dictate the differentiation of tumor-infiltrating leukocytes and shift the antitumor immune response into promoting tumor growth. With the advent of cancer immunotherapy, there has been a reinvigorated interest in defining how the TME shapes the antitumor immune response. This interest brought to light the microbiome as a novel player in shaping cancer immunosurveillance. Indeed, accumulating evidence now suggests that the microbiome may confer susceptibility or resistance to certain cancers and may influence response to therapeutics, particularly immune checkpoint inhibitors. As we move forward into the age of precision medicine, it is vital that we define the factors that influence the interplay between the triad immune system-microbiota-cancer. This knowledge will contribute to improve the therapeutic response to current approaches and will unravel novel targets for immunotherapy.

Inhibition of Human Cervical Cancer Hela Cell Line by Meat-Derived Lactic Acid Bacteria of Lactobacillus plantarum IIA-1A5 and Lactobacillus acidophilus IIA-2B4

<b>Background and Objective:</b> Two Indonesian lactic acid bacteria of<i> L. plantarum </i>I IA-1A5 and <i>L. acidophilus </i>IIA-2B4 were previously isolated from beef with some functional probiotic properties. Nevertheless, the possibility of these strains to have anticancer activity remains unknown. Current study aimed to evaluate the inhibitory properties of intra-and extracellular protein extracts of these two strains against cervical cancer HeLa cells. <b>Materials and Methods:</b> The intracellular and extracellular proteins extract from <i>L. plantarum </i>IIA-1A5 and <i>L. acidophilus </i>IIA-2B4 were collected and designated as IP-LP, IP-LA, EP-LP and EP-LA, respectively. The effect of these extracts on the viability and morphology of HeLa cells were observed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and confocal microscopy, respectively. <b>Results:</b> Both IP-LP and IP-LA inhibited HeLa cells in a concentration-dependent manner, with IC<sub>50</sub> values of 352.62 and 120.97 μg mL<sup>1</sup>, respectively. Meanwhile, the inhibition activity was also observed for EP-LP and EP-LA, <i>albeit</i> very low. The inhibition effect was also confirmed by morphological analysis under confocal electron microscopy which showed the changes in the cell shapes and numbers. <b>Conclusion:</b> Altogether, for the first time this study proposed that the probiotic isolated from Indonesian beef are promising to inhibit cancer cell lines.

Probiotic Pediococcus acidilactici strain from tomato pickle displays anti-cancer activity and alleviates gut inflammation in-vitro

The present study characterized the potential probiotic properties of Pediococcus acidilactici TMAB26 strain isolated from traditional Indian tomato pickle, and evaluated its possible therapeutic applications as an anti-cancer and anti-inflammatory agent in vitro. The 16S rRNA sequencing and primary screening demarcated TMAB26 strain as an ideal probiotic candidate, with distinctive properties of acid tolerance (58.02% at pH 2.5), bile tolerance (55.53% at 0.5%), and efficient adherence to the mucosal surface of the human intestinal cells in vitro, along with antagonistic, anti-inflammatory, and anti-cancer properties. The strain exhibited antagonism against standard intestinal pathogenic strains Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, E. coli, Klebsiella pneumonia, and Salmonella typhi with zones of inhibition in the range of 6-18 mm. The cytotoxicity evaluation of the probiotic isolate TMAB26 culture supernatant (1:1 dilution) showed significant cytotoxicity on HT-29 (94.91% ± 1.27) and Caco-2 (92.63% ± 0.63) cancer cells when compared to that of the peripheral blood mononuclear cells (PBMCs) alone. Furthermore, the strain culture supernatant reduced the mRNA levels of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) by threefold, Interleukin-6 (IL-6) by eightfold and increased the mRNA levels of the anti-inflammatory cytokine Interleukin-10 (IL-10) in lipopolysaccharide (LPS) pretreated HT-29 and peripheral blood mononuclear cells (PBMCs), suggesting the potential role of TMAB26 isolate, i.e., Pediococcus acidilactici MTCC 13014 in alleviating gut inflammation.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-020-02570-1.

Metabolite secretions of Lactobacillus plantarum YYC-3 may inhibit colon cancer cell metastasis by suppressing the VEGF-MMP2/9 signaling pathway

BACKGROUND

Colorectal cancer (CRC) is a major clinical challenge, and the gut microbiome plays important roles in the occurrence and metastasis of CRC. Lactobacillus and their metabolites are thought to be able to suppress the growth of CRC cells. However, the antimetastatic mechanism of Lactobacillus or their metabolites toward CRC cells is not clear. Therefore, the aim of this study was to assess the inhibitory mechanism of cell-free supernatants (CFSs) of L. rhamnosus GG, L. casei M3, and L. plantarum YYC-3 on metastasis of CRC cells.

