Oral supplementation with Lactobacillus rhamnosus CGMCC 1.3724 prevents development of atopic dermatitis in NC/NgaTnd mice possibly by modulating local production of IFN-gamma

Lactobacillus for the treatment and prevention of atopic dermatitis: Clinical and experimental evidence

Atopic dermatitis (AD) is a chronic inflammatory skin disease, accompanied by itching and swelling. The main pathological mechanism of AD is related to the imbalance between Type 2 helper cells (Th2 cells) and Type 1 helper cells (Th1 cells). Currently, no safe and effective means to treat and prevent AD are available; moreover, some treatments have side effects. Probiotics, such as some strains of Lactobacillus, can address these concerns via various pathways: i) facilitating high patient compliance; ii) regulating Th1/Th2 balance, increasing IL-10 secretion, and reducing inflammatory cytokines; iii) accelerating the maturation of the immune system, maintaining intestinal homeostasis, and improving gut microbiota; and iv) improving the symptoms of AD. This review describes the treatment and prevention of AD using 13 species of Lactobacillus. AD is commonly observed in children. Therefore, the review includes a higher proportion of studies on AD in children and fewer in adolescents and adults. However, there are also some strains that do not improve the symptoms of AD and even worsen allergies in children. In addition, a subset of the genus Lactobacillus that can prevent and relieve AD has been identified in vitro. Therefore, future studies should include more in vivo studies and randomized controlled clinical trials. Given the advantages and disadvantages mentioned above, further research in this area is urgently required.

Symbiotic microorganisms: prospects for treating atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common chronic recurrent inflammatory skin disease. The pathogenesis is unclear but may be related to genetic, immune, and environmental factors and abnormal skin barrier function. Symbiotic microorganisms in the gut and on the skin are associated with AD occurrence.

AREAS COVERED

We discuss the metabolism and distribution of intestinal and skin flora and review their relationship with AD, summarizing the recent applications of intestinal and skin flora in AD treatment, and discussing the prospect of research on these two human microbiota systems and their influence on AD treatment. The PubMed database was searched to identify relevant publications from 1949 to 2020 for the bibliometric analysis of atopic dermatitis and symbiotic microorganisms.

EXPERT OPINION

Many studies have suggested a potential contribution of microbes in the intestine and on the skin to AD. Bacteria living on the skin can aggravate AD by secreting numerous virulence factors. Moreover, the metabolism of intestinal flora can influence AD occurrence and development via the circulatory system. Current evidence suggests that by regulating intestinal and skin flora, AD can be treated and prevented.

Probiotic Supplementation and Food Intake and Knowledge Among Patients and Consumers

The consumption of probiotics has gained popularity, highlighting the importance for consumers and clinicians to be aware of their compositions and health effects. The primary objective was to determine incentives for taking probiotics and knowledge about probiotic composition among consumers of various education levels, ethnicities, and locations. A secondary objective was to determine brands, dosages, prices, advertised benefits, and refrigeration status of commercially available probiotics in the Sacramento region. This was a voluntary anonymous online survey conducted from May to August 2017. Surveys were administered at the University of California Davis (UCD) Dermatology Clinic, as well as at approved locations within a 100-mi. radius. Data analysis was performed at the UCD Dermatology clinic. Eligible participants age 18 years and older were asked to complete a voluntary anonymous online survey. A random sample of participants were recruited from the UCD Dermatology clinic, local schools, and health food stores within the designated parameters. We collected 396 surveys, 97% of which were completed. Of those surveyed, 39.4% have previously taken probiotics, 44.6% could identify at least one species present in their supplement, 42.5% could identify the number of strains, and 33.0% could identify the dosage. Gut health was the most common reason for taking probiotics (58.1%). Most rated price as important when purchasing probiotics (70.3%). Although probiotic use is prevalent in Sacramento, most people are unfamiliar with the composition of their supplement. More evidence is needed to guide consumers in making more educated decisions.

