Antitumor effect of heat-killed Lactobacillus plantarum L-137 through restoration of impaired interleukin-12 production in tumor-bearing mice

Beneficial effect of heat-killed Lactiplantibacillus plantarum L-137 on intestinal barrier function of rat small intestinal epithelial cells

Heat-killed Lactiplantibacillus plantarum L-137 (HK L-137) has been suggested to enhance the intestinal barrier in obese mice, leading to improvement of metabolic abnormalities and adipose tissue inflammation, and in healthy humans with overweight, leading to improvement of systemic inflammation. However, its detailed mechanism of action has not been clarified. Therefore, this study investigated the effects of HK L-137 on the permeability of rat small intestinal epithelial IEC-6 cells, tight junction-related gene and protein expression and localization, and intracellular signaling pathways involved in barrier function. Treatment of IEC-6 cells with HK L-137 for 26 h significantly reduced the permeability to fluorescein isothiocyanate-dextran (FD-4). HK L-137 also increased gene and protein expression of zonula occludens-1 (ZO-1), an important tight junction protein, without affecting the localization. Furthermore, inhibition of the extracellular signal-regulated kinase (ERK)1/2 pathway in IEC-6 cells canceled the HK L-137-related reduction in permeability to FD-4. Phosphorylation of ERK in IEC-6 cells was induced 15 min after the addition of HK L-137. These results suggest that HK L-137 reduces intestinal permeability partly through activating the ERK pathway and increasing expression of the ZO-1 gene and protein. Enhancement of intestinal barrier function with HK L-137 might be effective in preventing and treating leaky gut, for which no specific therapeutic tool has been established.

Current Knowledge about Gastric Microbiota with Special Emphasis on Helicobacter pylori-Related Gastric Conditions

The gastric milieu, because of its very low acidic pH, is very harsh for bacterial growth. The discovery of Helicobacter pylori (H.p.) has opened a new avenue for studies on the gastric microbiota, thus indicating that the stomach is not a sterile environment. Nowadays, new technologies of bacterial identification have demonstrated the existence of other microorganisms in the gastric habitat, which play an important role in health and disease. This bacterium possesses an arsenal of compounds which enable its survival but, at the same time, damage the gastric mucosa. Toxins, such as cytotoxin-associated gene A, vacuolar cytotoxin A, lipopolysaccharides, and adhesins, determine an inflammatory status of the gastric mucosa which may become chronic, ultimately leading to a gastric carcinoma. In the initial stage, H.p. persistence alters the gastric microbiota with a condition of dysbiosis, predisposing to inflammation. Probiotics and prebiotics exhibit beneficial effects on H.p. infection, and, among them, anti-inflammatory, antioxidant, and antibacterial activities are the major ones. Moreover, the association of probiotics with prebiotics (synbiotics) to conventional anti-H.p. therapy contributes to a more efficacious eradication of the bacterium. Also, polyphenols, largely present in the vegetal kingdom, have been demonstrated to alleviate H.p.-dependent pathologies, even including the inhibition of tumorigenesis. The gastric microbiota composition in health and disease is described. Then, cellular and molecular mechanisms of H.p.-mediated damage are clarified. Finally, the use of probiotics, prebiotics, and polyphenols in experimental models and in patients infected with H.p. is discussed.

Efficacy and safety of probiotic-supplemented bismuth quadruple therapy for the treatment of Helicobacter pylori infection: a systematic review and meta-analysis

OBJECTIVE

We performed a meta-analysis to determine whether the addition of probiotics to the bismuth quadruple therapy (BQT) for Helicobacter pylori would improve the incidence of eradication and reduce that of side effects.

METHODS

Randomized controlled trials matching the inclusion criteria were collected from PubMed, Embase, Web of Science, and The Cochrane Central Register of Controlled Trials. A Mantel-Haenszel random-effects model was used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for the incidences of eradication rate, side effects as a whole, diarrhea, and other side effects.

RESULTS

Ten studies were selected for inclusion in the meta-analysis. The pooled RRs for the eradication rates in intention-to-treat and per-protocol analyses of the probiotic group vs. the control group were 1.07 (95% CI: 1.02-1.11) and 1.04 (95% CI: 1.00-1.07), respectively. Probiotic supplementation reduced the incidences of side effects (RR 0.58, 95% CI: 0.37-0.91), diarrhea (RR 0.41, 95% CI: 0.25-0.67), and bitter taste (RR 0.63, 95% CI: 0.40-0.99).

CONCLUSIONS

The results of this meta-analysis support the use of probiotics in combination with BQT in the clinical management of patients with H. pylori infection.

Novel approach for the inhibition of Helicobacter pylori contamination in yogurt using selected probiotics combined with eugenol and cinnamaldehyde nanoemulsions

Different strains of probiotics were screened in vitro to select the one with the highest anti-H. pylori activity. Three nanoemulsions of eugenol, cinnamaldehyde and their mixture were fabricated and tested also in vitro against the same pathogen. The selected probiotic strains, the nanoemulsion mixture and their combination were imbedded in a lab-manufactured yogurt which is deliberately contaminated with 6.0 log cfu/g H. pylori during manufacture. The inhibitory activity of all treatments on the growth of H. pylori and the other microorganisms in yogurt was evaluated during 21 days. Combining the selected probiotic strains with the nanoemulsion mixture in the contaminated yogurt reduced the count of H. pylori by 3.9 log cycle. The nanoemulsion showed lower inhibitory effect against the other microorganisms like probiotics, starter culture and total bacterial count in the tested yogurt, where their enumeration did not fall below 10⁶ cfu/g at the end of yogurt storage period.

Implication of Paraprobiotics in Age-Associated Gut Dysbiosis and Neurodegenerative Diseases

Neurodegenerative diseases, including Alzheimer's and Parkinson's disease, are major age-related concerns in elderly people. Since no drug fully addresses the progression of neurodegenerative diseases, advance treatment strategies are urgently needed. Several studies have noted the senescence of immune system and the perturbation of gut microbiota in the aged population. In recent years, the role of gut microbiota has been increasingly studied in the manifestation of age-related CNS disorders. In this context, prebiotics, probiotics, and paraprobiotics are reported to improve the behavioural and neurobiological abnormalities in elderly patients. As live microbiota, prescribed in the form of probiotics, shows some adverse effects like sepsis, translocation, and horizontal gene transfer, paraprobiotics could be a possible alternative strategy in designing microbiome-based therapeutics. This review describes the health-beneficial effects of paraprobiotics in age-associated neurodegenerative diseases.

