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

Pullulan-spermine enhance the tolerance of probiotics and immune stimulation of macrophages

The application of probiotics as adjunctive therapy in colorectal cancer treatment is hindered by the paucity of strains with specialized functions and the instability of their in vivo efficacy. The design of innovative and simple encapsulation strategies to enhance their stability and efficacy of probiotics has garnered substantial interest. This study investigated four Bifidobacterium longum strains from human feces for tolerance and cytotoxicity, and then synthesized a cationic polysaccharide, pullulan-spermine (PS), for probiotic encapsulation. The results indicated that the encapsulation by PS hold superior protective capacity and elevated the level of TNF-α and IL-12. In vivo studies further confirmed the retention capacity and safety of this probiotic-PS complex. Generally, this research presents an effective probiotic encapsulation strategy that could enhance macrophage immune responses, offering novel insights for probiotic-based therapies in major diseases like colon cancer treatment.

Clinical Potential of Novel Microbial Therapeutic LP51 Based on Xerosis-Microbiome Index

Xerosis, characterized by dry, rough skin, causes discomfort and aesthetic concerns, necessitating effective treatment. Traditional treatments often show limited efficacy, prompting the need for innovative therapies. This study highlights the efficacy of microbiome therapeutic LP51, derived from a healthy vaginal microbiome, in improving xerosis. A double-blind clinical trial involving 43 subjects with dry inner arm skin compared the effects of a 2.9% LP51 extract formulation to a placebo over 4 weeks. The LP51 group exhibited a significant increase in stratum corneum hydration (10.0 A.U.) compared to the placebo group (4.8 A.U.) and a 21.4% decrease in transepidermal water loss (TEWL), whereas the placebo group showed no significant change. LP51 also demonstrated benefits in enhancing skin hydration, improving the skin barrier, and exhibited anti-atopic, anti-inflammatory, and antioxidant properties. Safety was confirmed through in vitro cytotoxicity tests. These effects are attributed to the microbiome-safe component in LP51 and its role in improving xerosis, reflected by an increase in the xerosis-microbiome index, defined by the Firmicutes/Actinobacteria ratio. These findings position microbiome therapeutic LP51 as a promising novel treatment for xerosis.

The role of microbiota in nasopharyngeal cancer: Where do we stand?

Nasopharyngeal carcinoma (NPC) is a common head and neck cancer with a poor prognosis. One of the crucial challenges regarding NPC is its pathogenesis. Recent findings highlight the significance of host microbiota in the development of NPC, affected locally by nasopharyngeal microbiota or remotely by oral microbiota. The oral microbiota can migrate to the nasopharyngeal space, thereby impacting the composition of the nasopharyngeal microbiota. Specific bacterial strains have been linked to the development of nasopharyngeal cancer, including Neisseria, Staphylococcus, Leptotrichia, Staphylococcaceae, Granulicatella, Corynebacterium, Fusobacterium, and Prevotella. Several mechanisms have been proposed to elucidate how microbiota dysbiosis contributes to the development of NPC, including triggering tumor-promoting inflammation, reactivating the Epstein-Barr virus (EBV), inducing oxidative stress, weakening the immune system, and worsening tumor hypoxia. In addition, the composition of nasopharyngeal microbiota and the number of tumor-infiltrating microbiota can influence the prognosis and treatment response in patients with NPC. To the best of our knowledge, this is the first review discussing the impacts of the host microbiota on nasopharyngeal cancer pathogenesis, progression, and treatment response.

Probiotics and the Role of Dietary Substrates in Maintaining the Gut Health: Use of Live Microbes and Their Products for Anticancer Effects against Colorectal Cancer

The gut microbiome is an important and the largest endocrine organ linked to the microbes of the GI tract. The bacterial, viral and fungal communities are key regulators of the health and disease status in a host at hormonal, neurological, immunological, and metabolic levels. The useful microbes can compete with microbes exhibiting pathogenic behavior by maintaining resistance against their colonization, thereby maintaining eubiosis. As diagnostic tools, metagenomic, proteomic and genomic approaches can determine various microbial markers in clinic for early diagnosis of colorectal cancer (CRC). Probiotics are live non-pathogenic microorganisms such as lactic acid bacteria, Bifidobacteria, Firmicutes and Saccharomyces that can help maintain eubiosis when administered in appropriate amounts. In addition, the type of dietary intake contributes substantially to the composition of gut microbiome. The use of probiotics has been found to exert antitumor effects at preclinical levels and promote the antitumor effects of immunotherapeutic drugs at clinical levels. Also, modifying the composition of gut microbiota by Fecal Microbiota Transplantation (FMT), and using live lactic acid producing bacteria such as Lactobacillus, Bifidobacteria and their metabolites (termed postbiotics) can contribute to immunomodulation of the tumor microenvironment. This can lead to tumor-preventive effects at early stages and antitumor effects after diagnosis of CRC. To conclude, probiotics are presumably found to be safe to use in humans and are to be studied further to promote their appliance at clinical levels for management of CRC.

