The use of transglutaminase in the reduction of immunoreactivity of wheat flour

The immune response of wheat flour modified by the treatment with transglutaminase under different conditions of temperature, incubation periods and the ratio of enzyme/wheat flour was investigated. The particular wheat protein fractions were examined for the immune reaction by the use of an indirect non-competitive ELISA. Commercially available antibodies, namely, monoclonal antihuman IgG and monoclonal antihuman IgE conjugates with alkaline phosphatase and human sera with elevated IgG as well as rabbit sera against QQQPP peptide were tested. The highest decrease in gliadins immunoreactivity was observed for wheat flour modified under following conditions: temperature 37°C, 18 h of incubation and the ratio enzyme/wheat flour 1:10 000. For all rabbit sera examined the residual immunoreactivity of glutenins was found to be below 30% of the level measured for the untreated protein. The large decrease in allergenicity of glutenins leads to the conclusion that wheat flour modified by treatment with transglutaminase may be used as a constituent of food products destined for people with a classic food allergy, i.e. the allergy elicited by that protein fraction.     

Hypoallergenic wheat bread: response to an emerging issue

The increasing prevalence of gluten intolerance raises the need to broaden the range of products that are suitable for coeliac. Usually, this means creating gluten-free (GF) products. However, limited amounts of wheat can be consumed safely by some people with moderate gluten intolerance. In this study, we attempted to produce high-quality bread with reduced immunoreactivity of wheat flour proteins by the partial replacement of wheat flour with wheat starch and by use of lactic acid fermentation. The resulting bread immunoreactivity was determined using the enzyme-linked immunosorbent assay (ELISA) method and compared to that of regular wheat bread. The combination of flour mixture modification and fermentation lowered the immune response in digested bread samples by more than 90% in the case of anti-QQQPP peptide antibodies and by over 40% for human anti-gliadin antibodies.     

Clinical significance of IgG subclass antibodies to wheat flour antigens in bakers

We measured the IgG subclass antibody levels to wheat flour in 42 bakers and 20 controls with an enzyme immunoassay. The levels of total IgG, IgG1 IgG2 and IgG4 antibodies were significantly higher in the bakers than in the unexposed controls. The presence of anti-wheat flour IgG subclass antibodies in the bakers was correlated with various clinical variables including IgE levels, duration of asthmatic or rhinitis symptoms, skin prick test response, peripheral blood eosinophil levels, bronchial histamine reactivity and responses to nasal challenge with wheat flour. The IgG subclass antibody levels of the total cohort of bakers did not correlate with any of the measured clinical variables. However, among men specific IgG4 and IgG1 antibody levels correlated negatively with total IgE levels and duration of rhinitis, respectively. We conclude that IgG and IgG subclass levels to wheat flour in bakers reflect exposure, but that it is not related to any specific clinical situation. The exact pathogenic role of these antibodies in the development of occupational asthma and rhinitis is thus not clear.     

Determination of IgG subclass antibodies against wheat flour antigens by an ELISA technique

We describe the assay conditions for an enzyme-linked immunoassay for the determination of IgG and IgG subclass antibodies in serum to water-soluble wheat flour antigens. The optimal antigen coating concentration was 5 micrograms/ml for total IgG, IgG1, IgG4 and 100 micrograms/ml for IgG2. Serial dilutions of test sera were used and commercially available monoclonal mouse anti-human IgG isotype antibodies (as ascites fluid) were diluted 1:500-1:1000. Specific wheat flour antibodies belonging to the IgG1, IgG2 and IgG4 subclasses were detected. Despite the lack of standardized isotype-specific second mouse monoclonal antibodies, the subclass antibody levels between flour-exposed bakers and controls could be compared. We observed significantly higher IgG1, IgG2, and IgG4 subclass antibodies among 23 bakers than among 12 non-exposed controls, but no IgG3 antibodies were detected. The differences in biological activities of the IgG subclass antibodies may explain the clinical and pathophysiological features for fluor-induced occupational allergic diseases among bakers.     

Food allergy to wheat: identification of immunogloglin E and immunoglobulin G-binding proteins with sequential extracts and purified proteins from wheat flour.