Effects of Heat-Killed Lactobacillus plantarum L-137 Supplementation on Growth Performance, Blood Profiles, Intestinal Morphology, and Immune Gene Expression in Pigs

In the present study, the effects of dietary heat-killed Lactobacillus plantarum L-137 (HK L-137) on the productive performance, intestinal morphology, and cytokine gene expression of suckling-to-fattening pigs were investigated. A total of 100 suckling pigs [(Large White × Landrace) × Duroc; 4.5 ± 0.54 kg initial body weight (BW)] were used and assigned to each of the four dietary treatments as follows: (1) a control diet with antibiotics as a growth promoter (AGP) from the suckling phase to the grower phase and no supplement in the finisher phases; (2) a control diet without antibiotics as a growth promoter (NAGP); (3) a control diet with HK L-137 at 20 mg/kg from the suckling phase to the starter phase and no supplement from the grower phase to the finisher phases (HKL1); and (4) a control diet with HK L-137 at 20 mg/kg from the suckling phase to the weaner phase, at 4 mg/kg from the starter phase to the finisher 1 phase, and no supplement in the finisher 2 phase (HKL2). During the weaner-starter period, the pigs fed on the AGP and HKL2 diets showed significantly higher weight gain and average daily gain (ADG) than those in the NAGP group (p < 0.05). The pigs in the AGP, HKL1, and HKL2 groups showed greater ADG than those in the NAGP groups (p < 0.05) throughout the grower-finisher period. The suckling pigs in the HKL1 and HKL2 groups showed a higher platelet count (484,500 and 575,750) than in the others (p < 0.05); however, there were no significant differences in the other hematological parameters among the treatment groups. The relative mRNA expression level of IFN- ß of the suckling and starter pigs were significantly higher in the HKL1 and HKL2 groups than in the others (p < 0.05), while the IFN-γ showed the highest level in the HKL2 suckling pigs (p < 0.05). These results demonstrate that a HK L-137 supplementation could stimulate the immune response in suckling and starter pigs and promote the growth performance in finishing pigs.

The interplay between Helicobacter pylori and the gut microbiota: An emerging driver influencing the immune system homeostasis and gastric carcinogenesis

The human gut microbiota are critical for preserving the health status because they are required for digestion and nutrient acquisition, the development of the immune system, and energy metabolism. The gut microbial composition is greatly influenced by the colonization of the recalcitrant pathogen Helicobacter pylori (H. pylori) and the conventional antibiotic regimens that follow. H. pylori is considered to be the main microorganism in gastric carcinogenesis, and it appears to be required for the early stages of the process. However, a non-H. pylori microbiota profile is also suggested, primarily in the later stages of tumorigenesis. On the other hand, specific groups of gut microbes may produce beneficial byproducts such as short-chain fatty acids (acetate, butyrate, and propionate) that can modulate inflammation and tumorigenesis pathways. In this review, we aim to present how H. pylori influences the population of the gut microbiota to modify the host immunity and trigger the development of gastric carcinogenesis. We will also highlight the effect of the gut microbiota on immunotherapeutic approaches such as immune checkpoint blockade in cancer treatment to present a perspective for further development of innovative therapeutic paradigms to prevent the progression of H. pylori-induced stomach cancer.

Therapeutic effect of heat-killed Lactobacillus plantarum L-137 on the gut health and growth of broilers

Although some studies on the effects of para-probiotics on the immune system and intestinal health have been conducted independently of research on antibiotics ass growth promoters. This study investigated the effects of heat-killed Lactobacillus plantarumL-137 (L-137) and antibiotics as preventive and/or therapeutic substances for broilers against subclinical necrotic enteritis caused by Clostridium perfringens (CP). In total, 300 1-day-old broilers (46.13 ± 1.38 g) were randomly stocked at 10 birds pen^-1 in five replicates and divided into six groups, namely T1 and T2, positive and negative control of CP challenge; T3 and T4, prevention with basal diet plus 10 and 50 mg/kg L-137; T5 and T6, prevention and treatment with basal diet plus 50 mg/kg of L-137 and bacitracin at 50 ppm, respectively. Broilers administered L-137 in T4, T5 and bacitracin in T6 showed an improved (p < 0.05) villus height/crypt depth ratio than control groups, suggesting that it might significantly boost growth performance. In contrast to bacitracin, a high dosage of L-137 significantly increased (p < 0.05) the spleen index value and the cytokine levels, as well as the expression of intestinal β-defensin genes on day 28. During the 42-day production period, broilers in T4 and T5 showed a significantly enhanced (p < 0.05) expression of cytokines, AvBD-1 and AvBD-7 on day 42 compared to the control and bacitracin groups. In particular, broilers given the L-137 diets demonstrated no cumulative mortality following CP exposure, compared to a 2% mortality in T6. Our findings provide insight into eco-friendly alternatives to antibiotics for maximizing growth performance, feed efficiency and long-term disease protection in chickens; however, this has to be proven in larger-scale commercial experiments.

Beneficial Effect of Heat-Killed Lactiplantibacillus plantarum L-137 on Skin Functions in Healthy Participants: A Randomized, Placebo-Controlled, Double-Blind Study

To determine whether consuming heat-killed Lactiplantibacillus plantarum L-137 (HK L-137) influences skin functions, we performed a randomized, placebo-controlled, double-blind study in healthy participants who were conscious of dry skin. A total of 80 healthy participants (20 men, 60 women; mean age, 47.3 years) were assigned to receive a tablet containing HK L-137 or a placebo tablet daily for 12 weeks. Every 4 weeks, the skin water content and transepidermal water loss (TEWL) were measured at the forearm and face, and participants completed two skin-related questionnaires, the Dermatology Life Quality Index and a self-evaluation. The HK L-137 group tended to show greater increases from baseline of water content at the forearm and larger decreases of TEWL at the face. The total scores of both questionnaires improved significantly more in the HK L-137 group. Water content and TEWL improved significantly in participants in the HK L-137 group who were above the median age of study participants or had relatively dry skin. These findings suggest that daily HK L-137 intake can improve dry skin, thereby contributing to skin satisfaction.