RESULTS

YYC-3 CFS showed the highest inhibitory effect on CRC cell growth, invasion and migration, and inhibited MMP2, MMP9, and VEGFA gene and protein expression, and protein secretion. Furthermore, it suppressed the activities of MMPs by gelatin zymography. Moreover, the effective compounds in these CFSs were analyzed by Q Exactive Focus liquid chromatography-mass spectrometry.

CONCLUSIONS

Our results showed that metabolite secretions of YYC-3 may inhibited cell metastasis by downregulating the VEGF/MMPs signaling pathway. These data suggest that treatment of CRC cells with metabolites from L. plantarum YYC-3 may reduce colon cancer metastasis.

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.

Therapeutic, Prophylactic, and Functional Use of Probiotics: A Current Perspective

Probiotics are considered as the twenty-first century panpharmacon due to their competent remedial power to cure from gastrointestinal dysbiosis, systematic metabolic diseases, and genetic impairments up to complicated neurodegenerative disorders. They paved the way for an innovative managing of various severe diseases through palatable food products. The probiotics' role as a "bio-therapy" increased their significance in food and medicine due to many competitive advantages over traditional treatment therapies. Their prophylactic and therapeutic potential has been assessed through hundreds of preclinical and clinical studies. In addition, the food industry employs probiotics as functional and nutraceutical ingredients to enhance the added value of food product in terms of increased health benefits. However, regardless of promising health-boosting effects, the probiotics' efficacy still needs an in-depth understanding of systematic mechanisms and factors supporting the healthy actions.

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.

Anti-tumor activities of probiotics in cervical cancer

Cervical cancer is considered as an important malignancy among women worldwide. Currently-used treatments of cervical cancer are reported to be cytotoxic for patients. Moreover, these therapies have shown some side effects which can negatively affect the lives of women suffering from this cancer. Therefore, there is need for anti-tumor agents that are less toxic than common therapeutic drugs. Besides, applying agents for preventing or reducing the side effects of cervical cancer therapies can be effective in improving the life quality of cervical cancer patients. Studies have shown that probiotics have several effects on biological processes. One of the most prominent aspects in which probiotics play a role is in the field of cancer. There are multiple studies which have focused on the functions of probiotics in diagnosis, prevention, or treatment of cancer. Besides their direct anti-tumor activities, probiotics can be used as an additional agent for enhancing or modulating other diagnostic and therapeutic methods. Herein, the effects of probiotics on cervical cancer cells are discussed, which may be useful in the prevention and treatment of this cancer. We review the studies concerned with the roles of probiotics in modulating and reducing the gastrointestinal adverse effects caused by cervical cancer therapies. Furthermore, we cover the investigations focusing on the combination of probiotics with other drugs for diagnosis or treatment of cervical cancer.

Isolation, characterization and identification of antigenotoxic and anticancerous indigenous probiotics and their prophylactic potential in experimental colon carcinogenesis

Colorectal cancer, the third most commonly diagnosed cancer, is a lifestyle disease where diet and gut microbiome contribute intricately in its initiation and progression. Prophylactic bio-interventions mainly probiotics offer an alternate approach towards reducing or delaying its progression. Therefore, the present study was designed wherein a robust protocol for the isolation, characterization, and identification of indigenous probiotics having antigenotoxic and anticancerous activity was followed along with their prophylactic potential assessment in early experimental colorectal carcinogenesis. Among forty-six isolated lactic acid bacterial strains, only three were selected on the basis of antigenotoxicity against N,N-Dimethyl dihydrazine dihydrochloride and 4-Nitroquinoline 1-oxide and probiotic attributes. All three selected probiotic strains exhibited anticancerous potential as is evident by the reduced Aberrant Crypt Foci, reduced fecal pH, enhanced fecal lactic acid bacteria and altered fecal enzymes (β-glucuronidase, nitroreductase, β-glucosidase) that modulated gut microbiota and microenvironment resulting into restored histoarchitecture of the colon. The results are a clear indicator of the prophylactic potential of selected indigenous probiotics which may be used as an alternative prophylactic biological therapy against colon carcinogenesis particularly in highly susceptible individuals.