In Vitro Effects of Postmetabolites from Limosilactobacillus fermentum 53 on the Survival and Proliferation of HT-29 Cells

Naturally fermented dairy products are an important component of the human diet. They are a valuable source of nutrients as well as vitamins and minerals. Their importance as a source of probiotic bacterial strains should not be overlooked. A number of studies highlight the positive effects of species of the probiotic lactic acid bacteria on the intestinal microbiome and the overall homeostasis of the body, as well as a complementary treatment for some diseases. However, data on the effects on the intestinal epithelial cells of postmetabolites released by probiotic bacteria are incomplete. This is likely due to the fact that these effects are species- and strain-specific. In the present study, we investigated the effects of postmetabolites produced by a pre-selected candidate probiotic strain Limosilactobacillus fermentum on HT-29 intestinal epithelial cells. Our data showed a pronounced proliferative effect, evaluated by flow cytometry, quantification of the cell population and determination of the mitotic index. This was accompanied by the stabilization of the cell monolayer, measured by an increase in TEER (transepithelial electric resistance) and the reorganization of actin filaments. The data obtained are a clear indication of the positive effects that the products secreted by L. fermentum strain 53 have on intestinal epithelial cells.

Initiation of Apoptotic Pathway by the Cell-Free Supernatant Synthesized from Weissella cibaria Through In-Silico and In-Vitro Methods

Globally, colorectal cancer is the most prevalent type of cancer. Even though multiple treatments such as surgery, radiation, chemotherapy, and immunotherapy are available, the adverse effects caused in patients seem remarkable. Therefore, the current work was deliberated to prepare the metabolites (cell-free supernatant-CFS) from Weissella cibaria RK-3-1 to conduct in-silico and in-vitro-based anticancer assays. First, the active biomolecules present in the CFS were screened using a GC-MS analyzer. In addition, in-silico-based pharmacokinetic and docking studies were performed to confirm the anticancer potential of metabolites. In-silico results suggested that the bioactive compounds such as filicinic acid, dibutyl phthalate, and 4H-pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl present in CFS possessed significant molecular docking interactions with anticancer hub proteins. Furthermore, in-vitro results displayed the inhibition of cell proliferation in HT-29 cells at an IC50 value of 22.5 ± 1.3 µg/ml with the least significant effect on HEK-293 cell lines. Moreover, bacterial metabolites-controlled cell proliferation during the cell cycle's synthesis phase (S). Furthermore, the gene expression results confirm the increased expression of Bad, Bax, Bcl2, caspase-3, and cytochrome-C genes involved in the intrinsic apoptotic pathway. Hence, our findings from the in-silico and the in-vitro study confirm the anticancer potential of cell free-supernatant synthesized by W. cibaria.

Harnessing the power of probiotic strains in functional foods: nutritive, therapeutic, and next-generation challenges

Functional foods have become an essential element of the diet in developed nations, due to their health benefits and nutritive values. Such food products are only called functional if they, "In addition to basic nutrition, have valuable effects on one or multiple functions of the human body, thereby enhancing general and physical conditions and/or reducing the risk of disease progression". Functional foods are currently one of the most extensively researched areas in the food and nutrition sciences. They are fortified and improved food products. Presently, probiotics are regarded as the most significant and commonly used functional food product. Diverse probiotic food products and supplements are used according to the evidence that supports their strength, functionality, and recommended dosage. This review provides an overview of the current functional food market, with a particular focus on probiotic microorganisms as pivotal functional ingredients. It offers insights into current research endeavors and outlines potential future directions in the field.

