Two potential probiotic lactobacillus strains isolated from olive microbiota exhibit adhesion and anti-proliferative effects in cancer cell lines

Monitoring the Bioprotective Potential of Lactiplantibacillus pentosus Culture on Pathogen Survival and the Shelf-Life of Fresh Ready-to-Eat Salads Stored under Modified Atmosphere Packaging

Globally, fresh vegetables or minimally processed salads have been implicated in several foodborne disease outbreaks. This work studied the effect of Lactiplantibacillus pentosus FMCC-B281 cells (F) and its supernatant (S) on spoilage and on the fate of Listeria monocytogenes and Escherichia coli O157:H7 on fresh-cut ready-to-eat (RTE) salads during storage. Also, Fourier transform infrared (FTIR) and multispectral imaging (MSI) analysis were used as rapid and non-destructive techniques to estimate the microbiological status of the samples. Fresh romaine lettuce, rocket cabbage, and white cabbage were used in the present study and were inoculated with L. pentosus and the two pathogens. The strains were grown at 37 °C for 24 h in MRS and BHI broths, respectively, and then were centrifuged to collect the supernatant and the pellet (cells). Cells (F, ~5 log CFU/g), the supernatant (S), and a control (C, broth) were used to spray the leaves of each fresh vegetable that had been previously contaminated (sprayed) with the pathogen (3 log CFU/g). Subsequently, the salads were packed under modified atmosphere packaging (10%CO2/10%O2/80%N2) and stored at 4 and 10 °C until spoilage. During storage, microbiological counts and pH were monitored in parallel with FTIR and MSI analyses. The results showed that during storage, the population of the pathogens increased for lettuce and rocket independent of the treatment. For cabbage, pathogen populations remained stable throughout storage. Regarding the spoilage microbiota, the Pseudomonas population was lower in the F samples, while no differences in the populations of Enterobacteriaceae and yeasts/molds were observed for the C, F, and S samples stored at 4 °C. According to sensory evaluation, the shelf-life was shorter for the control samples in contrast to the S and F samples, where their shelf-life was elongated by 1-2 days. Initial pH values were ca. 6.0 for the three leafy vegetables. An increase in the pH of ca. 0.5 values was recorded until the end of storage at both temperatures for all cases of leafy vegetables. FTIR and MSI analyses did not satisfactorily lead to the estimation of the microbiological quality of salads. In conclusion, the applied bioprotective strain (L. pentosus) can elongate the shelf-life of the RTE salads without an effect on pathogen growth.

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

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

Potential of Synbiotics and Probiotics as Chemopreventive Agent

Cancer remains a global problem, with millions of new cases diagnosed yearly and countless lives lost. The financial burden of cancer therapy, along with worries about the long-term safety of existing medicines, necessitates the investigation of alternative approaches to cancer prevention. Probiotics generate chemopreventive compounds such as bacteriocins, short-chain fatty acids (SCFA), and extracellular polymeric substances (EPS), which have demonstrated the ability to impede cancer cell proliferation, induce apoptosis, and bolster the expression of pro-apoptotic genes. On the other hand, prebiotics, classified as non-digestible food ingredients, promote the proliferation of probiotics within the colon, thereby ensuring sustained functionality of the gut microbiota. Consequently, the synergistic effect of combining prebiotics with probiotics, known as the synbiotic effect, in dietary interventions holds promise for potentially mitigating cancer risk and augmenting preventive measures. The utilization of gut microbiota in cancer treatment has shown promise in alleviating adverse health effects. This review explored the potential and the role of probiotics and synbiotics in enhancing health and contributing to cancer prevention efforts. In this review, the applications of functional probiotics and synbiotics, the mechanisms of action of probiotics in cancer, and the relationship of probiotics with various drugs were discussed, shedding light on the potential of probiotics and synbiotics to alleviate the burdens of cancer treatment.

Lacticaseibacillus paracasei AD22 Stress Response in Brined White Cheese Matrix: In Vitro Probiotic Profiles and Molecular Characterization

Functionalizing foods involve discovering and integrating new candidate health-promoting bacteria into the food matrix. This study aimed (i) to reveal the probiotic potential of autochthonous Lacticaseibacillus paracasei AD22 by a series of in vitro tests and molecular characterization and (ii) to evaluate its application to the matrix of brined white cheese, which is the most common cheese in Türkiye, in terms of survival and stress response. To evaluate in vitro probiotic characteristics, L. paracasei AD22 was exposed to functional, technological, and safety tests. Pilot scale production was conducted to integrate L. paracasei AD22 into the brined white cheese matrix. The expression levels of stress-related genes (dnaK, groES, ftsH, argH, and hsp20) were detected by reverse-transcriptase polymerase chain reaction to determine the transcriptional stress response during ripening. The presence of genes encoding stress-related proteins was determined by whole-genome sequence analysis using a subsystem approach; the presence of antibiotic resistance and virulence genes was determined by ResFinder4.1 and VirulenceFinder 2.0 databases. The BAGEL4 database determined the presence of bacteriocin clusters. L. paracasei AD22 was found to survive in pH 2 and medium with 12% NaCl and did not cause hemolysis. Adhesion of the strain to Caco2 cells was 76.26 ± 4.81% and it had coaggregation/autoaggregation properties. It was determined that L. paracasei AD22 exceeded 7 log cfu/g in the cheese matrix at the end of the ripening period. Total mesophilic aerobes decreased in the cheese inoculated with L. paracasei AD22 after the 45th day of ripening. While hsp20 and groES genes were downregulated during ripening, argH was upregulated. Both downregulation and upregulation were observed in dnaK and ftsH. Fold changes indicating the expression levels of dnaK, groES, ftsH, argH, and hsp20 genes were not statistically significant during ripening (p > 0.05). Whole-genome sequence profiles revealed that the strain did not contain antibiotic and virulence genes but bacteriocin clusters encoding Enterolysin A (Class III bacteriocin), Carnosine CP52 (class II bacteriocin), Enterocin X beta chain (Class IIc bacteriocin), and the LanT region. Subsystems approach manifested that the most functional part of the genomic distribution belonged to metabolism, protein processing, and stress response functions. The study findings highlight that L. paracasei AD22 will provide biotechnological innovation as a probiotic adjunct because it contains tolerance factors and probiotic characteristics to produce new functional foods.