Comparison of probiotic Lactobacillus strains isolated from dairy and Iranian traditional food products with those from human source on intestinal microbiota using BALB/C mice model

This study compares the probiotic Lactobacillus strains isolated from dairy and Iranian traditional food products with those from human sources on intestinal microbiota using BALB/C mice model. First, Lactiplantibacillus plantarum (M11), Limosilactobacillus fermentum (19SH), Lactobacillus acidophilus (AC2), and Lactobacillus gasseri (52b) strains, isolated from either Iranian traditionally fermented products or human (healthy woman vaginal secretions), identified with molecular methods and selected based on the surface hydrophobicity, auto- and co-aggregation, were investigated for their probiotic properties and compared with their standard probiotic strains in vitro. The native strains and their mixtures (MIX) were then orally fed to five groups of female inbred BALB/C mice over the course of 38 days by gavage at 0.5 and 4 McFarland, respectively, equal to 1.5 × 10⁸ and 1 × 10⁹ cfu/ml. Feeding paused for 6 days to test the bacteria's adhesion in vivo. According to the findings, the probiotic Lactobacillus strain isolated from human source (52b) exhibited the best in vitro and in vivo adhesion ability. Probiotic Lactobacillus strains isolated from Iranian traditional food products (19SH and AC2) had the most co-aggregation with Listeria monocytogenes (ATTC 7644), Salmonella enterica subsp. enterica (ATCC 13,076), and Escherichia coli (NCTC 12,900 O157:H7) in vitro. These strains produced the most profound decreasing effect on the mice intestinal microbiota and pathogens in vivo. The difference in the strains and their probiotic potential is related to the sources from which they are isolated as well as their cell walls. The results suggest that (19SH and 52b strains) are the best candidates to investigate the cell wall and its effect on the host immune system.

Safety and efficacy of using heat-killed Lactobacillus plantarum L-137: High-dose and long-term use effects on immune-related safety and intestinal bacterial flora

Heat-killed Lactobacillus plantarum L-137 (HK L-137) promotes immune function in animals. In healthy people, T-cell proliferation was shown to be enhanced by taking 10 mg HK L-137 daily for 12 weeks. However, the safety and efficacy of higher doses or longer treatments have not yet been investigated in humans. To investigate the high-dose and long-term use effects of HK L-137 on immune-related safety and on host intestinal bacterial flora, 15 healthy volunteers took a daily HK L-137 (50 mg) preparation for 4 weeks. An additional 29 participants who regularly visited a clinic for health care took HK L-137 (10 mg) daily for 12 months. Measures for anthropometrics, hematology, biochemistry, and urinalysis were taken at scheduled timepoints for all participants. Stool and blood samples were also collected and evaluated for microbes and short-chain fatty acids (SCFA); isolated T-cells were assessed for levels of proliferation induced by phytohemagglutinin in the long-term study. Adverse events or shifts in clinical measures from normal ranges due to the dietary intervention were not observed in the high-dose or long-term studies. Long-term intake also did not result in immune exhaustion due to any chronic immunostimulation; ex vivo T-cell proliferation was significantly greater at 12 months than at baseline (p < 0.01). In addition, the Firmicutes/Bacteroidetes ratio in stool samples was significantly lower at 12 months than at baseline (p < 0.05) due to the long-term intake of the HK L-137. Lastly, fecal SCFA concentrations were significantly greater (p < 0.05) at 6 months than at baseline. From these data, it can be concluded that the efficacy of HK L-137 is maintained with no overt adverse effects as a result of high-dose and/or long-term consumption.

Probiotics, Photobiomodulation, and Disease Management: Controversies and Challenges

In recent decades, researchers around the world have been studying intensively how micro-organisms that are present inside living organisms could affect the main processes of life, namely health and pathological conditions of mind or body. They discovered a relationship between the whole microbial colonization and the initiation and development of different medical disorders. Besides already known probiotics, novel products such as postbiotics and paraprobiotics have been developed in recent years to create new non-viable micro-organisms or bacterial-free extracts, which can provide benefits to the host with additional bioactivity to probiotics, but without the risk of side effects. The best alternatives in the use of probiotics and postbiotics to maintain the health of the intestinal microbiota and to prevent the attachment of pathogens to children and adults are highlighted and discussed as controversies and challenges. Updated knowledge of the molecular and cellular mechanisms involved in the balance between microbiota and immune system for the introspection on the gut-lung-brain axis could reveal the latest benefits and perspectives of applied photobiomics for health. Multiple interconditioning between photobiomodulation (PBM), probiotics, and the human microbiota, their effects on the human body, and their implications for the management of viral infectious diseases is essential. Coupled complex PBM and probiotic interventions can control the microbiome, improve the activity of the immune system, and save the lives of people with immune imbalances. There is an urgent need to seek and develop innovative treatments to successfully interact with the microbiota and the human immune system in the coronavirus crisis. In the near future, photobiomics and metabolomics should be applied innovatively in the SARS-CoV-2 crisis (to study and design new therapies for COVID-19 immediately), to discover how bacteria can help us through adequate energy biostimulation to combat this pandemic, so that we can find the key to the hidden code of communication between RNA viruses, bacteria, and our body.

Synergistic Therapeutic Effects of Probiotic Lactobacillus casei TD-2 Consumption on GM-CSF-Induced Immune Responses in a Murine Model of Cervical Cancer

We perceive the potential of combined immunotherapy for the synergistic treatment of human papillomavirus (HPV)-associated tumors. So, the tumor inhibiting effects of combination of L. casei TD2a and GM-CSF on the TC-1 growth were evaluated In Vivo using lymphocyte proliferation, lymphocyte cytotoxicity, splenocyte, and tumor cytokine assays. The results showed that tumor inhibition in transplanted mice in the GM-CSF combined with probiotic L. casei group was significantly higher than that observed in the other groups excluding GM-CSF group whose tumor inhibition effect was considerable. The findings also indicated that the combined group could generate tumor-specific cytolytic and splenocyte proliferative responses. The levels of IFN-γ, IL-4, and IL-12 after treating with GM-CSF combined with probiotic L. casei were significantly higher than those of other groups. The intratumoral Tumor Necrosis Factor Related Apoptosis-Inducing Ligand (TRAIL) was also significantly increased in the combined group. Tumor analysis further showed that the combined group decreased the accumulation of IL-10 in the tumor microenvironment of treated mice. Furthermore, tumor volume analysis demonstrated that combination group and even GM-CSF suppress tumor growth. Our findings showed that the combination of GM-CSF and probiotic results in improved tumor suppression against HPV-associated tumors and stimulates enhancement of specific antitumor immune responses.