BACKGROUND: Cereal-associated allergy is particularly considered a serious problem, because cereals are essential in our daily diet. Wheat proteins are classified into albumins, globulins and prolamins (insoluble gliadins and glutenins). OBJECTIVES: Our objectives were to study the involvement in food allergy to wheat of these different protein types by using purified fractions and to identify those binding IgE and IgG antibodies. METHODS: Sera were obtained from 28 patients with food allergy to wheat. Albumins/globulins, gliadins and glutenins were obtained by sequential extraction based on differential solubility; alpha-, beta-, gamma- and omega-gliadins and low molecular weight (LMW) and high molecular weight (HMW) glutenin subunits were purified by chromatography. IgE binding to these extracts and fractions were analysed by radioallergosorbent test (RAST), and immunoblotting; IgG binding was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: In RAST, 60% of sera were shown to have specific IgE antibodies against alpha-, beta-gliadins and LMW glutenin subunits, 55% to gamma-gliadins, 48% to omega-gliadins and 26% to HMW glutenins. Immunoblotting analysis confirmed results obtained in RAST concerning LMW and HMW glutenin subunits and showed that 67% of patients have IgE antibodies to the albumin/globulin fraction. CONCLUSION: Results obtained in the different tests showed common features and in agreement with other studies indicated the presence of numerous allergens in food allergy to wheat; alpha-, beta-, gamma- and omega-gliadins, LMW glutenin subunits and some water/salt-soluble proteins appeared as major IgE binding allergens, whereas HMW glutenins were only minor allergens. The same type of antigenic profile against gliadins and glutenins was observed with IgG antibodies. Important sequence or structural homologies between the various gliadins and LMW glutenin subunits could certainly explain similarity of IgE binding to these proteins.     

Rye flour induces a stronger early bronchial response than wheat flour in occupational asthma

BACKGROUND: Our aims were to compare the doses of wheat and rye flour that induce early bronchial responses in occupationally exposed asthmatic subjects and to assess the effects of the dose of inhaled flour, the duration of exposure and the dose rate. METHODS: Ten patients underwent tests with lactose, wheat flour and rye flour. We compared the decrease in forced expiratory volume in 1 s (FEV(1)) observed during the challenge with flour and with lactose. We also calculated the amount of flour that was instantaneously active. RESULTS: Seven subjects had significantly decreased FEV(1) values following exposure to wheat and rye flour and two subjects only did so for rye flour. The provocative dose (PD, dose required to reduce FEV(1) by 15%) of rye was lower than that of wheat flour (geometric mean; PD(15) rye: 95 microg; wheat: 368 microg). The calculated doses of rye and wheat flour were better correlated with the change in FEV(1) than were the cumulative doses. CONCLUSION: The bronchial response was greater with rye than with wheat flour. The response was related to the dose of allergen inhaled and to the dose rate.     

小鼠小肠派伊尔结巨噬细胞吸附乳杆菌的研究

研究小鼠小肠派伊尔结巨噬细胞吸附乳杆菌及其与乳杆菌免疫调节作用之间的关系,可以为免疫调节性乳杆菌或活菌疫苗载体的筛选提供理论依据。提取了小鼠小肠派伊尔结(PP)巨噬细胞,研究其吸附9株乳杆菌的性能。结果发现,PP巨噬细胞吸附不同乳杆菌的能力差别很大,其中PP巨噬细胞对植物乳杆菌Lp6(L.plantarumLp6)有最强的吸附性能。用中性红吞噬法测定了不同乳杆菌对PP巨噬细胞吞噬活性的调节作用,结果发现乳杆菌对巨噬细胞吞噬活性的增强作用与PP巨噬细胞吸附它们的能力有正相关关系。9株乳杆菌的细胞表面物理化学性质和其巨噬细胞吸附性之间没有直接关系,植物乳杆菌Lp6细胞表面的甘露糖特异性凝集素参与了PP巨噬细胞吸附该细菌的过程。     

Comparison of wheat and rye flour skin prick test solutions for diagnosis of baker's asthma

BACKGROUND: Skin prick tests (SPTs) play an important role in the diagnosis of baker's asthma and in the investigation of sensitization frequencies in field studies. It was the aim of our study to compare different SPT solutions for wheat and rye flour sensitization and to assess the validity of test results. METHODS: Skin prick tests with wheat and rye flour were performed in parallel with extracts from different companies and compared with the results of bronchial challenge tests with both flours (69 rye flour and 51 wheat flour challenge tests). Additionally, specific immunoglobulin E (sIgE) to wheat and rye flour were tested. SPT solutions were analysed for protein content and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: Skin prick test solutions for diagnosis of wheat and rye flour sensitization from three companies differed in protein concentrations and composition with the consequence of widely differing SPT results. Sensitivity of SPTs in comparison with allergen-specific bronchial challenge as a gold standard was between 40 and 67%, specificity was between 86 and 100%, the positive predictive value (PPV) ranged from 81 to 100% and the negative predictive value (NPV) from 44 to 70%. These numbers were only marginally affected by using a combination of challenge test result and sIgE value as a more specific gold standard. CONCLUSION: Improvement and standardization of SPT extracts for wheat and rye flour is highly recommended.     

