Selecting lactic acid bacteria for their safety and functionality by use of a mouse colitis model

Dietary Supplementation of Haskap Berry (Lonicera caerulea L.) Anthocyanins and Probiotics Attenuate Dextran Sulfate Sodium-Induced Colitis: Evidence from an Experimental Animal Model

Haskap berry (Lonicera caerulea L.) is a rich dietary source of anthocyanins with potent anti-inflammatory properties. In this study, isolated haskap berry anthocyanins were encapsulated in maltodextrin and inulin (3:1) by freeze-drying to improve stability and bioavailability. The structural properties of microcapsules, encapsulation yield, efficiency, recovery, and powder retention were evaluated. The microcapsules that exhibited the highest encapsulation efficiency (60%) and anthocyanin recovery (89%) were used in the dextran sulfate sodium (DSS)-induced acute colitis in mice. Thirty-five BALB/c male mice of seven weeks old were divided into seven dietary supplementation groups (n = 5) to receive either free anthocyanins, encapsulated anthocyanins (6.2 mg/day), or probiotics (1 × 109 CFU/day) alone or as combinations of anthocyanin and probiotics. As observed by clinical data, free anthocyanin and probiotic supplementation significantly reduced the severity of colitis. The supplementary diets suppressed the DSS-induced elevation of serum inflammatory (interleukin (IL)-6 and tumor necrosis factor) and apoptosis markers (B-cell lymphoma 2 and Bcl-2-associated X protein) in mice colon tissues. The free anthocyanins and probiotics significantly reduced the serum IL-6 levels. In conclusion, the dietary supplementation of haskap berry anthocyanins and probiotics protects against DSS-induced colitis possibly by attenuating mucosal inflammation, and this combination has the potential as a health-promoting dietary supplement and nutraceutical.

Effect of Lactiplantibacillus plantatum HFY11 on Colitis in Mice

This study aimed to examine the potential impact of the intervention of Lactiplantibacillus plantatum HFY11 (LP-HFY11) on colitis using in vivo animal trials. The impact of LP-HFY11 intervention on colitis was determined by measuring the levels of relevant indicators in the intestine, colon, and blood after oxazolone-induced colitis in BALB/c mice. The results of the trial show that LP-HFY11 improved the colon weight-to-length ratio, reduced the colitis-induced colon length shortening, and reduced colonic abstinence. Furthermore, it decreased the levels of myeloperoxidase, nitric oxide, and malondialdehyde activities while increasing the glutathione content in the colon tissue of colitis-affected animals. LP-HFY11 lowered the interleukin-10 (IL-10) level and increased the IL-2 level in the serum of colitis mice. LP-HFY11 also upregulated the expression of neuronal nitric oxide synthase, endothelial nitric oxide synthase, c-Kit, and stem cell factor (SCF), and downregulated the expression of IL-8, C-X-C chemokine receptor type 2 (CXCR2), and inducible nitric oxide synthase (iNOS) in the colon tissue of mice with colitis. LP-HFY11 decreased the expression of Firmicutes in the gut while increasing the expression of Bacteroidetes, Bifidobacteria, and Lactobacillus. This indicates that LP-HFY11 could control physiological alterations in the serum and colon tissue, as well as the expression of gut microorganism.

Lactobacillus acidophilus NCFM and Lactiplantibacillus plantarum Lp-115 inhibit Helicobacter pylori colonization and gastric inflammation in a murine model

Purpose

To determine the role of Lactobacillus strains and their combinations in inhibiting the colonization of H. pylori and gastric mucosa inflammation.

Methods

Human gastric adenocarcinoma AGS cells were incubated with H. pylori and six probiotic strains (Lactobacillus acidophilus NCFM, L. acidophilus La-14, Lactiplantibacillus plantarum Lp-115, Lacticaseibacillus paracasei Lpc-37, Lacticaseibacillus rhamnosus Lr-32, and L. rhamnosus GG) and the adhesion ability of H. pylori in different combinations was evaluated by fluorescence microscopy and urease activity assay. Male C57BL/6 mice were randomly divided into five groups (uninfected, H. pylori, H. pylori+NCFM, H. pylori+Lp-115, and H. pylori+NCFM+Lp-115) and treated with two lactobacilli strains (NCFM and Lp-115) for six weeks. H. pylori colonization and tissue inflammation statuses were determined by rapid urease test, Hematoxylin-Eosin (HE) staining, immunohistochemistry, and qRT-PCR and ELISA.

Results

L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, L. paracasei Lpc-37, L. rhamnosus Lr-32, and L. rhamnosus GG reduced H. pylori adhesion and inflammation caused by H. pylori infection in AGS cells and mice. Among all probiotics L. acidophilus NCFM and L. plantarum, Lp-115 showed significant effects on the H. pylori eradication and reduction of inflammation in-vitro and in-vivo. Compared with the H. pylori infection group, the mRNA and protein expression levels of IL-8 and TNF-α in the six Lactobacillus intervention groups were significantly reduced. The changes in the urease activity (ureA and ureB) for 1-7h in each group showed that L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, and L. rhamnosus GG effectively reduced the colonization of H. pylori. We observed a higher ratio of lymphocyte and plasma cell infiltration into the lamina propria of the gastric mucosa and neutrophil infiltration in H. pylori+NCFM+Lp-115 mice. The infiltration of inflammatory cells in lamina propria of the gastric mucosa was reduced in the H. pylori+NCFM+Lp-115 group. Additionally, the expression of IFN-γ was decreased significantly in the NCFM and Lp-115 treated C57BL/6 mice.

Conclusions

L. acidophilus NCFM and L. plantarum Lp-115 can reduce the adhesion of H. pylori and inhibit the gastric inflammatory response caused by H. pylori infection.

Strain-specific alterations in gut microbiome and host immune responses elicited by tolerogenic Bifidobacterium pseudolongum

The beneficial effects attributed to Bifidobacterium are largely attributed to their immunomodulatory capabilities, which are likely to be species- and even strain-specific. However, their strain-specificity in direct and indirect immune modulation remain largely uncharacterized. We have shown that B. pseudolongum UMB-MBP-01, a murine isolate strain, is capable of suppressing inflammation and reducing fibrosis in vivo. To ascertain the mechanism driving this activity and to determine if it is specific to UMB-MBP-01, we compared it to a porcine tropic strain B. pseudolongum ATCC25526 using a combination of cell culture and in vivo experimentation and comparative genomics approaches. Despite many shared features, we demonstrate that these two strains possess distinct genetic repertoires in carbohydrate assimilation, differential activation signatures and cytokine responses signatures in innate immune cells, and differential effects on lymph node morphology with unique local and systemic leukocyte distribution. Importantly, the administration of each B. pseudolongum strain resulted in major divergence in the structure, composition, and function of gut microbiota. This was accompanied by markedly different changes in intestinal transcriptional activities, suggesting strain-specific modulation of the endogenous gut microbiota as a key to immune modulatory host responses. Our study demonstrated a single probiotic strain can influence local, regional, and systemic immunity through both innate and adaptive pathways in a strain-specific manner. It highlights the importance to investigate both the endogenous gut microbiome and the intestinal responses in response to probiotic supplementation, which underpins the mechanisms through which the probiotic strains drive the strain-specific effect to impact health outcomes.

