Intestinal microflora: probiotics and autoimmunity

How xylitol, gluten, and lactose change human gut microbiota Escherichia coli and Lactobacillus rhamnosus GG biofilm

OBJECTIVE

The human gut microbiota is composed of many viruses, bacteria, and fungi. Escherichia coli representatives are facultative anaerobic bacteria in the colon that play a crucial role in the metabolism of lactose, vitamin synthesis, and immune system modulation. E. coli forms a biofilm on the epithelial cell surface of the intestine that can be modified by diet compounds, i.e., gluten, xylitol, lactose, and probiotics.

METHODS

In the present study, the impact of probiotic-derived Lactobacillus rhamnosus GG strain on non-pathogenic E. coli biofilm was examined. The mono- and multispecies biofilm was also treated with gluten, xylitol, and lactose. We used 96-well plates to obtain biofilm growth. Biofilm was stained using crystal violet. To evaluate the type of interaction in mono- and multispecies biofilm, a new formula was introduced: biofilm interaction ratio index (BIRI). To describe the impact of nutrients on biofilm formation, the biofilm formation impact ratio (BFIR) was calculated.

RESULTS

The biofilms formed by both examined species are stronger than in monocultures. All the BIRI values were above 3.0. It was found that the monospecies biofilm of L. rhamnosus is strongly inhibited by gluten (84.5%) and the monospecies biofilm of E. coli by xylitol (85.5%). The mixed biofilm is inhibited by lactose (78.8%) and gluten (90.6%).

CONCLUSION

The relations between bacteria in the mixed biofilm led to changes in biofilm formation by E. coli and L. rhamnosus GG. Probiotics might be helpful in rebuilding the gut microbiota after broad spectrum antibiotic therapy, but only if gluten and lactose are excluded from diet.

Contribution of Lactobacilli on Intestinal Mucosal Barrier and Diseases: Perspectives and Challenges of Lactobacillus casei

The intestine barrier, the front line of normal body defense, relies on its structural integrity, microbial composition and barrier immunity. The intestinal mucosal surface is continuously exposed to a complex and dynamic community of microorganisms. Although it occupies a relatively small proportion of the intestinal microbiota, Lactobacilli has been discovered to have a significant impact on the intestine tract in previous studies. It is undeniable that some Lactobacillus strains present probiotic properties through maintaining the micro-ecological balance via different mechanisms, such as mucosal barrier function and barrier immunity, to prevent infection and even to solve some neurology issues by microbiota-gut-brain/liver/lung axis communication. Notably, not only living cells but also Lactobacillus derivatives (postbiotics: soluble secreted products and para-probiotics: cell structural components) may exert antipathogenic effects and beneficial functions for the gut mucosal barrier. However, substantial research on specific effects, safety and action mechanisms in vivo should be done. In clinical application of humans and animals, there are still doubts about the precise evaluation of Lactobacilli's safety, therapeutic effect, dosage and other aspects. Therefore, we provide an overview of central issues on the impacts of Lactobacillus casei (L. casei) and their products on the intestinal mucosal barrier and some diseases and highlight the urgent need for further studies.

The Effect of Probiotics on Health Outcomes in the Elderly: A Systematic Review of Randomized, Placebo-Controlled Studies

Increasing evidence suggests that probiotic supplementation may be efficacious in counteracting age-related shifts in gut microbiota composition and diversity, thereby impacting health outcomes and promoting healthy aging. However, randomized controlled trials (RCTs) with probiotics in healthy older adults have utilized a wide variety of strains and focused on several different outcomes with conflicting results. Therefore, a systematic review was conducted to determine which outcomes have been investigated in randomized controlled trials with probiotic supplementation in healthy older adults and what has been the effect of these interventions. For inclusion, studies reporting on randomized controlled trials with probiotic and synbiotic supplements in healthy older adults (defined as minimum age of 60 years) were considered. Studies reporting clinical trials in specific patient groups or unhealthy participants were excluded. In addition to assessment of eligibility and data extraction, each study was examined for risk of bias and quality assessment was performed by two independent reviewers. Due to the heterogeneity of outcomes, strains, study design, duration, and methodology, we did not perform any meta-analyses and instead provided a narrative overview of the outcomes examined. Of 1997 potentially eligible publications, 17 studies were included in this review. The risk of bias was low, although several studies failed to adequately describe random sequence generation, allocation concealment, and blinding. The overall study quality was high; however, many studies did not include sample calculations, and the majority of studies had a small sample size. The main outcomes examined in the trials included microbiota composition, immune-related measurements, digestive health, general well-being, cognitive function, and lipid and other biomarkers. The most commonly assessed outcome with the most consistent effect was microbiota composition; all but one study with this outcome showed significant effects on gut microbiota composition in healthy older adults. Overall, probiotic supplementation had modest effects on markers of humoral immunity, immune cell population levels and activity, as well as the incidence and duration of the common cold and other infections with some conflicting results. Digestive health, general-well-being, cognitive function, and lipid and other biomarkers were investigated in a very small number of studies; therefore, the impact on these outcomes remains inconclusive. Probiotics appear to be efficacious in modifying gut microbiota composition in healthy older adults and have moderate effects on immune function. However, the effect of probiotic supplementation on other health outcomes remains inconclusive, highlighting the need for more well-designed, sufficiently-powered studies to investigate if and the mechanisms by which probiotics impact healthy aging.

