Oral therapeutic administration of a probiotic mixture suppresses established Th2 responses and systemic anaphylaxis in a murine model of food allergy

Effects of medicine food homologous materials on food allergy-associated factors: intestinal oxidative stress, intestinal inflammation and Th2 immune response

BACKGROUND

Food allergies could be regulated via Th1/Th2 balance, intestinal oxidative stress and inflammation, which were considered as food allergy-associated factors. Medicine-food homologous materials (MFHM) were considered as a significant factor with respect to preventing human diseases. To evaluate the associations between MFHM and food allergy-associated factors, two types of MFHM with the remarkable function of anti-oxidation and anti-inflammation, Gardeniae fructus (Gar) and Sophorae glos (Sop), were chosen.

RESULTS

By constructing an H2O2-induced oxidative stress model of Caco-2 cells and an intestinal inflammatory cell model of Caco-2 cells with tumor necrosis factor-α and interleukin (IL)-13, the contents of anti-oxidative enzymes (SOD and GSH), inflammatory factor (IL-8) and tight junction proteins (zonula occludens-1, occludin and claudin-1) in Caco-2 cells were determined. Moreover, the anti-allergic effects of digestive Sop and Gar were evaluated by measuring the levels of Th1/Th2/Treg cytokines in the spleen cells of sensitized mice. The results showed that the SOD and GSH were obviously increased and the gene and protein expression of IL-8 and claudin-1 were improved with the incubation of digested Sop. Th2 cytokine was reduced and Th1/Th2 balance was promoted on coincubation with ovalbumin (OVA) and digested Sop in the splenocytes. However, the digested Gar had no effect.

CONCLUSION

The digested Sop not only had suppressive effects on intestinal oxidative stress and inflammation, but also had regulative effects on Th1/Th2 balance. This finding demonstrated that not all of the MFHM with anti-oxidant and anti-inflammatory effects have anti-allergic activities. The present study may be contributing toward establishing a screening model to identify the anti-allergic MFHM. © 2024 Society of Chemical Industry.

Probiotics for inflammatory bowel disease: Is there sufficient evidence?

Inflammatory bowel disease (IBD) refers to chronic inflammatory disorders of the gut. Ulcerative colitis (UC) and Crohn's disease (CD) are two subtypes of IBD. Evidence suggests that the intestinal microbiota plays a role in the pathogenesis of IBD, so probiotics have garnered a lot of interest as a potential treatment or prevention for IBD. However, clinical evidence of the efficacy of probiotics is still debatable. We performed a literature review. An advanced search considered clinical studies on probiotic for IBD from inception to 2023 in PubMed, Embase, Cochrane Library, and Web of Science. In the treatment of UC with probiotics, only Escherichia coli Nissle 1917 for maintenance treatment of UC in remission, and Bifidobacterium and VSL#3 for induction of remission in patients with mild to moderately active UC have shown strong evidence. Currently, there are no definitive conclusions regarding the effectiveness of probiotics in CD. The mechanism of probiotic treatment for IBD may be related to reducing oxidative stress, repairing the intestinal barrier, regulating intestinal flora balance, and modulating intestinal immune response. Differences in the benefits of probiotics between CD and UC may be attributable to the different lesion extent and immune-mediated pathophysiology. More robust randomized clinical trials are required to validate the efficacy and safety of diverse probiotic strains in IBD.

The Role of Gut Microbiota and Leaky Gut in the Pathogenesis of Food Allergy

Food allergy (FA) is a growing public health concern, with an increasing prevalence in Western countries. Increasing evidence suggests that the balance of human gut microbiota and the integrity of our intestinal barrier may play roles in the development of FA. Environmental factors, including industrialization and consumption of highly processed food, can contribute to altering the gut microbiota and the intestinal barrier, increasing the susceptibility to allergic sensitization. Compositional and functional alterations to the gut microbiome have also been associated with FA. In addition, increased permeability of the gut barrier allows the translocation of allergenic molecules, triggering Th2 immune responses. Preclinical and clinical studies have highlighted the potential of probiotics, prebiotics, and postbiotics in the prevention and treatment of FA through enhancing gut barrier function and promoting the restoration of healthy gut microbiota. Finally, fecal microbiota transplantation (FMT) is now being explored as a promising therapeutic strategy to prevent FA in both experimental and clinical studies. In this review article, we aim to explore the complex interplay between intestinal permeability and gut microbiota in the development of FA, as well as depict potential therapeutic strategies.

Alterations of milk oligosaccharides in mothers with gestational diabetes mellitus impede colonization of beneficial bacteria and development of RORγt+ Treg cell-mediated immune tolerance in neonates

Gestational diabetes mellitus (GDM) is an increasing public health concern that significantly increases the risk of early childhood allergic diseases. Altered maternal milk glycobiome may strongly affect gut microbiota and enteric-specific Treg cell-mediated development of immune tolerance in GDM infants. In this study, we found that, compared with healthy Chinese mothers, mothers with GDM had significantly lower levels of total and specific human milk oligosaccharides (HMOs) in their colostrum that subsequently increased with extension of lactation. This alteration in HMO profiles significantly delayed colonization of Lactobacillus and Bifidobacterium spp. in their breast-fed infants, resulting in a distinct gut microbial structure and metabolome. Further experiments in GDM mouse models indicated that decreased contents of milk oligosaccharides, mainly 3'-sialyllactose (3'-SL), in GDM maternal mice reduced colonization of bacteria, such as L. reuteri and L. johnsonii, in the neonatal gut, which impeded development of RORγt+ regulatory T (Treg) cell-mediated immune tolerance. Treatment of GDM neonates with 3'-SL, Lactobacillus reuteri (L. reuteri) and L. johnsonii promoted the proliferation of enteric Treg cells and expression of transcription factor RORγt, which may have contributed to compromising ovalbumin (OVA)-induced allergic responses. In vitro experiments showed that 3'-SL, metabolites of L. johnsonii, and lysates of L. reuteri stimulated differentiation of mouse RORγt+ Treg cells through multiple regulatory effects on Toll-like receptor, MAPK, p53, and NOD-like receptor signaling pathways. This study provides new ideas for the development of gut microbiota and immune tolerance in GDM newborns.