Genomics of lactic acid bacteria: Current status and potential applications

Lactic acid bacteria (LAB) are widely used for the production of a variety of foods and feed raw materials where they contribute to flavor and texture of the fermented products. In addition, specific LAB strains are considered as probiotic due to their health-promoting effects in consumers. Recently, the genome sequencing of LAB is booming and the increased amount of published genomics data brings unprecedented opportunity for us to reveal the important traits of LAB. This review describes the recent progress on LAB genomics and special emphasis is placed on understanding the industry-related physiological features based on genomics analysis. Moreover, strategies to engineer metabolic capacity and stress tolerance of LAB with improved industrial performance are also discussed.     

Antibacterial activities of lactic acid bacteria isolated from cow faeces against potential enteric pathogens

BackgroundThe addition of sub therapeutic doses of antibiotics to cattle feed for growth promotion is a contributory factor to antibiotic resistance, thus an alternative to antibiotics is needed in animal feed additives.ObjectiveTo determine the antimicrobial activity of cow''s intestinal Lactic acid bacteria (LAB) against enteric commensals.MethodEscherichia coli, Klebsiella species (spp) and LAB were isolated from thirty different cow faecal samples and the LAB identified by partial sequencing of 16S rRNA. The antimicrobial activity of the LAB was determined against the test Escherichia coli and Klebsiella spp.ResultsFive species of LAB were isolated from thirty cow faecal samples and identified as Enterococcus hirae (8), Enterococcus durans (6), Enterococcus faecium (1), Enterococcus faecalis (1) and Weissella confusa (1). Viable cells and cell free supernatant (CFS) of the LAB were able to inhibit the growth of the test organisms with the largest zone of inhibition by the viable cells being 26mm against Escherichia coli CB6 produced by Enterococcus hirae CO6A while Weissella confusa CO29M and Enterococcus hirae CO2A produced the largest zones of inhibition (26mm) against Klebsiella CB2.ConclusionThis study shows that LAB from cow faeces possess considerable antimicrobial activity against resistant Escherichia coli from the same environment.     

Asthma induced by inhalation of flour in adults with food allergy to wheat

Background Wheat is one of the major food allergens and it is also an inhalant allergen in workers exposed to flour dusts. Food allergy to wheat in adulthood seems to be rare and has never been reported to be associated with asthma induced by flour inhalation.
Objective The study aimed at detecting adults with food allergy to wheat and screening them for the presence of specific bronchial reactivity to inhaled wheat proteins.
Methods Adults with a history of adverse reactions to ingestion of wheat underwent skin prick test with commercial wheat extract and were assessed for the presence of specific wheat IgE in the sera. Food sensitivity to wheat was confirmed by double-blind, placebo-controlled food challenge (DBPCFC). Specific bronchial reactivity was investigated through a specific bronchial challenge with wheat proteins.
Results In nine patients with evidence of specific IgE response to wheat, a diagnosis of food allergy was made by DBPCFC. Only two subjects had asthma as disease induced by ingestion of wheat. Seven subjects reported a history of respiratory symptoms when exposed to flour dusts. A significant reduction of forced expiratory volume in 1 s (FEV₁) was detected in these seven patients when a specific bronchial challenge with flour proteins was performed. Only three out of seven subjects with asthma induced by flour could be considered occupationally exposed to flour dusts.
Conclusion For the first time, it has been shown that specific bronchial reactivity to wheat proteins can be detected in patients with different disorders associated with food allergy to wheat. The presence of asthma induced by inhaled flour is not strictly related to occupational exposure and it may also occur in subjects not displaying asthma among symptoms induced by wheat ingestion.     