Heat-killed Lactobacillus plantarum L-137 attenuates obesity and associated metabolic abnormalities in C57BL/6 J mice on a high-fat diet

Heat-killed Lactobacillus plantarum L-137 (HK L-137) has anti-allergic, antitumor, and antiviral effects in mice, as well as an anti-inflammatory effect in rats with metabolic syndrome through regulation of immunity. To evaluate the influence of HK L-137 on chronic inflammation in mice with diet-induced obesity, C57BL/6 J mice were fed a normal diet (16% of energy as fat) or a high-fat diet (62% of energy as fat) with or without 0.002% HK L-137 for 4 to 20 weeks. It was found that HK L-137 supplementation alleviated weight gain and elevation of plasma glucose, cholesterol, alanine aminotransferase, and aspartate transaminase levels in mice with diet-induced obesity. Expression of several inflammation-related genes, including F4/80, CD11c, and IL-1β, in the epididymal adipose tissue of these mice was significantly downregulated by HK L-137. In addition, plasma levels of lipopolysaccharide-binding protein, a marker of endotoxemia, tended to be decreased by administration of HK L-137. These findings suggest that HK L-137 supplementation ameliorates obesity-induced metabolic abnormalities and adipose tissue inflammation, possibly through improvement of intestinal permeability.

Antimicrobial Efficacy of Five Probiotic Strains Against Helicobacter pylori

Treatment of Helicobacter pylori (H. pylori) infection is a challenge for clinicians. The large increase in drug-resistant strains makes the formulation of new therapeutic strategies fundamental. The frequent onset of side effects during antibiotic treatment (mainly due to intestinal dysbiosis) should not be underestimated as it may cause the interruption of treatment, failure of H. pylori eradication and clonal selection of resistant bacteria. Probiotic integration during antibiotic treatment can exert a dual function: a direct antagonistic effect on H. pylori and a balancing effect on dysbiosis. Therefore, it fulfills the definition of a new therapeutic strategy to successfully treat H. pylori infection. Data reported in literature give promising but discrepant results. Aim: To assess in vitro bacteriostatic and bactericidal activity of probiotic strains against H. pylori. Materials and methods: L. casei, L. paracasei, L. acidophilus, B. lactis and S. thermophilus strains were used. Agar well diffusion and time-kill curves were carried out to detect bacteriostatic and bactericidal activity, respectively. Results: All probiotic strains showed both bacteriostatic and bactericidal activity vs. H. pylori. Conclusions: Such findings prompted us to plan a protocol of treatment in which probiotics are given to infected patients in association with antibiotic therapy.

Heat-killed Mycobacterium paragordonae therapy exerts an anti-cancer immune response via enhanced immune cell mediated oncolytic activity in xenograft mice model

A therapeutic strategy capable of skewing toward a Th1-type immune response is crucial for cancer treatment. Recently, we reported Mycobacterium paragordonae (Mpg) as a potential live vaccine for mycobacterium infections. In this study, we explored the immunotherapeutic potential of heat-killed Mpg (HK-Mpg) in a mouse tumor xenograft model and elucidated its underlying antitumor mechanisms. MC38 cells derived from murine colon adenocarcinoma were implanted by subcutaneously injecting mice. The anticancer effects of HK-Mpg therapy were compared with HK-M. bovis BCG, an effective adjuvant for cancer immunotherapy. HK-Mpg treatment enhanced tumor reduction and mouse survival. Furthermore, HK-Mpg treatment synergistically enhanced the anticancer therapeutic effect of cisplatin. In addition, HK-Mpg enhanced inflammatory cytokine production and recruitment of immune cell into tumor-infiltrating sites and splenocytes in vaccinated mice. Our mechanistic study demonstrates that HK-Mpg therapy elicits a strong antitumor immune response in mice, mainly through natural killer cell-mediated oncolytic activity via the activation of dendritic cells (DCs) and by enhancing inflammatory cytokines production such as IL-12 from DC. Hence, HK-Mpg can be a potential immunotherapy adjuvant, enhancing the effect of cancer chemotherapy.

High dietary vitamin C intake reduces glucocorticoid-induced immunosuppression and measures of oxidative stress in vitamin C-deficient senescence marker protein 30 knockout mice

Vitamin C (VC) is a vital micronutrient for humans and some other mammals and also has antioxidant activity. Stress-induced elevation of glucocorticoid production is well known to cause immunosuppression. The present study evaluated the effect of high VC intake on glucocorticoid-induced immune changes in mice. Senescence marker protein 30 knockout mice with genetic VC deficiency were fed a diet containing the recommended VC content (20 mg/kg per d; 0·02 %VC group) or a high VC content (200 mg/kg per d; 0·2 %VC group) for 2 months, then dexamethasone was given by intraperitoneal injection. After administration of dexamethasone, the plasma ascorbic acid concentration decreased significantly in the 0·02 %VC group and was unchanged in wild-type C57BL/6 mice on a VC-deficient diet (wild-type group), while it was significantly higher in the 0·2 %VC group compared with the other two groups. In the 0·02 %VC and wild-type groups, dexamethasone caused a significant decrease in the cluster of differentiation (CD)4+ and CD8+ T cells among splenocytes as well as a significant decrease in IL-2, IL-12p40 and interferon-γ protein production by splenocytes and a significant decrease in T-cell proliferation among splenocytes. In the 0·2 %VC group, these dexamethasone-induced immunosuppression improved when compared with the other two groups. In addition, reduction in the intracellular levels of ascorbic acid, superoxide dismutase and glutathione in splenocytes by dexamethasone as well as elevation in thiobarbituric acid-reactive substances were significantly suppressed in the 0·2 %VC group. These findings suggest that high dietary VC intake reduces glucocorticoid-induced T-cell dysfunction by maintaining intracellular antioxidant activity.

Lactobacillus plantarum L-137 upregulates hyaluronic acid production in epidermal cells and fibroblasts in mice

Heat-killed Lactobacillus plantarum L-137 (HK L-137), an immunobiotic lactic acid bacterium, has been reported to enhance IFN-γ production through induction of IL-12. In this study, we investigated the effects of HK L-137 on skin moisturizing and production of hyaluronic acid (HA), an extracellular matrix associated with the retention of skin moisture. Oral administration of HK L-137 suppressed the loss of water content in the stratum corneum in hairless mice. Treatment of primary epidermal cells with HK L-137 increased HA production. Supernatant from immune cells stimulated by HK L-137, which contained proinflammatory cytokines such as IL-12, TNF-α, and IFN-γ, upregulated HA production and hyaluronan synthase 2 (HAS2) messenger RNA expression by BALB/3T3 fibroblasts via activation of transcription factor nuclear factor κB (NFκB). Although treatment of the supernatant with anti-TNF-α antibody (Ab) alone did not inhibit the HA production, combination of anti-TNF-α Ab with anti-IFN-γ Ab significantly inhibited the HA production. Thus, HK L-137-induced IFN-γ plays a critical role in upregulated HA production in collaboration with TNF-α. HK L-137 may be useful for improvement of skin functions such as moisture retention by inducing HA production.