Gut microbiome modulation by probiotics, prebiotics, synbiotics and postbiotics: a novel strategy in food allergy prevention and treatment

Food allergy has caused lots of global public health issues, particularly in developed countries. Presently, gut microbiota has been widely studied on allergy, while the role of dysbiosis in food allergy remains unknown. Scientists found that changes in gut microbial compositions and functions are strongly associated with a dramatic increase in the prevalence of food allergy. Altering microbial composition is crucial in modulating food antigens' immunogenicity. Thus, the potential roles of probiotics, prebiotics, synbiotics, and postbiotics in affecting gut bacteria communities and the immune system, as innovative strategies against food allergy, begins to attract high attention of scientists. This review briefly summarized the mechanisms of food allergy and discussed the role of the gut microbiota and the use of probiotics, prebiotics, synbiotics, and postbiotics as novel therapies for the prevention and treatment of food allergy. The perspective studies on the development of novel immunotherapy in food allergy were also described. A better understanding of these mechanisms will facilitate the development of preventive and therapeutic strategies for food allergy.

Capabilities of bio-binding, antioxidant and intestinal environmental repair jointly determine the ability of lactic acid bacteria to mitigate perfluorooctane sulfonate toxicity

Perfluorooctane sulfonate (PFOS) is a novel environmental contaminant that can be enriched in humans through the food chain, causing liver diseases, neurotoxicity and metabolic disorders. Lactic acid bacteria (LAB) are safe food-grade microorganisms that exhibit high antioxidant activity and bio-binding capacity towards toxins. Here, strains of LAB with different PFOS binding capacities and antioxidant activities were selected and analyzed for their ability in mitigating the toxic effects of PFOS. The results showed that the PFOS binding capacity and antioxidant activity of LAB largely influenced their ability in alleviating the toxic effects of PFOS. Notably, the individual LAB strains with low PFOS binding capacities and antioxidant activities also attenuated the toxic effects of PFOS, which was shown to up-regulate the contents of short-chain fatty acids (SCFAs) in the cecum and of tight junction proteins in the intestines of mice. Therefore, the mitigation pathway of PFOS-induced toxic damage by LAB is not limited to bio-binding and antioxidant. Repairing the gut environment damaged by PFOS is also essential for LAB to alleviate the toxic damage due to PFOS and may be partly independent of the bio-binding and antioxidant. Therefore, LAB as an alternative pathway for alleviating PFOS toxicity is suggested.

Immunomodulatory effects of probiotic Lactobacillus casei on GM-CSF-adjuvanted influenza DNA vaccine

Aim: This study investigates the protective efficacy of influenza DNA vaccine combined with a granulocyte macrophage-colony stimulating factor (GM-CSF) adjuvant, and probiotic Lactobacillus casei, an oral immunomodulator, in a BALB/c mice. Materials & methods: The mice were immunized with HA1 DNA vaccine along with GM-CSF and probiotic twice within a one-week interval. Results: The results showed that both adjuvants exert a synergistic effect in enhancing the humoral and cellular immune responses of the DNA vaccine. This combination also deceased IL-6 and IL-17A levels in the lung homogenates. The protection patterns were closely associated with influenza virus-specific splenocyte proliferative and serum IgG antibody (Ab) responses. Conclusion: The Findings demonstrate L. casei modulate balanced Th1/Th2 immune responses toward HA1 DNA vaccine adjuvanted by GM-CSF.

Widely Targeted Lipidomics and Transcriptomics Analysis Revealed Changes of Lipid Metabolism in Spleen Dendritic Cells in Shrimp Allergy

Shrimp allergy (SA) is pathological type 2 inflammatory immune responses against harmless shrimp protein allergen, which is caused by complex interactions between dendritic cells (DCs) and other immune cells. Lipid metabolism in different DCs states are significantly changed. However, the lipid metabolism of spleen DCs in SA remain ambiguous. In this study, we established a BALB/c mouse shrimp protein extract-induced allergy model to determine the lipid profile of spleen DCs in SA, and the molecular mechanism between lipid metabolism and immune inflammation was preliminarily studied. Spleen DCs were sorted by fluorescence-activated cell sorting, and then widely targeted lipidomics and transcriptomics analysis were performed. Principal component analysis presented the lipidome alterations in SA. The transcriptomic data showed that Prkcg was involved in lipid metabolism, immune system, and inflammatory signaling pathway. In the correlation analysis, the results suggested that Prkcg was positively correlated with triacylglycerol (Pearson correlation coefficient = 0.917, p = 0.01). The lipidomics and transcriptomics integrated pathway analysis indicated the activated metabolic conversion from triacylglycerol to 1,2-diacyl-sn-glycerol and the transmission of lipid metabolism to immune inflammation (from triacylglycerol and ceramide to Prkcg) in SA spleen DCs, and cellular experiments in vitro showed that glyceryl trioleate and C16 ceramide treatment induced immune function alteration in DCs.

