Are current analytical methods suitable to verify VITAL® 2.0/3.0 Allergen Reference doses for EU Allergens in Foods?
Food allergy affects up to 6% of Europeans. Allergen identification is important for the risk assessment and management of the inadvertent presence of allergens in foods. The VITAL® initiative for voluntary incidental trace allergen labeling suggests protein reference doses, based on clinical reactivity in food challenge studies, at or below which voluntary labelling is unnecessary. Here, we investigated if current analytical methodology could verify the published VITAL® 2.0 doses, that were available during this analysis, in serving sizes between 5 and 500 g. Available data on published and commercial ELISA, PCR and mass spectrometry methods, especially for the detection of peanuts, soy, hazelnut, wheat, cow's milk and hen's egg were reviewed in detail. Limit of detection, quantitative capability, matrix compatibility, and specificity were assessed. Implications by the recently published VITAL® 3.0 doses were also considered. We conclude that available analytical methods are capable of reasonably robust detection of peanut, soy, hazelnut and wheat allergens for levels at or below the VITAL® 2.0 and also 3.0 doses, with some methods even capable of achieving this in a large 500 gram serving size. Cow's milk and hen's egg are more problematic, largely due to matrix/processing incompatibility. An unmet need remains for harmonized reporting units, available reference materials, and method ring-trials to enable validation and the provision of comparable measurement results.
In vitro gastroduodenal and jejunal brush border membrane digestion of raw and roasted tree nuts.
Heat treatments induce chemical/physical modifications, which may affect the stability to enzymatic digestion and consequently the allergenicity of food proteins to a varying extent, depending on the time/temperature regimen. Herein, we evaluated the stability to digestion of whole tree nut (walnuts, hazelnuts and almonds) allergens in a food digestion model reflecting the real one by, taking into consideration the allergen-containing processed (roasted) food. To this aim, whole raw and roasted tree nuts were subjected to in vitro digestion combining the harmonized oral-gastric-duodenal digestion models with brush border membrane enzymes (BBM) to simulate the jejunal degradation of peptides. The degradation of allergens was monitored by integrated proteomic/peptidomic and bio-informatic tools. Roasting increased digestibility of tree nuts, since very few peptides were detected in digested samples (<6.5 kDa fraction). After BBM digestion step, the degradation of peptides was enhanced in roasted walnuts and hazelnuts compared to the raw counterpart. Conversely, almond allergens showed a different behaviour, since the presence of resistant peptides was more evident for roasted almonds, probably because of the hydrolysis of high molecular weight aggregates generated during roasting. Our results provide new insight into the relationship between thermal processing and metabolic fate of tree nut allergens, highlighting the importance of investigating the digestion stability of whole allergenic food, rather than purified proteins.
Risk of shared equipment in restaurants for peanut-allergic consumers: a simulation for preparing Asian foods.
Background: Allergic reactions to meals consumed outside the home are common, can be severe and sometimes fatal. Objective: To quantify the risk reduction potentially achieved by increasing an individual's threshold sensitivity to peanut (such as via immunotherapy) in scenarios of peanut exposure through shared kitchen materials in a restaurant setting. Methods: Three versions of popular peanut-containing sauces were selected to represent common ingredients used in Asian cooking. Different combinations of utensils, equipment, sauces and test conditions were prepared by a professional chef, with or without common cleaning procedures to represent normal daily practice. Residue amounts of peanut-containing material on kitchen equipment and utensils were measured and used for quantitative risk assessment to model the risk reduction associated with increasing an individual's threshold. Results: Shared utensils had mean residue amounts of 23-1519 mg peanut protein (no cleaning), and 3-82 mg peanut protein (after water rinse). Shared woks and pans had up to 20 mg peanut protein after rinsing. Individuals who reach a threshold of 300 mg peanut protein have a predicted relative risk reduction of 94.9 to >99.99% with brief cleaning. With no cleaning, relative risk reductions were 63.5 to 91.1% for individuals with a baseline threshold ≤100 mg peanut protein who reach a threshold of 300 mg peanut protein, increasing to 91 to 99.7% when reaching a threshold value of 1000 mg peanut protein. Conclusion: In all shared kitchen material scenarios that we studied, achieving an eliciting dose of 300 or 1000 mg peanut protein appears clinically relevant for the peanut-allergic population.
Prevalence of physician-reported food allergy in Canadian children.
Background: Food allergy prevalence data has largely been derived from self-report, and estimates vary.