Mechanisms of medicinal, pharmaceutical, and immunomodulatory action of probiotics bacteria and their secondary metabolites against disease management: an overview

Probiotics or bacteriotherapy is today's hot issue for public entities (Food and Agriculture Organization, and World Health Organization) as well as health and food industries since Metchnikoff and his colleagues hypothesized the correlation between probiotic consumption and human's health. They contribute to the newest and highly efficient arena of promising biotherapeutics. These are usually attractive in biomedical applications such as gut-related diseases like irritable bowel disease, diarrhea, gastrointestinal disorders, fungal infections, various allergies, parasitic and bacterial infections, viral diseases, and intestinal inflammation, and are also worth immunomodulation. The useful impact of probiotics is not limited to gut-related diseases alone. Still, these have proven benefits in various acute and chronic infectious diseases, like cancer, human immunodeficiency virus (HIV) diseases, and high serum cholesterol. Recently, different researchers have paid special attention to investigating biomedical applications of probiotics, but consolidated data regarding bacteriotherapy with a detailed mechanistically applied approach is scarce and controversial. The present article reviews the bio-interface of probiotic strains, mainly (i) why the demand for probiotics?, (ii) the current status of probiotics, (iii) an alternative to antibiotics, (iv) the potential applications towards disease management, (v) probiotics and industrialization, and (vi) futuristic approach.

Harnessing the Health and Techno-Functional Potential of Lactic Acid Bacteria: A Comprehensive Review

This review examines the techno-functional properties of lactic acid bacteria (LABs) in the food industry, focusing on their potential health benefits. We discuss current findings related to the techno-functionality of LAB, which includes acidification, proteolytic and lipolytic features, and a variety of other biochemical activities. These activities include the production of antimicrobial compounds and the synthesis of exopolysaccharides that improve food safety and consumer sensory experience. LABs are also known for their antioxidant abilities, which help reduce oxidative reactions in foods and improve their functional properties. In addition, LABs' role as probiotics is known for their promising effects on gut health, immune system modulation, cholesterol control, and general wellbeing. Despite these advantages, several challenges hinder the effective production and use of probiotic LABs, such as maintaining strain viability during storage and transport as well as ensuring their efficacy in the gastrointestinal tract. Our review identifies these critical barriers and suggests avenues for future research.

Enhanced Induction of Apoptosis and Cell Cycle Arrest in MCF-7 Breast Cancer and HT-29 Colon Cancer Cell Lines via Low-Dose Biosynthesis of Selenium Nanoparticles Utilizing Lactobacillus casei

As a leading global cause of mortality, cancer continues to pose a significant challenge. The shortcomings of prevalent cancer treatments, such as surgery, radiation therapy, and chemotherapy, necessitate the exploration of alternative therapeutic strategies. Selenium nanoparticles (SeNPs) have emerged as a promising solution, with their synthesis being widely researched due to their potential applications. Among the diverse synthesis methods for SeNPs, the green chemistry approach holds a distinctive position within nanotechnology. This research delves into the anti-proliferative and anticancer properties of green-synthesized SeNPs via the cell-free supernatant (CFS) of Lactobacillus casei (LC-SeNPs), with a specific focus on MCF-7 and HT-29 cancer cell lines. SeNPs were synthesized employing the supernatant of L. casei. The characterization of these green-synthesized SeNPs was performed using TEM, FE-SEM, XRD, FT-IR, UV-vis, energy-dispersive X-ray spectroscopy, and DLS. The biological impact of LC-SNPs on MCF-7 and HT-29 cancer cells was examined via MTT, flow cytometry, scratch tests, and qRT-PCR. Both FE-SEM and TEM images substantiated the spherical shape of the synthesized nanoparticles. The biosynthesized LC-SNPs reduced the survival of MCF-7 (by 20%) and HT-29 (by 30%) cells at a concentration of 100 μg/mL. Flow cytometry revealed that LC-SNPs were capable of inducing 28% and 23% apoptosis in MCF-7 and HT-29 cells, respectively. In addition, it was found that LC-SNPs treated MCF-7 and HT-29 cells were arrested in the sub-G1 phase. Gene expression analysis indicated that the expression levels of the CASP3, CASP9, and BAX genes were elevated after treating MCF-7 and HT-29 cells with LC-SNPs. Further, SeNPs were observed to inhibit migration and invasion of MCF-7 and HT-29 cancer cells. The SeNPs, produced via L. casei, demonstrated strong anticancer effects on MCF-7 and HT-29 cells, suggesting their potential as biological agents in cancer treatment following additional in vivo experiments.