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

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

Exploratory investigation of the anti-inflammatory effects of RNase A-treated Enterococcus faecalis strain EC-12

We previously reported that the major component of Enterococcus faecalis strain EC-12 (EC-12) inducing production of Interleukin (IL)-12 in mouse/human immune cells was its own RNA. This study aimed to investigate if RNase A-treated EC-12 could also produce IL-10 and to evaluate the possible effects of IL-10 produced by RNase A-treated EC-12. Three experiments were conducted: (1) Assessment of the effect of RNase A-treated EC-12 on transcriptome profiles and biological pathways in human peripheral blood mononuclear cells; (2) Determination of cytokine concentration in its culture supernatants; and (3) Supplementation of RNase A-treated EC-12 (RN) to mice with dextran sodium sulfate-induced colitis. Treatment of EC-12 with RNase A inhibited inflammatory response including the potency to induce IL-12 production, while it did not affect IL-10 production (Experiment 1 and 2). Colitis symptoms were milder in RN than in PBS-supplemented controls (Experiment 3). RNase A-treated EC-12 likely became an anti-inflammatory agent primarily inducing IL-10 production.

Probiotic therapy in Helicobacter pylori infection: a potential strategy against a serious pathogen?

Helicobacter pylori is a highly prevalent human pathogen responsible for chronic inflammation of the gastric tissues, gastroduodenal ulcers, and cancer. The treatment includes a pair of antibiotics with a proton pump inhibitor PPI. Despite the presence of different treatments, the infection rate is still increasing both in developed and developing states. The challenge of treatment failure is greatly due to the resistance of H. pylori to antibiotics and its side effects. Probiotics potential to cure H. pylori infection is well-documented. Probiotics combined with conventional treatment regime appear to have great potential in eradicating H. pylori infection, therefore, provide an excellent alternative approach to manage H. pylori load and its threatening disease outcome. Notably, anti-H. pylori activity of probiotics is strain specific,therefore establishing standard guidelines regarding the dose and formulation of individual strain is inevitable. This review is focused on probiotic's antagonism against H. pylori summarizing their three main potential aspects: their efficiency (i) as an alternative to H. pylori eradication treatment, (ii) as an adjunct to H. pylori eradication treatment and (iii) as a vaccine delivery vehicle.

Anti-inflammatory effects of heat-killed Lactobacillus plantarum L-137 on cardiac and adipose tissue in rats with metabolic syndrome

The effects of heat-killed Lactobacillus plantarum L-137 (HK L-137) on chronic inflammation associated with metabolic disorders have remained unknown. We examined the effects of HK L-137 on cardiac and adipose tissue pathophysiology in DahlS.Z-Lepr^fa/Lepr^fa (DS/obese) rats as a model of metabolic syndrome. DS/obese rats were treated orally with HK L-137 (2 or 75 mg kg⁻¹ day⁻¹) from 9 to 13 weeks of age. HK L-137 attenuated left ventricular (LV) inflammation and fibrosis as well as adipocyte hypertrophy, inflammation, and up-regulation of sterol regulatory element–binding protein–1c (SREBP-1c) gene expression in visceral and subcutaneous adipose tissue, without affecting body weight gain or hypertension. The low dose of HK L-137 also ameliorated LV diastolic dysfunction, the increase in subcutaneous fat mass, and insulin resistance as well as attenuated the down-regulation of Akt phosphorylation in visceral and subcutaneous adipose tissue, and the elevation of the circulating interleukin-6 concentration. Furthermore, the proportion of regulatory T (Treg) cells among CD4⁺ T cells in the spleen was increased by HK L-137. These results suggest that the anti-inflammatory effects of HK L-137 on the heart and adipose tissue are related, at least partly, to suppression of systemic inflammation associated with an increase in splenic Treg cell.

Proteinaceous Secretory Metabolites of Probiotic Human Commensal Enterococcus hirae 20c, E. faecium 12a and L12b as Antiproliferative Agents Against Cancer Cell Lines

Cancer is the second leading cause of death worldwide and its incidence is expected to grow by almost 70% in the coming 2 decades. Recent microbiome studies in cancer mice models have shown that certain commensal bacteria play protective roles against cancer. Thus, the use of commensal microflora having anticancer activities for the treatment of cancer appears to be an attractive alternative therapeutic strategy. Lactic acid bacteria (LAB) form an integral component of commensal microflora in healthy individuals. As the vaginal ecosystem is enriched in LAB genera, we screened the vaginal LAB microflora of healthy women for their anti-proliferative abilities against various human cancer cell lines. The secreted metabolites of three enterococcal strains, Enterococcus hirae 20c, Enterococcus faecium 12a and L12b, out of 92 LAB isolates selectively inhibited the in vitro proliferation of various human cancer cell lines in a dose-dependent manner but had no activity against normal human peripheral blood monocytes. Further, proteinase K-treatment of the cell-free supernatant (CS) of all the three enterococci abrogated their anti-proliferative abilities, thereby showing the proteinaceous nature of the secreted metabolites in the CS. The microscopic examination of the cell lines showed that CS-treatment induced apoptosis-like morphological changes in the cancer cells. Further, the probiotic characters of the strains were studied, which showed that all the three strains had broad spectrum antimicrobial activities against various Gram-positive and Gram-negative pathogens, including Mycobacterium smegmatis. All the strains tolerated the gastric acidity and bile juice treatments, and had strong adhesive abilities to the colonic epithelial cell line HCT-15. Furthermore, none of the strains had any known secreted virulence factors or harbored virulence genes. This preliminary study highlights an important functional role of the commensal probiotic enterococcal strains E. hirae and E. faecium for the first time by demonstrating their anticancer properties that should be further tested in the in vivo mammalian models.

Preventive Effects of Heat-Killed Enterococcus faecalis Strain EC-12 on Mouse Intestinal Tumor Development

Establishing effective methods for preventing colorectal cancer by so-called “functional foods” is important because the global burden of colorectal cancer is increasing. Enterococcus faecalis strain EC-12 (EC-12), which belongs to the family of lactic acid bacteria, has been shown to exert pleiotropic effects, such as anti-allergy and anti-infectious effects, on mammalian cells. In the present study, we aimed to evaluate the preventive effects of heat-killed EC-12 on intestinal carcinogenesis. We fed 5-week-old male and female Apc mutant Min mice diets containing 50 or 100 ppm heat-killed EC-12 for 8 weeks. In the 50 ppm treated group, there was 4.3% decrease in the number of polyps in males vs. 30.9% in females, and significant reduction was only achieved in the proximal small intestine of female mice. A similar reduction was observed in the 100 ppm treated group. Moreover, heat-killed EC-12 tended to reduce the levels of c-Myc and cyclin D1 mRNA expression in intestinal polyps. Next, we confirmed that heat-killed EC-12 suppressed the transcriptional activity of the T-cell factor/lymphoid enhancer factor, a transcriptional factor involved in cyclin D1 mRNA expression in intestinal polyps. Our results suggest that heat-killed EC-12 very weakly suppresses intestinal polyp development in Min mice, in part by attenuating β-catenin signaling, and this implies that heat-killed EC-12 could be used as a “functional food”.