Altered Metabolome of Lipids and Amino Acids Species: A Source of Early Signature Biomarkers of T2DM

Diabetes mellitus, a disease of modern civilization, is considered the major mainstay of mortalities around the globe. A great number of biochemical changes have been proposed to occur at metabolic levels between perturbed glucose, amino acid, and lipid metabolism to finally diagnoe diabetes mellitus. This window period, which varies from person to person, provides us with a unique opportunity for early detection, delaying, deferral and even prevention of diabetes. The early detection of hyperglycemia and dyslipidemia is based upon the detection and identification of biomarkers originating from perturbed glucose, amino acid, and lipid metabolism. The emerging “OMICS” technologies, such as metabolomics coupled with statistical and bioinformatics tools, proved to be quite useful to study changes in physiological and biochemical processes at the metabolic level prior to an eventual diagnosis of DM. Approximately 300–400 such metabolites have been reported in the literature and are considered as predicting or risk factor-reporting metabolic biomarkers for this metabolic disorder. Most of these metabolites belong to major classes of lipids, amino acids and glucose. Therefore, this review represents a snapshot of these perturbed plasma/serum/urinary metabolic biomarkers showing a significant correlation with the future onset of diabetes and providing a foundation for novel early diagnosis and monitoring the progress of metabolic syndrome at early symptomatic stages. As most metabolites also find their origin from gut microflora, metabolism and composition of gut microflora also vary between healthy and diabetic persons, so we also summarize the early changes in the gut microbiome which can be used for the early diagnosis of diabetes.

Severity of Candida-associated denture stomatitis is improved in institutionalized elders who consume Lactobacillus rhamnosus SP1

BACKGROUND

This study aimed to determine the effect of the consumption of a probiotic on the clinical characteristics of Candida-associated denture stomatitis (DS) and to determine the impact of a protocol of self-care measures in oral/prosthetic hygiene in institutionalized elders that wear removable prostheses (RP). The current treatment for DS is the systemic use of antifungals, as well as the replacement of these devices together with oral/prosthetic hygiene instructions.

METHODS

This study was a randomized, controlled and triple-blind trial. Thirty-six elders presenting DS of different severity and who carried RP consumed milk with/without the probiotic L. rhamnosus SP1. The prevalence and severity of DS and prevalence of Candida were determined and all participants/caregivers were trained in oral/prosthetic hygiene.

RESULTS

In both groups a decrease in the prevalence of DS was observed (P < 0.05) but only the group that consumed probiotic throughout the trial had a significant reduction in the severity of DS and reduced Candida counts (P < 0.05). Educational instruction in oral/prosthetic hygiene was relevant for the participants, regarding the prevalence of this lesion.

CONCLUSIONS

The frequent consumption of Lactobacillus rhamnosus SP1 and the establishment of a protocol of oral/prosthetic hygiene drastically reduced the severity of DS in institutionalized elders who wore RP.

Gut Microbiota, Host Organism, and Diet Trialogue in Diabetes and Obesity

The gastrointestinal tract with its microbiota is a complex, open, and integrated ecosystem with a high environmental exposure. It is widely accepted that the healthy gut microbiotais essential for host homeostasis and immunostasis, harboring an enormous number and variety of microorganisms and genes tailored by hundreds of exogenous and intrinsic host factors. The occurrence of dysbiosis may contribute to host vulnerability and progression to a large spectrum of infectious and non-communicable diseases, including diabetes and obesity, two metabolic disorders that are showing an endemic trend nowadays. There is an urgent need to develop efficient strategies to prevent and treat metabolic disorders such as diabetes and obesity which are often associated with serious complications. In this paper, we give an overview on the implications of gut microbiota in diabesity, with a focus on the triangle gut microbiota—diet-host metabolism and on the way to manipulate the gut microbial ecosystem toward achieving novel diagnosis and predictive biomarkers with the final goal of reestablishing the healthy metabolic condition. The current research data regarding the precision/personalized nutrition suggest that dietary interventions, including administration of pre-, pro-, and syn-biotics, as well as antibiotic treatment should be individually tailored to prevent chronic diseases based on the genetic background, food and beverage consumption, nutrient intake, microbiome, metabolome, and other omic profiles.

Metal bashing: iron deficiency and manganese overexposure impact on peripheral nerves

Iron (Fe) deficiency (FeD) and manganese (Mn) overexposure (MnOE) may result in several neurological alterations in the nervous system. Iron deficiency produces unique neurological deficits due to its elemental role in central nervous system (CNS) development and myelination, which might persist after normalization of Fe in the diet. Conversely, MnOE is associated with diverse neurocognitive deficits. Despite these well-known neurotoxic effects on the CNS, the influence of FeD and MnOE on the peripheral nervous system (PNS) remains poorly understood. The aim of the present investigation was to examine the effects of developmental FeD and MnOE or their combination on the sciatic nerve of young and adult rats. The parameters measured included divalent metal transporter 1 (DMT1), transferrin receptor (TfR), myelin basic protein (MBP) and peripheral myelin protein 22 (PMP22) expression, as well as Fe levels in the nerve. Our results showed that FeD produced a significant reduction in MBP and PMP22 content at P29, which persisted at P60 after Fe-sufficient diet replenishment regardless of Mn exposure levels. At P60 MnOE significantly increased sciatic nerve Fe content and DMT1 expression. However, the combination of FeD and MnOE produced no marked motor skill impairment. Evidence indicates that FeD appears to hinder developmental peripheral myelination, while MnOE may directly alter Fe homeostasis. Further studies are required to elucidate the interplay between these pathological conditions.

Antihypertensive Effects of Probiotics

PURPOSE OF REVIEW

The present review focuses in the hypertension-associated changes in the microbiota and the current insights regarding the impact of probiotics on blood pressure in animal models and in human hypertensive patients.

RECENT FINDINGS

Gut dysbiosis in hypertension is characterized by (i) the gut microbioma that is less diverse and less rich with an increased Firmicutes/Bacteroidetes ratio and (ii) a decrease in acetate- and butyrate-producing bacteria and an increase in lactate-producing bacterial populations. The meta-analysis of the human studies supports that supplementation with probiotics reduces blood pressure. The mechanism of this antihypertensive effect of probiotics and its protective effect on endothelial function has not been fully elucidated. Further investigations are needed to clarify if the effects of probiotic bacteria result from the changes in the gut microbiota and its metabolic by-products; the restoration of the gut barrier function; and the effects on endotoxemia, inflammation, and renal sympathetic nerve activity.