Lactobacillus rhamnosus sepsis, endocarditis and septic emboli in a patient with ulcerative colitis taking probiotics

A man in his 60s presented to the emergency room with fever and fatigue after a 2.5-month course of corticosteroids. His medical history was significant for bioprosthetic aortic valve replacement and moderately severe ulcerative colitis treated with balsalazide and daily lactobacillus-containing probiotics. Initial investigations revealed Lactobacillus rhamnosus bacteraemia without complication. Four days after hospital discharge, the patient experienced acute-onset right-sided paraesthesia and lower-limb paresis. On return to the emergency room, MRI of the brain demonstrated innumerable ring-enhancing lesions with haemorrhagic transformation. Transoesophageal echocardiogram revealed a small mobile density on the bioprosthetic aortic valve, raising the suspicion for L. rhamnosus infective endocarditis with secondary septic emboli to the brain. The patient was subsequently treated with intravenous gentamycin and ampicillin, with transition to indefinite oral amoxicillin suppressive therapy. The current case highlights the potential risk of lactobacilli translocation in an immunosuppressed patient with ulcerative colitis taking probiotics.

Whole genome sequencing for the risk assessment of probiotic lactic acid bacteria

Probiotic bacteria exhibit beneficial effects on human and/or animal health, and have been widely used in foods and fermented products for decades. Most probiotics consist of lactic acid bacteria (LAB), which are used in the production of various food products but have also been shown to have the ability to prevent certain diseases. With the expansion of applications for probiotic LAB, there is an increasing concern with regard to safety, as cases with adverse effects, i.e., severe infections, transfer of antimicrobial resistance genes, etc., can occur. Currently, in vitro assays remain the primary way to assess the properties of LAB. However, such methodologies are not meeting the needs of strain risk assessment on a high-throughput scale, in the context of the evolving concept of food safety. Analyzing the complete genetic information, including potential virulence genes and other determinants with a negative impact on health, allows for assessing the safe use of the product, for which whole-genome sequencing (WGS) of individual LAB strains can be employed. Genomic data can also be used to understand subtle differences in the strain level important for beneficial effects, or protect patents. Here, we propose that WGS-based bioinformatics analyses are an ideal and cost-effective approach for the initial in silico microbial risk evaluation, while the technique may also increase our understanding of LAB strains for food safety and probiotic property evaluation.

Lactiplantibacillus plantarum E51 protects against Clostridioides difficile-induced damages on Caco-2 intestinal barrier functions

Clostridioides difficile (C. difficile) infection is associated with high morbidity and mortality. This study aimed to evaluate the protective effect of Lactiplantibacillus plantarum E51 (L. plantarum E51) on C. difficile infection using the Caco-2 monolayer in vitro model. Caco-2 cells were infected with C. difficile in the presence/absence of L. plantarum E51 or Lacticaseibacillus rhamnosus GG (LGG). Caco-2 intestinal barrier functions, such as monolayer integrity, IL-8 secretion, and tight junction protein expression, were quantified to investigate the extent to which L. plantarum E51 protected against C. difficile infection in vitro. Furthermore, inhibition of C. difficile adhesion to Caco-2 cells by L. plantarum E51 was explored using competition, exclusion, and displacement assays. The results indicated that L. plantarum E51 inhibited C. difficile growth, ameliorated C. difficile-caused decrease in transepithelial/ transendothelial electrical resistance, attenuated C. difficile-induced IL8 secretion, and upregulated claudin-1 protein expression that was inhibited by C. difficile. Moreover, L. plantarum E51 suppressed C. difficile adhesion to Caco-2 cells. In conclusion, these findings demonstrated that L. plantarum E51 substantially protected against C. difficile-induced damages on intestinal barrier functions in Caco-2 cells. The probiotic potential of L. plantarum E51 against C. difficile infection warrants further investigation.

Incidence of virulence determinants and antibiotic resistance in lactic acid bacteria isolated from food products

Background: Lactic acid bacteria (LAB) confer beneficial health effects in humans. However, the safety of these bacteria and their potential to spread resistance in the environment must be evaluated. Materials & methods: Fifty-three LAB were isolated from different food samples and assessed for the prevalence of virulence determinants and antibiotic resistance profile. Results: Multiple resistance was reported for Lactobacillus brevis MIM04, having revealed phenotypic resistance to vancomycin (MIC >128 μg/ml), ampicillin, cefotaxime, oxacillin and gentamicin. Virulence traits (cylA, gelE, esp and agg) were detected using specific primers. Enterococcus faecium CHE32, Lactobacillus plantarum CHE37 and E. faecium MLK68 lack virulence genes, possess antimicrobial activity and survive in low pH and bile salt conditions. Conclusion: Isolated LAB revealed probiotic properties.

Ligilactobacillus salivarius functionalities, applications, and manufacturing challenges

Ligilactobacillus salivarius is a lactic acid bacteria that has been gaining attention as a promising probiotic. Numerous strains exhibit functional properties with health benefits such as antimicrobial activity, immunological effects, and the ability to modulate the intestinal microbiota. However, just a small number of them are manufactured at an industrial scale and included in commercial products. The under exploitation of L. salivarius strains that remain in the freezer of companies is due to their incapacity to overcome the environmental stresses induced by production and stabilization processes.The present study summarizes the functionalities and applications of L. salivarius reported to date. It aims also at providing a critical evaluation of the literature available on the manufacturing steps of L. salivarius concentrates, the bacterial quality after each step of the process, and the putative degradation and preservation mechanisms. Here, we highlight the principal issues and future research challenges for improving the production and long-term preservation at the industrial scale of this microorganism, and probably of other probiotics.Key points• L. salivarius beneficial properties and commercialized products.• Production conditions and viability of L. salivarius after stabilization processes.• Prospects for identifying preservation mechanisms to improve L. salivarius stability.

Microbiota Targeted Interventions of Probiotic Lactobacillus as an Anti-Ageing Approach: A Review

With the implementation of modern scientific protocols, the average human lifespan has significantly improved, but age-related problems remain a challenge. With the advent of ageing, there are alterations in gut microbiota and gut barrier functions, weak immune responses, increased oxidative stress, and other age-related disorders. This review has highlighted and discussed the current understanding on the significance of gut microbiota dysbiosis and ageing and its inherent effects against age-related oxidative stress as well as on the gut health and gut-brain axis. Further, we have discussed the key mechanism of action of Lactobacillus strains in the longevity of life, alleviating gut dysbiosis, and improving oxidative stress and inflammation to provide an outline of the role of Lactobacillus strains in restoration of gut microbiota dysbiosis and alleviating certain conditions during ageing. Microbiota-targeted interventions of some characterized strains of probiotic Lactobacillus for the restoration of gut microbial community are considered as a potential approach to improve several neurological conditions. However, very limited human studies are available on this alarmed issue and recommend further studies to identify the unique Lactobacillus strains with potential anti-ageing properties and to discover its novel core microbiome-association, which will help to increase the therapeutic potential of probiotic Lactobacillus strains to ageing.

Factors that influence clinical efficacy of live biotherapeutic products

Traditional probiotics are increasingly being used in a medical context. The use of these products as drugs is considerably different from the traditional use as food or food supplements, as, obviously, the target population is different (diseased versus healthy or at risk population). Besides the target population, also the regulatory context is different, mainly with respect to production, administration regime and type of clinical studies required. In this paper we will, besides the regulatory differences, focus on aspects that may impact the efficacy of a live biotherapeutic product (drug), especially in a clinical setting. The impact of the dosage seems to depend on the strain and the application and may follow some rationale. In contrast, information on the impact of the time of administration or diet, is often still lacking. The matrix and the use of protective measures may clearly have an impact on the survival and efficacy of the strain.