Capacity of lactic acid bacteria in immunity enhancement and cancer prevention

Lactic acid bacteria are associated with the human gastrointestinal tract. They are important for maintaining the balance of microflora in the human gut. An increasing number of published research reports in recent years have denoted the importance of producing interferon-gamma and IgA for treatment of disease. These agents can enhance the specific and nonspecific immune systems that are dependent on specific bacterial strains. The mechanisms of these effects were revealed in this investigation, where the cell walls of these bacteria were modulated by the cytokine pathways, while the whole bacterial cell mediated the host cell immune system and regulated the production of tumor necrosis factors and interleukins. A supplement of highly active lactic acid bacteria strains provided significant potential to enhance host's immunity, offering prevention from many diseases including some cancers. This review summarizes the current understanding of the function of lactic acid bacteria immunity enhancement and cancer prevention.

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

Background

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

Objectives

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

Materials and Methods

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

Results

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

Conclusions

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

Immunomodulatory effects of Lactobacillus strains: emphasis on their effects on cancer cells

Lactobacilli are a group of normal microbiota whose immunomodulatory effects have been known for a long time. Recently, they have gained more attention for their direct and indirect effects on cancer cells. Several cell line experiments, animal model studies as well as clinical trials have indicated their inhibitory effects on cancer initiation and progression. Different lactobacilli strains could modulate innate and adoptive immune system. Such effects have been documented in modulation of function of T cells, dendritic cells and macrophages as well as cytokine production. In this review, the various immunomodulatory effects of lactobacilli on tumor cells as well as their direct cytotoxic effects on cancer cells are discussed.

Purification of a dimeric arginine deiminase from Enterococcus faecium GR7 and study of its anti-cancerous activity

The arginine deiminase (ADI, E.C 3.5.3.6) - a key enzyme of ADI pathway of Enterococcus faecium GR7 was purified to homogeneity. A sequential purification strategy involving ammonium sulfate fractionation, molecular sieve followed by Sephadex G-100 gel filtration was applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified with a fold of 16.92 and showed a final specific activity of 76.65IU/mg with a 49.17% yield. The dimeric ADI has a molecular mass of about 94,364.929Da, and comprises of hetrodimers of 49.1kDa and 46.5kDa as determined by MALDI-TOF and PAGE analysis. To assess anti-cancerous activity of ADI by MTT assay was carried out against cancer cell lines (MCF-7, Sp2/0-Ag14 and Hep-G2). Purified ADI exhibited the most profound antiproliferative activity against Hep-G2 cells; with half-maximal inhibitory concentration (IC50) of 1.95μg/ml. Purified ADI from E. faecium GR7 was observed to induce apoptosis in the Hep-G2 cells by DNA fragmentation assay. Our findings suggest the possibility of a future use of ADI from E. faecium GR7 as a potential anticancer drug.

RNA of Enterococcus faecalis Strain EC-12 Is a Major Component Inducing Interleukin-12 Production from Human Monocytic Cells

Interleukin-12 (IL-12) is an important cytokine for the immunomodulatory effects of lactic acid bacteria (LAB). Using murine immune cells, we previously reported that the RNA of Enterococcus faecalis EC-12, a LAB strain exerting probiotic-like beneficial effects, is the major IL-12-inducing immunogenic component. However, it was recently revealed that bacterial RNA can be a ligand for Toll-like receptor (TLR) 13, which is only expressed in mice. Because TLR13 is not expressed in humans, the immuno-stimulatory and -modulatory effects of LAB RNA in human cells should be augmented excluding TLR13 contribution. In experiment 1 of this study, the role of LAB RNA in IL-12 induction in human immune cells was studied using three LAB strains, E.faecalis EC-12, Lactobacillus gasseri JCM5344, and Bifidobacterium breve JCM1192. RNase A treatment of heat-killed LAB significantly decreased the IL-12 production of human peripheral blood mononuclear cells on stimulation, while RNase III treatment revealed virtually no effects. Further, IL-12 production against heat-killed E. faecalis EC-12 was abolished by depleting monocytes. These results demonstrated that single stranded RNA (ssRNA) of LAB is a strong inducer of IL-12 production from human monocytes. In experiment 2, major receptor for ssRNA of E. faecalis EC-12 was identified using THP-1 cells, a human monocytic cell line. The type of RNA molecules of E. faecalis EC-12 responsible for IL-12 induction was also identified. IL-12 production induced by the total RNA of E. faecalis EC-12 was significantly reduced by the treatment of siRNA for TLR8 but not for TLR7. Furthermore, both 23S and 16S rRNA, but not mRNA, of E. faecalis EC-12 markedly induced IL-12 production from THP-1 cells. These results suggested that the recognition of ssRNA of E. faecalis EC-12 was mediated by TLR8 and that rRNA was the RNA molecule that exhibited IL-12-inducing ability in human cells.

Scavenger receptor for lipoteichoic acid is involved in the potent ability of Lactobacillus plantarum strain L-137 to stimulate production of interleukin-12p40

Heat-killed Lactobacillus plantarum strain L-137 (HK L-137) is a more potent inducer of interleukin (IL)-12 than other heat-killed Lactobacillus strains. To elucidate the mechanism involved in this IL-12p40 induction, we compared HK L-137 with heat-killed L. plantarum strain JCM1149 (HK JCM1149) by nuclear magnetic resonance and mass spectrometry. Results showed that HK L-137 contained lipoteichoic acid (LTA) with a chemical structure similar to that of JCM1149, except for a lower degree of glucosyl substitution in the poly(glycerol phosphate) backbone. Lysozyme sensitivity and electrophoretic moiety analysis revealed that HK L-137 exposed more LTA on its cell surface than HK JCM1149. Phagocytosis of HK L-137 by splenic adherent cells was significantly greater than that of HK JCM1149. Anti-LTA antibody and anti-scavenger receptor-A (SR-A) antibody selectively inhibited phagocytosis of HK L-137, as well as IL-12p40 production, by splenic adherent cells. Thus, a higher efficiency of phagocytosis of HK L-137 via SR-A for LTA is responsible for the potent IL-12p40 induction.