Fructose-rich niches traced the evolution of lactic acid bacteria toward fructophilic species

Fructophilic lactic acid bacteria (FLAB) are found in fructose-rich habitats associated with flowers, fruits, fermented foods, and the gastrointestinal tract of several insects having a fructose-based diet. FLAB are heterofermentative lactobacilli that prefer fructose instead of glucose as carbon source, although additional electron acceptor substrates (e.g. oxygen) remarkably enhance their growth on glucose. As a newly discovered bacterial group, FLAB are gaining increasing interest. In this review, the ecological context in which these bacteria exist and evolve was resumed. The wide frequency of isolation of FLAB from fructose feeding insects has been deepened to reveal their ecological significance. Genomic, metabolic data, reductive evolution, and niche specialization of the main FLAB species have been discussed. Findings to date acquired are consistent with a metabolic model in which FLAB display a reliance on environmental niches and the degree of host specificity. In light of FLAB proximity to lactic acid bacteria generally considered to be safe, and due to their peculiar metabolic traits, FLAB may be successfully exploited in food and pharmaceutical applications.     

Identification of the major water/salt insoluble wheat proteins involved in cereal hypersensitivity

Background Several studies have investigated water/salt soluble proteins which comprise 50% of the proteins in wheat. The remaining 50% of wheat proteins, are water/salt insoluble proteins of which there is limited information on their role in cereal hypersensitivity. Objectives To investigate the allergenicity of the water/salt insoluble gliadin and glutenin proteins (prolamins). Methods RAST, electrophoresis and Western blotting were used to identify water/salt insoluble wheat allergens. Competitive RAST inhibition was conducted to investigate cross-reactivity between prolamins and water/salt soluble wheat proteins. Results Specific IgE to α-gliadin and to total glutenins were detected in all sera. IgE to β-, γ-, fast ω-, and slow ω-gliadin were present in lower numbers of sera. Prolamin allergens of 90–11 kDa were identified by immunoblotting. Water/salt soluble proteins crossreacted with a-gliadin and total glutenins. Conclusions Individuals who are hypersensitive to water/salt soluble wheat proteins produce specific IgE to water/salt insoluble wheat proteins. Western blotting has shown that gliadins, glutenins and proteins with similar molecular weights as the endogenous water/salt soluble wheat enzyme inhibitors are important allergens. Alpha and fast ω- are the most allergenic gliadins. The water/salt insoluble proteins share cross-reacting epitopes with water/salt soluble proteins. These data show that the numbers of proteins involved in the development of cereal hypersensitivity is greater than previously believed and that the development of specific IgE to α-gliadin may in part depend on the presence of cross-reacting antibodies to water/salt soluble flour allergens.     

Study of some of the mechanisms involved in the prevention against Salmonella enteritidis serovar Typhimurium infection by lactic acid bacteria

The possible mechanism exerted by different lactic acid bacteria (LAB) in the protection against Salmonella enteritidis serovar Typhimurium (S. typhimurium) infection was determined. LAB was administered to BALB/c mice, and the animals were subsequently challenged with S. typhimurium. The inhibition of the translocation of S. typhimurium in the liver was correlated with a decrease in cellular apoptosis determined in slices from the small intestine of mice. The microbiocidal activity of peritoneal macrophages was increased by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, but not for the probiotic strain L. casei CRL 431. The levels of IFNγ and Bcl-2 positive cells in the small intestine of mice fed with the LAB were also determined by immunofluorescence. Using in vivo studies, we demonstrated that the biological and immune mechanisms induced by the LAB studied were different for each bacterium and were mediated by anti-S. typhimurium S-IgA microbiocidal activity and/or cellular apoptosis inhibition of infected immune cells.     

Interaction of aflatoxin B1 and fumonisin B1 in mice causes immunotoxicity and oxidative stress: Possible protective role using lactic acid bacteria

