Vitamin C: An immunomodulator that attenuates anaphylactic reactions to soybean glycinin hypersensitivity in a swine model

New Perspectives on Food Matrix Modulation of Food Allergies: Immunomodulation and Component Interactions

Food allergy is a multifactorial interplay process influenced not only by the structure and function of the allergen itself but also by other components of the food matrix. For food, before it is thoroughly digested and absorbed, numerous factors make the food matrix constantly change. This will also lead to changes in the chemistry, biochemical composition, and structure of the various components in the matrix, resulting in multifaceted effects on food allergies. In this review, we reveal the relationship between the food matrix and food allergies and outline the immune role of the components in the food matrix, while highlighting the ways and pathways in which the components in the food matrix interact and their impact on food allergies. The in-depth study of the food matrix will essentially explore the mechanism of food allergies and bring about new ideas and breakthroughs for the prevention and treatment of food allergies.

Gastrointestinal digestion and absorption of soybean β-conglycinin in an early weaned piglet model: An initial step to the induction of soybean allergy

To date, it still remains unknown how β-conglycinin, a major soybean allergen, crosses intestinal epithelial barrier to reach immune cells. The purpose of this study was to elucidate the pathway and molecular mechanism of β-conglycinin absorption and transport across intestinal mucosal epithelium using a β-conglycinin allergic piglet model. Ten-day old piglets were orally sensitized with diets containing 2% and 4% β-conglycinin. The digestion, absorption and transport of β-conglycinin in gastrointestinal tract was investigated. The results showed that β-conglycinin had a certain resistance to gastrointestinal digestion, and the digestion-resistant subunits and fragments were absorbed into the intestinal mucosa and then induced an anaphylaxis in early weaned piglets. The absorption occurred in the form of IgE-allergen immune complex through transcellular pathway with CD23 as the receptor. These results provided important clues for using the pathway and molecule as inhibitor target to prevent and alleviate soybean β-conglycinin allergy in infants.

The protective role of vitamin C on intestinal damage induced by high-dose glycinin in juvenile Rhynchocypris lagowskii Dybowski

This study was to evaluate the mitigative effects of vitamin C (VC) on growth inhibition and intestinal damage induced by glycinin in juvenile Rhynchocypris lagowskii Dybowski. 270 healthy juvenile Rhynchocypris lagowskii Dybowski (4.65 ± 0.04 g) were randomly divided into 3 treatments, and fed with control diet, 80 g/kg glycinin diet and 80 g/kg glycinin+200 mg/kg VC diet respectively for 8 weeks. The results showed that glycinin significantly decreased the weight gain rate, specific growth rate, protein efficiency rate, feed efficiency rate and feeding rate of fish compared with the control group (P < 0.05), while VC supplementation improved the growth performance and feed utilization efficiency, and reached a level similar to the control group. Similarly, VC significantly increased the crude protein content of muscle and whole-body, and hepatopancreas and intestinal protease activities of fish fed with glycinin diet (P < 0.05). The distal intestine of fish in glycinin group showed typical damage characteristics, including breakage and atrophy of intestinal mucosal fold, and increased intestinal mucosal permeability. However, fish fed the glycinin + VC diet showed an unimpaired normal intestinal morphology. Usefully, VC supplementation could also restore impaired immune function and antioxidant capacity. VC down-regulated the mRNA levels of pro-inflammatory cytokines TNF-α and IL-1β, and up-regulated the mRNA levels of anti-inflammatory cytokines IL-10 and TGF-β in the distal intestine of fish fed with glycinin. Furthermore, glycinin exposure could reduce the mRNA levels of HO-1, CAT and GPx by inhibiting the activation of Nrf2-Keap1 signaling pathway, while VC supplementation reversed this phenomenon and maintained the homeostasis of antioxidant defense system. Concluded, glycinin causes growth inhibition, digestive dysfunction and intestinal damage of Rhynchocypris lagowskii Dybowski, while sufficient VC intake is beneficial for fish to resist the adverse effects of glycinin.

Taurine can improve intestinal function and integrity in juvenile Rhynchocypris lagowskii Dybowski fed high-dose glycinin