Gut microbiota, hypertension and chronic kidney disease: Recent advances

A large number of different microbial species populates intestine. Extensive research has studied the entire microbial population and their genes (microbiome) by using metagenomics, metatranscriptomics and metabolomic analysis. Studies suggest that the imbalances of the microbial community causes alterations in the intestinal homeostasis, leading to repercussions on other systems: metabolic, nervous, cardiovascular, immune. These studies have also shown that alterations in the structure and function of the gut microbiota play a key role in the pathogenesis and complications of Hypertension (HTN) and Chronic Kidney Disease (CKD). Increased blood pressure (BP) and CKD are two leading risk factors for cardiovascular disease and their treatment represents a challenge for the clinicians. In this Review, we discuss mechanisms whereby gut microbiota (GM) and its metabolites act on downstream cellular targets to contribute to the pathogenesis of HTN and CKD, and potential therapeutic implications.

Rice bran nutraceutics: A comprehensive review

Agro-industry yields ample quantity of several byproducts with considerable importance. These byproducts are mostly under-utilized, often used as animal feed or rejected as waste; hence their true potential is not harnessed. The use of such superfluous resources is of not only economic significance but also a form of commercial recycling. Rice bran is an important byproduct of rice milling industry with a global potential of 29.3 million tons annually. It is gaining great attention of the researchers due to its nutrient-rich composition, easy availability, low cost, high antioxidant potential, and promising effects against several metabolic ailments. Bioactive components of rice bran, mainly γ-oryzanol, have been reported to possess antioxidant, anti-inflammatory, hypocholesterolemic, anti-diabetic, and anti-cancer activities. Rice bran oil contains appreciable quantities of bioactive components and has attained the status of "Heart oil" due to its cardiac-friendly chemical profile. Nutraceutics have successfully been extracted from rice bran using several extraction techniques such as solvent extraction, supercritical fluid extraction, microwave-, and ultrasonic-assisted extraction. Current paper is an attempt to highlight bioactive moieties of rice bran along with their extraction technologies and health benefits.

A bidirectional association between the gut microbiota and CNS disease in a biphasic murine model of multiple sclerosis

The gut microbiome plays an important role in the development of inflammatory disease as shown using experimental models of central nervous system (CNS) demyelination. Gut microbes influence the response of regulatory immune cell populations in the gut-associated lymphoid tissue (GALT), which drive protection in acute and chronic experimental autoimmune encephalomyelitis (EAE). Recent observations suggest that communication between the host and the gut microbiome is bidirectional. We hypothesized that the gut microbiota differs between the acute inflammatory and chronic progressive stages of a murine model of secondary-progressive multiple sclerosis (SP-MS). This non-obese diabetic (NOD) model of EAE develops a biphasic pattern of disease that more closely resembles the human condition when transitioning from relapsing-remitting (RR)-MS to SP-MS. We compared the gut microbiome of NOD mice with either mild or severe disease to that of non-immunized control mice. We found that the mice which developed a severe secondary form of EAE harbored a dysbiotic gut microbiome when compared with the healthy control mice. Furthermore, we evaluated whether treatment with a cocktail of broad-spectrum antibiotics would modify the outcome of the progressive stage of EAE in the NOD model. Our results indicated reduced mortality and clinical disease severity in mice treated with antibiotics compared with untreated mice. Our findings support the hypothesis that there are reciprocal effects between experimental CNS inflammatory demyelination and modification of the microbiome providing a foundation for the establishment of early therapeutic interventions targeting the gut microbiome that could potentially limit disease progression.

Therapeutic effects of orally administered CJLP55 for atopic dermatitis via the regulation of immune response

Atopic dermatitis (AD) is an inflammatory skin condition accompanied by symptoms such as edema and hemorrhage. Kimchi is a traditional fermented Korean dish consisting of various probiotics. In this study, the therapeutic effect of Lactobacillus plantarum CJLP55 isolated from Kimchi was studied in AD-induced mice. Orally administered Lactobacillus strain, CJLP55, suppressed AD symptoms and high serum IgE levels. CJLP55 administration reduced the thickness of the epidermis, infiltration of mast cells and eosinophils into the skin lesion, enlargement of axillary lymph nodes, and increase in cell population in axillary lymph nodes. CJLP55 treatment decreased the production of type 2 cytokines, such as interleukin (IL)-4, IL-5, IL-10, IL-12, interferon (IFN)-γ, and IL-6,which were stimulated by house dust mite extracts, in the axillary lymph node cells. Orally administered CJLP55 exhibited a therapeutic effect on house dust mite-induced AD in NC/Nga mice after onset of the disease by altering immune cell activation. The Lactobacillus strain, CJLP55, isolated from Kimchi, suppressed AD. Our results suggest its possible use as a potential candidate for management of AD.

Stabilization of freeze-dried Lactobacillus paracasei subsp. paracasei JCM 8130T with the addition of disaccharides, polymers, and their mixtures

Although freeze-drying is a widely used dehydration technique for the stabilizing of unstable lactic acid bacteria, Lactobacillus paracasei subsp. paracasei JCM 8130^T (L. paracasei) is destabilized after freeze-drying and subsequent storage. In order to improve the stability of freeze-dried L. paracasei, effects of disaccharides (sucrose and trehalose), polymers (maltodextrin; MD and bovine serum albumin; BSA), and their mixtures on the survival rate of freeze-dried L. paracasei were investigated. The survival rate of non-additive sample decreased slightly after freeze-drying but decreased drastically after subsequent storage at 37 °C for 4 weeks. The reduction was diminished by the addition of disaccharides and polymers. The stabilizing effect of disaccharides was not affected by the co-addition of MD. In contrast, the disaccharide-BSA mixtures had a synergistic stabilizing effect, and the survival rates were largely maintained even after storage. It is suggested that the synergistic effect originates from the conformational stabilization of the dehydrated bacteria.