Gut Microbiota and Cancer: From Pathogenesis to Therapy

Cancer is a multifactorial pathology and it represents the second leading cause of death worldwide. In the recent years, numerous studies highlighted the dual role of the gut microbiota in preserving host’s health. Gut resident bacteria are able to produce a number of metabolites and bioproducts necessary to protect host’s and gut’s homeostasis. Conversely, several microbiota subpopulations may expand during pathological dysbiosis and therefore produce high levels of toxins capable, in turn, to trigger both inflammation and tumorigenesis. Importantly, gut microbiota can interact with the host either modulating directly the gut epithelium or the immune system. Numerous gut populating bacteria, called probiotics, have been identified as protective against the genesis of tumors. Given their capability of preserving gut homeostasis, probiotics are currently tested to help to fight dysbiosis in cancer patients subjected to chemotherapy and radiotherapy. Most recently, three independent studies show that specific gut resident species may potentiate the positive outcome of anti-cancer immunotherapy. The highly significant studies, uncovering the tight association between gut microbiota and tumorigenesis, as well as gut microbiota and anti-cancer therapy, are here described. The role of the Lactobacillus rhamnosus GG (LGG), as the most studied probiotic model in cancer, is also reported. Overall, according to the findings here summarized, novel strategies integrating probiotics, such as LGG, with conventional anti-cancer therapies are strongly encouraged.

Role of Lactobacillus in cervical cancer

Cervical cancer is a common malignant cancer among women worldwide. Changes in the vaginal microecological environment lead to multiple gynecological diseases, including cervical cancer. Recent research has shown that Lactobacillus may play an important role in the occurrence and development of cervical cancer. This review explores the role of Lactobacillus in cervical cancer. A total of 29 articles were included after identification and screening. The pertinent literature on Lactobacillus in cervical cancer from two perspectives, including clinical studies and experimental studies, was analyzed. An association network for the mechanism by which Lactobacillus induces cervical cancer was constructed. In addition, we provide direction and insight for further research on the role of Lactobacillus in cervical cancer.

The Role of Probiotics in Cancer Treatment: Emphasis on their In Vivo and In Vitro Anti-metastatic Effects

Probiotics are defined as live bacteria and yeasts that exert beneficial effects for health. Among their various effects, anti-cancer properties have been highlighted in recent years. Such effects include suppression of the growth of microbiota implicated in the production of mutagens and carcinogens, alteration in carcinogen metabolism and protection of DNA from oxidative damage as well as regulation of immune system. We performed a computerized search of the MEDLINE/PUBMED databases with key words: cancer, probiotics, lactobacilli, metastasis and invasion. Cell line studies as well as animal models and human studies have shown the therapeutic effects of probiotics in reduction of invasion and metastasis in cancer cells. These results support the beneficial effects of probiotics both in vitro and in vivo. However, pre-clinical or clinical studies are not enough to decide about their application.

Lactobacilli Differentially Modulate mTOR and Wnt/ β-Catenin Pathways in Different Cancer Cell Lines

Background

Lactobacilli are a group of beneficial bacteria whose anti cancer effects have been evaluated in different cancer cell lines as well as animal models and human subjects. Such anti cancer effects can be exerted via different mechanisms such as modulation of immune response as well as inhibition of pathogens colonization. In addition, lactobacilli have direct cytotoxic effects against cancer cells which may be exerted through modulation of expression cancer related pathways.

Objectives

The aim of this study is to find the mechanism of anti cancer effects of two lactobacilli strains, Lactobacillus. crispatus (LC) and Lactobacillus. rhamnosus (LR).

Materials and Methods

We analyzed expression of some mTOR and Wnt/ β-catenin pathways genes in three cancer cell lines (HeLa, MDA-MB-231 and HT-29) following treatment with LC and LR culture supernatants.

Results

Of note, the expression of CCND1 as a marker of cell proliferation, survival, and angiogenesis, has been decreased following LR treatment in all cell lines. In addition, the expression of SFRP2, an antagonist of Wnt pathway, has been increased in HT-29 following LR treatment and in HeLa cells following LR and LC treatments. Furthermore, we have demonstrated the downregulation of S6K1 expression, a marker of poor prognosis, following LR treatment in HT-29 and following LR and LC treatments in MDA-MB-231 cell line.

Conclusions

Consequently, lactobacilli can modulate expression of mTOR and Wnt/ β-catenin pathways genes in cancer cell lines in a strain specific as well as cell type specific manner.