Anti-inflammatory effect a specific Lactiplantibacillus plantarum in an ovalbumin-induced asthma model

Autoimmune, allergic, and respiratory inflammatory diseases are some of the most important health issues worldwide. Disorders of the gut microbiota have been associated with the induction of allergic and inflammatory diseases, and probiotics are being tested for disease prevention. We examined functional Lactiplantibacillus plantarum RGU (Lp-1) to mice with ovalbumin (OVA)-induced asthma model to elucidate the inhibitory effect on pathological progression in asthma model. Prior to the experiments, the intestinal lactic acid bacteria were reduced by administering multiple antibiotics (MAB) to evaluate the administration effect of lactic acid bacteria. Mice were administered with Lp-1 or comparative control lactic acid bacteria in each group. After that, OVA-induced asthma was induced, and cytokine gene expression and histological findings were compared. Exacerbation of lung lesions was confirmed in the MAB group. The Lp-1 group mice had alleviated lung lesions with a decrease in IL-1β, IL-13, IL-17 and an increase in IL-10 of the splenocytes and bronchial lymph nodes compared with the MAB group, but not in the other groups. In OVA-induced asthma, administration of specific Lactiplantibacillus was confirmed to induce anti-inflammatory cytokines.

Parasite-Probiotic Interactions in the Gut: Bacillus sp. and Enterococcus faecium Regulate Type-2 Inflammatory Responses and Modify the Gut Microbiota of Pigs During Helminth Infection

Dietary probiotics may enhance gut health by directly competing with pathogenic agents and through immunostimulatory effects. These properties are recognized in the context of bacterial and viral pathogens, but less is known about interactions with eukaryotic pathogens such as parasitic worms (helminths). In this study we investigated whether two probiotic mixtures (comprised of Bacillus amyloliquefaciens, B. subtilis, and Enterococcus faecium [BBE], or Lactobacillus rhamnosus LGG and Bifidobacterium animalis subspecies Lactis Bb12 [LB]) could modulate helminth infection kinetics as well as the gut microbiome and intestinal immune responses in pigs infected with the nodular worm Oesophagostomum dentatum. We observed that neither probiotic mixture influenced helminth infection levels. BBE, and to a lesser extent LB, changed the alpha- and beta-diversity indices of the colon and fecal microbiota, notably including an enrichment of fecal Bifidobacterium spp. by BBE. However, these effects were muted by concurrent O. dentatum infection. BBE (but not LB) significantly attenuated the O. dentatum-induced upregulation of genes involved in type-2 inflammation and restored normal lymphocyte ratios in the ileo-caecal lymph nodes that were altered by infection. Moreover, inflammatory cytokine release from blood mononuclear cells and intestinal lymphocytes was diminished by BBE. Collectively, our data suggest that selected probiotic mixtures can play a role in maintaining immune homeostasis during type 2-biased inflammation. In addition, potentially beneficial changes in the microbiome induced by dietary probiotics may be counteracted by helminths, highlighting the complex inter-relationships that potentially exist between probiotic bacteria and intestinal parasites.

The Panda-Derived Lactobacillus plantarum G201683 Alleviates the Inflammatory Response in DSS-Induced Panda Microbiota-Associated Mice

Intestinal diseases are one of the main causes of captive giant panda death. Their special dietary habits and gastrointestinal tract structure often lead to intestinal epithelium damage and secondary intestinal infection. The captive giant panda is predisposed to suffer from microbiota dysbiosis due to long-term artificial feeding and antibiotic misuse. However, there are few reported probiotics to treat giant panda enteritis and the associated dysbiosis. This study aims to elucidate the mechanism by which Lactobacillus plantarum G201683 (L. plantarum G83), a promising panda-derived probiotic, exerts a protective effect on intestinal inflammation in the dextran sulfate sodium- (DSS) induced panda microbiota-associated (DPMA) mouse model. The DPMA mouse was generated by antibiotic treatment and 5% DSS drinking water administration to assess the effect of L. plantarum G83 on intestinal inflammation and microbiota in vivo. Our results demonstrated the successful generation of a DPMA mouse model with Enterobacteriaceae enrichment, consistent with the giant panda intestinal microbiota. L. plantarum G83 decreased clinical and histological severity of intestinal inflammation, enhanced intestinal tight junction protein expression (ZO-1, Occludin) and alleviated inflammatory cytokine production (TNF-) in the colon of DPMA mice. The administration of L. plantarum G83 altered the microbiota composition by decreasing pathogen associated taxa such as E. coli and increasing abundance of beneficial bacteria including Bifidobacterium spp. These changes in microbiota composition were associated with an increased concentration of short chain fatty acids (SCFA), reduced NF-κB signaling, and an altered balance of T helper cell subsets. Our findings support L. plantarum G83 as a promising probiotic to treat intestinal inflammation in the giant panda.

A New Formulation of Probiotics Attenuates Calcipotriol-Induced Dermatitis by Inducing Regulatory Dendritic Cells

Atopic dermatitis (AD) is a recurrent chronic inflammatory skin disease affecting up to 30% of the children population, and immuno-regulatory therapy that could modify the course of disease is urgently needed. Probiotics have demonstrated therapeutic effects on AD and could potentially regulate the disease process. However, the efficacy of probiotics for AD is inconsistent among different studies, which is mainly due to the elusive mechanism and different species and (or) strains used. In this study, we designed a mixture of five strains of probiotics (named IW5) and analyzed the effect and mechanism of IW5 on calcipotriol (MC903)-induced AD-like dermatitis. We found that IW5 significantly alleviated skin inflammation of the MC903-induced AD in mice. Administration with IW5 induced increased production of regulatory T cells and regulatory dendritic cells (DCregs) in the mesenteric lymph nodes. We also found that the diversity of the gut microbiota in the mice with MC903-induced dermatitis was increased after IW5 administration, and the level of butyrate in the gut was elevated. In cell culture, butyrate induced the production of DCregs. Our study revealed the therapeutic effects of a newly designed probiotics mixture and uncovered a possible mechanism, providing a foundation for future clinical studies.