Probiotic potential and wound-healing activity of Pediococcus pentosaceus strain AF2 isolated from Herniaria glabra L. which is traditionally used to make yogurt

Probiotics have been a part of our lives for centuries, primarily through fermented foods. They find applications in various fields such as food, healthcare, and agriculture. Nowadays, their utilization is expanding, highlighting the importance of discovering new bacterial strains with probiotic properties suitable for diverse applications. In this study, our aim was to isolate new probiotic bacteria. Herniaria glabra L., a plant traditionally used for yogurt making in some regions and recognized in official medicine in many countries, was chosen as the source for obtaining probiotic bacteria. We conducted bacterial isolation from the plant, molecularly identified the isolated bacteria using 16S rRNA sequencing, characterized their probiotic properties, and assessed their wound-healing effects. As a result of these studies, we identified the bacterium isolated from the plant as Pediococcus pentosaceus strain AF2. We found that the strain AF2 exhibited high resistance to conditions within the gastrointestinal tract. Our reliability analysis showed that the isolate had γ-hemolytic activity and displayed sensitivity to certain tested antibiotics. At the same time, AF2 did not show gelatinase and DNase activity. We observed that the strain AF2 produced metabolites with inhibitory activity against E. coli, B. subtilis, P. vulgaris, S. typhimurium, P. aeruginosa, K. pneumoniae, E. cloacae, and Y. pseudotuberculosis. The auto-aggregation value of the strain AF2 was calculated at 73.44%. Coaggregation values against E. coli and L. monocytogenes bacteria were determined to be 56.8% and 57.38%, respectively. Finally, we tested the wound-healing effect of the strain AF2 with cell culture studies and found that the strain AF2 promoted wound healing.

Isolation, identification, and molecular characterization of probiotic bacteria from locally selected Ethiopian free range chickens gastrointestinal tract

The poultry industry is facing continuous challenges with regard to increased feed costs and loss due to infectious disease. To overcome this challenge, several antibiotics have been used along with chicken feeds to promote growth. Nevertheless, the use of antibiotics as growth promoter has been banned in many countries, due to the concerns associated with potential risks of emerging and horizontal transfer of multidrug resistant genes to bacteria in animal tissues. The objective of this study was to identify and characterize potential probiotic bacteria strains from the gastrointestinal tract of free-range locally selected chickens. The bacterial isolates were screened, purified and characterized based on morphological, biochemical and molecular characteristics from 12 well-adopted free-range healthy young chickens. Low pH and bile salt tolerance, antagonistic activity, antibiotic activity, hemolysis activity, adhesion to the chicken intestine and carbohydrate fermentation tests was conducted to identify potential probiotic bacteria. Twelve bacterial isolates were screened based on their ability for their tolerance to low pH and bile salt. The isolates were identified by using 16S rRNA gene partial sequencing method. All screened isolates showed great survival percentage at low pH, that is (89.2 ± 0.75 to 97.1 ± 0.64) survived at 3 h and (83.6 ± 0.75 to 95.2 ± 0.63) at 6 h challenge at pH2. Isolate GCM112 was the least tolerant strain in 6.0% salt concentration at 12 and 24 h exposure time (82.1 ± 1.28 and 79.9 ± 1.96%) respectively. The result revealed no strain tests in this study exhibited α- and β-hemolytic activity when cultured in sheep blood agar. Most isolated strains showed best growth at 37°C temperature and up to 4% NaCl concentration. Based on the reported result from in vitro data, GCH212 and GCM412 isolates were recognized as best potential probiotic bacteria for chicken against pathogens but further studies are needed on in vivo assessment on the health benefits in the real life situation.

An Update on the Pivotal Roles of Probiotics, Their Components, and Metabolites in Preventing Colon Cancer

Diet, lifestyle, and gut microbiota composition are key risk factors for the progression of colon cancer. Probiotics are living microorganisms that can offer health benefits to the parasitifer when ingested in competent quantities. Several in vivo, in vitro, and clinical studies have demonstrated that probiotics can prevent and mitigate the development of colon cancer. The anti-colon cancer mechanisms of probiotics include the suppression of cell proliferation and the promotion of cancer cell apoptosis, immunomodulation, the modulation of intestinal microorganisms and their metabolism, strengthening the intestinal barrier, and antioxidant effects. This article describes the pathogenesis of colon cancer and the available therapeutic options. In addition, this paper reviews the mechanisms by which probiotics mitigate colon cancer as well as the mitigating effects of probiotic components and metabolites on colon cancer.

Relevance of tumor microbiome in cancer incidence, prognosis, and its clinical implications in therapeutics

The microbiota is garnering progressively greater consideration as an essential facet of the tumor microenvironment that regulates tumor proliferation and affects cancer prognosis. Microbial populations that inhabit different body locations are involved in the carcinogenesis and tumor progression of their corresponding malignancies. It has been learned that the microbial populations primarily thriving within tumors are tumor-type specific. Mechanistic studies have revealed that the tumor-associated microbiota contributes to playing a pivotal role in the establishment of the tumor microenvironment, regulation of local immunity, modulation of tumor cell biology, and directly influences the therapeutic efficacy of drug treatment for tumors. This review article incorporates the pertinent studies on recent advancements in tumor microbiome studies, the interplay between the intratumor microbiota and cancer, and, discusses their role and mechanism of action in the emergence and treatment of cancer, and their relationship to clinical characteristics.