Fermented blueberry and black rice containing Lactobacillus plantarum MG4221: a novel functional food for particulate matter (PM2.5)/dinitrochlorobenzene (DNCB)-induced atopic dermatitis

Particulate matter (PM_2.5) is a risk factor for the deterioration of atopic dermatitis (AD) and certain constituents of PM_2.5 can induce inflammation via oxidative stress. Natural functional foods, including antioxidative blueberry and black rice, can be the best alternative for the development of AD therapy. Thus, we investigated whether PM_2.5 regulated the expression of proinflammatory cytokines involved in the progression of AD and further investigated the improvement effect of fermented blueberry and black rice extract (FBBBR) containing Lactobacillus plantarum MG4221 in vitro and in vivo. The FBBBR treatment significantly ameliorated skin inflammation compared with the control treatments via regulation of the mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NF-κB) pathways in PM_2.5-treated HaCaT cells. In PM_2.5/dinitrochlorobenzene (DNCB)-treated NC/Nga mice, the oral administration of FBBBR significantly decreased transepidermal water loss and erythema, the incidence of scratching behavior, and the production of serum immunoglobin E and T helper 2-associated cytokine and, similar to dexamethasone treatment, up-regulated the protein expression of filaggrin and involucrin in skin tissue. Syringic acid and kuromanin, standard compounds found in FBBBR, significantly decreased the interleukin (IL)-1β, IL-6 and IL-8 levels in PM_2.5-treated HaCaT cells. Therefore, we can suggest that FBBBR may serve as an important functional food for AD.

Lactobacillus paracasei KBL382 administration attenuates atopic dermatitis by modulating immune response and gut microbiota

Administration of probiotics has been linked to immune regulation and changes in gut microbiota composition, with effects on atopic dermatitis (AD). In this study, we investigated amelioration of the symptoms of AD using Lactobacillus paracasei KBL382 isolated from the feces of healthy Koreans. Mice with Dermatophagoides farinae extract (DFE)-induced AD were fed 1 × 109 CFU d-1 of L. paracasei KBL382 for 4 weeks. Oral administration of L. paracasei KBL382 significantly reduced AD-associated skin lesions, epidermal thickening, serum levels of immunoglobulin E, and immune cell infiltration. L. paracasei KBL382-treated mice showed decreased production of T helper (Th)1-, Th2-, and Th17-type cytokines, including thymic stromal lymphopoietin, thymus, and activation-regulated chemokine, and macrophage-derived chemokine, and increased production of the anti-inflammatory cytokine IL-10 and transforming growth factor-β in skin tissue. Intake of L. paracasei KBL382 also increased the proportion of CD4+ CD25+ Foxp3+ regulatory T cells in mesenteric lymph nodes. In addition, administration of L. paracasei KBL382 dramatically changed the composition of gut microbiota in AD mice. Administration of KBL382 significantly ameliorates AD-like symptoms by regulating the immune response and altering the composition of gut microbiota.

Lactobacillus paracasei KBL382 administration attenuates atopic dermatitis by modulating immune response and gut microbiota

Administration of probiotics has been linked to immune regulation and changes in gut microbiota composition, with effects on atopic dermatitis (AD). In this study, we investigated amelioration of the symptoms of AD using Lactobacillus paracasei KBL382 isolated from the feces of healthy Koreans. Mice with Dermatophagoides farinae extract (DFE)-induced AD were fed 1 × 10⁹ CFU d^-1 of L. paracasei KBL382 for 4 weeks. Oral administration of L. paracasei KBL382 significantly reduced AD-associated skin lesions, epidermal thickening, serum levels of immunoglobulin E, and immune cell infiltration. L. paracasei KBL382-treated mice showed decreased production of T helper (Th)1-, Th2-, and Th17-type cytokines, including thymic stromal lymphopoietin, thymus, and activation-regulated chemokine, and macrophage-derived chemokine, and increased production of the anti-inflammatory cytokine IL-10 and transforming growth factor-β in skin tissue. Intake of L. paracasei KBL382 also increased the proportion of CD4+ CD25+ Foxp3+ regulatory T cells in mesenteric lymph nodes. In addition, administration of L. paracasei KBL382 dramatically changed the composition of gut microbiota in AD mice. Administration of KBL382 significantly ameliorates AD-like symptoms by regulating the immune response and altering the composition of gut microbiota.