Effect of Lactiplantibacillus plantarum HM-22 on immunoregulation and intestinal microbiota in α-lactalbumin-induced allergic mice

Milk protein is one of the eight major allergens, and α-lactalbumin (α-LA) is one of the major allergens of bovine milk protein. Our previous studies found that Lactiplantibacillus plantarum HM-22 (L. plantarum HM-22) showed a good gastrointestinal survival rate and intestinal colonization. To investigate the effect of L. plantarum HM-22 on intestinal inflammation and intestinal microbiota in α-LA-induced allergic mice, in this study, L. plantarum HM-22 at low and high doses was intragastrically administered to α-LA-induced allergic mice for 5 weeks. The results showed that L. plantarum HM-22 significantly relieved the weight loss and organ index of α-LA-induced allergic mice (p < 0.05). L. plantarum HM-22 increased the levels of interleukin-10 (IL-10), interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) in the serum of α-LA-induced allergic mice and decreased the levels of total immunoglobulin E (IgE) and the proinflammatory factor interleukin-4 (IL-4) (p < 0.05). The crypt structure of the colon tissues of α-LA-induced allergic mice changed, goblet cells decreased, and the phenomenon of a large number of inflammatory corpuscles that appeared was improved and alleviated with the intervention of L. plantarum HM-22 by hematoxylin-eosin (HE) staining. Western blot analysis showed that L. plantarum HM-22 significantly increased the expression of occludin and claudin-1 in the colon of α-LA-induced allergic mice and decreased the expression of the inflammatory proteins p65 and IκBα (p < 0.05). The intestinal microbiota of mice in each group was determined by 16S rRNA amplicon sequencing, and the results showed that intervention with L. plantarum HM-22 improved the intestinal microbes of α-LA-induced allergic mice. Spearman's correlation analysis revealed the correlation between intestinal microbiota changes and the α-LA-induced allergy-related index. This study provides a theoretical basis for probiotics to prevent allergies by changing the intestinal microbiota.

Lactiplantibacillus plantarum 22A-3 isolated from pickle suppresses ovalbumin-induced food allergy in BALB/c mice and 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice

In the previous study, pickle-derived Lactiplantibacillus plantarum 22A-3 (LP22A3) suppressed ear edema in passive cutaneous anaphylaxis by its oral administration. Moreover, LP22A3 treatment directly to RBL-2H3 cells shows no effect on β-hexosaminidase release from RBL-2H3 but inhibited its release using the Caco-2/RBL-2H3 cells co-culture system stimulated with LP22A3 from the apical side. In this study, oral administration of LP22A3 decreased total IgE and ovalbumin (OVA) specific IgE contents in blood of BALB/c mice induced food allergy by OVA. Moreover, its oral administration suppressed the development of dermatitis induced by 2,4-dinitrochlorobenzene (DNCB) which was used to develop atopic dermatitis-like lesions in NC/Nga mice. This alleviation was further correlated with a reduction of elevated serum total IgE, transepidermal water loss and elevated acanthosis in the LP22A3-treated group compared with vehicle-treated positive group. In co-culture system composed of Caco-2 and RBL-2H3 cells, LP22A3 treatment on apical side before or after the sensitization with anti-dinitrophenyl (DNP) IgE antibody indicated the different effect on β-hexosaminidase release from RBL-2H3. Its treatment before the sensitization decreased β-hexosaminidase release, but not after sensitization, indicating that LP22A3 affected mast cells sensitized with allergen through intestinal epithelial cells. These results suggest that LP22A3 may have a potential therapeutic property for Type 1 hypersensitivity and atopic dermatitis.

Suppression of Hippo Pathway by Food Allergen Exacerbates Intestinal Epithelia Instability and Facilitates Hypersensitivity

SCOPE

Hippo signaling is a crucial pathway in innate immune responses, but the relationship between food allergy and Hippo pathway is unknown. The aim of this work is to investigate the regulation of food allergy by Hippo pathway and reveal the molecular mechanisms.

METHODS AND RESULTS

Two food allergens tropomyosin and ovalbumin are used to challenge a mouse model and CMT93 intestinal epithelia cell model. The allergic responses and the activation of Hippo pathway are tested in these models. In the mouse model, both allergens trigged significant allergic responses, and Hippo pathway is suppressed after allergen challenge. In CMT93, both allergens upregulate the expression of allergic cytokines thymic stromal lymphopoietin, interleukin (IL)-25, and IL-33. In TAZ KD CMT93, the Hippo pathway is blocked, and the expression of allergenic cytokines are also suppressed.

CONCLUSIONS

Both in vivo and in vitro data demonstrate that the two food allergens suppressed Hippo pathway by downregulating TAZ expression, resulting in intestinal epithelia instability, and finally leading to hypersensitivity reactions. These findings provide potential therapeutic targets and molecular markers for food allergy, and provide dietary guidelines for allergenic individuals.

Effect of structural stability on endolysosomal degradation and T-cell reactivity of major shrimp allergen tropomyosin

BACKGROUND

Tropomyosins are highly conserved proteins, an attribute that forms the molecular basis for their IgE antibody cross-reactivity. Despite sequence similarities, their allergenicity varies greatly between ingested and inhaled invertebrate sources. In this study, we investigated the relationship between the structural stability of different tropomyosins, their endolysosomal degradation patterns, and T-cell reactivity.

METHODS

We investigated the differences between four tropomyosins-the major shrimp allergen Pen m 1 and the minor allergens Der p 10 (dust mite), Bla g 7 (cockroach), and Ani s 3 (fish parasite)-in terms of IgE binding, structural stability, endolysosomal degradation and subsequent peptide generation, and T-cell cross-reactivity in a BALB/c murine model.

RESULTS

Tropomyosins displayed different melting temperatures, which did not correlate with amino acid sequence similarities. Endolysosomal degradation experiments demonstrated differential proteolytic digestion, as a function of thermal stability, generating different peptide repertoires. Pen m 1 (Tm 42°C) and Der p 10 (Tm 44°C) elicited similar patterns of endolysosomal degradation, but not Bla g 7 (Tm 63°C) or Ani s 3 (Tm 33°C). Pen m 1-specific T-cell clones, with specificity for regions highly conserved in all four tropomyosins, proliferated weakly to Der p 10, but did not proliferate to Bla g 7 and Ani s 3, indicating lack of T-cell epitope cross-reactivity.