Protective effect of Lactobacillus plantarum YS3 on dextran sulfate sodium-induced colitis in C57BL/6J mice

The protective effect of Lactobacillus plantarum YS3 (LP-YS3) on ulcerative colitis (UC) was assessed using a mouse model of dextran sodium sulfate (DSS)-induced colitis. Different concentrations of LP-YS4 were administered to the experimental mice by daily gavage. Several inflammatory and biochemical indices, such as interleukin-2 (IL-2), interleukin-10 (IL-10), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO), were examined in mouse serum and colon tissue. The mRNA and protein expression levels of c-Kit, CXC chemokine receptor type 2 (CXCR2), interleukin-8 (IL-8), and stem cell factor (SCF) in mouse colon tissue were assessed using Western blot and quantitative polymerase chain reaction (qPCR) assays. The findings indicated that LP-YS3 remarkably decreased the disease activity index (DAI) of UC mice (p < .05), inhibited colon length shortening induced by UC, and elevated the value of colon weight/length ratio. LP-YS3 could also markedly reduce (p < .05) the activities of MDA, MPO, and NO; while an increase in the GSH content in the colonic tissue of UC mice. Moreover, LP-YS3 remarkably increased (p < .05) the serum level of IL-2 in UC mice, while reduced those of IL-10, IL-6, IL-1β, TNF-α cytokines. qPCR data revealed that LP-YS3 could markedly upregulate the expression levels of c-Kit and SCF, while downregulate those of CXCR2 and IL-8 in the colonic tissue of UC mice (p < .05). LP-YS3 exerted an outstanding protective effect on DSS-induced colitis in C57BL/6J mice, especially at higher concentrations. PRACTICAL APPLICATIONS: Lactobacillus plantarum YS3 is a newly isolated and identified lactic acid bacteria. This study confirmed that L. plantarum YS3 can inhibit colitis and has good probiotic potential, which needs further development and utilization.

The food-gut axis: lactic acid bacteria and their link to food, the gut microbiome and human health

Lactic acid bacteria (LAB) are present in foods, the environment and the animal gut, although fermented foods (FFs) are recognized as the primary niche of LAB activity. Several LAB strains have been studied for their health-promoting properties and are employed as probiotics. FFs are recognized for their potential beneficial effects, which we review in this article. They are also an important source of LAB, which are ingested daily upon FF consumption. In this review, we describe the diversity of LAB and their occurrence in food as well as the gut microbiome. We discuss the opportunities to study LAB diversity and functional properties by considering the availability of both genomic and metagenomic data in public repositories, as well as the different latest computational tools for data analysis. In addition, we discuss the role of LAB as potential probiotics by reporting the prevalence of key genomic features in public genomes and by surveying the outcomes of LAB use in clinical trials involving human subjects. Finally, we highlight the need for further studies aimed at improving our knowledge of the link between LAB-fermented foods and the human gut from the perspective of health promotion.

Live Biotherapeutic Products, A Road Map for Safety Assessment

Recent developments in the understanding of the relationship between the microbiota and its host have provided evidence regarding the therapeutic potential of selected microorganisms to prevent or treat disease. According to Directive 2001/83/EC, in the European Union (EU), any product intended to prevent or treat disease is defined as a medicinal product and requires a marketing authorization by competent authorities prior to commercialization. Even if the pharmaceutical regulatory framework is harmonized at the EU level, obtaining marketing authorisations for medicinal products remains very challenging for Live Biotherapeutic Products (LBPs). Compared to other medicinal products currently on the market, safety assessment of LBPs represents a real challenge because of their specific characteristics and mode of action. Indeed, LBPs are not intended to reach the systemic circulation targeting distant organs, tissues, or receptors, but rather exert their effect through direct interactions with the complex native microbiota and/or the modulation of complex host-microbiota relation, indirectly leading to distant biological effects within the host. Hence, developers must rely on a thorough risk analysis, and pharmaceutical guidelines for other biological products should be taken into account in order to design relevant non-clinical and clinical development programmes. Here we aim at providing a roadmap for a risk analysis that takes into account the specificities of LBPs. We describe the different risks associated with these products and their interactions with the patient. Then, from that risk assessment, we propose solutions to design non-clinical programmes and First in Human (FIH) early clinical trials appropriate to assess LBP safety.

Assessing the Safety and Efficacy of Lactobacillus plantarum MTCC 5690 and Lactobacillus fermentum MTCC 5689 in Colitis Mouse Model

Probiotic lactobacilli have an unprecedented history of safe use, although some cases of infections have raised concerns about their safety, and hence, a rigorous screening of any new strain even of Lactobacillus is a must in order to study possible adverse interactions with the host, particularly under unhealthy conditions. The present study was, therefore, undertaken to investigate the safety as well as therapeutic efficacy of probiotic Lactobacillus plantarum MTCC 5690 and L. fermentum MTCC 5689 strains in dextran sodium sulfate (DSS)-induced colitis mouse model. Both MTCC 5690 and MTCC 5689 did not induce any detrimental effect on the colitic mice, as was reflected by normal colon and caecum length, blood biochemistry, hematology, and absence of inflammation. Although translocation of both the strains was observed in extraintestinal organs, probiotic-fed mice had significantly improved intestinal permeability and decreased myeloperoxidase (MPO) activity. Probiotic interventions also led to an improved health index and better growth of colitis mice compared to colitis animals with no probiotic intervention. These results point towards the safe use of L. plantarum MTCC 5690 and L. fermentum MTCC 5689 as biotherapeutics for amelioration of inflammatory conditions after establishing their efficacy in human clinical trials.

Gut microbiome interventions in human health and diseases

Ongoing studies have determined that the gut microbiota is a major factor influencing both health and disease. Host genetic factors and environmental factors contribute to differences in gut microbiota composition and function. Intestinal dysbiosis is a cause or a contributory cause for diseases in multiple body systems, ranging from the digestive system to the immune, cardiovascular, respiratory, and even nervous system. Investigation of pathogenesis has identified specific species or strains, bacterial genes, and metabolites that play roles in certain diseases and represent potential drug targets. As research progresses, gut microbiome-based diagnosis and therapy are proposed and applied, which might lead to considerable progress in precision medicine. We further discuss the limitations of current studies and potential solutions.