Oral intake of heat-killed Lactobacillus plantarum L-137 decreases the incidence of upper respiratory tract infection in healthy subjects with high levels of psychological stress

The immunomodulatory effects of live or non-viable lactic acid bacteria have been extensively investigated. We reported that oral intake of heat-killed Lactobacillus plantarum L-137 (HK L-137) augmented innate and acquired immunity in mice and human subjects. To examine the effects of HK L-137 intake on upper respiratory tract infection (URTI) symptoms and immune functions in human subjects, a randomised, double-blind, placebo-controlled, parallel study was conducted in subjects with high psychological stress levels. A total of seventy-eight healthy subjects (thirty-three men and forty-five women; mean age 50·6 years) with scores of >41 on eighteen-item subscales of psychological distress in the Brief Job Stress Questionnaire were randomly assigned to receive a tablet containing HK L-137 (10 mg) or a placebo tablet daily for 12 weeks. The URTI symptoms were rated once daily on the validated twenty-one-item Wisconsin Upper Respiratory Symptom Survey-21. Immune functions, such as concanavalin A-induced proliferation and percentages of interferon (IFN)-γ- and IL-4-producing CD4 T cells of peripheral blood mononuclear cells (PBMC), and serum IFN-β concentrations were measured every 4 weeks. URTI incidence was significantly lower in the HK L-137 group than in the control group. URTI incidence, duration and severity, and duration of medication showed significant negative correlations with duration of HK L-137 intake. The percentage change from baseline of concanavalin A-induced proliferation of PBMC was significantly greater in the HK L-137 group than in the control group. These findings suggest that daily HK L-137 intake can decrease URTI incidence in healthy subjects, possibly through augmentation of immune functions.

Long-Term Use of Probiotic-Containing Yogurts Is a Safe Way to Prevent Helicobacter pylori: Based on a Mongolian Gerbil's Model

Background. The suppression of Helicobacter pylori (H. pylori) decreases H. pylori-related diseases. The probiotics have an inhibitory effect on H. pylori. Aim. We investigated the effects of long-term use of yogurt on H. pylori based on Mongolian gerbils' model. Materials and Methods. Yogurt (containing a supplement of Lactobacillus acidophilus, Bifidobacterium lactis, etc.) was used. Forty-six gerbils were divided into five groups. All groups were inoculated with H. pylori for 5 to 8 weeks. The yogurt was given as follows: Group (Gr.) A: from 1st to 4th week; Gr. B from 5th to 8th week; Gr. C: from 17th week to sacrifice; Gr. D: from 5th week to sacrifice. Gerbils were sacrificed on the 52nd week. Histology was evaluated according to the Sydney system. Results. The positive rates of H. pylori were 60% (Gr. A), 75% (Gr. B), 67% (Gr. C), 44% (Gr. D), and 100% (Gr. E). Gr. D showed lower inflammatory score. Only Gr. E (60%) had intestinal metaplasia. Gr. D showed higher IL-10 and lower TNF-α expression than Gr. E. Conclusion. Long-term intake of yogurt could decrease H. pylori infection. The long-term use of yogurt would be an alternative strategy to manage H. pylori infection.

Clinical application of probiotics in the treatment of Helicobacter pylori infection--a brief review

The role of probiotics in the treatment of gastrointestinal infections is increasingly being documented as an alternative or complement to antibiotics, with the potential to decrease the use of antibiotics or reduce their side effects. Although antibiotics-based Helicobacter pylori eradication treatment is 90% effective, it is expensive and causes antibiotic resistance associated with other adverse effects. Probiotics have an in vitro inhibitory effect on H. pylori. Animal studies demonstrated that probiotic treatment is effective in reducing H. pylori-associated gastric inflammation. About 12 human studies investigated the efficacy of combinations of antibiotics and probiotics, whereas 16 studies used probiotic alone as an alternative to antibiotics for the treatment of H. pylori infection. Most of the studies showed an improvement of H. pylori gastritis and decrease in H. pylori colonization after administration of probiotics. However, no study could demonstrate complete eradication of H. pylori infection by probiotic treatment. Probiotic combinations can reduce adverse effects induced by H. pylori eradication treatment and, thus, have beneficial effects in H. pylori-infected individuals. Long-term intakes of products containing probiotic strains may have a favorable effect on H. pylori infection in humans, particularly by reducing the risk of developing disorders associated with high degrees of gastric inflammation.

Palliative treatment of advanced cervical cancer with radiotherapy and thai herbal medicine as supportive remedy - analysis of survival

BACKGROUND

To evaluate outcomes using a Thai herbal medicine, Vilac Plus (G716/45) with standard radiotherapy in comparison with historic controls from literature reports of the results of treatment in stage IIIB cervical cancer.

MATERIALS AND METHODS

Between March 2003 and June 2005, thirty patients with advanced cervical cancer stage IIIB-IV who had a poor performance status were treated by palliative radiotherapy along with an adjuvant daily dose of 15-30 ml of Thai herbal tonic solution (Vilac Plus G716/45) administered orally three times after meals as an additional supportive therapy. The results were analyzed from the aspect of the overall survival rates with curves estimated by the Kaplan-Meier method.

RESULTS

The median follow -up time for stage IIIB was 4.2 years with a range of 7.9 months - 6.1 years. The overall 1, 3, and 5 year survival rates for stage IIIB were 88%, 60% and 52%.

CONCLUSIONS

The overall 5 year survival rate for stage IIIB with a poor performance status was 52% when compared with 34-54.8% for historic controls. The combined complementary palliative radiotherapy (CCPR) had low rates of radiation morbidity. It was a simple technique and feasible for developing countries. The pilot study was limited by the small number of patients and further research will be necessary to assess interrelated and confounding factors in treatment of cervical cancer patients.

Study of probiotic potential of four wild Lactobacillus rhamnosus strains

The four wild Lactobacillus rhamnosus strains were examined in vitro for resistance to simulated gastro and intestinal juices, adhesion to HT-29 cells, antagonistic activity against enteric pathogens and immunomodulating activity. The strains L. rhamnosus SB5L, J5L and IN1L were able to survive in simulated gastro juice while the strain L. rhamnosus SB31L lost viability exposed to simulated gastro juice for 3 h. The four strains had high viability in simulated small intestinal juice with little loss (<1.0 cycle reduction). The strains SB5L, J5L and IN1L antagonized against Escherichia coli ATCC 25922, Salmonella enterica serovar Typhimurium ATCC 14028, Shigella sonnei ATCC 25931. The strain L. rhamnosus IN1L had the highest adhesive capability to HT-29 cells in vitro (251 bacteria cells per 100 HT-29 cells) compared to the other three L. rhamnosus strains. The live bacteria, cell wall and DNA of the four L. rhamnosus induced the secretion of pro-inflammatory cytokines IL-12 (p70), IFN-γ and TNF-α by human peripheral blood mononuclear cells (PBMCs). The levels of IL-12 (p70), IFN-γ and TNF-α produced by stimulated PBMCs were significantly higher (P < 0.05) than those of the control. Those data indicated that the four L. rhamnosus strains have the potential as the probiotic for human being use, although further studies are still needed.