Probiotic-Derived Bioactive Compounds in Colorectal Cancer Treatment

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

Assessing the protection mechanisms on Enterobacter aerogenes ATCC 13048 by potentially probiotic strain Lacticaseibacillus casei XN18: An experimental and modeling study

In this study, Lacticaseibacillus casei XN18 had a remarkable resistant to simulated gastrointestinal conditions, hydrophobicity (38.60%), auto-aggregation (29.80%), co-aggregation (21.10%), adhesion (9.50%), anti-adhesion (24.40-36.90%), antioxidant activity (46.47%), cholesterol assimilation (41.10%), and antimicrobial effect on some pathogenic microorganisms. The modified double layer method, and Enterobacter aerogenes (inhibition zone (IZ) = 9.10 mm) and Listeria monocytogenes (IZ = 14.60 mm) were the most sensitive and resistant pathogens to the probiotic strain. The Lb. casei was sensitive to ciprofloxacin (IZ = 23 mm) and nitrofurantoin (IZ = 25.10 mm), semi-sensitive to imipenem (IZ = 18.80 mm), erythromycin (IZ = 16.90 mm), and chloramphenicol (IZ = 17.90 mm), and resistant to ampicillin (IZ = 9.60 mm) and nalidixic acid (IZ = 9.90 mm). The Lb. casei showed no haemolytic and DNase properties, and it could therefore be used for health-promoting purposes. In the next section, multilayer perceptron (MLP) neural network (NN) and gaussian process regression (GPR) models with k-fold cross validation method were used for predicting the rate of probiotic viability based on three levels of pH and time. The results showed that GPR has the lowest error. The mean absolute percentage error (MAPE), root mean absolute error (RMSE) and coefficient of determination (R²) for GPR and MLP models were 1.49 ± 0.40, 0.21 ± 0.03, 0.98 ± 0.05 and 6.66 ± 0.98, 0.83 ± 0.23 0.82 ± 0.09, respectively. So, the GPR model can be reliably used as a useful method to predict the probiotic viability in similar cases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Bioinformatics and its role in the study of the evolution and probiotic potential of lactic acid bacteria

Due to their numerous well-established applications in the food industry, there have been many studies regarding the adaptation and evolution of lactic acid bacteria (LAB) in a wide variety of hosts and environments. Progress in sequencing technology and continual decreases in its costs have led to the availability of LAB genome sequence data. Bioinformatics has been central to the extraction of valuable information from these raw genome sequence data. This paper presents the roles of bioinformatics tools and databases in understanding the adaptation and evolution of LAB, as well as the bioinformatics methods used in the initial screening of LAB for probiotic potential. Moreover, the advantages, challenges, and limitations of employing bioinformatics for these purposes are discussed.

Gut microbiome in tumorigenesis and therapy of colorectal cancer

Colorectal cancer (CRC) is the malignant tumor with the highest incidence in the digestive system, and the gut microbiome plays a crucial role in CRC tumorigenesis and therapy. The gastrointestinal tract is the organ harboring most of the microbiota in humans. Changes in the gut microbiome in CRC patients suggest possible host-microbe interactions, thereby hinting the potential tumorigenesis, which provides new perspective for preventing, diagnosing, or treating CRC. In this review, we discuss the effects of gut microbiome dysbiosis on CRC, and reveal the mechanisms by which gut microbiome dysbiosis leads to CRC. Gut microbiome modulation with the aim to reverse the established gut microbial dysbiosis is a novel strategy for the prevention and treatment of CRC. In addition, this review summarizes that probiotic antagonize CRC tumorigenesis by protecting intestinal barrier function, inhibiting cancer cell proliferation, resisting oxidative stress, and enhancing host immunity. Finally, we highlight clinical applications of the gut microbiome, such as gut microbiome analysis-based biomarker screening and prediction, and microbe modulation-based CRC prevention, treatment enhancement, and treatment side effect reduction. This review provides the reference for the clinical application of gut microbiome in the prevention and treatment of CRC.

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.

An In Vivo Study of Lactobacillus rhamnosus (PTCC 1637) as a New Therapeutic Candidate in Esophageal Cancer

Statement of Novelty. Esophageal cancer is one of the most common types of cancer globally. Nowadays, Lactobacilli with probiotic potency is a preventing factor in cancer and many diseases. The anti-tumor properties of these bacteria have been indicated in various studies. Objective. This study is aimed at investigating the effect of probiotic Lactobacillus rhamnosus on esophageal cancer in vivo and in vitro. Methods and Results. In this study, the cytotoxicity effects of L. rhamnosus supernatant and whole-cell culture on a cancer cell line (Kyse30) compared to 5fu were evaluated by the MTT assay. The real-time PCR method was used to analyse the L. rhamnosus supernatant effect on the expression of Wnt signaling pathway genes. An in vivo investigation in nude mice was done to assess the anti-tumor activity of L. rhamnosus supernatant and whole-cell culture. Both supernatant and whole-cell culture of L. rhamnosus reduced cell survival (Kyse30) $P<0.001$ . The supernatant of this bacterium significantly reduced the expression of Wnt signaling pathway genes. Administration of supernatant and whole-cell culture of L. rhamnosus expressively reduced tumor growth compared to the control group. The effects of this bacterium on tumor necrosis were quite evident, pathologically $P<0.01$ . Conclusion. This study is the first report that assessed the potential impact of L. rhamnosus, especially its supernatant on esophageal cancer and Wnt signaling pathway genes. Therefore, this bacterium can be a harmless candidate for esophageal cancer therapy.