Induction of regulatory T cells: A role for probiotics and prebiotics to suppress autoimmunity

Regulatory T cells (Tregs) are comprised of a heterogeneous population of cells that play a vital role in suppressing inflammation and maintaining immune tolerance. Given the crucial role of Tregs in maintaining immune homeostasis, it is probably not surprising that many microbial species and their metabolites have the potential to induce Tregs. There is now great interest in the therapeutic potential of probiotics and prebiotics based strategies for a range of autoimmune disorders. This review will summarise recent findings concerning the role of probiotics and prebiotics in induction of Tregs to ameliorate the autoimmune conditions. In addition, the article is focused to explain the different mechanisms of Treg induction and function by these probiotics and prebiotics, based on the available studies till date. The article further proposes that induction of Tregs by probiotics and prebiotics could lead to the development of new therapeutic approach towards curbing the autoimmune response and as an alternative to detrimental immunosuppressive drugs.

Allergic diseases among children: nutritional prevention and intervention

Allergic diseases comprise a genetically heterogeneous group of chronic, immunomediated diseases. It has been clearly reported that the prevalence of these diseases has been on the rise for the last few decades, but at different rates, in various areas of the world. This paper discusses the epidemiology of allergic diseases among children and their negative impact on affected patients, their families, and societies. These effects include the adverse effects on quality of life and economic costs. Medical interest has shifted from tertiary or secondary prevention to primary prevention of these chronic diseases among high-risk infants in early life. Being simple, practical, and cost-effective are mandatory features for any candidate methods delivering these strategies. Dietary therapy fits this model well, as it is simple, practical, and cost-effective, and involves diverse methods. The highest priority strategy is feeding these infants breast milk. For those who are not breast-fed, there should be a strategy to maintain beneficial gut flora that positively influences intestinal immunity. We review the current use of probiotics, prebiotics, and synbiotics, and safety and adverse effects. Other dietary modalities of possible potential in achieving this primary prevention, such as a Mediterranean diet, use of milk formula with modified (hydrolyzed) proteins, and the role of micronutrients, are also explored. Breast-feeding is effective in reducing the risk of asthma, allergic rhinitis, and atopic eczema among children. In addition, breast milk constitutes a major source of support for gut microbe colonization, due to its bifidobacteria and galactooligosaccharide content. The literature lacks consensus in recommending the addition of probiotics to foods for prevention and treatment of allergic diseases, while prebiotics may prove to be effective in reducing atopy in healthy children. There is insufficient evidence to support soy formulas or amino acid formulas for prevention of allergic disease. A healthy diet, such as the Mediterranean diet, may have a protective effect on the development of asthma and atopy in children. In children with asthma and allergic diseases, vitamin D deficiency correlates strongly with asthma, allergic rhinitis, and wheezing.

Probiotics for Prevention of Atopy and Food Hypersensitivity in Early Childhood: A PRISMA-Compliant Systematic Review and Meta-Analysis of Randomized Controlled Trials

Most studies investigated probiotics on food hypersensitivity, not on oral food challenge confirmed food allergy in children. The authors systematically reviewed the literature to investigate whether probiotic supplementation prenatally and/or postnatally could reduce the risk of atopy and food hypersensitivity in young children.PubMed, Embase, the Cochrane Central Register of Controlled Trials, and 4 main Chinese literature databases (Wan Fang, VIP, China National Knowledge Infrastructure, and SinoMed) were searched for randomized controlled trials regarding the effect of probiotics on the prevention of allergy in children. The last search was conducted on July 11, 2015.Seventeen trials involving 2947 infants were included. The first follow-up studies were analyzed. Pooled analysis indicated that probiotics administered prenatally and postnatally could reduce the risk of atopy (relative risk [RR] 0.78; 95% confidence interval [CI] 0.66-0.92; I = 0%), especially when administered prenatally to pregnant mother and postnatally to child (RR 0.71; 95% CI 0.57-0.89; I = 0%), and the risk of food hypersensitivity (RR 0.77; 95% CI 0.61-0.98; I = 0%). When probiotics were administered either only prenatally or only postnatally, no effects of probiotics on atopy and food hypersensitivity were observed.Probiotics administered prenatally and postnatally appears to be a feasible way to prevent atopy and food hypersensitivity in young children. The long-term effects of probiotics, however, remain to be defined in the follow-up of existing trials. Still, studies on probiotics and confirmed food allergy, rather than surrogate measure of food hypersensitivity, are warranted.

Therapeutic Application of Synbiotics, a Fusion of Probiotics and Prebiotics, and Biogenics as a New Concept for Oral Candida Infections: A Mini Review

Candida is a major human fungal pathogen causing infectious conditions predominantly in the elderly and immunocompromised hosts. Although Candida resides as a member of the oral indigenous microbiota in symbiosis, some circumstances may cause microbial imbalance leading to dysbiosis and resultant oral candidiasis. Therefore, oral microbial symbiosis that suppresses the overgrowth of Candida is important for a healthy oral ecosystem. In this regard, probiotics, prebiotics, and synbiotics can be considered a potential therapeutic and preventive strategy against oral candidiasis. Prebiotics have a direct effect on microbial growth as they stimulate the growth of beneficial bacteria and suppress the growth of pathogens. Probiotics render a local protective effect against pathogens and a systemic indirect effect on immunological amelioration. Synbiotics are fusion products of prebiotics and probiotics. This mini review discusses the potential use and associated limitations of probiotics, prebiotics, and synbiotics for the prevention and treatment of oral candidiasis. We will also introduce biogenics, a recent concept derived from the work on probiotics. Biogenics advocates the use of beneficial bioactive substances produced by probiotic bacteria, whose activities are independent from the viability of probiotic bacteria in human bodies.