CONCLUSIONS

Tropomyosin T-cell cross-reactivity, unlike IgE cross-reactivity, is dependent on structural stability rather than amino acid sequence similarity. These findings contribute to our understanding of cross-sensitization among different invertebrates and design of suitable T-cell peptide-based immunotherapies for shrimp and related allergies.

A Comprehensive Review on Natural Bioactive Compounds and Probiotics as Potential Therapeutics in Food Allergy Treatment

Food allergy is rising at an alarming rate and is a major public health concern. Globally, food allergy affects over 500 million people, often starting in early childhood and increasingly reported in adults. Commercially, only one approved oral immunotherapy-based treatment is currently available and other allergen-based immunotherapeutic are being investigated in clinical studies. As an alternative approach, a substantial amount of research has been conducted on natural compounds and probiotics, focusing on the immune modes of action, and therapeutic uses of such sources to tackle various immune-related diseases. Food allergy is primarily mediated by IgE antibodies and the suppression of allergic symptoms seems to be mostly modulated through a reduction of allergen-specific IgE antibodies, upregulation of blocking IgG, and downregulation of effector cell activation (e.g., mast cells) or expression of T-helper 2 (Th-2) cytokines. A wide variety of investigations conducted in small animal models or cell-based systems have reported on the efficacy of natural bioactive compounds and probiotics as potential anti-allergic therapeutics. However, very few lead compounds, unlike anti-cancer and anti-microbial applications, have been selected for clinical trials in the treatment of food allergies. Natural products or probiotic-based approaches appear to reduce the symptoms and/or target specific pathways independent of the implicated food allergen. This broad range therapeutic approach essentially provides a major advantage as several different types of food allergens can be targeted with one approach and potentially associated with a lower cost of development. This review provides a brief overview of the immune mechanisms underlying food allergy and allergen-specific immunotherapy, followed by a comprehensive collection of current studies conducted to investigate the therapeutic applications of natural compounds and probiotics, including discussions of their mode of action and immunological aspects of their disease-modifying capabilities.

Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases

Probiotics are known as “live microorganisms” and have been proven to have a health effect on hosts at the proper dose. Recently, a kind of probiotic mixture including eight live bacterial strains, VSL#3, has attracted considerable attention for its combined effect. VSL#3 is the only probiotic considered as a kind of medical food; it mainly participates in the regulation of the intestinal barrier function, including improving tight junction protein function, balancing intestinal microbial composition, regulating immune-related cytokine expression and so on. The objective of this review is to discuss the treatment action and mechanism for the administration of VSL#3 in chronic diseases of animals and humans (including children). We found that VSL#3 has a therapeutic or preventive effect in various systemic diseases per a large number of studies, including digestive systemic diseases (gastrointestinal diseases and hepatic diseases), obesity and diabetes, allergic diseases, nervous systemic diseases, atherosclerosis, bone diseases, and female reproductive systemic diseases.

Combined Effects of Lactobacillus rhamnosus and Egg Oral Immunotherapy in a Mouse Model of Egg Allergy

Purpose

Recent clinical trials have successfully used oral immunotherapy (OIT) to treat food allergies. Probiotics have immunomodulatory effects by balancing Th1/Th2 immunity and enhancing regulatory T-cell activity. In this study, we analyzed the effects of OIT, probiotics alone, and probiotics administered simultaneously with OIT in a mouse model of egg allergy.

Methods

C3H/HeJ mice were sensitized by intragastric administration of ovomucoid (OM) with cholera toxin. For the OIT regime, increasing doses of OM were administered orally to sensitized mice. Lactobacillus casei variety ramnosus (Lcr35) was also administered. The mice were divided into 4 groups: control (no OIT), OIT, Lcr35, and OIT plus Lcr35 (OIT + Lcr35). The effects of OIT and Lcr35 treatment were estimated based on the symptom score, rectal temperature, serum levels of OM-specific immunoglobulin (Ig)E, IgA, IgG1, and IgG2a immediately after and 2 weeks after ceasing treatment and histological staining of the small intestine.

Results

The severity of anaphylaxis decreased in all treatment groups. Simultaneous administration of Lcr35 and OIT decreased the severity of anaphylaxis compared to controls and the OIT group. The protective effects were sustained 2 weeks after ceasing treatment in all treatment groups. A significant decrease in OM-specific IgA, IgG1, and IgG2a levels was observed in both the OIT and OIT plus Lcr35 groups. However, a significant decrease in the OM-specific IgE level was observed only in OIT plus Lcr35 treated mice and was sustained 2 weeks after ceasing treatment. Mucin amounts in the small intestine decreased after OIT, OIT plus Lcr35, and Lcr35 treatment with the lowest in the OIT plus Lcr35 group.

Conclusions

Lcr35 treatment during OIT had some synergic effect for protection against anaphylaxis in a mice model of egg allergy. These findings should be confirmed in future animal studies including more detailed immunological profiles and human studies.