The present study evaluated the protective effect and the regulatory mechanism of taurine on growth inhibition and intestinal damage induced by glycinin in juvenile Rhynchocypris lagowskii Dybowski. The control diets had no glycinin and taurine, the glycinin diets contained only 80 g/kg glycinin, and the glycinin + taurine diets contained 80 g/kg glycinin+10 g/kg taurine. Juvenile Rhynchocypris lagowskii Dybowski (4.65 ± 0.03 g/tail) were respectively fed with these 3 diets for 8 weeks. The results showed that glycinin significantly decreased the final body weight, weight gain rate, specific growth rate, protein efficiency rate, feed efficiency rate and feeding rate of fish compared with the control group (P < 0.05). While taurine supplementation improved the growth performance and feed efficiency, but final body weight, weight gain rate, specific growth rate of the glycinin + taurine group were still significantly lower than the control group (P < 0.05). Compared with the glycinin group, taurine supplementation significantly increased whole-body and muscle crude protein content, and hepatopancreas and intestinal protease activities (P < 0.05). Distal intestinal villous dysplasia and mucosal damage, and increased intestinal mucosal permeability were observed in the glycinin group, while taurine supplementation alleviated these adverse effects. Usefully, taurine supplementation could also partially restore the impaired immune function and antioxidant capacity of fish fed glycinin diets. Compared with the glycinin group, taurine supplementation down-regulated pro-inflammatory cytokines TNF-α and IL-1β mRNA levels, and up-regulated anti-inflammatory cytokines IL-10 and TGF-β mRNA levels. Furthermore, taurine partially reversed the reduction of antioxidant genes Nrf2、HO-1, CAT and GPx mRNA levels in distal intestine induced by glycinin. Concluded, 80 g/kg glycinin led to intestinal damage, digestive dysfunction and increased intestinal mucosal permeability in juvenile Rhynchocypris lagowskii Dybowski, and these adverse effects were ultimately manifested in growth inhibition. But taurine supplementation could partially mitigate the negative effects induced by glycinin.

Progress towards pig nutrition in the last 27 years

Over the last 27 years (1990-2017), based on the revolutionary progresses of basic nutrition research, novel methods and techniques have been developed which bring a profound technological revolution to pig production from free-range system to intensive farming all over the world. Basic theoretical innovations and feed production studies have provided vital advancements in pig nutrition by developing formula feed, utilizing balanced diets, determining feed energy value, dividing pig physiological stages, enhancing gut health, and improving feed processing technique. Formula feed is the primary contributor of the rise of the mechanized farming industry, and meets comprehensive nutritional needs of the pig. The focuses of the development of a balanced diet by optimizing nutrient levels are the amino acids balance, the balance between amino acids and energy, the balance between calcium and phosphorus. Multiple-site-production and targeted feeding program have been applied extensively. Early weaning of piglets improves production efficiency, but piglets that have not yet fully developed their intestine are prone to diarrhea. Therefore, intestinal health has received special attention in recent years. Feed processing technologies, such as granulation, puffing, fermentation and enzymatic hydrolysis, can improve the utilization of feed nutrients and reduce production cost. However, increasing a sow's potential for production, seeking alternatives to antibiotics, reducing drug treatment in piglets, developing functional additives and improving meat quality remain future challenges. Herein, we outline the important progresses of pig nutrition in the past 27 years, which will shed light on the basic nutrition rules of pig production, and help to push forward its future development. © 2018 Society of Chemical Industry.

Effectiveness of probiotics, prebiotics, and prebiotic-like components in common functional foods

The bioactive ingredients in commonly consumed foods include, but are not limited to, prebiotics, prebiotic-like components, probiotics, and postbiotics. The bioactive ingredients in functional foods have also been associated with beneficial effects on human health. For example, they aid in shaping of gut microflora and promotion of immunity. These functional components also contribute in preventing serious diseases such as cardiovascular malfunction and tumorigenesis. However, the specific mechanisms of these positive influences on human health are still under investigation. In this review, we aim to emphasize the major contents of probiotics, prebiotics, and prebiotic-like components commonly found in consumable functional foods, and we present an overview of direct and indirect benefits they provide on human health. The major contributors are certain families of metabolites, specifically short-chain fatty acids and polyunsaturated fatty acids produced by probiotics, and prebiotics, or prebiotic-like components such as flavonoids, polyphenols, and vitamins that are found in functional foods. These functional ingredients in foods influence the gut microbiota by stimulating the growth of beneficial microbes and the production of beneficial metabolites that, in turn, have direct benefits to the host, while also providing protection from pathogens and maintaining a balanced gut ecosystem. The complex interactions that arise among functional food ingredients, human physiology, the gut microbiota, and their respective metabolic pathways have been found to minimize several factors that contribute to the incidence of chronic disease, such as inflammation oxidative stress.

Oceans as a Source of Immunotherapy

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules to mediate specific inhibitory activities has been demonstrated in a range of cellular processes, including apoptosis, angiogenesis, and cell migration and adhesion. Immunomodulators have been shown to have significant therapeutic effects on immune-mediated diseases, but the search for safe and effective immunotherapies for other diseases such as sinusitis, atopic dermatitis, rheumatoid arthritis, asthma and allergies is ongoing. This review focuses on the marine-originated bioactive molecules with immunomodulatory potential, with a particular focus on the molecular mechanisms of specific agents with respect to their targets. It also addresses the commercial utilization of these compounds for possible drug improvement using metabolic engineering and genomics.

