Effects of Lactobacillus strains on cancer cell proliferation and oxidative stress in vitro

It Is All about Probiotics to Control Cervical Cancer

Cervical cancer (CC) is the fourth most common malignancy in female patients. "Human papillomavirus" (HPV) contamination is a leading cause of all forms of cervical cancer, accounting for an expected 570,000 reported incidents in 2018. Two HPV strains (16 and 18) are responsible for 70% of CC and pre-cancerous cervical abnormalities. CC is one of the foremost reasons for the malignancy death rate in India among women ranging from 30 to 69 years of age in India, responsible for 17% of all cancer deaths. Currently approved cervical cancer treatments are associated with adverse reactions that might harm the lives of women affected by this disease. Consequently, probiotics can play a vital role in the treatment of CC. It is reflected from various studies regarding the role of probiotics in the diagnosis, prevention or treatment of cancer. In this review article, we have discussed the rationale of probiotics for treatment of CC, the role of probiotics as effective adjuvants in anti-cancer therapy and the combined effect of the anti-cancer drug along with probiotics to minimize the side effects due to chemotherapy.

Lactic Acid Bacteria-Derived Postbiotics as Adjunctive Agents in Breast Cancer Treatment to Boost the Antineoplastic Effect of a Conventional Therapeutic Comprising Tamoxifen and a New Drug Candidate: An Aziridine-Hydrazide Hydrazone Derivative

Breast cancer is associated with high mortality and morbidity rates. As about 20-30% of patients exhibiting ER-positive phenotype are resistant to hormonal treatment with the standard drug tamoxifen, finding new therapies is a necessity. Postbiotics, metabolites, and macromolecules isolated from probiotic bacteria cultures have been proven to have sufficient bioactivity to exert prohealth and anticancer effects, making them viable adjunctive agents for the treatment of various neoplasms, including breast cancer. In the current study, postbiotics derived from L. plantarum and L. rhamnosus cultures were assessed on an in vitro breast cancer model as potential adjunctive agents to therapy utilizing tamoxifen and a candidate aziridine-hydrazide hydrazone derivative drug. Cell viability and cell death processes, including apoptosis, were analyzed for neoplastic MCF-7 cells treated with postbiotics and synthetic compounds. Cell cycle progression and proliferation were analyzed by PI-based flow cytometry and Ki-67 immunostaining. Postbiotics decreased viability and triggered apoptosis in MCF-7, modestly affecting the cell cycle and showing a lack of negative impact on normal cell viability. Moreover, they enhanced the cytotoxic effect of tamoxifen and the new candidate drug toward MCF-7, accelerating apoptosis and the inhibition of proliferation. This illustrates postbiotics' potential as natural adjunctive agents supporting anticancer therapy based on synthetic drugs.

Bioconjugate based on cisplatin and bacterial exopolysaccharide with reduced side effects: A novel proposal for cancer treatment

BACKGROUND

In the search for alternatives that attenuate the toxicity associated to oncologic treatment with cisplatin (CDDP) and considering the potential health-beneficial properties of exopolysaccharides (EPS) produced by lactic acid bacteria, it was aimed on this study to evaluate the cytotoxic, toxicologic and antitumoral efficacy of a bioconjugate based on CDDP and EPS, on the experimental tumor of sarcoma 180.

METHODS

After the synthesis of the cis-[Pt(NH3)2(Cl)2] complex and of the conjugate containing Lactobacillus fermentum exopolysaccharide was tested both in vitro and in vivo for evaluating the acute toxicity.

RESULTS

The antitumoral study was performed using mice transplanted with sarcoma 180. The bioconjugate showed low to medium cytotoxicity for the cell lines tested, as well moderated acute toxicity. After determining the LD50, the following experimental groups were established for the antitumor assay: Control (NaCl 0,9%), CDDP (1 mg/kg), EPS and bioconjugate composition (200 mg/kg). The bioconjugate promoted a 38% regression in tumor mass when compared to the control, and a regression of 41% when compared to CDDP. Liver histopathological analysis revealed discrete alterations in animals treated with (CDDP + EPS) when compared to control. The bioconjugate also minimized changes in the renal parenchyma resulting from the tumor.

CONCLUSION

Our results indicate that when CDDP is associated with EPS, this composition was more biocompatible, showing itself as a potent chemotherapeutic agent and lower tissue toxicity.

Growth Suppression of Oral Squamous Cell Carcinoma Cells by Lactobacillus Acidophilus

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a highly aggressive form of oral cancer. Probiotic lactobacilli have demonstrated anticancer effects, whilst their interaction with Streptococcus mutans in this context remains unexplored. The objective of this study was to investigate the antiproliferative effect of Lactobacillus acidophilus on OSCC and to understand the effect of S mutans on OSCCs and whether it affects the antiproliferative potential of L acidophilus when co-exposed to OSCC.

METHODS

The human head and neck squamous cell carcinoma cells of the oral cavity (HNO97 cell line) were exposed to cultures of L acidophilus and S mutans separately and in combination. Further, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to assess the viability of HNO97 cells. Bacterial adhesion to HNO97 cells was examined by confocal microscopy and apoptosis by Nexin staining. To understand the underlying mechanism of apoptosis, expression of the tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) gene and protein were determined by real-time polymerase chain reaction and quantitative enzyme-linked immunosorbent assay, respectively.

RESULTS

A significant decrease (53%-56%) in the viability of HNO97 cells on exposure to L acidophilus, S mutans, and the 2 species together demonstrated the antiproliferative activity of L acidophilus and S mutans. Both bacteria showed adhesion to HNO97 cells. The expression of the TRAIL gene increased 5-fold in HNO97 cells on treatment with L acidophilus and S mutans, which further increased to ∼17-fold with both species present. Expression levels of the TRAIL protein were significantly (P < .05) increased in bacteria-treated cell lysates. Further, bacteria-treated HNO97 cells exhibited lower live and intact cell percentages with higher proportions of cells in early and late apoptotic stages.

CONCLUSIONS

L acidophilus exhibits the antiproliferative activity against OSCC cells possibly partially via a TRAIL-induced mechanism of apoptosis, which is not affected by the presence of S mutans. These findings may encourage further investigation into the possible therapeutic application of probiotic L acidophilus in OSCC.