Oral administration of whole dihomo-γ-linolenic acid-producing yeast suppresses allergic contact dermatitis in mice

Dihomo-γ-linolenic acid (DGLA, C20: 3n-6) is known to have an anti-inflammatory activity, but its range of effects was not well studied because of its limited natural sources. We addressed these issues by constructing an yeast Saccharomyces cerevisiae strain having a complete metabolic pathway for DGLA synthesis by introducing two desaturase and one elongase genes to convert endogenous oleic acid to DGLA. Taking advantage of well-known safety of S. cerevisiae, we previously investigated the efficacy of heat-killed whole DGLA-producing yeast cells on irritant contact dermatitis, and showed that oral intake of this yeast significantly suppressed inflammatory reactions, whereas no such suppression was observed by the intake of 25 times the amount of purified DGLA. Since this method is considered to be a simple and efficient way to suppress inflammation, we examined its effectiveness against allergic contact dermatitis (ACD) in this study and showed that this method was also effective against ACD.

A Probiotic Mixture Regulates T Cell Balance and Reduces Atopic Dermatitis Symptoms in Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with a complex etiology involving the immune response. Recent studies have demonstrated the role of certain probiotics in the treatment and prevention of AD. However, the mechanism by which these probiotics regulate the immune system remains unclear. In this study, we examined the immunomodulatory capacity of Duolac ATP, a mixed formulation of probiotics, both in vitro and in vivo. Results showed that the expression of programmed death-ligand 1(PD-L1) was significantly upregulated on bone marrow-derived dendritic cells (BMDCs) treated with Duolac ATP. Furthermore, the anti-inflammatory cytokines IL-10 and TGF-beta were both upregulated when BMDCs were treated with Duolac ATP. The percentage of proliferated regulatory T cells (Tregs) was enhanced when CD4⁺ T cells were co-cultured with Duolac ATP-treated BMDCs on plates coated with anti-CD3/CD28 antibodies. Intriguingly, IL-10 secretion from CD4⁺ T cells was also observed. The AD symptoms, histologic scores, and serum IgE levels in AD mice were significantly decreased after oral treatment with Duolac ATP. Moreover, the Th1-mediated response in AD-induced mice treated with oral Duolac ATP showed upregulation of IL-2 and IFN-gamma as well as of downstream signaling molecules T-bet, STAT-1, and STAT-4. Conversely, Duolac ATP suppressed Th2 and Th17 responses in AD-like mice, as evidenced by the downregulation of GATA-3, C-maf, IL-4, IL-5, and IL-17. Additionally, Duolac ATP increased the number of Tregs found at Peyer’s patches (PP) in treated AD mice. These results suggest that Duolac ATP modulates DCs to initiate both Th1 and Treg responses in AD mice. Thus, Duolac ATP represents a potential preventative agent against AD and could serve as an effective immunomodulator in AD patients.

Regulation of Allergic Immune Responses by Microbial Metabolites

Emerging evidence demonstrates that the microbiota plays an essential role in shaping the development and function of host immune responses. A variety of environmental stimuli, including foods and commensals, are recognized by the host through the epithelium, acting as a physical barrier. Two allergic diseases, atopic dermatitis and food allergy, are closely linked to the microbiota, because inflammatory responses occur on the epidermal border. The microbiota generates metabolites such as short-chain fatty acids and poly-γ-glutamic acid (γPGA), which can modulate host immune responses. Here, we review how microbial metabolites can regulate allergic immune responses. Furthermore, we focus on the effect of γPGA on allergic T helper (Th) 2 responses and its therapeutic application.

Therapeutic effect of tyndallized Lactobacillus rhamnosus IDCC 3201 on atopic dermatitis mediated by down-regulation of immunoglobulin E in NC/Nga mice

The therapeutic effect of oral administration of Lactobacillus rhamnosus IDCC 3201 tyndallizate (RHT3201) on atopic dermatitis (AD)-like skin lesions in NC/Nga mice were investigated. After induction of dermatitis in NC/Nga mice with house-dust mite extract, each group was fed RHT3201 with 1 × 10(8) , 1 × 10(9) , or 1 × 10(10) cells orally once a day for 8 weeks. Dermatitis scores and frequency of scratching were improved by oral feeding with RHT3201. In contrast to the control group, RHT3201-fed mice showed significantly down-regulated mast cell numbers and serum immunoglobulin E (IgE) concentrations had significantly less IL4 in their axillary lymph node cells. The therapeutic effect of RHT3201 was found to be dose-dependent. These findings indicate that RHT3201 has potential for treating AD.

