Selective induction of apoptosis in human gastric cancer cells by Lactobacillus kefiri (PFT), a novel kefir product

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.

A Critical Review on the Role of Probiotics in Lung Cancer Biology and Prognosis

Lung cancer remains the leading cause of cancer-related deaths worldwide. According to the American Cancer Society (ACS), it ranks as the second most prevalent type of cancer globally. Recent findings have highlighted bidirectional gut-lung interactions, known as the gut-lung axis, in the pathophysiology of lung cancer. Probiotics are live microorganisms that boost host immunity when consumed adequately. The immunoregulatory mechanisms of probiotics are thought to operate through the generation of various metabolites that impact both the gut and distant organs (e.g., the lungs) through blood. Several randomized controlled trials have highlighted the pivotal role of probiotics in gut health especially for the prevention and treatment of malignancies, with a specific emphasis on lung cancer. Current research indicates that probiotic supplementation positively affects patients, leading to a suppression in cancer symptoms and a shortened disease course. While clinical trials validate the therapeutic benefits of probiotics, their precise mechanism of action remains unclear. This narrative review aims to provide a comprehensive overview of the present landscape of probiotics in the management of lung cancer.

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.

Nutritional Characteristics, Health Impact, and Applications of Kefir

A global epidemiological shift has been observed in recent decades, characterized by an increase in age-related disorders, notably non-communicable chronic diseases, such as type 2 diabetes mellitus, cardiovascular and neurodegenerative diseases, and cancer. An appreciable causal link between changes in the gut microbiota and the onset of these maladies has been recognized, offering an avenue for effective management. Kefir, a probiotic-enriched fermented food, has gained significance in this setting due to its promising resource for the development of functional or value-added food formulations and its ability to reshape gut microbial composition. This has led to increasing commercial interest worldwide as it presents a natural beverage replete with health-promoting microbes and several bioactive compounds. Given the substantial role of the gut microbiota in human health and the etiology of several diseases, we conducted a comprehensive synthesis covering a total of 33 investigations involving experimental animal models, aimed to elucidate the regulatory influence of bioactive compounds present in kefir on gut microbiota and their potential in promoting optimal health. This review underscores the outstanding nutritional properties of kefir as a central repository of bioactive compounds encompassing micronutrients and amino acids and delineates their regulatory effects at deficient, adequate, and supra-nutritional intakes on the gut microbiota and their broader physiological consequences. Furthermore, an investigation of putative mechanisms that govern the regulatory effects of kefir on the gut microbiota and its connections with various human diseases was discussed, along with potential applications in the food industry.

A medical and molecular approach to kefir as a therapeutic agent of human microbiota

The imbalanced microbial composition called dysbiosis constitutes a tendency related to different kind of human diseases. To overcome the disadvantages of dysbiosis, the consumption of probiotics is an emerging and promising topic of the last decade. Kefir is a probiotic fermented beverage produced from the fermentation of kefir grains with changing varieties of milk and displays a symbiotic association of bacteria and yeast. The discovery of the concept that fermented foods/beverages such as kefir could modify gut microbiota in humans has widened the borders of precision medicine and now microbiome therapeutics can be considered as a significant part of this field. Kefir seems to have potential to guide and manipulate future replacement/complementary therapies with a variety of beneficial biological/medical properties it has. The aim of this review was a comprehensive recapitulation of probiotic beverage kefir's significant properties mainly focusing of antioxidative, immunomodulatory, apoptotic, antitumor and neuroprotective properties. Apoptotic/antimetastatic effects are regulated at the molecular level by increases in TGF-β1, caspase-3, p53, Bax, Bax:Bcl-2 ratio, p21 and decreases in TGF-α, Bcl-2 and MMP polarization. Neuroprotective effects are revealed upon upregulation of SOD/catalase and anti-inflammatory Treg cells, decreases in repetitive behavior and modulation of apoptotic genes. Besides these significant features that may offer advantages in supplementary cancer therapies, the scope was also extended to recent emerging medical topics and also discussed and evaluated the concept of "psychobiotics". The therapeutic potential of psychobiotic effect is majorly attributed to the increased ratios of Clostridium butyricum, Lactobacillus and Bifidobacterium.