Persistent infection by Salmonella enterica servovar Typhimurium: are synbiotics a therapeutic option? – a case report

Little is known about the prevalence of persistent human infections by nontyphoidal Salmonella (NTS). Recently published study results indicate that a small fraction (at least 2.2%) of NTS-infected patients continue to shed Salmonella for an extended period of time (up to years). Despite the recommendation not to use antibiotics for the treatment of uncomplicated NTS-Salmonella infection, little treatment guidance is available. Clinical findings from a NTS-patient indicate that administration of synbiotics (probiotic bacteria plus prebiotic) might be considered as a treatment option. We report data of a patient who was treated with a synbiotic preparation containing nine different probiotic bacteria and the prebiotic fructooligosaccharides (FOS). Starting from day one of the treatment, the patient experienced an improvement of symptoms and was symptom-free at the end of a 10 days treatment course. After finishing the treatment, the stool proved to be Salmonella enterica serovar Typhimurium negative. In vitro pathogenic inhibition studies showed the inhibitory effects of the multistrain synbiotic mixture against S. Typhimurium. Growth of S. Typhimurium was also inhibited by individual bacterial strains making part of the composition of the mixture. However, he inhibitory effects of individual strains varied significantly, with those of Streptococcus thermophilus St-21 and Lactobacillus helveticus SP-27 exhibiting the strongest inhibitory effect. Persistent infections by S. Typhimurium are a severe concern for the affected patients. Besides the symptomatic burden, infected persons are banned from work in certain areas (e.g. food related service). In addition, patients with persistent S. Typhimurium infections are a threat for the public health in general, as they serve as a reservoir for NTS transmission. The findings indicate that treatment with a synbiotic preparation might provide a treatment option for persistent S. Typhimurium infections. More clinical data have to be gathered to confirm the relevance of this potential treatment approach.

Evaluation of safety and antifungal activity of Lactobacillus reuteri and Pediococcus diacetilactis isolates against aflatoxigenic Aspergillus flavus

Biocontrol of moulds by lactic acid bacteria (LAB) instead of antibiotics and chemical preservatives is a new approach in veterinary medicine. The aims of present research were to perform molecular identification of dominant sourdough LAB isolates and to evaluate their in vivo safety and in vitro antifungal properties for using as biopreservative agents. Sequencing results of PCR products led to identification of Lactobacillus reuteri and Pediococcus diacetilactis as LAB isolates. Antifungal activity of the isolates and their cell-free culture filtrate (CCF) were also confirmed against aflatoxigenic Aspergillus flavus, respectively by overlay and spore spot methods. Accordingly, antagonistic effect of P. diacetilactis and its CCF were significantly (P<0.05) higher than L. reuteri and CCF of mentioned LAB isolate. Clinical chemistry and haematological findings in mice fed LAB demonstrated also insignificant difference vs control mice and were in the normal range, which confirmed the safety of LAB isolates. By considering the importance of safe, food grade biocontrol agents, L. reuteri and P. diacetilactis isolates and their CCF may be considered as an alternative for antibiotics and other chemical preservatives in food and feed processing chain

Qualification of tropical fruit-derived Lactobacillus plantarum strains as potential probiotics acting on blood glucose and total cholesterol levels in Wistar rats

Tropical fruit and their industrial processing byproducts have been considered sources of probiotic Lactobacillus. Sixteen tropical fruit-derived Lactobacillus strains were assessed for growth-promoting effects using a host-commensal nutrient scarcity model with Drosophila melanogaster (Dm). Two Lactobacillus strains (L. plantarum 49 and L. plantarum 201) presenting the most significant effects (p ≤ .005) on Dm growth were selected and evaluated for their safety and beneficial effects in adult male Wistar rats during 28 days of administration of 9 log CFU/day, followed by 14 days of wash-out. Daily administration of L. plantarum 49 and L. plantarum 201 did not affect (p > .05) food intake or morphometric parameters. Both strains were associated with reduction (p ≤ .05) in blood glucose levels after 28 days of administration and after wash-out period; glucose levels remained reduced only in the group that received L. plantarum 49. Both strains were able to reduce (p ≤ .05) total cholesterol levels after 14 days of administration; after the wash-out period these levels remained reduced only in the group that received L. plantarum 201. L. plantarum 49 and L. plantarum 201 were detected in the intestine and did not cause alteration or translocate to spleen, kidneys or liver during the experimental or wash-out period. These results indicate that L. plantarum 49 and L. plantarum 201 present potential for use as probiotics with intrinsic abilities to modulate biochemical parameters of interest for the management of metabolic diseases.

Using murine colitis models to analyze probiotics-host interactions

Probiotics are defined as 'live microorganisms which when administered in adequate amounts confer a health benefit on the host'. So, to consider a microorganism as a probiotic, a demonstrable beneficial effect on the health host should be shown as well as an adequate defined safety status and the capacity to survive transit through the gastrointestinal tract and to storage conditions. In this review, we present an overview of the murine colitis models currently employed to test the beneficial effect of the probiotic strains as well as an overview of the probiotics already tested. Our aim is to highlight both the importance of the adequate selection of the animal model to test the potential probiotic strains and of the value of the knowledge generated by these in vivo tests.

Lactic acid bacteria isolated from yak milk show probiotic potential

Probiotic industries strive for new, efficient and promising probiotic strains that impart a positive impact on consumer health. Challenges are persisting in isolation, screening, and selection of the new indigenous probiotic strains. In the present research, we explored the probiotic potential of 17 lactic acid bacteria isolated from Yak milk in a series of in vitro tests. We also demonstrated their health benefits, i.e., cholesterol degradation, lactose digestion, antimicrobial activity, antioxidant, and anticancer activities. Principal component analysis revealed that more than 50% of the strains fulfilled the examined criteria, e.g., survival in acidic pH, bile concentrations, and adherent property. Approximately all the strains produced antimicrobial substances against the maximum number of tested strains including clinical strains. Most strains degraded cholesterol in comparison to the reference probiotic strain whereas strain Yc showed 1.5 times higher the degradation efficiency of the control strain. Lan4 strain exhibited remarkable anticancer activity and induced the maximum apoptosis (87%) in the Hela cells and was non-toxic to the non-cancerous HEK293 cells. Around ten strains showed positive lactose digestion. Overall, this can be concluded that selected lactic acid bacteria revealed excellent probiotic properties along with desirable health benefits. These strains need to be further investigated in details for their application in the development of novel probiotic preparations for the improvement of public health.

Lactococcus lactis and Lactobacillus salivarius differently modulate early immunological response of Wistar rats co-administered with Listeria monocytogenes

In the light of the increasing resistance of bacterial pathogens to antibiotics, one of the main global strategies in applied science is development of alternative treatments, which would be safe both for the host and from the environmental perspective. Accordingly, the aim of this study was to test whether two lactic acid bacteria (LAB) strains, Lactococcus lactis BGBU1-4 and Lactobacillus salivarius BGHO1, could be applied as safe supplements for Listeria infection. Two major research objectives were set: to compare the effects of BGBU1-4 and BGHO1 on early immune response in gut tissue of Wistar rats co-administered with Listeria monocytogenes ATCC19111 and next, to test how this applies to their usage as therapeutics in acute ATCC19111 infection. Intestinal villi (IV), Peyer's patches (PP) and mesenteric lymph nodes (MLN) were used for the analysis. The results showed that BGHO1 increased the mRNA expression of innate immune markers CD14, interleukin (IL)-1β and tumour necrosis factor (TNF)-α in PP and IV, and, in parallel, caused a decrease of listeriolysin O (LLO) mRNA expression in same tissues. In MLN of BGHO1 treated rats, LLO expression was increased, along with an increase of the expression of OX-62 mRNA and CD69, pointing to the activation of adaptive immunity. On the other hand, in BGBU1-4 treated rats, there was no reduction of LLO mRNA expression and no induction of innate immunity markers in intestinal tissue. Additionally, CD14 and IL-1β, as well as LLO, but not OX-62 mRNA and CD69 expression, were elevated in MLN of BGBU1-4 treated rats. However, when applied therapeutically, both, BGBU1-4 and BGHO1, lowered Listeria count in spleens of infected rats. Our results not only reveal the potential of LAB to ameliorate Listeria infections, but suggest different immunological effects of two different LAB strains, both of which could be effective in Listeria elimination.