Sensitivity to oxazolone induced dermatitis is transferable with gut microbiota in mice

Atopic Dermatitis (AD) has been associated with gut microbiota (GM) dysbiosis in humans, indicating a causative role of GM in AD etiology. Furthermore, the GM strongly correlates to essential disease parameters in the well-known oxazolone-induced mouse model of AD. Here, we demonstrate that it is possible to transfer both a high-responding and a low-responding AD phenotype with GM from conventional mice to germ-free mice. The mice inoculated with the high-responding GM had significantly higher clinical score, increased ear thickness, and increased levels of IL-1β, TNFα, IL-4, IL-5, and IL-6 compared to the mice inoculated with the low-responding GM. The inter-individual variation was in general not affected by this increase in effect size. Germ-free mice induced with AD revealed a high disease response as well as high inter-individual variation indicating protective properties of certain microbial taxa in this model. This study underlines that the GM has a strong impact on AD in mouse models, and that the power of studies may be increased by the application of mice inoculated with a specific GM from high responders to increase the effect size.

A Review of Applied Aspects of Dealing with Gut Microbiota Impact on Rodent Models

The gut microbiota (GM) affects numerous human diseases, as well as rodent models for these. We will review this impact and summarize ways to handle this challenge in animal research. The GM is complex, with the largest fractions being the gram-positive phylum Firmicutes and the gram-negative phylum Bacteroidetes. Other important phyla are the gram-negative phyla Proteobacteria and Verrucomicrobia, and the gram-positive phylum Actinobacteria. GM members influence models for diseases, such as inflammatory bowel diseases, allergies, autoimmunity, cancer, and neuropsychiatric diseases. GM characterization of all individual animals and incorporation of their GM composition in data evaluation may therefore be considered in future protocols. Germfree isolator-housed rodents or rodents made virtually germ free by antibiotic cocktails can be used to study diverse microbial influences on disease expression. Through subsequent inoculation with selected strains or cocktails of microbes, new "defined flora" models can yield valuable knowledge on the impact of the GM, and of specific GM members and their interactions, on important disease phenotypes and mechanisms. Rodent husbandry and microbial quality assurance practices will be important to ensure and confirm appropriate and research relevant GM.

The influence of the young microbiome on inflammatory diseases--Lessons from animal studies

Chronic inflammatory diseases are on the rise in the Westernized world. This rise has been correlated to a range of environmental factors, such as birth mode, rural versus urban living conditions, and use of antibiotics. Such environmental factors also influence early life gut microbiota (GM) colonization and maturation--and there is growing evidence that the negative effects of these factors on human health are mediated via GM alterations. Colonization of the gut initiates priming of the immune system from birth, driving tolerance towards non-harmful microorganisms and dietary antigens and proper reactions towards invading pathogens. This early colonization is crucial for the establishment of a healthy GM, and throughout life the balanced interaction of GM and immune system is a key element in maintaining health. An immune system out of balance increases the risk for later life inflammatory diseases. Animal models are indispensable in the studies of GM influence on disease mechanisms and progression, and focus points include studies of GM modification during pregnancy and perinatal life. Here, we present an overview of animal studies which have contributed to our understanding of GM functions in early life and how alterations affect risk and expression of certain inflammatory diseases with juvenile onset, including interventions, such as birth mode, antibiotics, and probiotics.

Long-term effect of early-life supplementation with probiotics on preventing atopic dermatitis: A meta-analysis

The prevalence of allergic diseases has increased over the past few decades. Atopic dermatitis (AD) is a common allergic disease, for which there is currently no known cure. Administration of probiotics in early life may be an effective method to prevent AD, but very little is known about its long-time preventive effect. In this research, a meta-analysis has been conducted to evaluate the long-term effect of early-life supplementation with probiotics on preventing AD. Meta-analysis was performed by the Review Manager version 5.2 software. Risk ratio and 95% confidence intervals were calculated by a fixed effect model. Six trials and a total of 1955 patients were included in this meta-analysis. The combined risk ratio of the meta-analysis comparing probiotics with placebo for investigating the long-term preventive effect of AD was 0.86 (95% CI 0.77-0.96), which demonstrates that probiotics is likely to produce long-term prevention of AD.