Overview of the Mechanistic Potential of Probiotics and Prebiotics in Cancer Chemoprevention

Despite of strides in modern cancer therapeutic strategies, there has not been a successful cure for it until now and prognostic side effects and substantial toxicity to chemotherapy and subsequent homeostatic imbalance remains a major concern for professionals in this field. The significance of the human microbiome in the pathogenesis of cancer is being recognized, documented, and established worldwide. Probiotics and prebiotics are some of the most extensively researched approaches to modulate the microbiota for therapeutic purposes, and research on their potential to prevent and treat cancer has sparked an immense amount of interest. The characteristics of probiotics and prebiotics allow for an array of efficient applications in cancer preventive measures. Probiotics can also be administered coupled with chemotherapy and surgery to alleviate their side effects and help promote the effectiveness of chemotherapeutic drugs. Besides showing promising results they are accompanied by potential risks and controversies that may eventually result in clinical repercussions. This review emphasizes the mechanistic potential and oncosuppressive effects of probiotic and prebiotics through maintenance of intestinal barrier function, modifying innate immune system, immunomodulation, intestinal microbiota metabolism, inhibition of host cell proliferation, preventing pathogen colonization, and exerting selective cytotoxicity against tumor cells.

The potential role of prebiotics, probiotics, and synbiotics in adjuvant cancer therapy especially colorectal cancer

Cancer is a global health issue that is rising swiftly with younger people and an increased number of patients. The role of human microbiota in the pathophysiology of tumors has been paid more and more attention. Microecologics including prebiotics, probiotics, and synbiotics are among the best validated/proven resources for the application of microbiological prophylaxis and therapy. There is strong evidence that microecologics have anti-cancer activity and their potential association with cancer is significant. In this review, we will focus on the role of prebiotics, probiotics, and synbiotics in tumor suppression in maintaining the colon barrier, metabolism, immune regulation, inhibition of host tumor cell proliferation, and epidemiological-based recommendations. Besides, other signs illuminate the role of microecological agents to adjunct the cancer treatment and counter the toxic side effects of cancer drugs. In addition, we will explore their role in chemotherapy, where these probiotics can be used as an adjunct to chemotherapy, counteracting the toxic side effects of chemotherapy drugs to minimize or optimize the therapeutic effect. In the treatment of cancer, we can see the role of prebiotics, probiotics, synbiotics, and their application in cancer patients, and the effectiveness effect can be considered as a clinical benefit. PRACTICAL APPLICATIONS: A large number of studies have shown that microecologics including prebiotics, probiotics, and synbiotics play an important role in regulating intestinal microecology and contribute to the prevention and treatment of cancer, indicating that prebiotics, probiotics, and synbiotics have the potential to be used as microecological modulators in the adjuvant therapy of cancer. However, it is not clear what is the anti-tumor mechanism of these microecologics and how they antagonize the side effects of cancer chemotherapy and protect normal cells. This paper reviews the role of prebiotics, probiotics, and synbiotics in tumor suppression in maintaining the colon barrier, metabolism, immune regulation, and prevention of rapid growth of host cells, as well as their potential role in cancer chemotherapy. This review helps to better understand the relationship between prebiotics, probiotics, and synbiotics with immune regulation, intestinal microecology, metabolic regulation, and cell proliferation and provides strong evidence for their potential application as microecologics in cancer adjuvant therapy.

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.