Bifidobacterium animalis subsp. lactis 420 mitigates the pathological impact of myocardial infarction in the mouse

There is a growing appreciation that our microbial environment in the gut plays a critical role in the maintenance of health and the pathogenesis of disease. Probiotic, beneficial gut microbes, administration can directly attenuate cardiac injury and post-myocardial infarction (MI) remodelling, yet the mechanisms of cardioprotection are unknown. We hypothesised that administration of Bifidobacterium animalis subsp. lactis 420 (B420), a probiotic with known anti-inflammatory properties, to mice will mitigate the pathological impact of MI, and that anti-inflammatory T regulatory (T_reg) immune cells are necessary to impart protection against MI as a result of B420 administration. Wild-type male mice were administered B420, saline or Lactobacillus salivarius 33 (Ls-33) by gavage daily for 14 or 35 days, and underwent ischemia/reperfusion (I/R). Pretreatment with B420 for 10 or 28 days attenuated cardiac injury from I/R and reduced levels of inflammatory markers. Depletion of T_reg cells by administration of anti-CD25 monoclonal antibodies eliminated B420-mediated cardio-protection. Further cytokine analysis revealed a shift from a pro-inflammatory to an anti-inflammatory environment in the probiotic treated post-MI hearts compared to controls. To summarise, B420 administration mitigates the pathological impact of MI. Next, we show that T_reg immune cells are necessary to mediate B420-mediated protection against MI. Finally, we identify putative cellular, epigenetic and/or post-translational mechanisms of B420-mediated protection against MI.

Probiotics: The scientific evidence in the context of inflammatory bowel disease

Inflammatory bowel disease (IBD) generally comprises Crohn's disease (CD) and ulcerative colitis (UC), and their main characteristic is the intestinal mucosa inflammation. Although its origin is not yet fully known, there is growing evidence related to genetics, intestinal microbiota composition, and the immune system factors such as precursors for the initiation and progression of intestinal conditions. The use of certain probiotic microorganisms has been touted as a possible and promising therapeutic approach in reducing the risk of inflammatory bowel disease, specifically ulcerative colitis. Several mechanisms have been proposed to explain the benefits of probiotics, indicating that some bacterial strains are able to positively modulate the intestinal microbiota and the immune system, and to produce metabolites with anti-inflammatory properties. The aim of this paper is to bring together the various results and information, based on scientific evidence, that are related to probiotics and inflammatory bowel disease, emphasizing the possible mechanisms involved in this action.

A lactic acid bacterium isolated from kimchi ameliorates intestinal inflammation in DSS-induced colitis

Some species of lactic acid bacteria have been shown to be beneficial in inflammatory bowel disease (IBD). In the present study, a strain of lactic acid bacterium (Lactobacillus paracasei LS2) was isolated from the Korean food, kimchi, and was shown to inhibit the development of experimental colitis induced by dextran sulfate sodium (DSS). To investigate the role of LS2 in IBD, mice were fed DSS in drinking water for seven days along with LS2 bacteria which were administered intragastrically to some of the mice, while phosphate-buffered saline (PBS) was administered to others (the controls). The administration of LS2 reduced body weight loss and increased survival, and disease activity indexes (DAI) and histological scores indicated that the severity of colitis was significantly reduced. The production of inflammatory cytokines and myeloperoxidase (MPO) activity also decreased. Flow cytometry analysis showed that the number of Th1 (IFN-γ) population cells was significantly reduced in the LS2-administered mice compared with the controls. The administration of LS2 induced the increase of CD4⁺FOXP3⁺ Treg cells, which are responsible for IL-10. Numbers of macrophages (CD11b⁺ F4/80⁺), and neutrophils (CD11b⁺ Gr-1⁺) among lamina propria lymphocytes (LPL) were also reduced. These results indicate that LS2 has an anti-inflammatory effect and ameliorates DSS-induced colitis.

Local Treatment with Lactate Prevents Intestinal Inflammation in the TNBS-Induced Colitis Model

Lactate has long been considered as a metabolic by-product of cells. Recently, this view has been changed by the observation that lactate can act as a signaling molecule and regulates critical functions of the immune system. We previously identified lactate as the component responsible for the modulation of innate immune epithelial response of fermented milk supernatants in vitro. We have also shown that lactate downregulates proinflammatory responses of macrophages and dendritic cells. So far, in vivo effects of lactate on intestinal inflammation have not been reported. We evaluated the effect of intrarectal administration of lactate in a murine model of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS). The increase in lactate concentration in colon promoted protective effects against TNBS-induced colitis preventing histopathological damage, as well as bacterial translocation and rise of IL-6 levels in serum. Using intestinal epithelial reporter cells, we found that flagellin treatment induced reporter gene expression, which was abrogated by lactate treatment as well as by glycolysis inhibitors. Furthermore, lactate treatment modulated glucose uptake, indicating that high levels of extracellular lactate can impair metabolic reprograming induced by proinflammatory activation. These results suggest that lactate could be a potential beneficial microbiota metabolite and may constitute an overlooked effector with modulatory properties.

Effect of Lactobacillus paracasei Culture Filtrates and Artichoke Polyphenols on Cytokine Production by Dendritic Cells

The most recent trend in research on probiotic bacteria aims at the exploitation of bioactive bacterial compounds that are responsible for health-promoting effects and suitable for medical applications. Therefore, the main purpose of this study was to ascertain if the immunomodulatory effects of L. paracasei strains on dendritic cells (DCs) were caused by bacterial metabolites released in the culture medium. For that reason, bacterial strains were grown in two media generally used for the culture of DCs, and the effects of culture filtrates on the maturation of DCs and cytokine production were evaluated. Moreover, to reveal potential synergistic effects on the immunomodulation of DCs, an artichoke phenolic extract (APE) was added to the media before bacterial growth. The experiments pointed out an interesting anti-inflammatory activity of a culture filtrate obtained after growing a probiotic L. paracasei strain in one of the media supplemented with APE. Therefore, this culture filtrate—which combines the anti-inflammatory activity and the other well-known health-promoting properties of artichoke phenolic compounds—could represent the basis for future particular exploitations.

Integrated transcriptomic and proteomic analysis of the bile stress response in probiotic Lactobacillus salivarius LI01

Lactobacillus salivarius LI01, isolated from healthy humans, has demonstrated probiotic properties in the prevention and treatment of liver failure. Tolerance to bile stress is crucial to allow lactobacilli to survive in the gastrointestinal tract and exert their benefits. In this work, we used a Digital Gene Expression transcriptomic and iTRAQ LC-MS/MS proteomic approach to examine the characteristics of LI01 in response to bile stress. Using culture medium with or without 0.15% ox bile, 591 differentially transcribed genes and 347 differentially expressed proteins were detected in LI01. Overall, we found the bile resistance of LI01 to be based on a highly remodeled cell envelope and a reinforced bile efflux system rather than on the activity of bile salt hydrolases. Additionally, some differentially expressed genes related to regulatory systems, the general stress response and central metabolism processes, also play roles in stress sensing, bile-induced damage prevention and energy efficiency. Moreover, bile salts appear to enhance proteolysis and amino acid uptake (especially aromatic amino acids) by LI01, which may support the liver protection properties of this strain. Altogether, this study establishes a model of global response mechanism to bile stress in L. salivarius LI01.