Fermented foods and gastrointestinal health: underlying mechanisms

Although fermentation probably originally developed as a means of preserving food substrates, many fermented foods (FFs), and components therein, are thought to have a beneficial effect on various aspects of human health, and gastrointestinal health in particular. It is important that any such perceived benefits are underpinned by rigorous scientific research to understand the associated mechanisms of action. Here, we review in vitro, ex vivo and in vivo studies that have provided insights into the ways in which the specific food components, including FF microorganisms and a variety of bioactives, can contribute to health-promoting activities. More specifically, we draw on representative examples of FFs to discuss the mechanisms through which functional components are produced or enriched during fermentation (such as bioactive peptides and exopolysaccharides), potentially toxic or harmful compounds (such as phytic acid, mycotoxins and lactose) are removed from the food substrate, and how the introduction of fermentation-associated live or dead microorganisms, or components thereof, to the gut can convey health benefits. These studies, combined with a deeper understanding of the microbial composition of a wider variety of modern and traditional FFs, can facilitate the future optimization of FFs, and associated microorganisms, to retain and maximize beneficial effects in the gut.

Effects of dietary addition of ellagic acid on rumen metabolism, nutrient apparent digestibility, and growth performance in Kazakh sheep

Plant extracts have shown promise as natural feed additives to improve animal health and growth. Ellagic acid (EA), widely present in various plant tissues, offers diverse biological benefits. However, limited research has explored its effects on ruminants. This study aimed to investigate the effects of dietary addition EA on rumen metabolism, apparent digestibility of nutrients, and growth performance in Kazakh sheep. Ten 5-month-old Kazakh sheep with similar body weight (BW), fitted with rumen fistulas, were randomly assigned to two groups: the CON group (basal diet) and the EA group (basal diet + 30 mg/kg BW EA). The experiment lasted 30 days, and individual growth performance was assessed under identical feeding and management conditions. During the experimental period, rumen fluid, fecal, and blood samples were collected for analysis. The results indicated a trend toward increased average daily gain in the EA group compared to the CON group (p = 0.094). Compared with the CON group, the rumen contents of acetic acid and propionic acid were significantly increased in the EA group and reached the highest value at 2 h to 4 h after feeding (p < 0.05). Moreover, the relative abundances of specific rumen microbiota (Ruminococcaceae, uncultured_rumen_bacterium, unclassified_Prevotella, Bacteroidales, Bacteroidota, Bacteroidia, unclassified_Rikenellaceae, and Prevotella_spBP1_145) at the family and genus levels were significantly higher in the EA group (p < 0.05) compared to the CON group. The EA group exhibited significantly higher dry matter intake (p < 0.05) and increased the digestibility of neutral detergent fiber and ether extract when compared with the CON group (p < 0.05). Additionally, the plasma activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were significantly higher, while malondialdehyde (MDA) concentration was significantly lower in the EA group compared to the CON group (p < 0.05). In conclusion, dietary supplementation with 30 mg/kg BW EA in 5-month-old Kazakh sheep increased the dry matter intakQ16e, apparent digestibility of neutral detergent fiber, and ether extract, as well as the contents of acetic acid and propionic acid in rumen fluid. Moreover, EA supplementation regulated the ruminal microbiota, enhanced antioxidant capacity, and improved daily weight gain.

Antitumor effect of exopolysaccharide from Lactiplantibacillus plantarum WLPL09 on melanoma mice via regulating immunity and gut microbiota

Exopolysaccharide (EPS-09) from L. plantarum WLPL09 was systemically investigated for the antitumor effect in B16F10 melanoma bearing mice model. The results showed that administraion of EPS-09 (200 mg/kg) could sigificantly inhibit the tumor growth of melanoma bearing mice, with a inhibition rate of 42.53 %. Meanwhile, compared to the Model group, high dose of EPS-09 (200 mg/kg) administraion could increase the spleen index (P = 0.10), promote the splenic lymphocytes proliferation under the stimulation of ConA and LPS with a proliferation rate of 120.58 % and 169.88 %, respectively, enhance the amount of CD4+ and CD8+ T cells (P < 0.0001, P = 0.0149) in tumor tissue, as well as the serum content of cytokines, i.e., TNF-α, IFN-γ, IL-2 (P < 0.05) and IL-6 (P = 0.039) of B16F10 melanoma bearing mice. The transcriptional level analysis revealed that EPS-09 (200 mg/kg) administraion could sigificantly (P < 0.05) upregulate the transcription of apoptosis raleted genes, i.e., P53, Caspase-3 and Caspase-9, and the ratio of Bax/Bcl-2, downregulate the transcription of angiogenesis markers, i.e., Vegf and Fgf2 compared with Model group. Furthermore, administration of EPS-09 could increase the abundance of phylum Firmicutes, family Ruminococcaceae and Lachnospiraceae, and genus Ruminococcus, but reduce the abundance of genus Prevotella, Akkermansia and Oscillospira. Taken together, these results indicate that administration of EPS-09 can induce apoptosis of tumor cell, inhibit tumor angiogenesis, improve the immunity, regulate the intestinal microbiota composition of B16F10 melanoma bearing mice, and play positive roles in the antitumor activity against melanoma.

Postbiotics: Functional Food Materials and Therapeutic Agents for Cancer, Diabetes, and Inflammatory Diseases

Postbiotics are (i) "soluble factors secreted by live bacteria, or released after bacterial lysis, such as enzymes, peptides, teichoic acids, peptidoglycan-derived muropeptides, polysaccharides, cell-surface proteins and organic acids"; (ii) "non-viable metabolites produced by microorganisms that exert biological effects on the hosts"; and (iii) "compounds produced by microorganisms, released from food components or microbial constituents, including non-viable cells that, when administered in adequate amounts, promote health and wellbeing". A probiotic- and prebiotic-rich diet ensures an adequate supply of these vital nutrients. During the anaerobic fermentation of organic nutrients, such as prebiotics, postbiotics act as a benevolent bioactive molecule matrix. Postbiotics can be used as functional components in the food industry by offering a number of advantages, such as being added to foods that are harmful to probiotic survival. Postbiotic supplements have grown in popularity in the food, cosmetic, and healthcare industries because of their numerous health advantages. Their classification depends on various factors, including the type of microorganism, structural composition, and physiological functions. This review offers a succinct introduction to postbiotics while discussing their salient features and classification, production, purification, characterization, biological functions, and applications in the food industry. Furthermore, their therapeutic mechanisms as antibacterial, antiviral, antioxidant, anticancer, anti-diabetic, and anti-inflammatory agents are elucidated.