FcεRI-HDAC3-MCP1 Signaling Axis Promotes Passive Anaphylaxis Mediated by Cellular Interactions

Anaphylaxis is an acute and life-threatening systemic reaction. Food, drug, aero-allergen and insect sting are known to induce anaphylaxis. Mast cells and basophils are known to mediate Immunoglobulin E (IgE)-dependent anaphylaxis, while macrophages, neutrophils and basophils mediate non IgE-dependent anaphylaxis. Histone deacetylases (HDACs) play various roles in biological processes by deacetylating histones and non-histones proteins. HDAC inhibitors can increase the acetylation of target proteins and affect various inflammatory diseases such as cancers and allergic diseases. HDAC3, a class I HDAC, is known to act as epigenetic and transcriptional regulators. It has been shown that HDAC3 can interact with the high-affinity Immunoglobulin E receptor (FcεRI), to mediate passive anaphylaxis and cellular interactions during passive anaphylaxis. Effects of HDAC3 on anaphylaxis, cellular interactions involving mast cells and macrophages during anaphylaxis, and any tumorigenic potential of cancer cells enhanced by mast cells will be discussed in this review. Roles of microRNAs that form negative feedback loops with hallmarks of anaphylaxis such as HDAC3 in anaphylaxis and cellular interactions will also be discussed. The roles of MCP1 regulated by HDAC3 in cellular interactions during anaphylaxis are discussed. Roles of exosomes in cellular interactions mediated by HDAC3 during anaphylaxis are also discussed. Thus, review might provide clues for development of drugs targeting passive anaphylaxis.

Food Allergies: Current and Future Treatments

Food allergies are an increasingly public health problem, affecting up to 10% of children and causing a significant burden on affected patients, resulting in dietary restrictions, fear of accidental ingestion and related risk of severe reactions, as well as a reduced quality of life. Currently, there is no specific cure for a food allergy, so the only available management is limited to strict dietary avoidance, education on prompt recognition of symptoms, and emergency treatment of adverse reactions. Several allergen specific- and nonspecific-therapies, aiming to acquire a persistent food tolerance, are under investigation as potential treatments; however, to date, only immunotherapy has been identified as the most promising therapeutic approach for food allergy treatment. The aim of this review is to provide an updated overview on changes in the treatment landscape for food allergies.

Gut Microbiome as Target for Innovative Strategies Against Food Allergy

The dramatic increase in food allergy prevalence and severity globally requires effective strategies. Food allergy derives from a defect in immune tolerance mechanisms. Immune tolerance is modulated by gut microbiota function and structure, and microbiome alterations (dysbiosis) have a pivotal role in the development of food allergy. Environmental factors, including a low-fiber/high-fat diet, cesarean delivery, antiseptic agents, lack of breastfeeding, and drugs can induce gut microbiome dysbiosis, and have been associated with food allergy. New experimental tools and technologies have provided information regarding the role of metabolites generated from dietary nutrients and selected probiotic strains that could act on immune tolerance mechanisms. The mechanisms are multiple and still not completely defined. Increasing evidence has provided useful information on optimal bacterial species/strains, dosage, and timing for intervention. The increased knowledge of the crucial role played by nutrients and gut microbiota-derived metabolites is opening the way to a post-biotic approach in the stimulation of immune tolerance through epigenetic regulation. This review focused on the potential role of gut microbiome as the target for innovative strategies against food allergy.

Varied doses and chemical forms of selenium supplementation differentially affect mouse intestinal physiology

Varied doses and chemical forms of selenium supplementation differentially affect mouse intestinal physiology and perturbed the fecal metabolic profiles of and jejunal protein expression in mice.

Mechanisms by which gut microorganisms influence food sensitivities

Finely tuned mechanisms enable the gastrointestinal tract to break down dietary components into nutrients without mounting, in the majority of cases, a dysregulated immune or functional host response. However, adverse reactions to food have been steadily increasing, and evidence suggests that this process is environmental. Adverse food reactions can be divided according to their underlying pathophysiology into food intolerances, when, for instance, there is deficiency of a host enzyme required to digest the food component, and food sensitivities, when immune mechanisms are involved. In this Review, we discuss the clinical and experimental evidence for enteric infections and/or alterations in the gut microbiota in inciting food sensitivity. We focus on mechanisms by which microorganisms might provide direct pro-inflammatory signals to the host promoting breakdown of oral tolerance to food antigens or indirect pathways that involve the metabolism of protein antigens and other dietary components by gut microorganisms. Better understanding of these mechanisms will help in the development of preventive and therapeutic strategies for food sensitivities.

Effect of administration of a probiotic preparation on gut microbiota and immune response in healthy women in India: an open-label, single-arm pilot study

Background

Probiotics have been shown to be useful for the treatment of many disease conditions. These beneficial effects are believed to be mediated by change in the composition of gut microbiota and modulation of the host immune responses. However, the available data on the effect of probiotics on these parameters are quite limited.

Methods

We studied the composition of fecal microbiota, using 16S rRNA sequencing, and host immune responses in peripheral blood (plasma cytokine levels, T cell subsets and in vitro cytokine production after stimulation with anti-CD3/CD28 antibody or lipopolysaccharide) in a group of 14 healthy women at three time-points – before and after administration of a probiotic preparation (a capsule of VSL#3, each containing 112.5 billion freeze-dried bacterial cells belonging to 8 species, twice a day for 4 weeks), and 4-weeks after discontinuation of the probiotic administration.

Results

There was no change in the abundance of various bacterial taxa as well as in the alpha diversity of gut microbiota following administration of the probiotic, or following its discontinuation. Probiotic administration led to a reduction in the relative frequency of circulating Th17 cells, and in vitro production of cytokines in whole-blood cultures in response to lipopolysaccharide stimulation. However, it had no effect on the relative frequencies of Th1, Th2 and T regulatory cells among circulating peripheral blood mononuclear cells, on plasma cytokine levels and on in vitro production of cytokines by T cells.

Conclusions

We found that VSL#3 administration did not lead to any changes in gut flora, but led to a reduction in the frequency of Th17 cells and in the production of pro-inflammatory cytokine on lipopolysaccharide stimulation. These findings suggest that the beneficial anti-inflammatory effect of this preparation in patients with autoimmune and allergic disorders may be related to reduced production of monocyte-derived cytokines rather than to changes in the composition of gut microbiota.

Trial registration

NCT03330678, Date of registration 30th October 2017. Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0819-6) contains supplementary material, which is available to authorized users.