Efficacy of Lactobacillus casei Shirota for patients with irritable bowel syndrome

BACKGROUND AND AIMS

Meta-analyses point to a modest but significant effect of probiotics on symptoms in irritable bowel syndrome (IBS). We aimed to assess the effect of the probiotic Lactobacillus casei Shirota (LcS) on symptoms and quality of life in IBS patients in a randomized, double-blind, placebo-controlled intervention study.

MATERIALS AND METHODS

IBS patients (Rome II) between 18 and 65 years of age were included. The study consisted of an 8-week intervention period in which the participants received probiotic (LcS) or placebo twice daily, followed by an 8-week follow-up period. Symptom diaries and quality of life were scored at weeks 0, 8 and 16. The primary outcome parameter was a decrease of at least 30% in a composite mean symptom score (MSS) at week 8 on the basis of an intention-to-treat analysis.

RESULTS

Thirty-nine individuals (67% women) were included in the probiotic group and 41 individuals (71% women) were included in the placebo group. After the intervention period, the mean relative improvement did not reach 30% for MSS or any individual symptom score. After follow-up (week 16), a mean improvement of at least 30% was achieved for MSS in the probiotic group, but no significant difference was found between both treatment groups (mean±SD: 34±7%; 13±8%, P=0.06).

CONCLUSION

After probiotic treatment with LcS, no improvement of 30% in MSS was observed after 8 weeks.

Cardiovascular benefits of probiotics: a review of experimental and clinical studies

The microbiota inhabiting the human gastro-intestinal tract is reported to have a significant impact on the health of an individual.

Cancer Preventive Potential of Kimchi Lactic Acid Bacteria (Weissella cibaria, Lactobacillus plantarum)

The number of death due to cancer has been increasing in Korea. Chemotherapy is known to cause side effects because it damages not only cancerous cells but healthy cells. Recently, attention has focused on food-derived chemopreventive and anti-tumor agents or formulations with fewer side effects. Kimchi, most popular and widely consumed in Korea, contains high levels of lactic acid bacteria and has been shown to possess chemopreventive effects. This review focuses on Weissella cibaria and Lactobacillus plantarum, the representatives of kimchi lactic acid bacteria, in terms of their abilities to prevent cancer. Further studies are needed to understand the mechanisms by which lactic acid bacteria in kimchi prevent carcinogenic processes and improve immune functions.

Basic and clinical research on the regulation of the intestinal barrier by Lactobacillus and its active protein components: a review with experience of one center

Probiotics got protective effects on the intestinal barrier. Our present study is to review the basic and clinical progress on the regulation of the intestinal barrier by Lactobacillus and its active protein components, combing the study of our center. Our study have isolated the active component of micro integral membrane protein (MIMP) within the media place of the integral membrane protein of Lactobacillus plantarum, which was verified about the protective effects against the intestinal epithelial dysfunction. On the other hand, we also found the effects of perioperative use of probiotics in the prevention and treatment of postoperative intestinal barrier dysfunction, and reduction of the postoperative infective complications. In this review, we would like to report the founding of our center, involving in the basic and clinical research progress of regulation of intestinal barrier by Lactobacillus and its active protein component MIMP. Furthermore, we may also promote our following studies about the MIMP and its clinical verification.

Lactobacillus gasseri SBT2055 induces TGF-β expression in dendritic cells and activates TLR2 signal to produce IgA in the small intestine

Probiotic bacteria provide benefits in enhancing host immune responses and protecting against infection. Induction of IgA production by oral administration of probiotic bacteria in the intestine has been considered to be one reason for this beneficial effect, but the mechanisms of the effect are poorly understood. Lactobacillus gasseri SBT2055 (LG2055) is a probiotic bacterium with properties such as bile tolerance, ability to improve the intestinal environment, and it has preventive effects related to abdominal adiposity. In this study, we have found that oral administration of LG2055 induced IgA production and increased the rate of IgA(+) cell population in Peyer's patch and in the lamina propria of the mouse small intestine. The LG2055 markedly increased the amount of IgA in a co-culture of B cells and bone marrow derived dendritic cells (BMDC), and TLR2 signal is critical for it. In addition, it is demonstrated that LG2055 stimulates BMDC to promote the production of TGF-β, BAFF, IL-6, and IL-10, all critical for IgA production from B cells. Combined stimulation of B cells with BAFF and LG2055 enhanced the induction of IgA production. Further, TGF-β signal was shown to be critical for LG2055-induced IgA production in the B cell and BMDC co-culture system, but TGF-β did not induce IgA production in a culture of only B cells stimulated with LG2055. Furthermore, TGF-β was critical for the production of BAFF, IL-6, IL-10, and TGF-β itself from LG2055-stimulated BMDC. These results demonstrate that TGF-β was produced by BMDC stimulated with LG2055 and it has an autocrine/paracrine function essential for BMDC to induce the production of BAFF, IL-6, and IL-10.

Growth inhibition of hepatocellular carcinoma Huh7 cells by Lactobacillus casei extract

PURPOSE

Lactobacillus casei (L. casei) is known to exert anti-proliferation effects on many types of cancer cells. However, the effect of L. casei on liver cancer has not been reported. Accordingly, the aim of this study was to determine the anti-cancer effect of L. casei extract on Huh7 cells.

MATERIALS AND METHODS

L. casei ATCC393 extract was prepared and purified. After the treatment of L. casei extract on Huh7 cells, cell viability, cell cycle arrest and cell death were analyzed by flow cytometry. The expression levels of tumor necrosis factor-α receptor 1 (TNFR1) and death receptor 3 (DR3) mRNA related with extrinsic apoptosis were assessed by reverse transcription polymerase chain reaction. Additionally, P21 and P27 cell cycle proteins as well as Caspase-3, -8, -9, phospho-Bad and Bcl-2 apoptosis proteins were analyzed by western blot analysis. To determine the effect of L. casei extract on cancer stem-like cells, we analyzed changes in side population fraction through flow cytometry.