Lactobacillus acidophilus could modulate the immune response against breast cancer in murine model

Cancer immune-therapy is an interesting avenue of studying the effects of deviating immune system responses to achieve the desired result. Lactobacilli are inhabitants of the GI tract which have shown beneficial health effects on various ailments including malignancies. Their mechanisms of action comprise a very intense area of research. In this study we evaluated the immunomodulatory effects of Lactobacillus acidophilus in in vivo model of breast cancer. Lactobacillus acidophilus (L.a) was isolated from traditional home-made yogurt and also from neonatal stool by aerobic overnight culture at 37°C in MRS broth. Delayed Type Hypersensitivity (DTH) assay was performed to find the best immunostimulant dose. 4T1 tumour bearing mice were treated with 2 × 10(8) cfu of isolated L. acidophilus and 20 mg/kg Cyclophosphamide for 15 consecutive days. Tumour volume was measured using a digital vernier calliper. Lymphocyte proliferation was done using MTT proliferation assay. Production of IFNγ, IL-4 and TGF-β from cultured Splenocytes was assessed in the presence of purified tumour antigen. According to results administration of L.a induced a significant decrease in tumour growth pattern (P value = 0.00). Significant alterations in splenocyte production of IFN-γ, IL-4 and TGf-β (P values < 0.05) and also lymphocyte proliferation in L.a treated animals was evident (P value < 0.05). This study indicated that oral administration of L.a is able to alter the cytokine production in tumour bearing mice into a Th1 protective pattern, favourable to anti tumour immunity. Reduced tumour growth rate and increased lymphocyte proliferation are also thus supportive. Further studies are required to elucidate the exact mechanism by which local actions of probiotics affect the systemic immune responses against transformed cells.

Daily intake of heat-killed Lactobacillus plantarum L-137 enhances type I interferon production in healthy humans and pigs

We have previously reported that oral administration of heat-killed Lactobacillus plantarum L-137 (HK L-137) stimulates innate immunity for production of type I interferon (IFN) which subsequently augments host defense against influenza A virus infection in mice. We here examined the effect of HK L-137 intake on type I IFN in humans. Sixteen subjects were randomly assigned to receive a tablet containing 10 mg of HK L-137 or a matching tablet for 8 weeks and the serum levels of type I IFN were examined before and after the first or second dose of the trivalent inactivated influenza vaccine. There were no differences in the seroresponse rate, the seroprotection rate and the geometric mean Ab titers after either the first or second dose of vaccine between the HK L-137 group and the control group. On the other hand, the levels of IFN-β were significantly higher in the HK L-137 group than in the control group before vaccination although the vaccination conferred little additional induction of IFN-β. We further examined IFN-β gene expression in the whole blood cells of pigs fed on a diet containing HK L-137 and found that the IFN-β mRNA levels were significantly higher in the HK L-137 group than in the control group. The finding that daily intake of HK L-137 enhances type I IFN production and host defense against influenza A virus infection in mice may be applied to at least two additional species.

Immunomodulatory and antioxidant potential of Lactobacillus exopolysaccharides

BACKGROUND

Immunomodulation by probiotic microorganisms has become a topic of increasing interest in food microbiology. Polysaccharides are broadly used in the food industry as gelling, thickening, stabilizing, or emulsifying agents. Some probiotics such as lactic acid bacteria also produce exopolysaccharides that stimulate macrophage production of cytokines. The aim of this study was to characterize the effects of exopolysaccharides of Lactobacillus paracasei subsp. paracasei NTU 101 (101EP) and Lactobacillus plantarum NTU 102 (102EP) exopolysaccharides on antioxidant activity and immunomodulation in vitro.

RESULTS

The sugar composition (including arabinose, galactose, glucose, fructose, mannose, and maltose) of 101EP and 102EP was quantified by high-performance anion-exchange chromatography. Cytokine production (including IL-6, TNF-α, and IL-1β) was induced by 101EP and 102EP in Raw 264.7 in a dose-dependent manner (5-500 µg mL(-1) ). 101EP and 102EP also demonstrated potential antioxidant properties (1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, chelation of ferrous ions, inhibition of linoleic acid peroxidation, and reducing power) in vitro.

CONCLUSION

101EP and 102EP stimulate cell proliferation and may be useful as a mild immune modulator of macrophages.

Cancer-preventing attributes of probiotics: an update

Cancer is a serious global public health problem. Cancer incidence and mortality have been steadily rising throughout the past century in most places of the world. There are several epidemiological evidences that support a protective role of probiotics against cancer. Lactic acid bacteria and their probioactive cellular substances exert many beneficial effects in the gastrointestinal tract, and also release various enzymes into the intestinal lumen and exert potential synergistic (LAB) effects on digestion and alleviate symptoms of intestinal malabsorption. Consumption of fermented dairy products with LAB may elicit anti-tumor effects. These effects are attributed to the inhibition of mutagenic activity, the decrease in several enzymes implicated in the generation of carcinogens, mutagens, or tumor-promoting agents, suppression of tumors, and epidemiology correlating dietary regimes and cancer. Specific cellular components in lactic acid bacteria seem to induce strong adjuvant effects including modulation of cell-mediated immune responses, activation of the reticulo-endothelial system, augmentation of cytokine pathways, and regulation of interleukins and tumor necrosis factors. Studies on the effect of probiotic consumption on cancer appear promising, since recent in vitro and in vivo studies have indicated that probiotic bacteria might reduce the risk, incidence and number of tumors of the colon, liver and bladder. The protective effect against cancer development may be ascribed to binding of mutagens by intestinal bacteria, may suppress the growth of bacteria that convert procarcinogens into carcinogens, thereby reducing the amount of carcinogens in the intestine, reduction of the enzymes beta-glucuronidase and beta-glucosidase and deconjugation of bile acids, or merely by enhancing the immune system of the host. There are isolated reports citing that administration of LAB results in increased activity of anti-oxidative enzymes or by modulating circulatory oxidative stress that protects cells against carcinogen-induced damage. These include glutathione-S-transferase, glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. However, there is no direct experimental evidence for cancer suppression in human subjects as a result of the consumption of probiotic cultures in fermented or unfermented dairy products, but there is a wealth of indirect evidence based largely on laboratory studies.