The inhibition effects of Lentilactobacillus buchneri-derived membrane vesicles on AGS and HT-29 cancer cells by inducing cell apoptosis

In recent years, probiotics and their derivatives have been recognized as important therapeutic agents in the fight against cancer. Therefore, this study aimed to investigate the anticancer effects of membrane vesicles (MVs) from Lentilactobacillus buchneri strain HBUM07105 probiotic isolated from conventional and unprocessed yogurt in Arak province, Iran, against gastric and colon cancer cell lines. The MVs were prepared from the cell-free supernatant (CFS) of L. buchneri and characterized using field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) and SPS-PAGE techniques. The anticancer activity of MVs was evaluated using MTT, flow cytometry, qRT-PCR techniques, and a scratch assay. The study investigated the anti-adenocarcinoma effect of MVs isolated from L. buchneri on a human gastric adenocarcinoma cell line (AGS) and a human colorectal adenocarcinoma cell line (HT-29) at 24, 48, and 72-h time intervals. The results demonstrated that all prepared concentrations (12.5, 25, 50, 100, and 200 µg/mL) of MVs reduced the viability of both types of human adenocarcinoma cells after 24, 48, and 72 h of treatment. The analysis of the apoptosis results revealed that the percentage of AGS and HT-29 cancer cells in the early and late stages of apoptosis was significantly higher after 24, 48, and 72 h of treatment compared to the untreated cancer cells. After treating both AGS and HT-29 cells with the MVs, the cells were arrested in the G0/G1 phase. These microvesicles demonstrate apoptotic activity by increasing the expression of pro-apoptotic genes (BAX, CASP3, and CASP9). According to the scratch test, MVs can significantly decrease the migration of HT-29 and AGS cancer cells after 24, 48, and 72 h of incubation compared to the control groups. The MVs of L. buchneri can also be considered a potential option for inhibiting cancer cell activities.

Synergistic effects of Bacillus coagulans and Newcastle disease virus on human colorectal adenocarcinoma cell proliferation

Background and Objectives

Colorectal cancer (CRC) is a common type of cancer that has a high death rate and is becoming more common in developed countries. Currently, there are several treatment options available for CRC patients, and clinical trials are being conducted to improve conventional therapies. This study investigates the combined impact of Bacillus coagulans (B.C) and Newcastle disease virus (NDV) on the growth of human colorectal adenocarcinoma cells (HT29 cell line).

Materials and Methods

The HT29 cell line was cultured under controlled laboratory conditions. They were treated with Fluorouracil (5-FU), NDV, and B.C., after which various assessments were conducted to determine the effects of these treatments. These assessments included MTT assay for cytotoxicity, evaluation of cell viability, and measurement of caspase 8 and 9 activity levels. The significance of the data was determined at a threshold of P<0.05 following analysis.

Results

The usage of NDV and B.C significantly increased cell death and reduced cell growth in the HT29 cell line, when compared to the control group. Moreover, the combined application of NDV and B.C along with 5-FU exhibited a synergistic effect in decreasing the proliferation of HT29 cells. Additionally, the results indicated that intrinsic apoptosis pathway was activated by B.C and NDV.

Conclusion

It appears that utilizing oncolytic viruses (OV) and bacteria in conjunction with chemotherapy drugs could potentially aid in reducing the growth of colorectal cancer cells. However, further research is necessary, including animal studies, to confirm the efficacy of this treatment method.

Investigating the therapeutic potential of Bifidobacterium breve and Lactobacillus rhamnosus postbiotics through apoptosis induction in colorectal HT-29 cancer cells

Background and Objectives

Colorectal cancer (CRC) is a prevalent form of cancer worldwide. Recent studies suggest that postbiotics derived from probiotic bacteria have the potential as an adjunct therapy for CRC. This study investigates the anti-cancer effects of Bifidobacterium breve (B. breve) and Lactobacillus rhamnosus (L. rhamnosus) postbiotics on the HT-29 cell line.

Materials and Methods

Through MTT and scratch assay, we investigated the anti-proliferation and anti-migration effects of B. breve and L. rhamnosus postbiotics on HT-29 cells. Furthermore, postbiotic-mediated apoptosis was assessed by analyzing the expression of Bax, Bcl-2, and caspase-3. We also investigated the effects of B. breve postbiotics on the expression of three important genes involved in metastasis, including RSPO2, NGF, and MMP7. Consequently, we validated the expression of selected genes in twelve adenocarcinoma tissues.

Results

The results demonstrated the significant impact of postbiotics on HT-29 cells, highlighting their ability to induce anti-proliferation, anti-migration, and apoptosis-related effects. Notably, these effects were more pronounced using B. breve postbiotics than L. rhamnosus. Additionally, B. breve postbiotics could inhibit metastasis through upregulation of RSPO2 while downregulating NGF and MMP7 expression in HT-29 cells.

Conclusion

Our research suggests that postbiotic metabolites may be effective biological products for the prevention and treatment of cancer.