Seafood allergy: A comprehensive review of fish and shellfish allergens

Seafood refers to several distinct groups of edible aquatic animals including fish, crustacean, and mollusc. The two invertebrate groups of crustacean and mollusc are, for culinary reasons, often combined as shellfish but belong to two very different phyla. The evolutionary and taxonomic diversity of the various consumed seafood species poses a challenge in the identification and characterisation of the major and minor allergens critical for reliable diagnostics and therapeutic treatments. Many allergenic proteins are very different between these groups; however, some pan-allergens, including parvalbumin, tropomyosin and arginine kinase, seem to induce immunological and clinical cross-reactivity. This extensive review details the advances in the bio-molecular characterisation of 20 allergenic proteins within the three distinct seafood groups; fish, crustacean and molluscs. Furthermore, the structural and biochemical properties of the major allergens are described to highlight the immunological and subsequent clinical cross-reactivities. A comprehensive list of purified and recombinant allergens is provided, and the applications of component-resolved diagnostics and current therapeutic developments are discussed.

Augmentation of the expression of the eotaxin receptor on duodenal neutrophils by IL-21

Inflammation can occur via different mechanisms, such as via acute and chronic responses, on numerous occasions and function accordingly through various roles. There are more than five subsets of neutrophils; neutrophilic heterogeneity is modulated by the inflammatory condition. To understand the characteristics of inflammation, identification of atypical neutrophils is important. In this study, we found that the expression of eotaxin receptor (CD193) on atypical neutrophils in the duodenum is augmented in IL-21 isoform transgenic (Tg) mice. In a series of studies, we have established a Tg mouse strain to further investigate the functions of IL-21 in vivo. Interestingly, Tg mice immunized with ovalbumin (OVA) were more sensitive to OVA-induced systemic anaphylaxis as compared with wild type mice with duodenal and splenic gross congestion. Further analysis conducted in the duodenum of Tg mice revealed that only the number of neutrophils migrating into the duodenum was significantly increased prior to immunization. Previous studies have shown that the gastrointestinal compartment and the spleen constantly produce eotaxin, which regulates basal levels of tissue eosinophils. Therefore, we analyzed CD193 expression on neutrophils and eosinophils. As expected, its expression by duodenal neutrophils was upregulated in Tg mice. Furthermore, the addition of IL-21 into bone marrow cell culture increased the number of CD193⁺ neutrophils, which easily migrated into the duodenum. These observations suggested that CD193⁺ neutrophils increase in number under inflammatory conditions due to chronic IL-21 production.

Lactic acid bacteria-specific induction of CD4+Foxp3+T cells ameliorates shrimp tropomyosin-induced allergic response in mice via suppression of mTOR signaling

The beneficial effects of probiotics have been described in allergic sensitization and diseases; however, many questions remain unanswered, such as characteristics of the most effective strains in modulation of allergic responses and how orally administered probiotics affect the systemic immune system. In the present work, oral administration of five lactic acid bacteria strains showed variable effects on protection against the allergic reaction in a mouse model of food allergy to shrimp tropomyosin (ST). The most effective anti-allergic strain, Bacillus coagulans 09.712 (Bc), greatly improved epithelial barrier function and increased lymphocytes proliferation. Moreover, Bc suppresses ST sensitization by altering Th1/Th2/Treg balance as a result of strong induction of CD4⁺Foxp3⁺Tregs in combination with IL-10 producing. Bc-specific induction of CD4⁺Foxp3⁺ Tregs also suppresses Th17 pro-inflammatory response in this mouse model. Finally, the intake of Bc suppresses mTOR activation and thus the phosphorylation of downstream factors. Inhibition of mTOR signaling by Bc further results in FOXP3 up-regulation and GATA-3 down-regulation, which, in turn, facilitate to control Th2-predominant and Th17 pro-inflammatory responses caused by ST. Our work provides further characterization of the anti-allergic effects of probiotic LAB strains, and identifies new targets for preventive and curative treatment of food allergies.

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.

Novel Mechanisms Underlying the Therapeutic Effect of Glycomacropeptide on Allergy: Change in Gut Microbiota, Upregulation of TGF-β, and Inhibition of Mast Cells

BACKGROUND

The prevalence of allergic diseases is globally increasing. We have previously described that glycomacropeptide (GMP), a bioactive milk peptide, has therapeutic value in experimental models of skin hypersensitivity, anaphylaxis, and asthma, as it prevents an excessive T helper type 2 cell immune response. The aim of this study was to analyze the effect of GMP on key elements directly involved in the development or control of allergy, in order to improve the precise knowledge about its mechanism of action.

METHODS

Rats were systemically sensitized with ovalbumin and orally treated with GMP. Levels of Lactobacillus, Bifidobacterium, and Bacteroides were analyzed in their feces. Splenocytes were isolated and the production of transforming growth factor (TGF)-β by allergens was measured. Intradermal skin reactions were developed to evaluate in vivo activation of mast cells. Peritoneal mast cells were isolated and activated by the allergen, and histamine secretion was determined.

RESULTS

GMP administration increased the amount of intestinal Lactobacillus and Bifidobacterium of allergen-sensitized animals after 3 days of treatment. The increase in Bacteroides was also significant, but only after 17 days of GMP administration. Ten days after treatment cessation, Lactobacillus and Bacteroides were still elevated. GMP intake also elevated the production of TGF-β in the splenocytes of sensitized animals. In addition, treatment with GMP attenuated mast cell activation by the allergen and inhibited histamine secretion, without affecting the number of mast cells.

CONCLUSIONS

The prebiotic action of GMP on allergy-protective microbiota, an increase in TGF-β production, and a reduction in mast cell response to allergens are novel mechanisms that explain the antiallergic activity of GMP.

New pharmaceutical approaches for the treatment of food allergies

INTRODUCTION

Allergic diseases constitute one of the most common causes of chronic illness in developed countries. The main mechanism determining allergy is an imbalance between Th1 and Th2 response towards Th2.