Lactobacillus paracasei R3 Alleviates Tumor Progression in Mice with Colorectal Cancer

Lactobacillus paracasei (L. paracasei), a common probiotic lactobacillus, has important functions in the food industry and human health. However, different strains of L. paracasei inevitably show differences in activity and colonization resistance, leading to differentiation in their functions, as well as their physical or chemical properties. The purpose of this study was to evaluate the characteristics of L. paracasei R3 (L.p R3) isolated from healthy human feces and determine whether the criteria for edible probiotics is met. The hemolysis type, biofilm-forming ability, antibiotic susceptibility, toxicity, and effective activity of L.p R3 were determined by establishing its probiotic activity traits in vitro and in vivo. The results showed that L.p R3 had a moderate biofilm formation ability, was sensitive to 11 antibiotics, was resistant to eight antibiotics, and was not hemolytic. The culture characteristics, morphology, and biochemical responses of the strain were consistent with the seed batch characteristics. In toxicity assays, L.p R3-fed mice showed no abnormalities in body weight, growth, or various organs. Additionally, L.p R3 was found to be effective in the prevention and treatment of colorectal cancer. In conclusion, our results revealed that L.p R3 has potential value as an edible probiotic without toxic side effects and alleviated the tumor progression of colorectal cancer in mice.

Postbiotics as Potential Detoxification Tools for Mitigation of Pesticides

Pesticides possess a pivotal role in the realm of agriculture and food manufacturing, as they effectively manage the proliferation of weeds, insects, plant pathogens, and microbial contaminations. They are valuable in some ways, but if misused, they can cause health issues like cancer, reproductive toxicity, neurological illnesses, and endocrine system disturbances. In this regard, practical methods for reducing pesticide residue in food should be used. For reducing pesticide residue in food processing, some strategies have been suggested. Recent research has been done on detoxification processes, including microorganisms like probiotics and their metabolites. The term "postbiotics" describes soluble substances, such as peptides, enzymes, teichoic acids, muropeptides generated from peptidoglycans, polysaccharides, proteins, and organic acids that are secreted by living bacteria or released after bacterial lysis. Due to their distinct chemical makeup, safe dosage guidelines, lengthy shelf lives, and presence of various signaling molecules that may have antioxidant, anti-inflammatory, anti-obesogenic, immunomodulatory, anti-hypertensive, and immunomodulatory effects, these postbiotics have attracted interest. They also can detoxify heavy metals, mycotoxins, and pesticides. Hydrolytic enzymes have been proposed as a potential mechanism for pesticide degradation. Postbiotics can also reduce reactive oxygen species production, enhance gastrointestinal barrier function, reduce inflammation, and modulate host xenobiotic metabolism. This review highlights pesticide residues in food products, definitions and safety aspect of postbiotics, as well as their biological role in detoxification of pesticides and the protective role of these compounds against the adverse effects of pesticides.

Use of Postbiotic as Growth Promoter in Poultry Industry: A Review of Current Knowledge and Future Prospects

Health-promoting preparations of inanimate microorganisms or their components are postbiotics. Since probiotics are sensitive to heat and oxygen, postbiotics are stable during industrial processing and storage. Postbiotics boost poultry growth, feed efficiency, intestinal pathogen reduction, and health, making them acceptable drivers of sustainable poultry production. It contains many important biological properties, such as immunomodulatory, antioxidant, and anti-inflammatory responses. Postbiotics revealed promising antioxidant effects due to higher concentrations of uronic acid and due to some enzyme's production of antioxidants, e.g., superoxide dismutase, glutathione peroxidase, and nicotinamide adenine dinucleotide oxidases and peroxidases. Postbiotics improve intestinal villi, increase lactic acid production, and reduce Enterobacteriaceae and fecal pH, all of which lead to a better immune reaction and health of the gut, as well as better growth performance. P13K/AKT as a potential target pathway for postbiotics-improved intestinal barrier functions. Similarly, postbiotics reduce yolk and plasma cholesterol levels in layers and improve egg quality. It was revealed that favorable outcomes were obtained with various inclusion levels at 1 kg and 0.5 kg. According to several studies, postbiotic compounds significantly increased poultry performance. This review article presents the most recent research investigating the beneficial results of postbiotics in poultry.

Evaluating Alterations of the Oral Microbiome and Its Link to Oral Cancer among Betel Quid Chewers: Prospecting Reversal through Probiotic Intervention

Areca nut and slaked lime, with or without tobacco wrapped in Piper betle leaf, prepared as betel quid, is extensively consumed as a masticatory product in many countries across the world. Betel Quid can promote the malignant transformation of oral lesions as well as trigger benign cellular and molecular changes. In the oral cavity, it causes changes at the compositional level in oral microbiota called dysbiosis. This dysbiosis may play an important role in Oral Cancer in betel quid chewers. The abnormal presence and increase of bacteria Fusobacterium nucleatum, Capnocytophaga gingivalis, Prevotella melaninogenica, Peptostreptococcus sp., Porphyromonas gingivalis, and Streptococcus mitis in saliva and/or other oral sites of the cancer patients has attracted frequent attention for its association with oral cancer development. In the present review, the authors have analysed the literature reports to revisit the oncogenic potential of betel quid and oral microbiome alterations, evaluating the potential of oral microbiota both as a driver and biomarker of oral cancer. The authors have also shared a perspective that the restoration of local microbiota can become a potentially therapeutic or prophylactic strategy for the delay or reversal of lip and oral cavity cancers, especially in high-risk population groups.