A Combination of Curcumin and Lactobacillus rhamnosus GG Inhibits Viability and Induces Apoptosis in SCC-9 Human Oral Squamous Cell Carcinoma Cells

The aim of this study was to evaluate the effect of curcumin combined with Lactobacillus rhamnosus GG cell-free supernatant (LGG CFS) on the proliferation and induction of apoptosis in SCC-9 oral squamous cell carcinoma (OSCC) cells. Curcumin (40 µg/ml) and 25% v/v LGG CFS (108 CFU/ml), both alone and in a combination regimen, significantly decreased the viability of SCC-9 cells and normal human gingival fibroblast (HGF) cells. Interestingly, the combination of low doses of curcumin (5 µg/ml) and 25% v/v LGG CFS (106 CFU/ml) had no effect on the HGF cells but significantly inhibited the viability of SCC-9 cells (p < 0.05). Flow cytometric analysis revealed that SCC-9 cells treated with the combination of low-dose curcumin and low-dose LGG CFS had a higher apoptotic rate than the cells in the control group and the single treatment groups (p < 0.05). The combined treatment also significantly increased the Bax/Bcl2 mRNA and protein expression in SCC-9 cells (p < 0.05) but not in HGF cells, indicating the underlying mechanism of the combination regimen. There was no significant difference in caspase-3 protein expression or the Bcl-xL/Bak and Mcl-1/Bak ratios between the treatment and control groups in both cell lines. These findings suggested that the coadministration of curcumin and LGG could exhibit anticancer effects in SCC-9 cells without causing toxicity to normal fibroblast cells.

Probiotic-Derived Bioactive Compounds in Colorectal Cancer Treatment

Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates globally. Despite advanced chemotherapeutic approaches for the treatment of CRC, low survival rates due to the regular occurrence of drug resistance and deleterious side effects render the need for alternative anticancer agents imperative. Accumulating evidence supports that gut microbiota imbalance precedes the establishment of carcinogenesis, subsequently contributing to cancer progression and response to anticancer therapy. Manipulation of the gut microbiota composition via the administration of probiotic-derived bioactive compounds has gradually attained the interest of scientific communities as a novel therapeutic strategy for CRC. These compounds encompass miscellaneous metabolic secreted products of probiotics, including bacteriocins, short-chain fatty acids (SCFAs), lactate, exopolysaccharides (EPSs), biosurfactants, and bacterial peptides, with profound anti-inflammatory and antiproliferative properties. This review provides a classification of postbiotic types and a comprehensive summary of the current state of research on their biological role against CRC. It also describes how their intricate interaction with the gut microbiota regulates the proper function of the intestinal barrier, thus eliminating gut dysbiosis and CRC development. Finally, it discusses the future perspectives in precision-medicine approaches as well as the challenges of their synthesis and optimization of administration in clinical studies.

Probiotics formulation and cancer nanovaccines show synergistic effect in immunotherapy and prevention of colon cancer

Probiotics play essential roles in immune modulation. Combining probiotics with cancer vaccines potentially can achieve a synergistic effect. To maximize the efficacy of probiotics, proper probiotics formulation is necessary. Herein, Lactobacillus rhamnosus and Bifidobacterium longum are coated with lipid membrane to achieve the goal of losing less activity and bettering colonization in colon. In the subcutaneous transplanted colon cancer mouse model, probiotics formulation showed potent preventive and therapeutic efficacy, and the efficacy could be further improved by combining with cancer nanovaccines. Probiotics formulation can perform as immune adjuvants to enhance the innate immune response or as in-situ cancer vaccines. In the study of preventing chemical-induced orthotopic colon cancer model, probiotics formulation alone efficiently reduced tumor number in colon and the efficacy is improved by combining with cancer nanovaccines. All in all, the studies demonstrated that probiotics formulation can assist to maximize the efficacy of cancer nanovaccines.

Lactobacillus paracasei subsp. paracasei X12 Strain Induces Apoptosis in HT-29 Cells through Activation of the Mitochondrial Pathway

L. paracasei subsp. paracasei X12 was obtained from traditional cheese produced in northwestern China. In this study, we showed that whole peptidoglycan (WPG), extracted from L. paracasei subsp. paracasei X12, inhibited proliferation and induced apoptosis in HT-29 cells in a dose-dependent manner. In addition, WPG-induced apoptosis was associated with the loss of mitochondrial membrane potential (Ψm), the release of cytochrome c (Cyto-C) from mitochondrialto cytosolic spaces, activation of Caspase 3, and accumulation of intracellular reactive oxygen species (ROS). Finally, semi-quantitative RT-PCR showed that these events were accompanied by upregulation of proapoptotic genes (Bax or Bad) and downregulation of antiapoptotic genes (Bcl-xl). Taken together, our results demonstrated that WPG induced apoptosis in HT-29 cells through activation of the mitochondrial pathway. WPG exerted only minor toxicity upon noncancerous cells and therefore might be used as a natural agent in the treatment of cancer in future.