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

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

Potentiality of Food-Isolated Lentilactobacillus kefiri Strains as Probiotics: State-of-Art and Perspectives

Lentilactobacillus kefiri is one of the main lactic acid bacteria species in kefir and it was also isolated from other fermented foods. Numerous strains have been isolated and characterized regarding its potential as probiotics for the development of novel functional foods. To our knowledge this is the first review focused on highlighting safety aspects and health beneficial effects reported for L. kefiri strains. Several L. kefiri strains lack of transmissible antibiotic resistance genes, are tolerant to the harsh conditions of the gastrointestinal environment, and could resist different preservation procedures. Moreover, many of the isolated strains have shown antimicrobial activity against pathogens and their toxins, exhibited immunomodulatory activity as well as induced some beneficial effects at metabolic level. Regarding all the scientific evidence, certain L. kefiri strains emerge as excellent candidates to be applied to the development of both food supplements and new fermented foods with health-promoting properties. However, the availability of genomic information is still very limited, so much more work must be done in order to explore the potentiality of L. kefiri as a probiotic and a source of bioactive metabolites.

Enhancement of Insulin/PI3K/Akt Signaling Pathway and Modulation of Gut Microbiome by Probiotics Fermentation Technology, a Kefir Grain Product, in Sporadic Alzheimer's Disease Model in Mice

Sporadic Alzheimer's disease (AD) is the most common neurodegenerative disorder with cognitive dysfunction. Remarkably, alteration in the gut microbiome and resultant insulin resistance has been shown to be connected to metabolic syndrome, the crucial risk factor for AD, and also to be implicated in AD pathogenesis. Thus, this study, we assessed the efficiency of probiotics fermentation technology (PFT), a kefir product, in enhancing insulin signaling via modulation of gut microbiota to halt the development of AD. We also compared its effectiveness to that of pioglitazone, an insulin sensitizer that has been confirmed to substantially treat AD. AD was induced in mice by a single injection of intracerebroventricular streptozotocin (STZ; 3 mg/kg). PFT (100, 200, 400 mg/kg) and pioglitazone (30 mg/kg) were administered orally for 3 weeks. Behavioral tests were conducted to assess cognitive function, and hippocampal levels of acetylcholine (Ach) and β-amyloid (Aβ1-42) protein were assessed along with histological examination. Moreover, the expression of the insulin receptor, insulin degrading enzyme (IDE), and the phosphorylated forms of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), glycogen synthase kinase-3β (GSK-3β), mammalian target of rapamycin (mTOR), and tau were detected. Furthermore, oxidative stress and inflammatory biomarkers were estimated. Treatment with PFT reversed STZ-induced neurodegeneration and cognitive impairment, enhanced hippocampal Ach levels, and reduced Aβ1-42 levels after restoration of IDE activity. PFT also improved insulin signaling, as evidenced by upregulation of insulin receptor expression and activation of PI3K/Akt signaling with subsequent suppression of GSK-3β and mTOR signaling, which result in the downregulation of hyperphosphorylated tau. Moreover, PFT significantly diminished oxidative stress and inflammation induced by STZ. These potential effects were parallel to those produced by pioglitazone. Therefore, PFT targets multiple mechanisms incorporated in the pathogenesis of AD and hence might be a beneficial therapy for AD.

Probiotics Fermentation Technology, a Novel Kefir Product, Ameliorates Cognitive Impairment in Streptozotocin-Induced Sporadic Alzheimer's Disease in Mice

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment. Gut microbiota dysfunction (dysbiosis) is implicated in the pathology of AD and is associated with several detrimental consequences, including neurotransmitter depletion, oxidative stress, inflammation, apoptosis, and insulin resistance, which all contribute to the onset of AD. The objective of this study was to assess the effectiveness of Probiotics Fermentation Technology (PFT), a kefir product, in alleviating AD symptoms via regulation of the gut microbiota using a streptozotocin- (STZ-) induced AD mouse model and to compare its activity with simvastatin, which has been proven to effectively treat AD. Mice received one intracerebroventricular injection of STZ (3 mg/kg). PFT (100, 300, 600 mg/kg) and simvastatin (20 mg/kg) were administered orally for 3 weeks. PFT supplementation mitigated STZ-induced neuronal degeneration in the cortex and hippocampus, restored hippocampal acetylcholine levels, and improved cognition in a dose-dependent manner. These effects were accompanied by reductions in oxidative damage, proinflammatory cytokine expression, apoptosis, and tau hyperphosphorylation. Moreover, PFT hindered amyloid plaque accumulation via the enhancement of insulin-degrading enzyme. These beneficial effects were comparable to those produced by simvastatin. The results suggest that PFT can alleviate AD symptoms by regulating the gut microbiota and by inhibiting AD-related pathological events.