Plasmodium berghei infection ameliorates atopic dermatitis-like skin lesions in NC/Nga mice

Background

Atopic diseases are more prevalent in industrialized countries than in developing countries. In addition, significant differences in the prevalence of allergic diseases are observed between rural and urban areas within the same country. This difference in prevalence has been attributed to what is called the ‘hygiene hypothesis’. Although parasitic infections are known to protect against allergic reactions, the mechanism is still unknown. The aim of this study was to investigate whether or not malarial infections can inhibit atopic dermatitis (AD)-like skin lesions in a mouse model of AD.

Methods

We used NC/Nga mice which are a model for AD. The NC/Nga mice were intraperitoneally infected with 1 × 10⁵Plasmoduim berghei (Pb) XAT-infected erythrocytes.

Results

Malarial infections ameliorated AD-like skin lesions in the NC/Nga mice. This improvement was blocked by the administration of anti-asialo GM1 antibodies, which are anti-natural killer (NK) cells. Additionally, adoptive transfer of NK cells markedly improved AD-like skin lesions in conventional NC/Nga mice; these suggest that the novel protective mechanism associated with malaria parasitic infections is at least, in part, dependent on NK cells.

Conclusions

We have experimentally demonstrated for the first time that malarial infections ameliorated AD-like skin lesions in a mouse model of AD. Our study could explain in part the mechanism of the ‘hygiene hypothesis’, which states that parasitic infections can inhibit the development of allergic diseases.

Oral administration of whole dihomo-γ-linolenic acid-producing Saccharomyces cerevisiae suppresses cutaneous inflammatory responses induced by croton oil application in mice

Polyunsaturated fatty acids have been attracting considerable interest because of their many biological activities and important roles in human health and nutrition. Dihomo-γ-linolenic acid (DGLA; C20: 3n-6) is known to have an anti-inflammatory activity, but its range of effects was not well studied because of its limited natural sources. Taking advantage of genetic tractability and increasing wealth of accessible data of Saccharomyces cerevisiae, we have previously constructed a DGLA-producing yeast strain by introducing two types of desaturase and one elongase genes to convert endogenous oleic acid (C18:1n-9) to DGLA. In this study, we investigated the efficacy of oral intake of heat-killed whole DGLA-producing yeast cells in the absence of lipid purification on cutaneous inflammation. Topical application of croton oil to mouse ears induces ear swelling in parallel with the increased production of chemokines and accumulation of infiltrating cells into the skin sites. These inflammatory reactions were significantly suppressed in a dose-dependent manner by oral intake of the DGLA-producing yeast cells for only 7 days. This suppression was not observed by the intake of the γ-linolenic acid-producing (C18:3n-6, an immediate precursor of DGLA) yeast, indicating DGLA itself suppressed the inflammation. Further analysis demonstrated that DGLA exerted an anti-inflammatory effect via prostaglandin E1 formation because naproxen, a cyclooxygenase inhibitor, attenuated the suppression. Since 25-fold of purified DGLA compared with that provided as a form of yeast was not effective, oral administration of the whole DGLA-producing yeast is considered to be a simple but efficient method to suppress inflammatory responses.

Preventative and therapeutic probiotic use in allergic skin conditions: experimental and clinical findings

Probiotics are ingested live microbes that can modify intestinal microbial populations in a way that benefits the host. The interest in probiotic preventative/therapeutic potential in allergic diseases stemmed from the fact that probiotics have been shown to improve intestinal dysbiosis and permeability and to reduce inflammatory cytokines in human and murine experimental models. Enhanced presence of probiotic bacteria in the intestinal microbiota is found to correlate with protection against allergy. Therefore, many studies have been recently designed to examine the efficacy of probiotics, but the literature on the allergic skin disorders is still very scarce. Here, our objective is to summarize and evaluate the available knowledge from randomized or nonrandomized controlled trials of probiotic use in allergic skin conditions. Clinical improvement especially in IgE-sensitized eczema and experimental models such as atopic dermatitis-like lesions (trinitrochlorobenzene and picryl chloride sensitizations) and allergic contact dermatitis (dinitrofluorobenzene sensitization) has been reported. Although there is a very promising evidence to recommend the addition of probiotics into foods, probiotics do not have a proven role in the prevention or the therapy of allergic skin disorders. Thus, being aware of possible measures, such as probiotics use, to prevent/heal atopic diseases is essential for the practicing allergy specialist.