Fructo-Oligosaccharide Alleviates Soybean-Induced Anaphylaxis in Piglets by Modulating Gut Microbes

Soybean-induced anaphylaxis poses a severe threat to the health of humans and animals. Some commensal bacteria, such as Lactobacillus and Bifidobacteria, can prevent and treat allergic diseases. Prebiotic oligosaccharides, a food/diet additive, can enhance health and performance via modulating gut microbes and immune responses. The purpose of this study was to examine whether fructo-oligosaccharides (FOS) could alleviate soybean-induced anaphylaxis by modulating gut microbes. Piglets (21 days of age) were sensitized with a diet containing 5% soybean and 30% peeled soybean meal. The treatment with 0.6% FOS started 1 day prior to sensitization and continued everyday thereafter. Blood was collected for measurements of immune indices. The DNA samples isolated from fresh intestinal contents of the middle jejunum (M-jejunum), posterior jejunum (P-jejunum), ileum, and cecum were used for gene sequencing based on 16S rRNA. Our results showed that there was an increase of glycinin-specific IgG, β-conglycinin-specific IgG, total serum IgG and IgE, and occurrence of diarrhea in piglets sensitized with soybean antigen. There was a decrease in interleukin 4 (IL-4) and IL-10 and an increase of interferon-γ (IFN-γ) in piglets with FOS treatment, compared with the piglets without FOS treatment. Improvement of intestinal microbes was indicated mostly by the increase of Lactobacillus and Bifidobacteria in M-jejunum and the decrease of Proteobacteria in P-jejunum and ileum. The correlation analysis indicated that FOS treatment decreased those closely related to the key species of gut microbes. These results suggest that FOS can alleviate soybean antigen-induced anaphylaxis, which is associated with increased Lactobacillus and Bifidobacteria in M-jejunum and declined Proteobacteria in P-jejunum and ileum of piglets.

Immunomodulatory basis of antioxidant therapy and its future prospects: an appraisal

Antioxidants are agents which can modulate oxidant-antioxidant profile of body system by neutralizing pro-oxidant molecules. The current scientific knowledge on mechanisms of antioxidant activity of biomolecules was critically reviewed with a special emphasis on immunomodulation. The immuno-oxidative wreckage of animals in various disease conditions and the role of biomodulators in curbing the oxidative stress through immune pathways were analyzed. The critical role of immunomodulatory mechanisms in controlling oxidative damage was identified. Selection of antioxidant therapy considering the immunopharmacology of the drug as well as immunological basis of disease may reduce treatment failure and adverse health effects. Hence, it is suggested that future studies on antioxidants may focus on the immuno-oxidative pathobiology to better understand its clinical effects and effective disease management.

Ascorbate-dependent decrease of the mucosal immune inflammatory response to gliadin in coeliac disease patients

BACKGROUND

The IL-15/NF-κB axis has an important role in coeliac disease (CD) and may represent a molecular target for immunomodulation. Ascorbate (vitamin C) is known to show inhibitory effects on NF-κB. Therefore, we studied if ascorbate supplementation to gliadin gliadin-stimulated biopsy culture could down-regulate the mucosal immune response to gliadin in CD.

METHODS

Duodenal biopsy explants from treated CD patients were gliadin challenged in vitro (100 μg/ml) with and without 20mM ascorbate. An extra tissue explant in basal culture was used as internal control. Secretion levels of nitrites (3h), and IFNγ, TNFα, IFNα, IL-17, IL-13, and IL-6 (24h) were measured on the supernatants. IL-15 was assayed by western-blot on whole protein duodenal explants.

RESULTS

The addition of ascorbate to in vitro culture gliadin-challenged biopsies blocked the secretion of nitrites (p=0.013), IFNγ (p=0.0207), TNFα (p=0.0099), IFNα (p=0.0375), and IL-6 (p=0.0036) compared to samples from non-ascorbate supplemented culture. Cytokine secretion was downregulated by ascorbate even to lower values than those observed in basal cultures (IFNγ: p=0.0312; TNFα: p=0.0312; IFNα: p=0.0312; and IL-6: p=0.0078). Gliadin-challenge induced IL-15 production in biopsies from treated CD patients, while the addition of ascorbate to culture medium completely inhibited IL-15 production. Moreover, the inhibition of IL-15 by ascorbate took place even in the only treated CD-patient who had basal IL-15 production.

CONCLUSIONS

Ascorbate decreases the mucosal inflammatory response to gluten in an intestinal biopsy culture model, so it might have a role in future supplementary therapy in CD.

Lipoic acid: an immunomodulator that attenuates glycinin-induced anaphylactic reactions in a rat model

The purpose of this study was to evaluate the attenuation effects of consuming a small dose of lipoic acid on soybean glycinin-induced hypersensitivity using a rat model. Sensitized by gavage with glycinin, weaned rats were orally supplemented with the diet containing 12.5 mug of lipoic acid/g (per diet). Results showed that untreated, sensitized rats demonstrated an increase in the level of serum IgE, the level of histamine release, and incidence of diarrhea and reduced growth performance compared with the controls (P < 0.05). Lipoic acid significantly (P < 0.05) improved growth performance while reducing mast cell numbers, the level of serum IgE, and the level of histamine release. Lipoic acid supplementation altered the balance of cytokines, attenuated the Th2-type immune response, and amended the ratio of CD4(+) to CD8(+) T cells (P < 0.05). Our results suggest that a small dose of lipoic acid has the potential to be an immunomodulator to prevent soybean-induced allergies.