Aflatoxins (AF) are important foodborne mycotoxins implicated in human health and have immunocytotoxic effects. The aims of this study were to evaluate a new aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁)-binding/degrading micro-organism for biological detoxification, to examine its ability to degrade AFB₁ and FB₁ in liquid medium, and to evaluate its potential in vivo protective role against any combined effects from AFB₁ and FB₁ on host splenocyte caspase-3 activity (reflecting DNA damage/cell death) and mRNA levels of select inflammation-regulating cytokines. Balb/c mice were divided into groups (10/group) and treated daily for 2 weeks by oral gavage with AFB₁ (80?µg/kg BW), FB₁ (100?µg/kg), AFB₁?+?FB₁, or lactic acid bacteria (Lactobacillus paracasei BEJ01, 2?×?10⁹?CFU/L, ～2?mg/kg) – alone or in combination with the AFB₁ and/or FB₁. After the exposures, spleens were collected for measures of caspase-3 activity, lipid peroxidation (LP), and glutathione (GSH) content, expression of anti-oxidation protective enzymes (GPx and SOD), and mRNA levels of inflammation-regulating cytokines (e.g. IL-10, IL-4, IFNγ, TNFα). Thymii were also removed for analysis of apoptosis. The results indicated that, in the spleen, exposure to the mycotoxins led to increased caspase-3 activity, LP, and IL-10 and IL-4 mRNA levels, but decreased GSH content and down-regulated expression of GPx and SOD, and of IFNγ and TNFα mRNA. Co-treatment using Lactic Acid Bacteria (LAB) with AFB₁ or FB₁ suppressed levels of DNA fragmentation, normalized splenic LP and increased GSH levels, up-regulated expression of GPx and SOD, and normalized mRNA levels of the analyzed cytokines. It is concluded that AFB₁ and FB₁ might have combinational (synergistic moreso than additive) toxic effects in situ. Further, it can be seen that use of LAB induced protective effects against the oxidative stress and (immuno)toxicity of these agents in part through adhesion (and so likely diminished bioavalability).     

The effect of enzymatic modification and genetic background on wheat gliadin immunological properties

The immune response to gliadins extracted from 35 wheat cultivars, strains and species was investigated. With the use of a non-competitive ELISA method, we sought to examine if immune reaction occurs between wheat proteins and sera from patients sensitive to gluten, as well as between wheat proteins and rabbit antibodies against pentapeptide QQQPP. Results showed considerable differences among cultivars. Breeding strains STH 183, STH 650, STH 2804, Triticum aethiopicum and Triticum durum showed the lowest immunoreactivity of the native samples. Seventeen of selected wheat flour samples were subjected to enzymatic modifications by subtilisin and transglutaminase. Samples modified by subtilisin exhibited the most extensive change in the level of immunoreactivity of gliadin proteins. The lowest immunoreactivity was reported for the breeding strains STH 1596, STH 2804 and cultivars Tonacja and Zyta. One wheat cultivar (Tonacja), known for its high native gliadin immunoreactivity, was shown to be very susceptible to enzymatic digestion, which resulted in a reduction of its initial immunoreactivity level to low values. Immunoreactivity analysis was also conducted on extracted gliadin fractions from winter wheat strain Ostka strzelecka. The highest level of immunoreactivity to both types of antibodies we used was indicated for ω5-gliadins. It was, however, abrogated in the aftermath of enzymatic modifications.     

Dietary flour supplementation decreases post-menopausal hot flushes: Effect of soy and wheat

Plants contain compounds with oestrogen — like action called phytoestrogens. Soy contains daidzin, a potent phytoestrogen, and wheat flour contains less potent enterolactones. We aimed to show in 58 postmenopausal women (age 54, range 30–70 years) with at least 14 hot flushes per week, that their daily diet supplemented with soy flour (n = 28) could reduce flushes compared with wheat flour (n = 30) over 12 weeks when randomised and double blind. Hot flushes significantly decreased in the soy and wheat flour groups (40% and 25% reduction, respectively <0.001 for both) with a significant rapid response in the soy flour group in 6 weeks (P < 0.001) that continued. Menopausal symptom score decreased significantly in both groups (P < 0.05). Urinary daidzein excretion confirmed compliance. Vaginal cell maturation, plasma lipids and urinary calcium remained unchanged. Serum FSH decreased and urinary hydroxyproline increased in the wheat flour group.     

Beneficial effects of lactic acid bacteria on human beings

Lactic acid bacteria are a diverse group of bacteria that produce lactic acid as their major fermented product. Most of them are normal flora of human being and animals and produce myriad beneficial effects for human beings include, alleviation of lactose intolerance, diarrhea, peptic ulcer, stimulation of immune system, antiallergic effects, antifungal actions, preservation of food, and prevention of colon cancer. This review highlights the potential species of Lactic acid bacteria responsible for producing these effects. It has been concluded that lactic acid bacteria are highly beneficial microorganisms for human beings and are present abundantly in dairy products so their use should be promoted for good human health.