Counteracting gemcitabine+nab-paclitaxel induced dysbiosis in KRAS wild type and KRASG12D mutated pancreatic cancer in vivo model

Pancreatic cancer (PC) has a very low survival rate mainly due to late diagnosis and refractoriness to therapies. The latter also cause adverse effects negatively affecting the patients' quality of life, often requiring dose reduction or discontinuation of scheduled treatments, compromising the chances of cure. We explored the effects of a specific probiotic blend on PC mice xenografted with KRAS wild-type or KRASG12D mutated cell lines alone or together with gemcitabine+nab-paclitaxel treatment to then assess tumor volume and clinical pathological variables. Beside a semi-quantitative histopathological evaluation of murine tumor and large intestine samples, histochemical and immunohistochemical analyses were carried out to evaluate collagen deposition, proliferation index Ki67, immunological microenvironment tumor-associated, DNA damage markers and also mucin production. Blood cellular and biochemical parameters and serum metabolomics were further analyzed. 16S sequencing was performed to analyze the composition of fecal microbiota. Gemcitabine+nab-paclitaxel treatment impaired gut microbial profile in KRAS wild-type and KRASG12D mice. Counteracting gemcitabine+nab-paclitaxel- induced dysbiosis through the administration of probiotics ameliorated chemotherapy side effects and decreased cancer-associated stromatogenesis. Milder intestinal damage and improved blood count were also observed upon probiotics treatment as well as a positive effect on fecal microbiota, yielding an increase in species richness and in short chain fatty acids producing- bacteria. Mice' serum metabolomic profiles revealed significant drops in many amino acids upon probiotics administration in KRAS wild-type mice while in animals transplanted with PANC-1 KRASG12D mutated all treated groups showed a sharp decline in serum levels of bile acids with respect to control mice. These results suggest that counteracting gemcitabine+nab-paclitaxel-induced dysbiosis ameliorates chemotherapy side effects by restoring a favorable microbiota composition. Relieving adverse effects of the chemotherapy through microbiota manipulation could be a desirable strategy in order to improve pancreatic cancer patients' quality of life and to increase the chance of cure.

Lactobacillus rhamnosus GG cell-free supernatant as a novel anti-cancer adjuvant

BACKGROUND

Gut microbiota modulation has been demonstrated to be effective in protecting patients against detrimental effects of anti-cancer therapies, as well as to improve the efficacy of certain anti-cancer treatments. Among the most characterized probiotics, Lactobacillus rhamnosus GG (LGG) is currently utilized in clinics to alleviate diarrhea, mucositis or intestinal damage which might be associated with several triggers, including Clostridium difficile infections, inflammatory gut diseases, antibiotic consumption, chemotherapy or radiation therapy. Here, we investigate whether LGG cell-free supernatant (LGG-SN) might exert anti-proliferative activity toward colon cancer and metastatic melanoma cells. Moreover, we assess the potential adjuvant effect of LGG-SN in combination with anti-cancer drugs.

METHODS

LGG-SN alone or in combination with either 5-Fuorouracil and Irinotecan was used to treat human colon and human melanoma cancer cell lines. Dimethylimidazol-diphenyl tetrazolium bromide assay was employed to detect cellular viability. Trypan blue staining, anti-cleaved caspase-3 and anti-total versus anti-cleaved PARP western blots, and annexin V/propidium iodide flow cytometry analyses were used to assess cell death. Flow cytometry measurement of cellular DNA content (with propidium iodide staining) together with qPCR analysis of cyclins expression were used to assess cell cycle.

RESULTS

We demonstrate that LGG-SN is able to selectively reduce the viability of cancer cells in a concentration-dependent way. While LGG-SN does not exert any anti-proliferative activity on control fibroblasts. In cancer cells, the reduction in viability is not associated with apoptosis induction, but with a mitotic arrest in the G2/M phase of cell cycle. Additionally, LGG-SN sensitizes cancer cells to both 5-Fluorouracil and Irinotecan, thereby showing a positive synergistic action.

CONCLUSION

Overall, our results suggest that LGG-SN may contain one or more bioactive molecules with anti-cancer activity which sensitize cancer cells to chemotherapeutic drugs. Thus, LGG could be proposed as an ideal candidate for ground-breaking integrated approaches to be employed in oncology, to reduce chemotherapy-related side effects and overcome resistance or relapse issues, thus ameliorating the therapeutic response in cancer patients.