Probiotics, prebiotics and immunomodulation of gut mucosal defences: homeostasis and immunopathology

Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. There is a growing body of evidence documenting the immune-modulatory ability of probiotic bacteria, it is therefore reasonable to suggest that this is potentiated via a combination of prebiotics and probiotics as a symbiotic mix. The need for probiotic formulations has been appreciated for the health benefits in "topping up your good bacteria" or indeed in an attempt to normalise the dysbiotic microbiota associated with immunopathology. This review will focus on the immunomodulatory role of probiotics and prebiotics on the cells, molecules and immune responses in the gut mucosae, from epithelial barrier to priming of adaptive responses by antigen presenting cells: immune fate decision-tolerance or activation? Modulation of normal homeostatic mechanisms, coupled with findings from probiotic and prebiotic delivery in pathological studies, will highlight the role for these xenobiotics in dysbiosis associated with immunopathology in the context of inflammatory bowel disease, colorectal cancer and hypersensitivity.

Can nutritional modulation of maternal intestinal microbiota influence the development of the infant gastrointestinal tract?

The gastrointestinal microbiota plays an important role in maintaining host health by preventing the colonization of pathogens, fermenting dietary compounds, and maintaining normal mucosal immunity. Particularly in early life, the composition of the microbiota profoundly influences the development and maturation of the gastrointestinal tract (GIT) mucosa, which may affect health in later life. Therefore, strategies to manipulate the microbiota during infancy may prevent the development of some diseases later in adult life. Earlier research suggested that term fetuses are sterile and that the initial bacterial colonization of the newborn GIT occurs only after the baby transits through the birth canal. However, recent studies have demonstrated that the colonization and/or contact of the fetus with the maternal GIT microbiota may start in utero. After vaginal birth, the colonization of the neonate GIT continues through contact with maternal feces and vaginal bacteria, leading to a relatively simple microbial community that is influenced by feeding type (breast vs. formula feeding). Maternal GIT microbiota, vaginal microbiota, and breast milk composition are influenced by maternal diet. Alterations of the maternal GIT microbiota composition via supplementation with probiotics and prebiotics have been shown; however, transfer of these benefits to the offspring remains to be demonstrated. This review focuses on the influence of maternal GIT microbiota during the pre- and postpartum periods on the colonization of the infant GIT. In particular, it examines the manipulation of the maternal GIT microbiota composition through the use of probiotics and/or prebiotics and subsequent consequences for the health of the offspring.

Supplementation of the fermented soy product ImmuBalance™ effectively reduces itching behavior of atopic NC/Tnd mice

BACKGROUND

Effects of probiotics on the prevention of atopic diseases have been proposed recently. Although we have already reported the suppressive effects of the probiotic, ImmuBalance™, on a mouse model for peanuts allergy, its influence on atopic diseases remains unclear.

OBJECTIVE

Potential efficacy of ImmuBalance™, which is the fermented soy product, on treatment of atopic dermatitis (AD) was investigated using a mouse model for human AD, NC/Tnd mice.

METHODS

For in vivo study, ImmuBalance containing chow or a control diet were fed to NC/Tnd mice with moderate dermatitis for 2 weeks. Topical application of FK506 ointment was used as a positive control. Clinical skin severity scores, scratching behaviors, trans-epidermal water loss (TEWL), and histological features were analyzed. For in vitro study, suppressive effect of ImmuBalance™ on nerve growth factor (NGF)-activated neurite outgrowth of PC12 cells was examined.

RESULTS

Clinical skin severity scores of the mice fed with ImmuBalance containing chow were gradually reduced as well as the mice treated with FK506. Feeding with ImmuBalance completely inhibited the increase in scratching behavior of NC/Tnd mice. The value of TEWL of NC/Tnd mice fed with ImmuBalance was significantly decreased. In addition, histological examination revealed that application of ImmuBalance decreased the number of PGP9.5-positive neuronal fibers in the lesional skin. When ImmuBalance extract was added to the culture, NGF-activated neurite outgrowth of PC12 cells was diminished through the inhibition of the phosphatidylinositol 3-kinase phosphorylation.

CONCLUSION

ImmuBalance could exhibit favorable alterations on AD symptoms, particularly through down regulation of the itch sensation.