Probiotic and Antifungal Attributes of Lactic Acid Bacteria Isolates from Naturally Fermented Brazilian Table Olives

Research with fermented olives as a source of wild Lactic Acid Bacteria (LAB) strains with probiotic and biotechnological characteristics constitutes a promising field of work. The present study evaluated in vitro probiotic, antifungal, and antimycotoxigenic potential of LAB isolates from naturally fermented Brazilian table olives. Among fourteen LAB isolates, the Levilactobacillus brevis CCMA 1762, Lactiplantibacillus pentosus CCMA 1768, and Lacticaseibacillus paracasei subsp. paracasei CCMA 1770 showed potential probiotic and antifungal properties. The isolates showed resistance to pH 2.0 (survival ≥ 84.55), bile salts (survival ≥ 99.44), and gastrointestinal tract conditions (survival ≥ 57.84%); hydrophobic cell surface (≥27%); auto-aggregation (≥81.38%); coaggregation with Escherichia coli INCQS 00181 (≥33.97%) and Salmonella Enteritidis ATCC 564 (≥53.84%); adhesion to the epithelial cell line Caco-2 (≥5.04%); antimicrobial activity against the bacteria S. Enteritidis ATCC 564 (≥6 mm), Listeria monocytogenes ATCC 19117 (≥6 mm), Staphylococcus aureus ATCC 8702 (≥3 mm), and the fungi Penicillium nordicum MUM 08.16 (inhibition ≥ 64.8%). In addition, the strains showed the ability to adsorb the mycotoxins aflatoxin B1 (≥40%) and ochratoxin A (≥34%). These results indicate that LAB strains from naturally fermented Brazilian table olives are potentially probiotic and antifungal candidates that can be used for food biopreservation.

Encapsulation of Lactic Acid Bacteria by Lyophilisation with Its Effects on Viability and Adhesion Properties

Lactobacillus (LAB) genera are considered important functional food but are found to have a short shelf life. In this study, two LAB, Lactobacillus plantarum (Lp) and Lactobacillus rhamnosus (Lr), were isolated from sheep's milk, and whole-genome sequencing was carried out by using 16s rRNA Illumina Nextseq, the Netherlands. The LAB were encapsulated by the lyophilisation technique using different lyoprotective pharmaceutical excipients. This process was carried out using a freeze dryer (U-TECH, Star Scientific Instruments, India). Shelf-life determination was carried out by a 12-month study using the viability survival factor (Vsf). The in vitro cell adhesion technique was carried out by using the red snapper fish along with autoaggregation and cell surface hydrophobicity as vital probiotic properties. It was observed that Lp has a significantly higher (P < 0.001) Vsf of 7.2, while Lr has a Vsf of 7 (P < 0.05) when both are encapsulated with 10% maltodextrin + 5% sucrose kept at 4°C for 12 months. The result demonstrated that Lp had significantly high (P < 0.05) cell adhesion, 96% ± 1.2 autoaggregation, and 6% cell surface hydrophobicity as compared to Lr. Moreover, this study demonstrated that lyophilised LAB with lyoprotective excipients enhances shelf life without any changes in probiotic properties when kept at 4°C exhibiting all its probiotic properties.

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.

Probiotic-derived heptelidic acid exerts antitumor effects on extraintestinal melanoma through glyceraldehyde-3-phosphate dehydrogenase activity control

Background

Several microorganisms inhabit the mammalian gastrointestinal tract and are associated with the pathogenesis of various diseases, including cancer. Recent studies have indicated that several probiotics produce antitumor molecules and inhibit host tumor progression. We demonstrated that heptelidic acid (HA), a sesquiterpene lactone derived from the probiotic Aspergillus oryzae, exerts antitumor effects against pancreatic cancer in vitro and in vivo. In this study, the antitumor effects of HA against extraintestinal melanoma were assessed in vitro and in vivo.

Results

Sulforhodamine B (SRB) assay revealed that the growth of B16F10 cells was significantly inhibited by HA in a concentration-dependent manner. The enzymatic activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) decreased in proportion with the growth inhibition effect of HA. Moreover, oral HA administration significantly suppressed the growth of transplanted B16F10 tumors without any significant changes in biochemical test values. Moreover, GAPDH activity in the transplanted tumor tissues in the HA group significantly decreased compared with that in the PBS group.

Conclusion

This study suggests that orally administered HA was absorbed in the gastrointestinal tract, reached the cancer cells transplanted in the skin, and inhibited GAPDH activity, thereby inhibiting the growth of extraintestinal melanoma cells. Thus, this study proposes a novel system for extraintestinal tumor regulation via gut bacteria-derived bioactive mediators.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02530-0.

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.

Bacteria and bacterial derivatives as delivery carriers for immunotherapy

There is growing interest in the role of microorganisms in human health and disease, with evidence showing that new types of biotherapy using engineered bacterial therapeutics, including bacterial derivatives, can address specific mechanisms of disease. The complex interactions between microorganisms and metabolic/immunologic pathways underlie many diseases with unmet medical needs, suggesting that targeting these interactions may improve patient treatment. Using tools from synthetic biology and chemical engineering, non-pathogenic bacteria or bacterial products can be programmed and designed to sense and respond to environmental signals to deliver therapeutic effectors. This review describes current progress in biotherapy using live bacteria and their derivatives to achieve therapeutic benefits against various diseases.