Therapeutic and immunomodulatory role of probiotics in breast cancer: A mechanistic review

Breast cancer has become the most prevalent and noxious type of malignancy around the globe (Giaquinto et al., 2022). Multiple clinical strategies including chemotherapy, radiotherapy, and immunotherapy have been in practice to manage breast cancer. Besides the protective roles of conventional remedial approaches, and non-reversible and deteriorative impacts like healthy cell damage, organ failure, etc., the world scientific community is in a continuous struggle to find some alternative biocompatible and comparatively safe solutions. Among novel breast cancer management/treatment options, the role of probiotics has become immensely important. The current review encompasses the prevalence statistics of breast cancer across the globe concerning developed and undeveloped counties, intestinal microbiota linkage with breast cancer, and association of breast microbiome with breast carcinoma. Furthermore, this review also narrates the role of probiotics against breast cancer and their mode of action. In Vivo and In Vitro studies under breast cancer research regarding probiotics are mechanistically explained. The current review systematically explains the immunomodulatory role of probiotics to prevent breast cancer. Last, but not the least, current review concludes the use of probiotics in the treatment of breast cancer through various mechanisms and future recommendations for molecular basis studies.

BLAB2CancerKD: a knowledge graph database focusing on the association between lactic acid bacteria and cancer, but beyond

In a broad sense, lactic acid bacteria (LAB) is a general term for Gram-positive bacteria that can produce lactic acid by utilizing fermentable carbohydrates. It is widely used in essential fields such as industry, agriculture, animal husbandry and medicine. At the same time, LAB are closely related to human health. They can regulate human intestinal flora and improve gastrointestinal function and body immunity. Cancer, a disease in which some cells grow out of control and spread to other body parts, is one of the leading causes of human death worldwide. In recent years, the potential of LAB in cancer treatment has attracted attention. Mining knowledge from the scientific literature significantly accelerates its application in cancer treatment. Using 7794 literature studies of LAB cancer as source data, we have processed 16 543 biomedical concepts and 23 091 associations by using automatic text mining tools combined with manual curation of domain experts. An ontology containing 31 434 pieces of structured data is constructed. Finally, based on ontology, a knowledge graph (KG) database, which is called Beyond 'Lactic acid bacteria to Cancer Knowledge graph Database' (BLAB2CancerKD), is constructed by using KG and web technology. BLAB2CancerKD presents all the relevant knowledge intuitively and clearly in various data presentation forms, and the interactive system function also makes it more efficient. BLAB2CancerKD will be continuously updated to advance the research and application of LAB in cancer therapy. Researchers can visit BLAB2CancerKD at. Database URL http://110.40.139.2:18095/.

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.

Lactic acid bacteria as an adjunct starter culture in the development of metabiotic functional turmeric (Curcuma longa Linn.) beverage

Turmeric (Curcuma longa) is a highly nutritious rhizomatous herbaceous plant with remarkable chemical composition and biologically active compounds. This study aimed to evaluate the turmeric, ginger and lemon blend as a fermentable substrate by lactic acid bacteria to develop a fermented nondairy beverage. Results showed that turmeric blend (turmeric 2%w/v, ginger 1.5% v/v, 5% v/v) was an excellent matrix for lactic acid bacteria growth and fermentation dramatically increased total phenolic, flavonoid content and antioxidants capacities impacting the color and sensory properties. Moreover, the formulated fermented turmeric blend was stable for more than 90 days at 4°C with a healthy bacterial population and nutraceutical stability. Turmeric beverage also inhibited the growth of Caco-2 and MOLT 4 cancerous cell lines in a dosage and time-reliant manner. This way, lactic acid fermentation can be considered as an appropriate tool for developing turmeric based novel bio-intervention with enhanced bioactivity and antagonistic efficacy against recurring food-borne pathogen in this post-antibiotic era.

Recent Perspective of Lactobacillus in Reducing Oxidative Stress to Prevent Disease

During oxidative stress, an important factor in the development of many diseases, cellular oxidative and antioxidant activities are imbalanced due to various internal and external factors such as inflammation or diet. The administration of probiotic Lactobacillus strains has been shown to confer a range of antibacterial, anti-inflammatory, antioxidant, and immunomodulatory effects in the host. This review focuses on the potential role of oxidative stress in inflammatory bowel diseases (IBD), cancer, and liver-related diseases in the context of preventive and therapeutic effects associated with Lactobacillus. This article reviews studies in cell lines and animal models as well as some clinical population reports that suggest that Lactobacillus could alleviate basic symptoms and related abnormal indicators of IBD, cancers, and liver damage, and covers evidence supporting a role for the Nrf2, NF-κB, and MAPK signaling pathways in the effects of Lactobacillus in alleviating inflammation, oxidative stress, aberrant cell proliferation, and apoptosis. This review also discusses the unmet needs and future directions in probiotic Lactobacillus research including more extensive mechanistic analyses and more clinical trials for Lactobacillus-based treatments.

The role of the gut microbiota and probiotics associated with microbial metabolisms in cancer prevention and therapy

Cancer is the second leading cause of elevated mortality worldwide. Thus, the development of drugs and treatments is needed to enhance the survival rate of the cancer-affected population. Recently, gut microbiota research in the healthy development of the human body has garnered widespread attention. Many reports indicate that changes in the gut microbiota are strongly associated with chronic inflammation-related diseases, including colitis, liver disease, and cancer within the intestine and the extraintestinal tract. Different gut bacteria are vital in the occurrence and development of tumors within the gut and extraintestinal tract. The human gut microbiome has significant implications for human physiology, including metabolism, nutrient absorption, and immune function. Moreover, diet and lifestyle habits are involved in the evolution of the human microbiome throughout the lifetime of the host and are involved in drug metabolism. Probiotics are a functional food with a protective role in cancer development in animal models. Probiotics alter the gut microbiota in the host; thus, beneficial bacterial activity is stimulated, and detrimental activity is inhibited. Clinical applications have revealed that some probiotic strains could reduce the occurrence of postoperative inflammation among cancer patients. An association network was constructed by analyzing the previous literature to explore the role of probiotics from the anti-tumor perspective. Therefore, it provides direction and insights for research on tumor treatment.

Allergic Inflammation: Effect of Propolis and Its Flavonoids

The incidence of allergic diseases and their complications are increasing worldwide. Today, people increasingly use natural products, which has been termed a "return to nature". Natural products with healing properties, especially those obtained from plants and bees, have been used in the prevention and treatment of numerous chronic diseases, including allergy and/or inflammation. Propolis is a multi-component resin rich in flavonoids, collected and transformed by honeybees from buds and plant wounds for the construction and adaptation of their nests. This article describes the current views regarding the possible mechanisms and multiple benefits of flavonoids in combating allergy and allergy-related complications. These benefits arise from flavonoid anti-allergic, anti-inflammatory, antioxidative, and wound healing activities and their effects on microbe-immune system interactions in developing host responses to different allergens. Finally, this article presents various aspects of allergy pathobiology and possible molecular approaches in their treatment. Possible mechanisms regarding the antiallergic action of propolis on the microbiota of the digestive and respiratory tracts and skin diseases as a method to selectively remove allergenic molecules by the process of bacterial biotransformation are also reported.