RESULTS

The cell viability of Huh7 cells treated with L. casei extract was decreased by 77%, potentially owing to increases in the rates of Huh7 cells arrested in the G2/M phase (3% increase) and that underwent apoptosis (6% increase). The expression levels of TNFR1 and DR3 mRNA, as well as P21 and P27 cell cycle proteins, were increased. Meanwhile, the expressions of caspase-8, -9, phospho-Bad and Bcl-2 proteins decreased. However, in the case of side population cells, no remarkable changes were observed.

CONCLUSION

L. casei extract exerts a potent anti-tumor effect on the viability of liver cancer cells, although not on cancer stem-like cells.

Probiotics as potential biotherapeutics in the management of type 2 diabetes - prospects and perspectives

Diabetes mellitus is a looming epidemic worldwide, affecting almost all major sections of society, creating burdens on global health and economy. A large number of studies have identified a series of multiple risk factors such as genetic predisposition, epigenetic changes, unhealthy lifestyle, and altered gut microbiota that cause increased adiposity, β-cell dysfunction, hyperglycemia, hypercholesterolemia, adiposity, dyslipidaemia, metabolic endotoxemia, systemic inflammation, intestinal permeability (leaky gut), defective secretion of incretins and oxidative stress associated with type 2 diabetes (T2D). Recent studies have proposed multifactorial interventions including dietary manipulation in the management of T2D. The same interventions have also been recommended by many national and international diabetes associations. These studies are aimed at deciphering the gut microbial influence on health and disease. Interestingly, results from several genomic, metagenomic and metabolomic studies have provided substantial information to target gut microbiota by dietary interventions for the management of T2D. Probiotics particularly lactobacilli and bifidobacteria have recently emerged as the prospective biotherapeutics with proven efficacy demonstrated in various in vitro and in vivo animal models adequately supported with their established multifunctional roles and mechanism of action for the prevention and disease treatment. The dietary interventions in conjunction with probiotics - a novel multifactorial strategy to abrogate progression and development of diabetes - hold considerable promise through improving the altered gut microbial composition and by targeting all the possible risk factors. This review will highlight the new developments in probiotic interventions and future prospects for exploring probiotic therapy in the prevention and control of lifestyle diseases like T2D.

Effects of probiotic bacteria on Candida presence and IgA anti-Candida in the oral cavity of elderly

Imbalance in the resident microbiota may promote the growth of opportunistic microorganisms, such as yeasts of Candida genus and the development of diseases, especially in aged people. This study evaluated whether the consumption of the probiotic Yakult LB® (Lactobacillus casei and Bifidobacterium breve) was able to influence on the specific immunological response against Candida and on the presence of these yeasts in the oral cavity of 42 healthy aged individuals. Saliva samples were collected before and after the probiotic use for 30 days, 3 times a week. The samples were plated in Dextrose Saboraud Agar with chloramphenicol, the colony-forming units (CFU/mL) were counted and the Candida species were identified. Anti-Candida IgA analysis was conducted using the ELISA technique. ANOVA and Student's t-test were used for normally distributed data and the Wilcoxon test was used for data with non-normal distribution (α=0.05). The results showed a statistically significant reduction (p<0.05) in Candida prevalence (from 92.9% to 85.7%), in CFU/mL counts of Candida and in the number of non-albicans species after consumption of the probiotic. Immunological analysis demonstrated a significant increase (p<0.05) in anti-Candida IgA levels. In conclusion, probiotic bacteria reduced Candida numbers in the oral cavity of the elderly and increased specific secretory immune response against these yeasts, suggesting its possible use in controlling oral candidosis.

Involvement of the mannose receptor and p38 mitogen-activated protein kinase signaling pathway of the microdomain of the integral membrane protein after enteropathogenic Escherichia coli infection

The microdomain of the integral membrane protein (MIMP) has been shown to adhere to mucin and to antagonize the adhesion of enteropathogenic Escherichia coli (EPEC) to epithelial cells; however, the mechanism has not been fully elucidated. In this study, we further identified the receptor of MIMP on NCM460 cells and investigated the mechanism (the p38 mitogen-activated protein kinase [MAPK] pathway) following the interaction of MIMP and its corresponding receptor, mannose receptor. We first identified the target receptor of MIMP on the surfaces of NCM460 cells using immunoprecipitation-mass spectrometry technology. We also verified the mannose receptor and examined the degradation and activation of the p38 MAPK signaling pathway. The results indicated that MIMP adhered to NCM460 cells by binding to the mannose receptor and inhibited the phosphorylation of p38 MAPK stimulated after EPEC infection via inhibition of the Toll-like receptor 5 pathway. These findings indicated that MIMPs relieve the injury of NCM460 cells after enteropathogenic E. coli infection through the mannose receptor and inhibition of the p38 MAPK signaling pathway, both of which may therefore be potential therapeutic targets for intestinal diseases, such as inflammatory bowel disease.

Effects of perioperative synbiotic treatment on infectious complications, intestinal integrity, and fecal flora and organic acids in hepatic surgery with or without cirrhosis

BACKGROUND

The aim of this study was to assess the effect of preoperative and postoperative synbiotic treatment in hepatectomy patients with or without liver cirrhosis.

METHODS

Sixty-one patients with hepatic cancer were assigned randomly to receive either oral synbiotics that consisted of Bifidobacterium, Lactobacillus, and galactooligosaccharides or no synbiotics (control) preoperatively for 14 days and postoperatively for 11 days. Infectious complications, intestinal mucosal integrity as measured by serum diamine oxidase (DAO) activity, and fecal flora and organic acid concentrations were compared between synbiotic treatment (n = 32) and control (n = 29) groups.