Lacticaseibacillus rhamnosus—A Promising Tool for Colorectal Cancer Treatment

Probiotic strains such as Lactobacillus spp. are already known for their beneficial effect on human health and new research supports their role in colon cancer prevention and treatment. The current study reports the effect of different concentrations of Lacticaseibacillus rhamnosus (LGG, 106–109 CFU/mL), alone or in association with 5-fluorouracil (5-FU, 10 μM), tested against normal HaCaT cells, HT-29 colorectal adenocarcinoma and HCT-116 colorectal carcinoma cell lines. The underlying cytotoxic effect was further investigated. LGG treatment of HT-29 and HCT-116 cells caused a variety of apoptotic-related nuclear morphological changes, as revealed by DAPI staining. ELISA studies showed that LGG treatment increased caspase-3 activity and pro-apoptotic BAX protein levels while decreasing anti-apoptotic Bcl-2 protein levels and the proto-oncogene Cyclin D1. A more detailed examination of the mitochondrial function revealed that high concentrations of LGG can impair mitochondrial function in HT-29 and HCT-116 cancer cells. All of these findings suggest that LGG has a pro-apoptotic, mitochondrial-targeted, cytotoxic effect on both colon cancer cell lines studied.

Anticancer properties of curcumin-treated Lactobacillus plantarum against the HT-29 colorectal adenocarcinoma cells

Probiotic bacteria with functions of importance to the health and well-being of the host exhibit various medicinal properties including anti-proliferative properties against cancer cells. There are observations demonstrating probiotic bacteria and their metabolomics can be different in various populations with different eating habits. Here, Lactobacillus plantarum was treated with curcumin (the major compound of turmeric), and its resistance to the curcumin was determined. After then the cell-free supernatants of untreated bacteria (CFS) and bacteria treated with curcumin (cur-CFS) were isolated and their anti-proliferative properties against HT-29 colon cancer cells were compared. The ability of L. plantarum treated with curcumin to combat a variety of pathogenic bacterial species and its ability to survive in acidic conditions were evidence that the probiotic properties of the bacterium were unaffected by the curcumin treatment. L. plantarum treated with curcumin and intact L. plantarum were both able to live in acidic conditions, according to the results of the resistance to low pH test. The MTT result showed that CFS and cur-CFS dose-dependently decreased the growth of HT29 cells with a half-maximal inhibitory concentration of 181.7 and 116.3 µL/mL at 48 h, respectively. Morphological alteration of DAPI-stained cells also exhibited significant fragmentation in the chromatin within the nucleus of cur-CFS-treated cells compared to CFS-treated HT29 cells. Moreover, flow cytometry analyses of apoptosis and cell cycle confirmed DAPI staining and MTT assay results and stipulated the increased occurrence of programmed cell death (apoptosis) in cur-CFS-treated cells (~ 57.65%) compared to CFS-treated cells (~ 47%). These results were more confirmed with qPCR and exhibited the upregulation of Caspase 9-3 and BAX genes, and downregulation of the BCL-2 gene in cur-CFS- and CFS-treated cells. In conclusion, turmeric spice and curcumin may affect the metabolomics of probiotics in intestinal flora which could subsequently influence their anticancer properties.

Evaluation of the Anticancer and Probiotic Potential of Autochthonous (Wild) Lacticaseibacillus paracasei Strains from New Ecological Niches as a Possible Additive for Functional Dairy Foods

Probiotics such as Lactobacillus spp. could modulate the intestinal microbiota composition, supporting gastrointestinal tract barrier function and benefiting human health. To evaluate the anticancer and probiotic properties of potentially active autochthonous Lacticaseibacillus paracasei strains on proliferating and differentiated enterocytes, human colon adenocarcinoma cell line HT29 was used as a model. The lactic acid bacteria (LAB) were isolated from new ecological niches—mountain anthills populated by redwood ants (Formica rufa L.). Human colorectal adenocarcinoma cells (HT29, ATCC, HTB-38™) were treated for twenty-four hours with supernatants (SNs) derived from four strains of Lacticaseibacillus paracasei: P4, C8, C15 and M2.1. An MTT assay, alkaline phosphatase activity, IAP, Bax and Bcl-2 gene expression analysis (RT-qPCR) and the Bax/Bcl-2 ratio were evaluated. The MTT assay revealed that the observed effects varied among groups. However, 10% neutralized supernatants from P4, C8, C15 and M2.1 strains did not show cytotoxic effects. In contrast to non-differentiated cells, a significant (p < 0.001) rise in ALP activity in all treatments, with an average of 18%, was established in differentiated cells. The IAP expression was remarkably downregulated in the differentiated M2.1 group (p < 0.05) and upregulated in the non-differentiated P4 (p < 0.05) and M2.1 (p < 0.05) groups. The Bax/Bcl-2 quantity expression ratio in P4 was significantly (p < 0.05) upregulated in proliferating cancer cells, but in P4- and M2.1-differentiated cells these values were downregulated (p < 0.05). The obtained results indicate that the isolated L. paracasei strains possess anticancer and probiotic properties and could be used as additives for functional dairy foods and thus benefit human health.