Anti-cancer activity of human gastrointestinal bacteria

Malignant neoplasm is one of the most incurable diseases among inflammatory diseases. Researchers have been studying for decades to win over this lethal disease and provide the light of hope to humankind. The gastrointestinal bacteria of human hold a complex ecosystem and maintain homeostasis. One hundred trillion microbes are residing in the gastrointestinal tract of human. Disturbances in the microbiota of human's gastrointestinal tract can create immune response against inflammation and also can develop diseases, including cancer. The bacteria of the gastrointestinal tract of human can secrete a variety of metabolites and bioproducts which aid in the preservation of homeostasis in the host and gut. During pathogenic dysbiosis, on the other hand, numerous microbiota subpopulations may increase and create excessive levels of toxins, which can cause inflammation and cancer. Furthermore, the immune system of host and the epithelium cell can be influenced by gut microbiota. Probiotics, which are bacteria that live in the gut, have been protected against tumor formation. Probiotics are now studied to see if they can help fight dysbiosis in cancer patients undergoing chemotherapy or radiotherapy because of their capacity to maintain gut homeostasis. Countless numbers of gut bacteria have demonstrated anti-cancer efficiency in cancer treatment, prevention, and boosting the efficiency of immunotherapy. The review article has briefly explained the anti-cancer immunity of gut microbes and their application in treating a variety of cancer. This review paper also highlights the pre-clinical studies of probiotics against cancer and the completed and ongoing clinical trials on cancers with the two most common and highly effective probiotics Lactobacillus and Bacillus spp.

Do Bacteria Provide an Alternative to Cancer Treatment and What Role Does Lactic Acid Bacteria Play?

Cancer is one of the leading causes of mortality and morbidity worldwide. According to 2022 statistics from the World Health Organization (WHO), close to 10 million deaths have been reported in 2020 and it is estimated that the number of cancer cases world-wide could increase to 21.6 million by 2030. Breast, lung, thyroid, pancreatic, liver, prostate, bladder, kidney, pelvis, colon, and rectum cancers are the most prevalent. Each year, approximately 400,000 children develop cancer. Treatment between countries vary, but usually includes either surgery, radiotherapy, or chemotherapy. Modern treatments such as hormone-, immuno- and antibody-based therapies are becoming increasingly popular. Several recent reports have been published on toxins, antibiotics, bacteriocins, non-ribosomal peptides, polyketides, phenylpropanoids, phenylflavonoids, purine nucleosides, short chain fatty acids (SCFAs) and enzymes with anticancer properties. Most of these molecules target cancer cells in a selective manner, either directly or indirectly through specific pathways. This review discusses the role of bacteria, including lactic acid bacteria, and their metabolites in the treatment of cancer.

Exopolysaccharides of Lactic Acid Bacteria: Production, Purification and Health Benefits towards Functional Food

Lactic acid bacteria (LAB) are capable of synthesising metabolites known as exopolysaccharides (EPS) during fermentation. Traditionally, EPS plays an important role in fermented dairy products through their gelling and thickening properties, but they can also be beneficial to human health. This bioactivity has gained attention in applications for functional foods, which leads them to have prebiotic, immunomodulatory, antioxidant, anti-tumour, cholesterol-lowering and anti-obesity activity. Understanding the parameters and conditions is crucial to optimising the EPS yields from LAB for applications in the food industry. This review provides an overview of the functional food market together with the biosynthesis of EPS. Factors influencing the production of EPS as well as methods for isolation, characterisation and quantification are reviewed. Finally, the health benefits associated with EPS are discussed.

Alteration of intestinal microecology by oral antibiotics promotes oral squamous cell carcinoma development

Oral antibiotics can influence cancers and immunotherapy by interfering with the intestinal microbiota. However, the association between oral antibiotics and oral squamous cell carcinoma (OSCC) as well as the mechanisms underlying the effects of oral antibiotics on OSCC remain unclear. Here, we found that oral antibiotics cocktail (4Abx) promoted the tumor development and shifted the microbiota, decreasing the abundance of probiotic bacteria, and altered microbial metabolism in the gut of OSCC mice, increasing tyrosine and decreasing glutamate levels. In vitro experiments showed that tyrosine upregulated the PD-1 expression in T cells, SCC7 cell proliferation, and necroptosis expression. IL-10 expression level in CD11c+ cells was reduced by glutamate. Furthermore, the expression of the necroptosis-related proteins, including receptor-interacting protein kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like (MLKL), was higher in the OSCC mice treated with 4Abx. Supplementation with glutamate or healthy mouse feces by gavage alleviated the tumor-promoting effect of 4Abx with restored balance of microbial metabolism. Overall, we identified the detrimental role of oral antibiotics in promoting OSCC development through altered intestinal microbiota, microbial metabolism, and immune dysbiosis, implying the need for antibiotic stewardship in OSCC treatment.

Lactobacillus brevis MTCC 1750 enhances oxidative stress resistance and lifespan extension with improved physiological and functional capacity in Caenorhabditis elegans via the DAF-16 pathway

Redox imbalance plays a crucial role in the development of age-related diseases, and resistance to oxidative stress is crucial for optimum longevity and healthy aging. Using the wild-type, mutant and transgenic strains, this study explored the antioxidative potential and lifespan extension benefits of different Lactobacillus strains in Caenorhabditis elegans (C. elegans). We observed that Lactobacillus brevis MTCC 1750 could enhance the resistance of C. elegans against juglone induced oxidative stress by reducing its intracellular reactive oxygen species (ROS) accumulation. Also, live L. brevis MTCC 1750 could prolong the worm's lifespan. These effects are dependent on transcription factor DAF-16 evident with significant upregulation of its target gene sod-3. This also explained the significant improvements in different age-associated changes in physiological and mechanical parameters of the worm by L. brevis MTCC 1750. Further investigations revealed that DAF-16 activation and, its enhanced translocation in the nucleus is independent of DAF-2 or JNK pathway. These findings highlighted L. brevis MTCC 1750 as a potent anti-oxidant source for complementing current antioxidant therapeutic strategies. Nonetheless, the findings showed how different signaling events are regulated based on an organism's diet component, and their consequences on the aging process in multiple species.