BIOLOGICAL SIGNIFICANCE

L. salivarius strain LI01 exhibits not only antibacterial and antifungal properties but also exerts a good health-promoting effect in acute liver failure. As a potential probiotic strain, the bile-tolerance trait of strain LI01 is important, though this has not yet been explored. In this study, an analysis based on DGE and iTRAQ was performed to investigate the gene expression in strain LI01 under bile stress at the mRNA and protein levels, respectively. To our knowledge, this work also represents the first combined transcriptomic and proteomic analysis of the bile stress response mechanism in L. salivarius.

Effective treatment of hypertension by recombinant Lactobacillus plantarum expressing angiotensin converting enzyme inhibitory peptide

Background

Hypertension is considered the most serious risk factor for cardiovascular disease. Angiotensin-converting enzyme inhibitory peptides (ACEIPs), which are made from tuna frame protein (TFP) and yellow fin sole frame protein (YFP), have been used previously to treat hypertension. However, the production of these short peptides is usually dependent on enzymatic hydrolysis, resulting in a digested mixture that makes it difficult to purify the ACEIPs. Although it has been reported that ACEIPs could be produced in recombinant Escherichia coli strains, the use of lactic acid bacteria in the production of ACEIPs has not been demonstrated.

Results

In this study, the ACEIP coding sequences from TFP and YFP were joined through an arginine linker and expressed in the Lactobacillus plantarum (Lb. plantarum) NC8 strain by an inducible vector pSIP-409. Then, the antihypertensive effects were determined in the model of spontaneously hypertensive rats (SHRs) by measuring the blood pressure, hematology, blood biochemistry and nitric oxide (NO), endothelin (ET) and angiotensin II (Ang II) levels. The results showed that oral administration of recombinant Lb. plantarum NC8 (RLP) significantly decreased systolic blood pressure (P < 0.01) during treatment, which lasted for at least 10 days after the last dose. Furthermore, the presence of RLP resulted in an increased level of NO, as well as decreased levels of ET and Ang II in plasma, heart, and kidney. In addition, a dramatically decreased triglyceride level was also observed even though there was no significant change in hematology or blood biochemistry. Although some drawbacks were still observed, such as the presence of an antibiotic selection marker, no obvious side effects or bacterial translocation were observed in vivo, indicating the potential application of RLP in the treatment of hypertension.

Conclusion

These results demonstrated the effectiveness and safety of RLP on the treatment of hypertension.

The biofilm mode of life boosts the anti-inflammatory properties of Lactobacillus

The predominant form of life for microorganisms in their natural habitats is the biofilm mode of growth. The adherence and colonization of probiotic bacteria are considered as essential factors for their immunoregulatory function in the host. Here, we show that Lactobacillus casei ATCC334 adheres to and colonizes the gut of zebrafish larvae. The abundance of pro-inflammatory cytokines and the recruitment of macrophages were low when inflammation was induced in probiotic-fed animals, suggesting that these bacteria have anti-inflammatory properties. We treated human macrophage-differentiated monocytic THP-1 cells with supernatants of L. casei ATCC334 grown in either biofilm or planktonic cultures. TNF-α production was suppressed and the NF-κB pathway was inhibited only in the presence of supernatants from biofilms. We identified GroEL as the biofilm supernatant compound responsible, at least partially, for this anti-inflammatory effect. Gradual immunodepletion of GroEL demonstrated that the abundance of GroEL and TNF-α were inversely correlated. We confirmed that biofilm development in other Lactobacillus species affects the immune response. The biofilms supernatants of these species also contained large amounts of GroEL. Thus, our results demonstrate that the biofilm enhances the immunomodulatory effects of Lactobacillus sp. and that secreted GroEL is involved in this beneficial effect.

Lactobacillus plantarum CLP-0611 ameliorates colitis in mice by polarizing M1 to M2-like macrophages

The TNF-α expression-inhibitory effect of lactic acid bacteria (LAB) isolated from kimchi were measured in lipopolysaccharide (LPS)-stimulated peritoneal macrophages. Among the LAB evaluated, Lactobacillus plantarum CLP-0611 inhibited the IL-1β and IL-6 expression, as well as the NF-κB and AP1 activation in LPS-stimulated peritoneal macrophages. Therefore, we investigated its inhibitory effect on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. TNBS significantly induced colon shortening, as well as myeloperoxidase activity and macroscopic score. Oral administration of CLP-0611 significantly reduced TNBS-induced body weight loss, colon shortening, myeloperoxidase activity, IRAK-1 phosphorylation, NF-κB and MAP kinase (p38, ERK, JNK) activation, and iNOS and COX-2 expression. CLP-0611 also inhibited TNBS-induced expression of TNF-α, IL-1β, and IL-6. However, IL-10 expression was induced. CLP-0611 also induced the production of M2 macrophage markers (IL-10, arginase I and CD206). Based on these findings, CLP-0611 inhibits TLR-4-linked NF-κB and MAPK signaling pathways and polarizes M1 to M2-like macrophages, thus ameliorating colitis.

Investigation into in vitro and in vivo models using intestinal epithelial IPEC-J2 cells and Caenorhabditis elegans for selecting probiotic candidates to control porcine enterotoxigenic Escherichia coli

AIMS

To identify a fast, economic and reliable method for preselecting lactic acid-producing bacterial (LAB) isolates to control enterotoxigenic Escherichia coli (ETEC).

METHODS AND RESULTS

Two assays with porcine intestinal epithelial IPEC-J2 cells or Caenorhabditis elegans for selecting effective probiotic candidates were compared. Both assays were based on measuring death of cells or worms caused by ETEC strain JG280. Six of 13 LAB isolates showed ≥50% protection in each assay, among which only four isolates (≥50% protection) were consistently selected by both assays. Isolate CL9 (Lactobacillus reuteri) was further studied. It reduced gene expression of estA, estB and elt in JG280 in both assays. Furthermore, the isolate protected IPEC-J2 and C. elegans from cell and worm death caused by STa, STb or LT enterotoxin expressed in E. coli DH5α. CL9 also promoted host defensive responses by decreasing IL-8 and increasing IL-10 production in IPEC-J2 cells and expression of antimicrobial peptide genes clec-60, clec-85 in C. elegans.

CONCLUSIONS

Caenorhabditis elegans is useful for preselecting probiotic candidates to control ETEC after initial screening with IPEC-J2 cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

A combination of IPEC-J2 cell and C. elegans assays can improve the effectiveness in preselecting probiotic candidates.

Lactobacillus zeae protects Caenorhabditis elegans from enterotoxigenic Escherichia coli-caused death by inhibiting enterotoxin gene expression of the pathogen

BACKGROUND

The nematode Caenorhabditis elegans has become increasingly used for screening antimicrobials and probiotics for pathogen control. It also provides a useful tool for studying microbe-host interactions. This study has established a C. elegans life-span assay to preselect probiotic bacteria for controlling K88(+) enterotoxigenic Escherichia coli (ETEC), a pathogen causing pig diarrhea, and has determined a potential mechanism underlying the protection provided by Lactobacillus.