RESULTS

Fecal flora culture and organic acid concentrations were changed after hepatectomy in both groups. The postsurgery decrease in DAO activity was less profound in the synbiotic-treated group (P < .01) and was correlated negatively with serum interleukin 6 and C-reactive protein concentrations (P < .001). Infectious complications occurred in 5 (17.2%) patients in the control group and no patients in the synbiotic-treated group (P < .05).

CONCLUSION

Perioperative synbiotic treatment attenuated the decrease in intestinal integrity and reduced the rate of infectious complications in patients with or without liver cirrhosis who underwent hepatic surgery.

Anti-inflammatory and immunomodulatory efficacy of indigenous probiotic Lactobacillus plantarum Lp91 in colitis mouse model

Probiotics can affect the immune homeostasis by altering the gut microbial balance and enhancing the immune system of gut, thus benefits in Inflammatory Bowel Disease, including Crohn's disease and Ulcerative colitis. Relative gene expression of pro, anti-inflammatory cytokines and other molecules in 2,4,6-trinitrobenzene sulfonic acid-induced colitis mouse model against Lactobacillus plantarum Lp91 (L. plantarum Lp91) was investigated by reverse transcription-quantitative PCR (RT-qPCR) using relative expression software tool (REST 2008 V2.0.7). L. plantarum Lp91 evoked significant down regulation of TNF-α and COX2 to 0.026 and 0.077 fold in colitis mouse model. No significant difference in expression of IL-12a cytokine in colitis mouse challenged with L. plantarum Lp91 was also observed. IL-10 was significantly up-regulated to 37.813 and 1.327 fold in colitis and non-colitis mouse challenged with L. plantarum Lp91. While, other anti-inflammatory markers i.e. COX1, IL-4 and IL-6 were significantly up regulated in colitis mouse challenged with L. plantarum Lp91. MUC2 gene was significantly up regulated to 2.216 fold in non-colitis group. L. plantarum Lp91, an indigenous probiotic culture, the main subject of this project exhibited strong immunemodulatory properties under in vivo conditions in mouse colitis model.

Assessment of Lactobacillus gasseri as a candidate oral vaccine vector

Lactobacillus species are commensal bacteria that have long been recognized as probiotic microbes and are generally regarded as safe (GRAS) for human consumption. We have investigated the use of L. gasseri as a vaccine vector for oral immunization against mucosal pathogens. Recent research has shown that the immune response to different lactobacilli can vary widely depending on the species or subspecies of Lactobacillus being studied. While some lactobacilli seem to induce oral tolerance, others induce an adaptive immune response. This study characterized the systemic and mucosal immune response to wild-type and genetically modified L. gasseri. L. gasseri primarily activates TLR2/6, with additional activation through the TLR2 homodimer. To expand the Toll-like receptor (TLR) activation profile of L. gasseri and the immunogenicity of the vector, a plasmid containing fliC, the gene encoding bacterial flagellin, was introduced which resulted in the strong activation of TLR5. The treatment of human myeloid dendritic cells with recombinant lactobacilli expressing flagellin triggered phenotypic maturation and the release of proinflammatory cytokines. In contrast, bacterial treatment also resulted in a statistically significant increase in IL-10 production. In vivo studies established that treatment with L. gasseri led to a diversification of B-cell populations in the lamina propria of the murine colon. Furthermore, treatment with genetically modified L. gasseri led to a significant decrease in the percentage of FoxP3(+) colonic lymphocytes. Taken together, these data clarify the interaction of L. gasseri with the host immune system and support further investigation of the in vivo immunogenicity of L. gasseri expressing both flagellin and candidate vaccine antigens.

Longevity in mice is promoted by probiotic-induced suppression of colonic senescence dependent on upregulation of gut bacterial polyamine production

Background

Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs) decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations.

Methodology/Principal Findings

We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan–Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001); moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05). Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger) mice.

Conclusion/Significance

Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon induced by higher PA levels. This indicates that ingestion of specific probiotics may be an easy approach for improving intestinal health and increasing lifespan. Further studies are required to clarify its effectiveness in humans.

Lactobacillus gasseri OLL2809 and its RNA suppress proliferation of CD4(+) T cells through a MyD88-dependent signalling pathway

Recent studies have shown that probiotics are beneficial in prevention and improvement of inflammatory diseases. Accumulating evidence indicates that probiotics can modulate immune cell responses, although the specific molecular mechanism by which probiotics work remains elusive. Because T cells express receptors for microbial components, we examined whether the probiotic strain Lactobacillus gasseri OLL2809 (LG2809) and its components regulate murine CD4(+) T-cell activation. LG2809, as well as two other Lactobacillus strains, inhibited proliferation of CD4(+) T cells; LG2809 had the strongest suppressive activity among them. RNA isolated from LG2809 was also shown to have suppressive activity. We observed this suppressive effect in the culture of CD4(+) T cells stimulated with anti-CD3/CD28 treatment, suggesting a direct effect on CD4(+) T cells. In contrast, the suppressive effect was not observed for CD4(+) T cells from myeloid differentiation primary response gene 88 (MyD88) protein-deficient mice, and was abrogated in the presence of an anti-oxidant reagent, N-acetyl-cysteine (NAC). These results demonstrate that the suppressive effect of LG2809 and its RNA occurred through a MyD88-dependent signalling pathway and suggest involvement of a reactive oxygen species-dependent mechanism. LG2809 RNA injected subcutaneously suppressed delayed-type-hypersensitivity response in DO11.10 mice, and the suppression was abrogated by treatment with NAC. Collectively, these results suggest that suppression of T-cell proliferation by RNA may be one of the mechanisms when a probiotic bacterial strain exerts suppressive effects on inflammatory responses.