Postbiotics as potential new therapeutic agents for metabolic disorders management

The prevalence of obesity, diabetes, non-alcoholic fatty liver disease, and related metabolic disorders has been steadily increasing in the past few decades. Apart from the establishment of caloric restrictions in combination with improved physical activity, there are no effective pharmacological treatments for most metabolic disorders. Many scientific-studies have described various beneficial effects of probiotics in regulating metabolism but others questioned their effectiveness and safety. Postbiotics are defined as preparation of inanimate microorganisms, and/or their components, which determine their safety of use and confers a health benefit to the host. Additionally, unlike probiotics postbiotics do not require stringent production/storage conditions. Recently, many lines of evidence demonstrated that postbiotics may be beneficial in metabolic disorders management via several potential effects including anti-inflammatory, antibacterial, immunomodulatory, anti-carcinogenic, antioxidant, antihypertensive, anti-proliferative, and hypocholesterolaemia properties that enhance both the immune system and intestinal barrier functions by acting directly on specific tissues of the intestinal epithelium, but also on various organs or tissues. In view of the many reports that demonstrated the high biological activity and safety of postbiotics, we summarized in the present review the current findings reporting the beneficial effects of various probiotics derivatives for the management of metabolic disorders and related alterations.

Characterization of Some Microorganisms from Human Stool Samples and Determination of Their Effects on CT26 Colorectal Carcinoma Cell Line

The present study aimed to isolate and identify the potential probiotic, pathobiont, and pathogenic microorganisms in the stool samples of 12 healthy individuals and evaluate their in vitro effects on cancer formation. A total of 83 strains were isolated from the stool samples and identified using MALDI-Biotyper. Fourteen of the isolates were identified as Candida spp., three isolates were identified as Cryptococcus neoformans, 55 isolates were identified as lactic acid bacteria, and the remaining isolates belonged to different 11 bacterial genera. Important microbial properties for cancer prevention and some probiotic properties were examined. All strains maintained their viability under acidic conditions and in media containing bile salts. Of the bacterial strains, 62.5% were resistant to ampicillin, chloramphenicol, gentamicin, erythromycin, kanamycin, penicillin, streptomycin, tetracycline, and vancomycin. All yeast strains were resistant to ketoconazole and susceptible to nystatin. The susceptibility of the strains to fluconazole, voriconazole, amphotericin B, and itraconazole varied. Fifty-nine percent of the strains produced EPS and 21.7% showed proteolytic activity (PA). Of the strains, 15.7% both produced exopolysaccharides (EPS) and had PA. The antioxidant activity (AOA) varied depending on the strains. The pathobiont and pathogenic microorganisms promoted tumor formation, while potential probiotic microorganisms had a suppressive effect on tumor formation (P > 0.01). One yeast (Candida kefyr MK17) and three lactic acid bacteria strains (Lacticaseibacillus paracasei MK73, Lactiplantibacillus plantarum MK55, Limosilactobacillus mucosae MK45) have superior potential thanks to their anticarcinogenic properties as well as tolerance to gastrointestinal tract conditions. Stool samples of each individual contain various potential probiotic, pathobiont, and pathogenic microorganisms.

Gastrointestinal Microbiota and Their Manipulation for Improved Growth and Performance in Chickens

The gut of warm-blooded animals is colonized by microbes possibly constituting at least 100 times more genetic material of microbial cells than that of the somatic cells of the host. These microbes have a profound effect on several physiological functions ranging from energy metabolism to the immune response of the host, particularly those associated with the gut immune system. The gut of a newly hatched chick is typically sterile but is rapidly colonized by microbes in the environment, undergoing cycles of development. Several factors such as diet, region of the gastrointestinal tract, housing, environment, and genetics can influence the microbial composition of an individual bird and can confer a distinctive microbiome signature to the individual bird. The microbial composition can be modified by the supplementation of probiotics, prebiotics, or synbiotics. Supplementing these additives can prevent dysbiosis caused by stress factors such as infection, heat stress, and toxins that cause dysbiosis. The mechanism of action and beneficial effects of probiotics vary depending on the strains used. However, it is difficult to establish a relationship between the gut microbiome and host health and productivity due to high variability between flocks due to environmental, nutritional, and host factors. This review compiles information on the gut microbiota, dysbiosis, and additives such as probiotics, postbiotics, prebiotics, and synbiotics, which are capable of modifying gut microbiota and elaborates on the interaction of these additives with chicken gut commensals, immune system, and their consequent effects on health and productivity. Factors to be considered and the unexplored potential of genetic engineering of poultry probiotics in addressing public health concerns and zoonosis associated with the poultry industry are discussed.

Lactiplantibacillus plantarum inhibits colon cancer cell proliferation as function of its butyrogenic capability

Lactobacilli have been shown to inhibit or suppress cancer cell growth through the release of strain-specific bioactive metabolites and their inclusion in functional foods could exert a health promoting activity on human health. Herein, we examined the antiproliferative activity of the Lactiplantibacillus plantarum strains S2T10D and O2T60C, which have been previously shown to exert different butyrogenic activities. Human HT-29 cells were employed as an in vitro colon cancer model and both bacterial strains were found to inhibit their growth. However, the strain S2T10D showed a greater antiproliferative activity which, interestingly, was correlated to its butyrogenic capability. Noteworthy, for the non-butyrogenic strain O2T60C, the growth inhibitory capability was rather limited. Furthermore, both the butyrate-containing supernatant of S2T10D and glucose-deprived cell culture medium supplemented with the same concentration of butyrate found in S2T10D supernatant, induced a pH-independent cancer cell growth inhibition accompanied by downregulation of cyclin D1 at mRNA level. The downregulation of cyclin D1 gene expression was accompanied by cell cycle arrest in G2/M phase and decrease of cyclin B1 and D1 protein levels. This in vitro study underlines the impact of Lpb. plantarum in the growth inhibition of cancer cells, and proposes butyrate-mediated cell cycle regulation as a potential involved mechanism. Since the production of butyric acid in Lpb. plantarum has been proven strain-dependent and differentially boosted by specific prebiotic compounds, our results open future research paths to determine whether this metabolic activity could be modulated in vivo by enhancing this antiproliferative effects on cancer cells.