Kefir and Its Biological Activities

Kefir is a fermented beverage with renowned probiotics that coexist in symbiotic association with other microorganisms in kefir grains. This beverage consumption is associated with a wide array of nutraceutical benefits, including anti-inflammatory, anti-oxidative, anti-cancer, anti-microbial, anti-diabetic, anti-hypertensive, and anti-hypercholesterolemic effects. Moreover, kefir can be adapted into different substrates which allow the production of new functional beverages to provide product diversification. Being safe and inexpensive, there is an immense global interest in kefir’s nutritional potential. Due to their promising benefits, kefir and kefir-like products have a great prospect for commercialization. This manuscript reviews the therapeutic aspects of kefir to date, and potential applications of kefir products in the health and food industries, along with the limitations. The literature reviewed here demonstrates that there is a growing demand for kefir as a functional food owing to a number of health-promoting properties.

Lactobacillus Kefiri LKF01 (Kefibios®) for Prevention of Diarrhoea in Cancer Patients Treated with Chemotherapy: A Prospective Study

Diarrhoea is one of the main side effects that cancer patients face. The literature showsthat the incidence of chemotherapy (CT)-induced diarrhoea (grade 3–4) in treated patients is in the range of 10–20%, particularly after 5-fluorouracil (5-FU) bolus or some combination therapies of irinotecan and fluoropyrimidines. The aim of the present study was to evaluate the clinical effectiveness of Lactobacillus kefiri LKF01 (Kefibios^®) in the prevention or treatment of CT-related diarrhoea in the cancer population. We conducted a prospective observational study. Patients enrolled were adults treated for at least four months with 5-FU-based CT. Kefibios^® was administered to patients every day. The primary outcome was the evaluation of the incidence of grade 3–4 CT-induced diarrhoea. We included 76 patients in the final analysis. A 6.6% incidence of high-grade diarrhoea was found in the evaluated population (4.7% of patients treated with 5-FU-based therapy and 8.5% of patients treated with capecitabine-based CT). The overall incidence of high-grade diarrhoea observed was higher in the 1st and 2nd cycles (3.9%), with a subsequent sharp reduction from the 3rd cycle (1.3%) and negativisation from the 5th cycle. Lactobacillus kefiri LKF01 (Kefibios^®) is safe and effective in preventing severe diarrhoea in cancer patients receiving 5-FU or capecitabine-based treatment.

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.

A novel kefir product (PFT) inhibits Ehrlich ascites carcinoma in mice via induction of apoptosis and immunomodulation

BACKGROUND

The popularity of fermented foods such as kefir, kuniss, and tofu has been greatly increasing over the past several decades, and the ability of probiotic bacteria to exert anticancer effects has recently become the focus of research. While we have recently demonstrated the ability of the novel kefir product PFT (Probiotics Fermentation Technology) to exert anticancer effects in vitro, here we demonstrate its ability to inhibit Ehrlich ascites carcinoma (EAC) in mice.