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.

Genomic and Phylogenetic Analysis of Lactiplantibacillus plantarum L125, and Evaluation of Its Anti-Proliferative and Cytotoxic Activity in Cancer Cells

Lactiplantibacillus plantarum is a diverse species that includes nomadic strains isolated from a variety of environmental niches. Several L. plantarum strains are being incorporated in fermented foodstuffs as starter cultures, while some of them have also been characterized as probiotics. In this study, we present the draft genome sequence of L. plantarum L125, a potential probiotic strain presenting biotechnological interest, originally isolated from a traditional fermented meat product. Phylogenetic and comparative genomic analysis with other potential probiotic L. plantarum strains were performed to determine its evolutionary relationships. Furthermore, we located genes involved in the probiotic phenotype by whole genome annotation. Indeed, genes coding for proteins mediating host–microbe interactions and bile salt, heat and cold stress tolerance were identified. Concerning the potential health-promoting attributes of the novel strain, we determined that L. plantarum L125 carries an incomplete plantaricin gene cluster, in agreement with previous in vitro findings, where no bacteriocin-like activity was detected. Moreover, we showed that cell-free culture supernatant (CFCS) of L. plantarum L125 exerts anti-proliferative, anti-clonogenic and anti-migration activity against the human colon adenocarcinoma cell line, HT-29. Conclusively, L. plantarum L125 presents desirable probiotic traits. Future studies will elucidate further its biological and health-related properties.

Fermentation Supernatants of Pleurotus eryngii Mushroom Ameliorate Intestinal Epithelial Barrier Dysfunction in Lipopolysaccharide-Induced Caco-2 Cells via Upregulation of Tight Junctions

In recent years, modulation of gut microbiota through prebiotics has garnered interest as a potential to ameliorate intestinal barrier dysfunction. The aim of the study was to examine the in vitro effect of fermentation supernatants (FSs) from rich in β-glucan Pleurotus eryngii mushrooms on the expression levels of tight junctions (TJs) genes in Caco-2 cells stimulated by bacterial lipopolysaccharides (LPS). Mushrooms were fermented using fecal inocula in an in vitro batch culture model. Caco-2 cells were subjected to LPS and FS treatment under three different conditions: pre-incubation with FS, co- and post-incubation. Reverse transcription PCR was applied to measure the expression levels of zonulin-1, occludin and claudin-1 genes. FSs from P. eryngii mushrooms led to a significant upregulation of the TJs gene expression in pre-incubation state, indicating potential preventive action. Down-regulation of all TJs gene expression levels was observed when the cells were challenged with LPS. The FS negative control (gut microbiota of each donor with no carbohydrate source) exhibited a significant upregulation of TJs expression levels compared to the cells that were challenged with LPS, for all three conditions. Overall, our data highlighted the positive and potential protective effects of P. eryngii mushrooms in upregulation of TJs’ genes.

Probiotics: A Promising Candidate for Management of Colorectal Cancer

Colorectal cancer (CRC) is the World's third most frequently diagnosed cancer type. It accounted for about 9.4% mortality out of the total incidences of cancer in the year 2020. According to estimated facts by World Health Organization (WHO), by 2030, 27 million new CRC cases, 17 million deaths, and around 75 million people living with the disease will appear. The facts and evidence that establish a link between the intestinal microflora and the occurrence of CRC are quite intuitive. Current shortcomings of chemo- and radiotherapies and the unavailability of appropriate treatment strategies for CRC are becoming the driving force to search for an alternative approach for the prevention, therapy, and management of CRC. Probiotics have been used for a long time due to their beneficial health effects, and now, it has become a popular candidate for the preventive and therapeutic treatment of CRC. The probiotics adopt different strategies such as the improvement of the intestinal barrier function, balancing of natural gut microflora, secretion of anticancer compounds, and degradation of carcinogenic compounds, which are useful in the prophylactic treatment of CRC. The pro-apoptotic ability of probiotics against cancerous cells makes them a potential therapeutic candidate against cancer diseases. Moreover, the immunomodulatory properties of probiotics have created interest among researchers to explore the therapeutic strategy by activating the immune system against cancerous cells. The present review discusses in detail different strategies and mechanisms of probiotics towards the prevention and treatment of CRC.

Probiotics for the Chemoprotective Role Against the Toxic Effect of Cancer Chemotherapy

BACKGROUND

The processes of chemo- and radiation therapy-based clinical management of different types of cancers are associated with toxicity and side effects of chemotherapeutic agents. So, there is always an unmet need to explore agents to reduce such risk factors. Among these, natural products have generated much attention because of their potent antioxidant and antitumor effects. In the past, some breakthrough outcomes established that various bacteria in the human intestinal gut are bearing growth-promoting attributes and suppressing the conversion of pro-carcinogens into carcinogens. Hence, probiotics integrated approaches are nowadays being explored as rationalized therapeutics in the clinical management of cancer.

METHODS

Here, published literature was explored to review chemoprotective roles of probiotics against toxic and side effects of chemotherapeutics.

RESULTS

Apart from excellent anti-cancer abilities, probiotics are bearing and alleviate toxicity and side effects of chemotherapeutics, with a high degree of safety and efficiency.

CONCLUSION

Preclinical and clinical evidence suggested that due to the chemoprotective roles of probiotics against side effects and toxicity of chemotherapeutics, their integration in chemotherapy would be a judicious approach.

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.