The role of gut microbiota (commensal bacteria) and the mucosal barrier in the pathogenesis of inflammatory and autoimmune diseases and cancer: contribution of germ-free and gnotobiotic animal models of human diseases

Metagenomic approaches are currently being used to decipher the genome of the microbiota (microbiome), and, in parallel, functional studies are being performed to analyze the effects of the microbiota on the host. Gnotobiological methods are an indispensable tool for studying the consequences of bacterial colonization. Animals used as models of human diseases can be maintained in sterile conditions (isolators used for germ-free rearing) and specifically colonized with defined microbes (including non-cultivable commensal bacteria). The effects of the germ-free state or the effects of colonization on disease initiation and maintenance can be observed in these models. Using this approach we demonstrated direct involvement of components of the microbiota in chronic intestinal inflammation and development of colonic neoplasia (i.e., using models of human inflammatory bowel disease and colorectal carcinoma). In contrast, a protective effect of microbiota colonization was demonstrated for the development of autoimmune diabetes in non-obese diabetic (NOD) mice. Interestingly, the development of atherosclerosis in germ-free apolipoprotein E (ApoE)-deficient mice fed by a standard low-cholesterol diet is accelerated compared with conventionally reared animals. Mucosal induction of tolerance to allergen Bet v1 was not influenced by the presence or absence of microbiota. Identification of components of the microbiota and elucidation of the molecular mechanisms of their action in inducing pathological changes or exerting beneficial, disease-protective activities could aid in our ability to influence the composition of the microbiota and to find bacterial strains and components (e.g., probiotics and prebiotics) whose administration may aid in disease prevention and treatment.

Protective effects of Lactobacillus plantarum against epithelial barrier dysfunction of human colon cell line NCM460

AIM: To investigate the effects of Lactobacillus plantarum (L. plantarum) in the intestinal permeability and expression of tight junction (TJ) using the normal human colon cell line NCM460.

METHODS: Paracellular permeability of NCM460 monolayers was determined by transepithelial electrical resistance and dextran permeability. Expression of TJ proteins in NCM460 cell monolayers was detected by Western blotting and quantitative real-time polymerase chain reaction.

RESULTS: L. plantarum played an important role in increasing transepithelial electrical resistance and decreasing the permeability to macromolecules of NCM460 monolayers against the disruption caused by enteropathogenic Escherichia coli (E. coli) or enteroinvasive E. coli. L. plantarum also prevented the decrease in the expression of TJ proteins and F-actin in NCM460 cells.

CONCLUSION: L. plantarum can protect against dysfunction of NCM460 intestinal epithelial barrier caused by enteropathogenic E. coli or enteroinvasive E. coli, and thus can be a potential candidate of therapeutic agents for the treatment of intestinal diseases.

Probiotics and prebiotics in pediatrics

This clinical report reviews the currently known health benefits of probiotic and prebiotic products, including those added to commercially available infant formula and other food products for use in children. Probiotics are supplements or foods that contain viable microorganisms that cause alterations of the microflora of the host. Use of probiotics has been shown to be modestly effective in randomized clinical trials (RCTs) in (1) treating acute viral gastroenteritis in healthy children; and (2) preventing antibiotic-associated diarrhea in healthy children. There is some evidence that probiotics prevent necrotizing enterocolitis in very low birth weight infants (birth weight between 1000 and 1500 g), but more studies are needed. The results of RCTs in which probiotics were used to treat childhood Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, and infantile colic, as well as in preventing childhood atopy, although encouraging, are preliminary and require further confirmation. Probiotics have not been proven to be beneficial in treating or preventing human cancers or in treating children with Crohn disease. There are also safety concerns with the use of probiotics in infants and children who are immunocompromised, chronically debilitated, or seriously ill with indwelling medical devices. Prebiotics are supplements or foods that contain a nondigestible food ingredient that selectively stimulates the favorable growth and/or activity of indigenous probiotic bacteria. Human milk contains substantial quantities of prebiotics. There is a paucity of RCTs examining prebiotics in children, although there may be some long-term benefit of prebiotics for the prevention of atopic eczema and common infections in healthy infants. Confirmatory well-designed clinical research studies are necessary.

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.

Gut microbiota and probiotics in modulation of epithelium and gut-associated lymphoid tissue function

The intestinal tract mucosa is exposed to a vast number of environmental antigens and a large community of commensal bacteria. The mucosal immune system has to provide both protection against pathogens and tolerance to harmless bacteria. Immune homeostasis depends on the interaction of indigenous commensal and transient bacteria (probiotics) with various components of the epithelium and the gut-associated lymphoid tissue. Herein, an update is given of the mechanisms by which the gut microbiota and probiotics are translocated through the epithelium, sensed via pattern-recognition receptors, and activate innate and adaptive immune responses.

Nutrition, geoepidemiology, and autoimmunity

As well represented by the impaired immune function of malnourished individuals encountered in developing countries and the incidence of specific diseases following local nutrient deficiencies, nutrition and immunity have been linked to each other for centuries while the specific connection between dietary factors and autoimmunity onset or modulation is a more recent acquisition. Autoimmune diseases manifest limited prevalence rates in developing countries while numerous immunity-related claims have been proposed in the field of functional foods. Nevertheless, over the past years multiple lines of evidence have supported a major role for specific dietary factors (including vitamin D, vitamin A, selenium, zinc, omega-3 fatty acids, probiotics, and flavanols) in determining the immune responses involved in infections, allergies, and autoimmune diseases. Interestingly, the link between nutrition and autoimmunity may well contribute to the geoepidemiology observed for numerous conditions. In general terms, most data that will be discussed herein were obtained in experimental or animal models while human data from real-life clinical settings or randomized clinical trials remain largely unsatisfactory. Our current knowledge on the beneficial impact of nutrition on autoimmunity prompts us to encourage the search for evidence-based nutrition to support the everyday diet choices of patients.