METHODS

Mice were inoculated intramuscularly with EAC cells to develop solid tumors. PFT was administered orally (2 g/kg/day) to mice 6 days/week, either 2 days before tumor cell inoculation or 9 days after inoculation to mice bearing solid tumors. Tumor growth, blood lymphocyte levels, cell cycle progression, apoptosis, apoptotic regulator expression, TNF-α expression, changes in mitochondrial membrane potential (MMP), PCNA, and CD4+ and CD8+ T cells in tumor cells were quantitatively evaluated by flow cytometry or RT-PCR. Further studies in vitro were carried out where EAC cells along with several other human cancer cell lines were cultured in the presence of PFT (0-5 mg/mL). Percent cell viability and IC₅₀ was estimated by MTT assay.

RESULTS

Our data shows that PFT exerts the following: 1) inhibition of tumor incidence and tumor growth; 2) inhibition of cellular proliferation via a marked decrease in the expression of tumor marker PCNA; 3) arrest of the tumor cell cycle in the sub-G0/G1 phase, signifying apoptosis; 4) induction of apoptosis in cancer cells via a mitochondrial-dependent pathway as indicated by the up-regulation of p53 expression, increased Bax/Bcl-2 ratio, decrease in the polarization of MMP, and caspase-3 activation; and 5) immunomodulation with an increase in the number of infiltrating CD4⁺ and CD8⁺ T cells and an enhancement of TNF-α expression within the tumor.

CONCLUSIONS

PFT reduces tumor incidence and tumor growth in mice with EAC by inducing apoptosis in EAC cells via the mitochondrial-dependent pathway, suppressing cancer cell proliferation, and stimulating the immune system. PFT may be a useful agent for cancer prevention.

Reversal of age-associated oxidative stress in mice by PFT, a novel kefir product

INTRODUCTION

Oxidative stress is a key contributor to aging and age-related diseases. In the present study, we examine the protective effects of PFT, a novel kefir product, against age-associated oxidative stress using aged (10-month-old) mice.

METHODS

Mice were treated with PFT orally at a daily dose of 2 mg/kg body weight over 6 weeks, and antioxidant status, protein oxidation, and lipid peroxidation were studied in the brain, liver, and blood.

RESULTS

PFT supplementation significantly reduced the oxidative stress biomarkers malondialdehyde (MDA) and nitric oxide; reversed the reductions in glutathione (GSH) levels, total antioxidant capacity (TAC), and anti-hydroxyl radical (AHR) content; enhanced the antioxidant enzyme activities of glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD); inhibited the liver enzyme levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT); significantly reduced triglyceride (TG), total cholesterol (TC), and low density lipoprotein (LDL) levels; and significantly elevated high density lipoprotein (HDL) levels. Interestingly, PFT supplementation reversed the oxidative changes associated with aging, thus bringing levels to within the limits of the young control mice in the brain, liver, and blood. We also note that PFT affects the redox homeostasis of young mice and that it is corrected post-treatment with PFT.

CONCLUSION

Our findings show the effectiveness of dietary PFT supplementation in modulating age-associated oxidative stress in mice and motivate further studies of PFT's effects in reducing age-associated disorders where free radicals and oxidative stress are the major cause.

Analysis of Health Benefits Conferred by Lactobacillus Species from Kefir

Lactobacilli are among the most common microorganisms found in kefir; a traditional fermented milk beverage produced locally in many locations around the world. Kefir has been associated with a wide range of purported health benefits; such as antimicrobial activity; cholesterol metabolism; immunomodulation; anti-oxidative effects; anti-diabetic effects; anti-allergenic effects; and tumor suppression. This review critically examines and assesses these claimed benefits and mechanisms with regard to particular Lactobacillus species and/or strains that have been derived from kefir; as well as detailing further potential avenues for experimentation.