Immune disorders and its correlation with gut microbiome

Allergic disorders such as atopic dermatitis and asthma are common hyper-immune disorders in industrialized countries. Along with genetic association, environmental factors and gut microbiota have been suggested as major triggering factors for the development of atopic dermatitis. Numerous studies support the association of hygiene hypothesis in allergic immune disorders that a lack of early childhood exposure to diverse microorganism increases susceptibility to allergic diseases. Among the symbiotic microorganisms (e.g. gut flora or probiotics), probiotics confer health benefits through multiple action mechanisms including modification of immune response in gut associated lymphoid tissue (GALT). Although many human clinical trials and mouse studies demonstrated the beneficial effects of probiotics in diverse immune disorders, this effect is strain specific and needs to apply specific probiotics for specific allergic diseases. Herein, we briefly review the diverse functions and regulation mechanisms of probiotics in diverse disorders.

Time to include the gut microbiota in the hygienic standardisation of laboratory rodents

The gut microbiota (GM) composition and its impact on animal experiments has become currently dramatically relevant in our days: (1) recent progress in metagenomic technologies, (2) the availability of large scale quantitative analyses to characterize even subtle phenotypes, (3) the limited diversity of laboratory rodent GM due to strict barriers at laboratory animal vendors, and (4) the availability of up to 300.000 different transgenic mouse strains from different sources displaying a huge variety in their GM composition. In this review the GM is described as a variable in animal experiments which need to be reduced for scientific as well as ethical reasons, and strategies how to implement this in routine diagnostic procedures are proposed. We conclude that we have both enough information available to state that the GM has an essential impact on animal models, as well as the methods available to start dealing with these impacts.

Mast cells function as an alternative modulator of adipogenesis through 15-deoxy-delta-12, 14-prostaglandin J2

Mast cells are one of the major producers of prostaglandins (PGs). The final metabolite of PGs 15-deoxy-delta-12,14-PGJ(2) (15-deoxy-delta PGJ(2)) is the endogenous ligand of the peroxisome proliferator-activated receptor (PPAR) γ. PPARγ modulates adipocyte differentiation; therefore, we attempted to investigate whether PGs derived from mast cells influenced on adipogenesis. We found the increase of mast cell numbers in fat tissue of obese mice fed with a high-fat diet allowed us to speculate contributions of mast cells to adipogenesis. Mast cell-mediated induction of adipogenesis was evaluated by using 3T3 L1 cells. Supernatants obtained from mast cells stimulated with calcium ionophore or the high-glucose condition contained 15-deoxy-delta PGJ(2) and induced adipogenesis of 3T3 L1 cells. Agonistic activity of PGJ(2) from the supernatants on PPARγ was confirmed by a reporter gene assay. Culture medium collected from calcium ionophore-stimulated bone marrow-derived cultured mast cells (BMCMC) activated PPAR-responsive element in NIH3T3 fibroblasts, and the specific inhibitor of PPARγ canceled the activation. Contribution of mast cells to obesity was evaluated by using mast cell-deficient mice fed with a Western diet. Weight gain of mast cell-deficient mice during high-fat feeding was impaired compared with their littermate wild-type mice; on the other hand, transplantation of bone marrow-derived cultured mast cells to mast cell-deficient mice restored the weight gain by intake of a high-fat diet. In this study, we clearly demonstrated that mast cells produced PGs in response to the high-glucose condition and induced adipocyte differentiation and possibly obesity. This is the first study that provides evidence for a novel role of mast cells in adipogenesis via PPARγ activation.

Evaluation of itch by using NC/NgaTnd mice: a model of human atopic dermatitis

Atopic dermatitis (AD) is the extremely complicated syndrome that various abnormalities develop in a heap. There are various factors in patients for the onset and exacerbation of AD, including genetic cofactors of individuals, environmental factors, the failure of the skin barrier function, unfavorable regulation of the immune system, and the hypersensitivity of sensory nerves. In recent years, there have been many trials of the drug discovery that targets itch, because itch is one of the most serious clinical symptoms of AD. The selection of the suitable animal model that represents the condition of patients, as well as innovative analyzing protocols that can precisely evaluate itch, is indispensable for investigation of an effective drug for AD. In the paper, the unique spontaneous animal model for AD (NC/NgaTnd mice) and the novel quantification system of the laboratory animals that may bring a great progress in the future study of itch are outlined.