METHODOLOGY/PRINCIPAL FINDINGS

Life-span of C. elegans was used to measure the response of worms to ETEC infection and protection provided by lactic acid-producing bacteria (LAB). Among 13 LAB isolates that varied in their ability to protect C. elegans from death induced by ETEC strain JG280, Lactobacillus zeae LB1 offered the highest level of protection (86%). The treatment with Lactobacillus did not reduce ETEC JG280 colonization in the nematode intestine. Feeding E. coli strain JFF4 (K88(+) but lacking enterotoxin genes of estA, estB, and elt) did not cause death of worms. There was a significant increase in gene expression of estA, estB, and elt during ETEC JG280 infection, which was remarkably inhibited by isolate LB1. The clone with either estA or estB expressed in E. coli DH5α was as effective as ETEC JG280 in killing the nematode. However, the elt clone killed only approximately 40% of worms. The killing by the clones could also be prevented by isolate LB1. The same isolate only partially inhibited the gene expression of enterotoxins in both ETEC JG280 and E. coli DH5α in-vitro.

CONCLUSIONS/SIGNIFICANCE

The established life-span assay can be used for studies of probiotics to control ETEC (for effective selection and mechanistic studies). Heat-stable enterotoxins appeared to be the main factors responsible for the death of C. elegans. Inhibition of ETEC enterotoxin production, rather than interference of its intestinal colonization, appears to be the mechanism of protection offered by Lactobacillus.

Potential fate of ingested Lactobacillus plantarum and its occurrence in human feces

Lactobacillus plantarum has been used in human clinical trials to promote beneficial effects in the immune system, to alleviate intestinal disorders, and to reduce the risk of cardiovascular disease. It is also involved in many fermentation processes in the food industry. However, information on the fate of ingested L. plantarum is limited. In this study, 61 subjects received daily doses of fermented milk containing 2 × 10(11) cells of L. plantarum Lp115 for different periods of time. The target microorganism was monitored in the fecal microbiota via quantitative PCR (qPCR). L. plantarum was detected and quantified in all of the subjects during the ingestion periods. The differences between the L. plantarum levels at time zero and during all the different ingestion periods were statistically significant (P = 0.001). However, at 15 and 45 days after discontinuing supplementation, the number of lactobacilli was reduced to the baseline level (those at time zero). A longer period with L. plantarum in the diet did not result in increased levels of this bacterium in the stool, based on postconsumption evaluations (P = 0.001). The qPCR method was specific and sensitive for L. plantarum quantification in such a complex microbial environment as the gastrointestinal tract.

Anti-inflammatory properties of Streptococcus salivarius, a commensal bacterium of the oral cavity and digestive tract

Streptococcus salivarius is one of the first colonizers of the human oral cavity and gut after birth and therefore may contribute to the establishment of immune homeostasis and regulation of host inflammatory responses. The anti-inflammatory potential of S. salivarius was first evaluated in vitro on human intestinal epithelial cells and human peripheral blood mononuclear cells. We show that live S. salivarius strains inhibited in vitro the activation of the NF-κB pathway on intestinal epithelial cells. We also demonstrate that the live S. salivarius JIM8772 strain significantly inhibited inflammation in severe and moderate colitis mouse models. These in vitro and in vivo anti-inflammatory properties were not found with heat-killed S. salivarius, suggesting a protective response exclusively with metabolically active bacteria.

Microbial characterization of probiotics--advisory report of the Working Group "8651 Probiotics" of the Belgian Superior Health Council (SHC)

When ingested in sufficient numbers, probiotics are expected to confer one or more proven health benefits on the consumer. Theoretically, the effectiveness of a probiotic food product is the sum of its microbial quality and its functional potential. Whereas the latter may vary much with the body (target) site, delivery mode, human target population, and health benefit envisaged microbial assessment of the probiotic product quality is more straightforward. The range of stakeholders that need to be informed on probiotic quality assessments is extremely broad, including academics, food and biotherapeutic industries, healthcare professionals, competent authorities, consumers, and professional press. In view of the rapidly expanding knowledge on this subject, the Belgian Superior Health Council installed Working Group "8651 Probiotics" to review the state of knowledge regarding the methodologies that make it possible to characterize strains and products with purported probiotic activity. This advisory report covers three main steps in the microbial quality assessment process, i.e. (i) correct species identification and strain-specific typing of bacterial and yeast strains used in probiotic applications, (ii) safety assessment of probiotic strains used for human consumption, and (iii) quality of the final probiotic product in terms of its microbial composition, concentration, stability, authenticity, and labeling.

Interaction of Lactobacillus fermentum BGHI14 with rat colonic mucosa: implications for colitis induction

The present study was carried out to test the colonic mucosal response of rats to oral supplementation with Lactobacillus fermentum BGHI14 and to correlate the tissue reaction to trinitrobenzenesulfonate (TNBS)-induced colitis with mucosal barrier alterations caused by bacterial ingestion. An immune cell-mediated reaction of healthy colonic tissue was noticed after bacterial feeding. After prolonged bacterial treatment, the observed reaction had retreated to normality, but the mRNA levels of proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) remained elevated. These data point to the chronic low-grade inflammation that could be caused by long-term probiotic consumption. Although no detrimental effects of bacterial pretreatment were noticed in colitic rats, at least in the acute state of disease, the results obtained in our study point to the necessity of reassessment of existing data on the safety of probiotic preparations. Additionally, probiotic effects in experimental colitis models might depend on time coordination of disease induction with treatment duration.

Lactobacillus brevis G-101 ameliorates colitis in mice by inhibiting NF-κB, MAPK and AKT pathways and by polarizing M1 macrophages to M2-like macrophages

AIM

We isolated Lactobacillus brevis G-101 from kimchi lactic acid bacteria (LAB) strains, which induced IL-10 expression in lipopolysaccharide (LPS)-stimulated peritoneal macrophages. To evaluate the inflammatory effect of G-101, we examined its inhibitory effect in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitic mice.

MATERIALS AND RESULTS

The colitic mice were prepared by intrarectal injection of TNBS. We measured intestinal mucosal cytokines by enzyme-linked immunosorbent assay; activation of transcription factors, by immunoblotting; and macrophage polarization markers, by real-time polymerase chain reaction. Of 200 LAB strains tested, Lact. brevis G-101 showed most potent activity for induction of IL-10 expression in LPS-stimulated peritoneal macrophages. However, it significantly inhibited the expression of TNF-α, IL-1β and IL-6 and the phosphorylation of IRAK1 and AKT, and activated NF-κB and MAPKs. Treatment with TNBS caused colon shortening; increased myeloperoxidase activity; and increased IL-1β, IL-6 and TNF-α expression in mice. Oral administration of Lact. brevis G-101 significantly inhibited these activities. Lactobacillus brevis G-101 inhibited TNBS-induced IRAK-1 phosphorylation and NF-κB activation, as well as the expression of COX-2 and iNOS. Lactobacillus brevis G-101 inhibited the expression of M1 macrophage markers, but increased the expression of M2 macrophages in the colons of TNBS-treated mice.

CONCLUSIONS

Lactobacillus brevis G-101 may improve colitis by inhibiting the IRAK1/NF-κB, MAPK and AKT pathways and by polarizing M1 macrophages to M2-like macrophages.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results suggest that IL-10 expression-inducing LAB can ameliorate colitis by inhibiting NF-κB activation and macrophage polarization.