Heat-killed probiotic bacteria induce apoptosis of HT-29 human colon adenocarcinoma cell line via the regulation of Bax/Bcl2 and caspases pathway

Apoptosis induction in cancer cells is one of the most efficient ways to treat cancer and find anticancer compounds. The aim of this study was to evaluate the cytotoxic effects of heat-killed indigenous probiotic bacteria and apoptosis induction in the HT-29 human colon adenocarcinoma cell line. The growth-inhibitory effects of probiotic heat-killed Lactobacillus brevis and Lactobacillus paracasei isolated from the traditional Iranian food "Terxine" on the HT-29 cell line were determined by 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry by Annexin-FITC kit, DNA fragmentation assay, 4,6-diamidino-2-phenylindole staining, and the expression of Bax, Bcl2, caspase-3, and caspase-9 were used to analyze apoptosis. MTT results demonstrated that the heat-killed bacteria inhibited the proliferation of HT-29 cells and induced apoptosis in a time-, dose-, and strain-dependent manner. The results demonstrated that both bacteria could induce apoptosis in the HT-29 cell line. Heat-killed probiotic bacteria increased the expression of Bax, caspase-3, and caspase-9 mRNA levels in HT-29 cell lines. Also, heat-killed probiotic bacteria reduced the expression of Bcl2 in HT-29 cells. The heat-killed probiotic bacteria in this study exhibited potent growth inhibitory effects on cancer cells. The results demonstrated that L. brevis has a greater ability to inhibit the growth of HT-29 cells and induce apoptosis, compared with L. paracasei. It is proposed that these bacteria can be used as biological products for the treatment and prevention of cancer, pending further investigation.

Probiotics and Colon Cancer

Literature has recently highlighted the enormous scientific interest on the relationship between the gut microbiota and colon cancer, and how the use of some selected probiotics can have a future impact on the adverse events which occur during this disease. Although there is no clear evidence to claim that probiotics are effective in people with cancer, recent reviews have found that probiotics can significantly reduce the incidence of diarrhea and the average frequency of daily bowel movements. However, most of this evidence needs to be more clinically convincing and further discussed. Undoubtedly, some probiotics, when properly dosed and administered, can have a strong rebalance effect on the gut microbiota and as a consequence a possible positive action on immune modulation of the gastrointestinal tract and on inflammation of the intestinal mucosa. Many recent findings indeed support the hypothesis that the daily use of some selected probiotics can be a feasible approach to effectively protect patients against the risk of some severe consequences due to radiation therapy or chemotherapy. This paper aims to review the most recent articles in order to consider a possible adjuvant approach for the use of certain well-balanced probiotics to help prevent colon cancer and the adverse effects caused by related therapies.

Lactobacillus casei Strain Shirota Enhances the In Vitro Antiproliferative Effect of Geniposide in Human Oral Squamous Carcinoma HSC-3 Cells

This study investigated the enhanced antiproliferative effect of Lactobacillus casei strain Shirota (LcS) on geniposide actions in human oral squamous carcinoma HSC-3 cells. An MTT assay, flow cytometry, qPCR assay, western blot and HPLC were used for this study. The concentration of 1.0 × 10⁶ CFU/mL of LcS had no effect on the HOK normal oral epithelial cells and HSC-3 cancer cells. The 25 and 50 µg/mL geniposide concentrations also had no impact on HOK normal oral epithelial cells, but they had remarkable inhibitory effects on the growth of HSC-3 cancer cells, which are enhanced in the presence of LcS. By the flow cytometry assay, the LcS-geniposide-H (1.0 × 10⁶ CFU/mL LcS and 50 µg/mL geniposide)-treated HSC-3 cancer cells had the largest number of cells undergoing apoptosis compared to cells treated with other combinationsand obviously more than cells treated with only geniposide-H (50 µg/mL geniposide). Geniposide-H could increase the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax, p53, p21, IκB-α, Fas, FasL, TIMP-1, and TIMP-2 as well as decrease those of Bcl-2, Bcl-xL, HIAP-1, HIAP-2, NF-κB, COX-2, iNOS, MMP-2, and MMP-9 compared to other groups of cells, and LcS further enhanced these changes, with results that are greater than for the cells treated with only a high concentration of geniposide. The results of this study show thatLcS enhanced the antiproliferative effect of geniposide in HSC-3 cancer cells.