Bioprophylactic potential of novel human colostrum probiotics via apoptotic induction of colon cancer cells and cell immune activation

The potential and modes of action of novel human colostrum probiotics were investigated with the aim of studying their application as an alternative in the bioprophylactic and biotherapy of colon cancer. A total of 218 isolates of Gram-positive rod and cocci bacteria obtained from the colostrum of 50 healthy lactating females were collected. Beneficial probiotic criteria from these isolates, which included growth inhibition against seven foodborne pathogens (Helicobacter pylori, Escherichia coli, Salmonella Enteritidis, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes), no blood haemolysis and tolerance to acid and bile salt conditions, resulted in only eight probiotic bacteria successfully inhibiting the proliferation of colon cancer cells at rates of 32.47-61.21%. Two probiotic bacteria with higher anticancer efficacy (Streptococcus salivarius CP163 and S. salivarius CP208) were identified using 16S rRNA sequences. High rates of cell surface hydrophobicity, autoaggregation and coaggregation were obtained from both probiotics. The probiotic mode of action involved synergic probiotic adhesion to colon cancer cells that triggered SCFA bioproduction. Apoptotic induction of colon cancer cell death through caspase-2 activity, DNA fragmentation and morphological change as assessed by AO/PI staining were also observed. Immune stimulation by S. salivarius CP163 and S. salivarius CP208 resulted in B and T-cell lymphocyte activation. This study suggests that these novel human colostrum probiotics could be applied as a functional food to facilitate a bioprophylactic strategy in colon cancer.

Biological Functions of Exopolysaccharides from Lactic Acid Bacteria and Their Potential Benefits for Humans and Farmed Animals

Lactic acid bacteria (LAB) synthesize exopolysaccharides (EPS), which are structurally diverse biopolymers with a broad range of technological properties and bioactivities. There is scientific evidence that these polymers have health-promoting properties. Most commercialized probiotic microorganisms for consumption by humans and farmed animals are LAB and some of them are EPS-producers indicating that some of their beneficial properties could be due to these polymers. Probiotic LAB are currently used to improve human health and for the prevention and treatment of specific pathologic conditions. They are also used in food-producing animal husbandry, mainly due to their abilities to promote growth and inhibit pathogens via different mechanisms, among which the production of EPS could be involved. Thus, the aim of this review is to discuss the current knowledge of the characteristics, usage and biological role of EPS from LAB, as well as their postbiotic action in humans and animals, and to predict the future contribution that they could have on the diet of food animals to improve productivity, animal health status and impact on public 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.

Postbiotics as the new frontier in food and pharmaceutical research

Food is the essential need of human life and has nutrients that support growth and health. Gastrointestinal tract microbiota involves valuable microorganisms that develop therapeutic effects and are characterized as probiotics. The investigations on appropriate probiotic strains have led to the characterization of specific metabolic byproducts of probiotics named postbiotics. The probiotics must maintain their survival against inappropriate lethal conditions of the processing, storage, distribution, preparation, and digestion system so that they can exhibit their most health effects. Conversely, probiotic metabolites (postbiotics) have successfully overcome these unfavorable conditions and may be an appropriate alternative to probiotics. Due to their specific chemical structure, safe profile, long shelf-life, and the fact that they contain various signaling molecules, postbiotics may have anti-inflammatory, immunomodulatory, antihypertensive properties, inhibiting abnormal cell proliferation and antioxidative activities. Consequently, present scientific literature approves that postbiotics can mimic the fundamental and clinical role of probiotics, and due to their unique characteristics, they can be applied in an oral delivery system (pharmaceutical/functional foods), as a preharvest food safety hurdle, to promote the shelf-life of food products and develop novel functional foods or/and for developing health benefits, and therapeutic aims. This review addresses the latest postbiotic applications with regard to pharmaceutical formulations and commercial food-based products. Potential postbiotic applications in the promotion of host health status, prevention of disease, and complementary treatment are also reviewed.

Beneficial Effects of Laurel (Laurus nobilis L.) and Myrtle (Myrtus communis L.) Extract on Rat Health

Polyphenols of Laurel and Myrtle exhibit structural diversity, which affects bioavailability, metabolism, and bioactivity. The gut microbiota plays a key role in modulating the production, bioavailability and, thus the biological activities of phenolic metabolites, particularly after the intake of food containing high-molecular-weight polyphenols. The aim of this study was to investigate whether the polyphenolic components of Laurel and Myrtle aqueous extract have beneficial effects on rat health. The growth of lactic acid bacteria (LAB), β-glucuronidase, β-glucosidase, β-galactosidase activity, pH value, body weight change and food efficacy ratio after intragastric treatment of rats with Laurel and Myrtle extract at doses of 50 and 100 mg/kg for two weeks were investigated. The endogenous populations of colonic probiotic bacteria (Lactobacilli and Bifidobacteria) were counted on selective media. According to the obtained data, Laurel extract in the applied dose of 50 and 100 and Myrtle extract (100 mg/kg) positively affects the rats health by increasing the number of colonies of Lactobacilli and Bifidobacteria compared to the control group, causes changes in glycolytic enzymatic activity and minor change in antioxidative tissue activity. In addition, high doses of Laurel increase food efficiency ratio, while Myrtle has the same effect at a lower dose.

Gold (III) Derivatives in Colon Cancer Treatment

Cancer is one of the leading causes of morbidity and mortality worldwide. Colorectal cancer (CRC) is the third most frequently diagnosed cancer in men and the second in women. Standard patterns of antitumor therapy, including cisplatin, are ineffective due to their lack of specificity for tumor cells, development of drug resistance, and severe side effects. For this reason, new methods and strategies for CRC treatment are urgently needed. Current research includes novel platinum (Pt)- and other metal-based drugs such as gold (Au), silver (Ag), iridium (Ir), or ruthenium (Ru). Au(III) compounds are promising drug candidates for CRC treatment due to their structural similarity to Pt(II). Their advantage is their relatively good solubility in water, but their disadvantage is an unsatisfactory stability under physiological conditions. Due to these limitations, work is still underway to improve the formula of Au(III) complexes by combining with various types of ligands capable of stabilizing the Au(III) cation and preventing its reduction under physiological conditions. This review summarizes the achievements in the field of stable Au(III) complexes with potential cytotoxic activity restricted to cancer cells. Moreover, it has been shown that not nucleic acids but various protein structures such as thioredoxin reductase (TrxR) mediate the antitumor effects of Au derivatives. The state of the art of the in vivo studies so far conducted is also described.