Effect of Lactobacillus salivarius Ls-33 on fecal microbiota in obese adolescents

BACKGROUND & AIMS

This study is a part of the clinical trials with probiotic bacterium Lactobacillus salivarius Ls-33 conducted in obese adolescents. Previously reported clinical studies showed no effect of Ls-33 consumption on the metabolic syndrome in the subject group. The aim of the study was to investigate the impact of L. salivarius Ls-33 on fecal microbiota in obese adolescents.

METHODS

The study was a double-blinded intervention with 50 subjects randomized to intake of L. salivarius Ls-33 or placebo for 12 weeks. The fecal microbiota was assessed by real-time quantitative PCR before and after intervention. Concentrations of fecal short chain fatty acids were determined using gas chromatography.

RESULTS

Ratios of Bacteroides-Prevotella-Porphyromonas group to Firmicutes belonging bacteria, including Clostridium cluster XIV, Blautia coccoides_Eubacteria rectale group and Roseburia intestinalis, were significantly increased (p ≤ 0.05) after administration of Ls-33. The cell numbers of fecal bacteria, including the groups above as well as Clostridium cluster I, Clostridium cluster IV, Faecalibacterium prausnitzii, Enterobacteriaceae, Enterococcus, the Lactobacillus group and Bifidobacterium were not significantly altered by intervention. Similarly, short chain fatty acids remained unaffected.

CONCLUSION

L. salivarius Ls-33 might modify the fecal microbiota in obese adolescents in a way not related to metabolic syndrome.

CLINICAL TRIAL NUMBER

NCT 01020617.

Probiotics to adolescents with obesity: effects on inflammation and metabolic syndrome

OBJECTIVES

The connections between gut microbiota, energy homeostasis, and inflammation and its role in the pathogenesis of obesity-related disorders are increasingly recognized. We aimed to investigate the effect of the probiotic strain Lactobacillus salivarius Ls-33 on a series of biomarkers related to inflammation and the metabolic syndrome (MS) in adolescents with obesity.

METHODS

The study was a double-blind placebo-controlled trial including 50 adolescents with obesity randomized to Ls-33 (10 CFU) or placebo daily for 12 weeks.

RESULTS

The average body mass index-for-age z-score was 2.6 ± 0.5. There were no differences in biomarkers of inflammation and parameters related to the MS at baseline between the probiotic and placebo groups. Furthermore, there were no differences in changes from baseline to 12-week intervention with regard to any anthropometric measures, blood pressure (systolic and diastolic), fasting glucose and insulin, homeostasis model assessment of insulin resistance, C-peptide, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, free fatty acids, C-reactive protein, interleukin-6, tumor necrosis factor alpha, or fecal calprotectin, despite the increased values of biomarkers of inflammation and of several parameters related to the MS at baseline when compared with normal-weight adolescents. The levels of L salivarius in fecal samples from the probiotic group in the present study were comparable with the levels reported for the other probiotic lactobacilli and bifidobacteria using quantitative polymerase chain reaction.

CONCLUSIONS

It was not possible to detect any beneficial effect of the probiotic intervention with Ls-33 on inflammatory markers or parameters related to the MS in adolescents with obesity being in a state of low-grade systemic inflammation.

Lactobacillus pentosus var. plantarum C29 protects scopolamine-induced memory deficit in mice

AIMS

In the preliminary study, kimchi, a traditional food fermented with Chinese cabbage, protected scopolamine-induced mouse memory deficit in passive avoidance test. Therefore, we screened protective ingredients, particularly lactic acid bacteria, from Chinese cabbage kimchi against scopolamine-induced memory deficit in mice.

METHODS AND RESULTS

Lactic acid bacteria, isolated from Chinese cabbage kimchi, were identified by 16S rDNA sequence analysis, G+C content and cellular fatty acid composition and sugar fermentation test. Memory deficit was induced in mice by intraperitoneally injecting with scopolamine. Kimchi, particularly its supernatant, protected scopolamine-induced memory deficit in mice in passive avoidance test. Of kimchi ingredients, a lactic acid bacterium, strain C29, potently protected scopolamine-induced memory deficit in mice. C29 was a gram-positive, catalase-negative, anaerobic and non-motile rod. Its pylogenetic property was near to Lactobacillus pentosus (99%) and Lact. plantarum (99%). However, C29 fermented inulin and L-rhamnose and grew in pH 3 and at 45°C in contrast with Lact. pentosus and Lact. plantarum. Therefore, it named to be Lact pentosus var. plantarum C29. The strain C29 protected scopolamine-induced memory deficit in Y-maze and Morris water maze tests. Furthermore, C29 increased hippocampal BDNF and p-CREB expressions, which were reduced by scopolamine.

CONCLUSION

Lactobacillus pentosus var. plantarum C29 may protect memory deficit by inducing BDNF and p-CREB expressions.

SIGNIFICANCE AND IMPACT OF THE STUDY

Lactic acid bacteria, such as Lact pentosus var. plantarum C29, may prevent memory deficit and its contained fermented foods may be beneficial for dementia.

Lactobacillus crispatus M206119 exacerbates murine DSS-colitis by interfering with inflammatory responses

AIM: To investigate the role of Lactobacillus crispatus (L. crispatus) strain China Center for Type Culture Collection (CCTCC) M206119 in intestinal inflammation.

METHODS: Forty 8-wk-old Balb/c mice (20 ± 2 g) were divided into four groups of 10 mice each. Three groups that had received dextran sulfate sodium (DSS) were administered normal saline, sulfasalazine or CCTCC M206119 strain, and the fourth group received none of these. We assessed the severity of colitis using a disease activity index, measured the colon length and weight, collected stools and mesenteric lymph nodes for bacterial microflora analysis. One centimeter of the proximal colon, middle colon and distal colon were collected and fixed in 10% buffered formalin, dehydrated in ethanol, and embedded in paraffin. Interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α expression was detected using reverse transcription polymerase chain reaction. Protective factors zonula occludens (ZO)-1 and β-defensin 2 were detected by immunoblotting. The features of CCTCC M206119 strain were identified based on morphology, biochemical profile, and 16S RNA sequencing.

RESULTS: DSS-colitis animals treated with CCTCC M206119 had markedly more severe disease, with greater weight loss, diarrhea, fecal bleeding, and shortened colon length. In addition, the CCTCC-M206119-treated group had comparatively higher histological scores and more neutrophil infiltration than the controls. Expression of protective factors ZO-1 and β-defensin 2 was downregulated due to destruction of the mucosal barrier after CCTCC M206119 strain treatment. An in vitro assay demonstrated that CCTCC M206119 strain increased the nuclear translocation of nuclear factor-κB in epithelial cells. Intestinal proinflammatory or anti-inflammatory cytokine responses were evaluated. Proinflammatory colonic cytokine (IL-1β, IL-6 and TNF-α) levels were clearly increased in CCTCC-M206119-treated animals, whereas anti-inflammatory colonic cytokine (IL-10) level was lowered compared with saline or 5-aminosalicylic-acid-treated DSS-colitis mice. Next, CCTCC M206119 strain was characterized as L. crispatus by microscopic morphology, biochemical tests and 16S rRNA gene level.

CONCLUSION: Not all lactobacilli are beneficial for intestinal inflammation, and L. crispatus CCTCC M206119 strain is involved in exacerbation of intestinal inflammation in DSS-colitis mice.