Antibacterial Activity and Toxicity of Zinc Oxide Nanoparticles Combined with Supernatants of Lactobacillus spp. Against ESKAPE Bacteria: A Novel Mixture

Background

The emergence of multidrug resistance among nosocomial pathogens has prompted researchers to look for new antibacterial sources. Metal nanoparticles and probiotic products have attracted the attention of researchers. However, combination therapy is an attractive alternative in this field.

Objectives

This study evaluated the antibacterial activity and toxicity of Zinc Oxide nanoparticles (ZnO-NPs) combined with cell-free supernatant (CFS) of Lactobacillus plantarum and Lactobacillus acidophilus alone and in a novel mixture.

Methods

Antibacterial effects and cytotoxic properties of ZnO-NPs, CFS of L. plantarum (SLP), and CFS of L. acidophilus (SLA) were determined alone and in a mixture against ESKAPE strains. In addition, the viability percentage of the cells was evaluated after exposure to these agents.

Results

Antibacterial mixtures (ZnO-NPs with SLP or ZnO-NPs with SLA) demonstrated synergistic and additive effects against Pseudomonas aeruginosa (FIC≤0.75), Acinetobacter baumannii (FIC = 1), and Escherichia coli (FIC≤0.75). The viability percentage of the cells after 24 h of exposure to a mixture of ZnO-NPs and SLA (about 50%) was more than when the cells were exposed to ZnO-NPs alone (about 30%) at the same concentration.

Conclusions

A mixture of ZnO-NPs and CFS of probiotics can be an alternative to antibiotics, with more effectiveness and fewer side effects.

Gut Microbiota Eubacterium callanderi Exerts Anti-Colorectal Cancer Activity

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

Modulation of intestinal epithelial cell proliferation and apoptosis by Lactobacillus gasseri SF1183

The gut microbiota exerts a variety of positive effects on the intestinal homeostasis, including the production of beneficial molecules, control of the epithelial barrier integrity and the regulation of the balance between host's cell death and proliferation. The interactions between commensal bacteria and intestinal cells are still under-investigated and is then of paramount importance to address such interactions at the molecular and cellular levels. We report an in vitro analysis of the effects of molecules secreted by Lactobacillus gasseri SF1183 on HCT116 cells, selected as a model of intestinal epithelial cells. SF1183 is a L. gasseri strain isolated from an ileal biopsy of a human healthy volunteer, able to prevent colitis symptoms in vivo. Expanding previous findings, we show that bioactive molecules secreted by SF1183 reduce the proliferation of HCT116 cells in a reversible manner determining a variation in cell cycle markers (p21WAF, p53, cyclin D1) and resulting in the protection of HCT116 cells from TNF-alfa induced apoptosis, an effect potentially relevant for the protection of the epithelial barrier integrity and reconstitution of tissue homeostasis. Consistently, SF1183 secreted molecules increase the recruitment of occludin, a major component of TJ, at the cell-cell contacts, suggesting a reinforcement of the barrier function.

Gut Microbes in Gynecologic Cancers: Causes or Biomarkers and Therapeutic Potential

The human intestine is home to a variety of microorganisms. In healthy populations, the intestinal flora shares a degree of similarity and stability, and they have a role in the metabolism, immunological response, and physiological function of key organs. With the rapid advent of high-throughput sequencing in recent years, several researchers have found that dysbiosis of the human gut microflora potentially cause physical problems and gynecological malignancies among postmenopausal women. Besides, dysbiosis hinders tumor treatment. Nonetheless, the importance of maintaining homeostatic gut microbiota and the effective use of probiotics in the treatment of gynecological malignancies should not be disregarded. Moreover, intestinal flora regulation and the involvement of probiotics as well as associated biologically active substances in gynecological malignancies could be an adjuvant treatment modality related to surgery and chemoradiotherapy in the future. Herein, this article aims to review the potential relationship between gut microorganisms and postmenopausal status as well as gynecologic malignancies; then the relationship between gut microbes and early screening as well as therapeutic aspects. Also, we describe the role of probiotics in the prevention, treatment, and prognosis of gynecologic malignancies.

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.