Isolation of a Lactobacillus paracasei Strain with Probiotic Attributes from Kefir Grains

Κefir is a rich source of potentially probiotic bacteria. In the present study, firstly, in vitro screening for probiotic characteristics of ten lactic acid bacteria (LAB) isolated from kefir grains was performed. Strain AGR 4 was selected for further studies. Molecular characterization of strain AGR 4, confirmed that AGR 4 belongs to the Lactobacillus paracasei (reclassified to Lacticaseibacillus paracasei subsp. paracasei) species. Further testing revealed that L. paracasei AGR 4 displayed adhesion capacity on human adenocarcinoma cells, HT-29, similar to that of the reference strain, L. casei ATCC 393. In addition, the novel strain exerted significant time- and dose-dependent antiproliferative activity against HT-29 cells and human melanoma cell line, A375, as demonstrated by the sulforhodamine B cytotoxicity assay. Flow cytometry analysis was employed to investigate the mechanism of cellular death; however, it was found that AGR 4 did not act by inducing cell cycle arrest and/or apoptotic cell death. Taken together, these findings promote the probiotic character of the newly isolated strain L. paracasei AGR 4, while further studies are needed for the detailed description of its biological properties.

Probiotic Properties of Lactiplantibacillus plantarum LB5 Isolated from Kimchi Based on Nitrate Reducing Capability

The purpose of this study was to investigate the probiotic properties of lactic acid bacteria isolated from Korean radish water kimchi (dongchimi). A total of 800 isolates of lactic acid bacteria were isolated from kimchi, and the strain having reduction and tolerance capability for nitrate and nitrite was selected and identified as Lactiplantibacillus plantarum LB5 (LPLB5) by 16S rRNA sequencing. LPLB5 showed higher tolerance to acidic pH values (pH 2.5), 0.3% bile salts, and heat treatment (40, 50, and 60 °C). Antibacterial activity showed strong inhibition against four food-borne pathogenic bacteria (E. coli O157:H7 ATCC 35150, Pseudomonas aeruginosa KCCM 12539, Listeria monocytogenes KCCM 40307, and Staphylococcus aureus ATCC 25923). The strain did not show any antibiotic resistance, β-hemolytic activity, or ability to produce β-glucuronidase. LPLB5 also exhibited a 30% auto-aggregation ability and 33–60% co-aggregation ability with four pathogenic bacteria (E. coli O157: H7 ATCC 35150, E. coli KCTC 2571, L. monocytogenes ATCC 51776, and S. aureus ATCC 25923). Moreover, the strain showed approximately 40% 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical- and 10% 2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging activity. In cell culture studies, human colon epithelial cells (Caco-2) were treated with LPLB5 (10⁶ and 10⁷ CFU/mL); the bacteria showed more than 70% adherence onto and a 32% invasion rate into the Caco-2 cells. LPLB5 significantly decreased the mRNA expression levels of pro-inflammatory cytokines (interleukin-1 beta (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α)) and increased the mRNA expression levels of anti-inflammatory cytokines (interleukin-4 (IL-4), interleukin-10 (IL-10), and interferon-gamma (IFN-γ)) in lipopolysaccharide-stimulated Caco-2 cells. Our data suggest that LPLB5 is safe and possesses probiotic, antioxidant, and anti-inflammatory activities.

Molecular mechanisms of postbiotics in colorectal cancer prevention and treatment

The occurrence of colorectal cancer (CRC) has been rising expeditiously and anticipated that 2.4 million new occasions of CRC will be detected yearly around the world until the year 2035. Due to some side-effects and complications of conventional CRC therapies, bioactive components such as microbial-derived biomolecules (postbiotics) have been attaining great significance by researchers for adjuvant therapy in CRC patients. The term 'postbiotics' encompasses an extensive range of complex micro- and macro-molecules (<50, 50-100, and 100< kDa) such as inactivated microbial cells, cell fractions or metabolites, which confer various physiological health benefits to the host when administered in adequate amounts. Postbiotics modulate the composition of the gut microbiota and the functionality of the immune system, as well as promote the CRC treatment effectiveness and reduces its side-effects in CRC patients due to possessing anti-oxidant, anti-proliferative, anti-inflammatory, and anti-cancer activities. Presently scientific literature confirms that postbiotics with their unique characteristics in terms of clinical (safe origin), technological (stability), and economic (low production costs) aspects can be used as promising tools for both prevent and adjuvant treat strategies in CRC patients without any serious undesirable side-effects. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the prevention and treatment of CRC.

Multivariate Analysis of Increase in Life Span of Caenorhabditis elegans Through Intestinal Colonization by Indigenous Probiotic Strains

The present study aimed to analyze the colonization potential of indigenous probiotic strains and to assess their effects on physiology of Caenorhabditis elegans. The protective effect of probiotics was evaluated in terms of increase in life span of the worm through colonization in the intestine. A total of 15 probiotic cultures were evaluated for their effect on mean life span, pharyngeal pumping, and normal reproduction behavior in the worms. The chemotactic behavior in terms of binary choice index was also evaluated. The adherence and colonization of the intestine of the worm by probiotics were monitored at different time intervals by enumerating the microbial population and fluorescent microscopic observations. The survival analysis-based Kaplan-Meier method indicated that the probiotic cultures increased the survival probability as compared to control strain E. coli OP50. There was no effect of feeding probiotics on physiological responses of the worm such as pharyngeal pumping and reproduction. The principal component analysis (PCA) of the results indicated Lactobacillus plantarum K90 and L. paracasei CD4 as potential probiotics with binary choice index of 0.8 as food preference of C. elegans. The strains exhibit higher adherence and colonization in the gut of worms and increased the life span by 5 days as compared to control E. coli OP50. In conclusion, feeding with probiotic cultures is effective in extending the lifespan of C. elegans; however, the colonization ability differs among the strains.