Lactobacillus plantarum-derived metabolites sensitize the tumor-suppressive effects of butyrate by regulating the functional expression of SMCT1 in 5-FU-resistant colorectal cancer cells

A critical obstacle to the successful treatment of colorectal cancer (CRC) is chemoresistance. Chemoresistant CRC cells contribute to treatment failure by providing a mechanism of drug lethargy and modifying chemoresistance-associated molecules. The gut microbiota provide prophylactic and therapeutic effects by targeting CRC through anticancer mechanisms. Among them, Lactobacillus plantarum contributes to the health of the host and is clinically effective in treating CRC. This study confirmed that 5-fluorouracil (5-FU)-resistant CRC HCT116 (HCT116/5FUR) cells acquired butyrate-insensitive properties. To date, the relationship between 5-FU-resistant CRC and butyrate resistance has not been elucidated. Here, we demonstrated that the acquisition of butyrate resistance in HCT116/5FUR cells was strongly correlated with the inhibition of the expression and function of SMCT1, a major transporter of butyrate in colonocytes. L. plantarum-cultured cell-free supernatant (LP) restored the functional expression of SMCT1 in HCT116/5FUR cells, leading to butyrate-induced antiproliferative effect and apoptosis. These results suggest that LP has a synergistic effect on the SMCT1/butyrate-mediated tumor suppressor function and is a potential chemosensitizer to overcome dual 5-FU and butyrate resistance in HCT116 cells.

Common Inflammatory Mechanisms in COVID-19 and Parkinson's Diseases: The Role of Microbiome, Pharmabiotics and Postbiotics in Their Prevention

In the last decade, metagenomic studies have shown the key role of the gut microbiome in maintaining immune and neuroendocrine systems. Malfunction of the gut microbiome can induce inflammatory processes, oxidative stress, and cytokine storm. Dysfunction of the gut microbiome can be caused by short-term (virus infection and other infectious diseases) or long-term (environment, nutrition, and stress) factors. Here, we reviewed the inflammation and oxidative stress in neurodegenerative diseases and coronavirus infection (COVID-19). Here, we reviewed the renin-angiotensin-aldosterone system (RAAS) involved in the processes of formation of oxidative stress and inflammation in viral and neurodegenerative diseases. Moreover, the coronavirus uses ACE2 receptors of the RAAS to penetrate human cells. The coronavirus infection can be the trigger for neurodegenerative diseases by dysfunction of the RAAS. Pharmabiotics, postbiotics, and next-generation probiotics, are considered as a means to prevent oxidative stress, inflammatory processes, neurodegenerative and viral diseases through gut microbiome regulation.

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.

Biomarkers and Utility of the Antioxidant Potential of Probiotic Lactobacilli and Bifidobacteria as Representatives of the Human Gut Microbiota

Lactobacilli and bifidobacteria are an important part of human gut microbiota. Among numerous benefits, their antioxidant properties are attracting more and more attention. Multiple in vivo and in vitro studies have demonstrated that lactobacilli and bifidobacteria, along with their cellular components, possess excellent antioxidant capacity, which provides a certain degree of protection to the human body against diseases associated with oxidative stress. Recently, lactobacilli and bifidobacteria have begun to be considered as a new source of natural antioxidants. This review summarizes the current state of research on various antioxidant properties of lactobacilli and bifidobacteria. Special emphasis is given to the mechanisms of antioxidant activity of these bacteria in the human gut microbiota, which involve bacterial cell components and metabolites. This review is also dedicated to the genes involved in the antioxidant properties of lactobacilli and bifidobacteria strains as indicators of their antioxidant potential in human gut microbiota. Identification of the antioxidant biomarkers of the gut microbiota is of great importance both for creating diagnostic systems for assessing oxidative stress and for choosing strategies aimed at restoring the normal functioning of the microbiota and, through it, restoring human health. In this review, the practical application of probiotic strains with proven antioxidant properties to prevent oxidative stress is also considered.

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

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

Lactobacillus sakei Pro-Bio65 Reduces TNF-α Expression and Upregulates GSH Content and Antioxidant Enzymatic Activities in Human Conjunctival Cells

Purpose

The study investigates the regulatory effects exhibited by lysate of Lactobacillus sakei pro-Bio65 (4%; L.SK) on the human conjunctival epithelial (HCE) cell line.

Methods

Trypan blue and methylthiazol tetrazolium (MTT) methods were used to assess cell growth and viability. Mitochondrial membrane potential was assessed by JC-1 staining and cytofluorimetric detection methods. The antioxidant pattern and the intracellular reactive oxygen species (ROS) levels were analyzed by spectrophotometric and spectrofluorimetric methods. NF-κB luciferase activity was quantified by luminometric detection. NF-κB nuclear translocation, as well as mitochondrial morphology, were investigated by immunofluorescence using confocal microscopy. Cytokines and COX2 expression levels were determined by Western blot analyses.

Results

This study demonstrates that L.SK exposure does not influence HCE cell proliferation and viability in vitro. L.SK paraprobiotic induces mild-low levels of intracellular ROS. It is coupled to changes in the mitochondrial membrane potential (ΔΨm), in a context of a regular mitochondrial-network organization. The negative modulation of tumor necrosis factor alpha (TNF-α) expression levels and rising antioxidant defense efficiency, mediated by the upregulation of glutathione (GSH) and increased antioxidant enzymatic activities, were observed.

Conclusions

This study demonstrates that L.SK empowers the antioxidant endogenous efficiency of HCE cells, by the upregulation of the GSH content and the enzymatic antioxidant pattern, and concurrently reduces TNF-α protein expression.

Translational Relevance

Although the obtained in vitro results should be confirmed by in vivo investigations, our data suggest the possibility of L.SK paraprobiotic application for promoting eye health, exploring its use as an endogen antioxidant system inducer in preventing and treating different oxidative stress-based, inflammatory, and age-related conditions.