AREAS COVERED

This review describes the mechanisms underlying the natural tolerance to food components and the development of an allergic response in sensitized individuals. Furthermore, therapeutic approaches proposed to manage these abnormal immunologic responses food are also presented and discussed.

EXPERT OPINION

In the past, management of food allergies has consisted of the education of patients to avoid the ingestion of the culprit food and to initiate the therapy (e.g. self-injectable epinephrine) in case of accidental ingestion. In recent years, sublingual/oral immunotherapies based on the continuous administration of small amounts of the allergen have been developed. However, the long periods of time needed to obtain significant desensitization and the generation of adverse effects, limit their use. In order to solve these drawbacks, strategies to induce tolerance are being studied, such as the use of either adjuvant immunotherapy in order to facilitate the reversion of the Th2 response towards Th1 or the use of monoclonal antibodies to block the main immunogenic elements.

Influence of microbiome and diet on immune responses in food allergy models

The intestinal immune system is intimately connected with the vast array of microbes present within the gut and the diversity of food components that are consumed daily. The discovery of novel molecular mechanisms, which mediate host-microbe-nutrient communication, have highlighted the important roles played by microbes and dietary factors in influencing mucosal inflammatory and allergic responses. In this review, we summarize the recent important findings in this field, which are important for food allergy and particularly relevant to animal models of food allergy.

Immunomodulatory Effects of Different Lactic Acid Bacteria on Allergic Response and Its Relationship with In Vitro Properties

Some studies reported that probiotic could relieve allergy-induced damage to the host, but how to get a useful probiotic is still a challenge. In this study, the protective effects of three lactic acid bacteria (La, Lp and Lc) were evaluated in a mouse model, and its relationship with the in vitro properties was analyzed. The in vitro results indicated that La with the capacity to inhibit IL-4 production could have a better anti-allergy effect in vivo than two others. However, the animal trials showed that all LAB strains could alleviate allergen-induced airway inflammation. Among them, LAB strain Lp had a better effect in inhibiting allergic response through a modulation of Th1/Th2 balance and an increase of regulatory T cells. This difference could be explained by that different LAB strains have a strain-specific effect on gut microbiota closely associated with host immune responses. Finally, this study did not only obtain an effective anti-allergy probiotic strain via animal study, but also indicate that probiotic-induced effect on intestinal microbiota should be considered as an important screening index, apart from its inherent characteristics.

Oral Administration of Probiotics Inhibits Absorption of the Heavy Metal Cadmium by Protecting the Intestinal Barrier

The heavy metal cadmium (Cd) is an environmental pollutant that causes adverse health effects in humans and animals. Our previous work demonstrated that oral administration of probiotics can significantly inhibit Cd absorption in the intestines of mice, but further evidence is needed to gain insights into the related protection mode. The goal of this study was to evaluate whether probiotics can inhibit Cd absorption through routes other than the Cd binding, with a focus on gut barrier protection. In the in vitro assay, both the intervention and therapy treatments of Lactobacillus plantarum CCFM8610 alleviated Cd-induced cytotoxicity in the human intestinal cell line HT-29 and protected the disruption of tight junctions in the cell monolayers. In a mouse model, probiotics with either good Cd-binding or antioxidative ability increased fecal Cd levels and decreased Cd accumulation in the tissue of Cd-exposed mice. Compared with the Cd-only group, cotreatment with probiotics also reversed the disruption of tight junctions, alleviated inflammation, and decreased the intestinal permeability of mice. L. plantarum CCFM8610, a strain with both good Cd binding and antioxidative abilities, exhibited significantly better protection than the other two strains. These results suggest that along with initial intestinal Cd sequestration, probiotics can inhibit Cd absorption by protecting the intestinal barrier, and the protection is related to the alleviation of Cd-induced oxidative stress. A probiotic with both good Cd-binding and antioxidative capacities can be used as a daily supplement for the prevention of oral Cd exposure.

IMPORTANCE

The heavy metal cadmium (Cd) is an environmental pollutant that causes adverse health effects in humans and animals. For the general population, food and drinking water are the main sources of Cd exposure due to the biomagnification of Cd within the food chain; therefore, the intestinal tract is the first organ that is susceptible to Cd contamination. Moreover, Cd exposure causes the disruption of the intestinal barrier and further induces the amplification of Cd absorption. The present study confirms that, along with initial intestinal Cd sequestration, oral administration of probiotics can inhibit Cd absorption by protecting the intestinal barrier. A probiotic with both good Cd-binding and antioxidative capacities can be used as a daily supplement for the prevention of oral Cd exposure.

Probiotics and allergic diseases

The prevalence of allergic diseases including atopic dermatitis, asthma, allergic rhinitis (AR) and food allergy is increasing worldwide and they cause a big economic and social burden. Understanding of reasons that contribute to the etiology of allergic diseases as well as new treatment approaches are very important for the follow-up and prevention of these diseases. In recent years, probiotics seem to be promising for allergic diseases. The effect of probiotics in the prevention and treatment of eczema is more extensively studied, but little is known about the association of the microbial flora of the host and allergic airway diseases and the efficacy of probiotics in decreasing the symptoms of patients with asthma and rhinitis. Hitherto, there is no strong evidence for use of probiotics in the treatment of eczema; however, administration of probiotics in breastfeeding mothers in the prenatal period and infants in the postnatal period can be accepted as a safe and helpful option in the prevention of eczema. In contrast, there is not yet reliable evidence or recommendations on use of probiotics for the prevention or treatment of asthma, AR, food allergy, and anaphylaxis currently. More standardized studies should be performed with different strains of probiotics to evaluate the protective and therapeutic effects of probiotics on other allergic diseases as well as eczema. In this review, the relationship between allergy and probiotics is handled in the light of current literature.