Probiotic Bacteria: A Promising Tool in Cancer Prevention and Therapy

Gut microbiota is widely considered to be one of the most important components to maintain balanced homeostasis. Looking forward, probiotic bacteria have been shown to play a significant role in immunomodulation and display antitumour properties. Bacterial strains could be responsible for detection and degradation of potential carcinogens and production of short-chain fatty acids, which affect cell death and proliferation and are known as signaling molecules in the immune system. Lactic acid bacteria present in the gut has been shown to have a role in regression of carcinogenesis due to their influence on immunomodulation, which can stand as a proof of interaction between bacterial metabolites and immune and epithelial cells. Probiotic bacteria have the ability to both increase and decrease the production of anti-inflammatory cytokines which play an important role in prevention of carcinogenesis. They are also capable of activating phagocytes in order to eliminate early-stage cancer cells. Application of heat-killed probiotic bacteria coupled with radiation had a positive influence on enhancing immunological recognition of cancer cells. In the absence of active microbiota, murine immunity to carcinogens has been decreased. There are numerous cohort studies showing the correlation between ingestion of dairy products and the risk of colon and colorectal cancer. An idea of using probiotic bacteria as vectors to administer drugs has emerged lately as several papers presenting successful results have been revealed. Within the next few years, probiotic bacteria as well as gut microbiota are likely to become an important component in cancer prevention and treatment.

Microencapsulation of endophytic LAB (KCC-41) and its probiotic and fermentative potential for cabbage kimchi

The aim of the present study was to isolate novel lactic acid bacteria (LAB) from hairy vetch forage crop and characterize their probiotic and fermentative potential for preparing Korean cabbage kimchi. First, functional characterization of isolated strains such as antagonistic property, auto-aggregation, antibiotic susceptibility, and extracellular enzyme production was performed. The isolated Lactobacillus plantarum KCC-41 strain was able to inhibit pathogenic fungal spore formation. It showed susceptibility to common commercial antibiotics drugs. The selected LAB strain was then subjected to microencapsulation with alginate biopolymer. Its ability to survive in in vitro simulated gastro-intestinal fluid was evaluated. It was also used in the fermentation of cabbage kimchi samples. The encapsulated KCC-41 strain could effectively lead to kimchi fermentation in terms of reducing its pH and dominating bacterial count. It also significantly increased organic acid production than non-encapsulated LAB (KCC-41) for cabbage kimchi samples.

Application of A Novel Potential Probiotic Lactobacillus paracasei Strain Isolated from Kefir Grains in the Production of Feta-Type Cheese

In the present study 38 lactic acid bacteria strains were isolated from kefir grains and were monitored regarding probiotic properties in a series of established in vitro tests, including resistance to low pH, resistance to pepsin and pancreatin, and tolerance to bile salts, as well as susceptibility against common antibiotics. Among them, the strain SP3 displayed potential probiotic properties. Multiplex PCR analysis indicated that the novel strain belongs to the paracasei species. Likewise, the novel strain (Lactobacillus paracasei SP3) was applied as a starter culture for Feta-type cheese production. Feta-type cheese production resulted in significantly higher acidity; lower pH; reduced counts of coliforms, yeasts and fungi; and improved quality characteristics compared with cheese samples produced with no starter culture. Finally, it is highlighted that the application of the novel strain led to Feta-type cheese production with improved overall quality and sensory characteristics.

Lactobacillus paracasei K5 displays adhesion, anti-proliferative activity and apoptotic effects in human colon cancer cells

Lactobacillus paracasei K5 is a lactic acid bacteria (LAB) strain, isolated recently from feta-type cheese. Its probiotic potential has been demonstrated in a series of established in vitro tests. Moreover, incorporation of L. paracasei K5 as starter culture offered organoleptic and technological advantages to novel fermented food products. In the present study, further investigation of the potential probiotic activity of L. paracasei K5 was performed and its mechanisms of action were investigated. Employing quantitative analysis and confocal, fluorescent microscopy the adhesion properties of the above strain were studied. L. paracasei K5 displayed efficient adherence capacity to Caco-2 colon cancer cells, similarly to the reference strains Lactobacillus casei ATCC 393 and Lactobacillus rhamnosus GG. Moreover, treatment of Caco-2 cells with L. paracasei K5 inhibited cell proliferation in a time-and dose-dependent manner. The anti-proliferative effects appear to be mediated through induction of apoptosis via modulation of expression of specific Bcl-2 family proteins. These results elucidate the mechanisms of action of L. paracasei K5 and enhance its potential probiotic activity.

Lactobacillus plantarum with Functional Properties: An Approach to Increase Safety and Shelf-Life of Fermented Foods

Lactobacillus plantarum (widespread member of the genus Lactobacillus) is one of the most studied species extensively used in food industry as probiotic microorganism and/or microbial starter. The exploitation of Lb. plantarum strains with their long history in food fermentation forms an emerging field and design of added-value foods. Lb. plantarum strains were also used to produce new functional (traditional/novel) foods and beverages with improved nutritional and technological features. Lb. plantarum strains were identified from many traditional foods and characterized for their systematics and molecular taxonomy, enzyme systems (α-amylase, esterase, lipase, α-glucosidase, β-glucosidase, enolase, phosphoketolase, lactase dehydrogenase, etc.), and bioactive compounds (bacteriocin, dipeptides, and other preservative compounds). This review emphasizes that the Lb. plantarum strains with their probiotic properties can have great effects against harmful microflora (foodborne pathogens) to increase safety and shelf-life of fermented foods.

Screening probiotics from Lactobacillus strains according to their abilities to inhibit pathogen adhesion and induction of pro-inflammatory cytokine IL-8

Probiotics can be screened according to their abilities to inhibit pathogen adhesion and inhibit the production of pro-inflammatory cytokines. Eleven Lactobacillus strains isolated from traditional fermented dairy foods in Xinjiang, China, were studied for their potential to inhibit adhesion of Escherichia coli to intestinal epithelial cells and to inhibit E. coli-induced production of interleukin (IL)-8 by intestinal epithelial cells. The results showed that the 11 strains could inhibit adhesion of E. coli to Caco-2 cell monolayers and inhibit the induction of IL-8 production by E. coli in HT-29 cells. The inhibiting activities of the Lactobacillus strains against E. coli adhesion and IL-8 induction were strain-specific and not positively correlated, whereas the excluding activity of the strains against E. coli adhesion and their coaggregation with E. coli were positively correlated. The effector molecules of the strains with probiotic potential should be identified to explain the mechanism behind these observations.

Probiotic potential of novel Lactobacillus strains isolated from salted-fermented shrimp as antagonists for Vibrio parahaemolyticus

Lactobacillus strains have been considered good candidates as biological control agents for prevention or treatment of plant and animal infections. One L. plantarum strain FB003 and three strains (FB011, FB081, and FB110) which closed to L. sakei were isolated from fermented and salted shrimp and their abilities in inhibiting growth of Vibrio parahaemolyticus were characterized. These strains were selected as potential probiotics based on their oro-gastro-intestinal resistance, gut colonization, adhesion to Caco-2 cells, antimicrobial activities, antibiotic resistance, and safety aspects. Results of this study revealed that these isolates possessed high aggregation activities against pathogens in host intestines. Strain FB011 strain showed higher coaggregation and immunomodulatory activity in the gastro-intestinal tract than L. plantarum. These difference effects of Lactobacillus strains provide valuable information about using them to prevent Vibrio infections in the aquaculture industry.

Anticancer potential against cervix cancer (HeLa) cell line of probiotic Lactobacillus casei and Lactobacillus paracasei strains isolated from human breast milk

The CFCS of Lactobacilli strains from human breast milk induced apoptosis in HeLa cells ROS related mitochondrial pathway.

Antiproliferation effects and antioxidant activity of two new Lactobacillus strains

Abstract The microorganisms most commonly used as probiotics are lactic acid bacteria, especially those of the genus Lactobacillus. In the present study, two Lactobacillus strains, L. pentosus ITA23 and L. acidipiscis ITA44, previously isolated from mulberry silage, were characterized for their antiproliferative and antioxidant activities. The antiproliferative effects of the strains were investigated using the MTT assay with breast cancer (MDA-MB-231), liver cancer (HepG2) and normal liver (Chang) cell lines. The strains were tested for their antioxidant activity using the FRAP and ABTS methods. The results showed that the two Lactobacillus strains had good antiproliferative effects against both cancer cell lines tested, while their effects on the normal cells were weak. Based on the results of the antioxidant tests, the intact cells and cell-free extracts of the two Lactobacillus strains showed more than 135 and less than 50 µg trolox/ml of antioxidant activity, respectively. Lactobacillus pentosus ITA23 and L. acidipiscis ITA44 can be considered as potential probiotic candidates for humans because of their antioxidant activity and antiproliferation effects against cancer cells.

Probiotics-mediated suppression of cancer

PURPOSE OF REVIEW

Probiotics can be used as an adjuvant for cancer prevention or/and treatment through their abilities to modulate intestinal microbiota and host immune response. Although most of the recent reviews have focused on the potential role of probiotics against colon cancer, only few of them include the probiotic effect on extraintestinal cancers. The present review covers the most important findings from the literature published during the past 20 months (from January 2015 to August 2016) regarding the probiotics-mediated suppression of both gastrointestinal and extraintestinal cancers and the underlying mechanisms.

RECENT FINDINGS

A comprehensive literature search in Pubmed, Science direct and Google scholar databases was conducted to locate all relevant articles that investigated the effect of probiotics on prevention/treatment of both gastrointestinal and extraintestinal cancers. Different mechanisms for the beneficial effects of probiotics against cancer were also discussed, mainly via modulation of gut microbiota which thereby influences host metabolism and immunity.

SUMMARY

Despite laboratory-based studies having demonstrated encouraging outcomes that probiotics possess antitumor effects, the benefits should not be exaggerated before we get more results from human clinical trials. These are very important before the medical community can accept the use of probiotics as an alternative therapy for cancer control.

Survival, Intestinal Mucosa Adhesion, and Immunomodulatory Potential of Lactobacillus plantarum Strains

Survival during transit through the gastrointestinal track, intestinal mucosa adhesion, and a potential immunomodulatory effect of Lactobacillus plantarum strains 2035 and ACA-DC 2640 were investigated in a rat model. According to microbiological and multiplex PCR analysis, both strains were detected in feces 24 h after either single-dose or daily administration for 7 days. Intestinal mucosa adhesion of L. plantarum 2035 was noted in the large intestine at 24 h after single-dose administration, while it was not detected at 48 h. Daily dosing, prolonged detection of the strain up to 48 h post-administration, and expanded adhesion to the small intestine. Adhesion of L. plantarum ACA-DC 2640 to the intestinal mucosa after single-dose administration was prolonged and more extended compared to L. plantarum 2035. Daily dosing increased both the levels and the rate of positive cultures of the strains compared to those of the single-dose scheme. In addition, both strains increased total IgG while decreased IgM and IgA serum levels. In conclusion, L. plantarum 2035 and L. plantarum ACA-DC 2640 survived transit through the gastrointestinal track, exhibited transient distinct adhesion to the intestinal mucosa and modulated the systemic immune response.