Objective: Determine the prevalence of physician-reported food allergy in children using Electronic Medical Record (EMR) data from the Canadian Primary Care Sentinel Surveillance Network (CPSSN). Methods: Retrospective cohort study using the CPCSSN repository, Canada's only primary care practice-based surveillance system. Machine learning algorithms were applied to assess for food allergy documentation. Demographic information, chronic diseases of interest, prescribed medications, and health behaviours from the CPCSSN repository were identified. Results: The prevalence of physician-reported food allergy in Canadian children was 2.53% (95% CI:2.48%-2.59%). The most common food allergies documented were peanut (0.8% of children), tree nut (0.6%), cow's milk (0.4%), egg (0.3%), fruit (0.2%), finned fish (0.2%) and shellfish (0.2%). Among children with food allergy only 33.7% had an epinephrine autoinjector prescription. In logistic regression analysis, children with food allergy were more likely to have an atopic comorbidity (OR 2.20, 95%CI,2.06-2.35) and less likely to be obese than non-food allergic children (OR 0.84, 95%CI,0.78-0.90). In the age and sex-adjusted models, patients with food allergy were significantly more likely to have a psychiatric morbidity, specifically: ADHD (OR 1.81, 95%CI,1.66-1.96), autism (OR 1.89, 95%CI,1.63-2.19), and depression (OR 1.17, 95%CI,1.02-1.35). Conclusion: Our study is the first to estimate national physician-reported prevalence of food allergy, and demonstrates a lower rate than that based on self-report. Further studies into the association of food allergy and psychiatric comorbidities (ADHD, autism, depression) and the association of food allergy and obesity are needed.
Heat-Stable Hazelnut Profilin: Molecular Dynamics Simulations and Immunoinformatics Analysis.
Heat treatment can modify the allergenic potential, reducing allergenicity in specific proteins. Profilins are one of the important hazelnut allergens; these proteins are considered panallergens due to their high capacity for cross-reactivity with other allergens. In the present work, we evaluated the thermostability of hazelnut profilin, combining molecular dynamics simulation and immunoinformatic techniques. This approach helped us to have reliable results in immunogenicity studies. We modeled Cor a 2 profilin and applied annealing simulation, equilibrium, and production simulation at constant temperatures ranging from 300 to 500 K using Gromacs software. Despite the hazelnut profilins being able to withstand temperatures of up to 400 K, this does not seem to reduce its allergenicity. We have found that profilin subjected to temperatures of 450 and 500 K could generate cross-reactivity with other food allergens. In conclusion, we note a remarkable thermostability of Cor a 2 at 400 K which avoids its structural unfolding.
Implementation of the Addendum Guidelines for Peanut Allergy Prevention by US Allergists, a Survey conducted by the NIAID, in Collaboration with the AAAAI.
Background: In 2017, the Addendum Guidelines for the Prevention of Peanut Allergy were published with recommendations on early introduction of peanut-containing foods based on infants' clinical history. Objective: To conduct a nationwide U.S. survey to assess Guidelines implementation among allergists and immunologists who manage infants for food allergy. Methods: Survey invitations were delivered to 3281 non-retired, U.S. members of the American Academy of Asthma, Allergy, and Immunology, board certified in allergy and immunology. The survey assessed awareness and implementation of the Guidelines and barriers to implementation. Descriptive statistics were generated. Results: Twenty-nine percent (946 of 3281) of surveyed allergists/immunologists responded, and 87.1% (825 of 946) of responders met eligibility criteria. Among eligible responders, 97.1% were aware of the Guidelines. Of those, 64.5% reported full implementation of the Guidelines as published, 34.4% reported partial implementation, and 1.1% reported using none of the Guidelines. Barriers to Guidelines use included parental (47.6%) and self (21.8%) concerns about allergic reactions, lack of referrals (33.6%), parents uninterested in early feeding (28.2%), and lack of clinic time (20.9%). The two most common deviations from the Guidelines were considering additional factors not specified in the Guidelines such as family history (50.2%) and conducting skin prick testing in non-high-risk children (43.9%). Of respondents using the Guidelines, 45.7% indicated they needed more education or training. Conclusion: Essentially all allergists/immunologists who responded to the survey reported full or partial Guidelines implementation. Parental concerns and lack of referrals are major identifiable barriers. Improved Guidelines messaging to parents and referring physicians is warranted.
Potential of dates (Phoenix dactylifera L.) as natural antioxidant source and functional food for healthy diet.
Date fruit is well known for their taste and concentrated nutritional components. Present study investigated two Omani date varieties i.e., Umsellah and Khalas, related to their physical traits, antioxidant properties, carbohydrates and nutritional values. Results showed that total-phenolic in Umsellah were 62% higher compared to Khalas, i.e., 164.22 and 103.85 mg/100 g. Among antioxidants, gallic acid in both Umsellah and Khalas were 35.77 and 27.41 mg/ 100 g respectively. Caffeic and syringic acid resulted 50% greater in Umsellah compared to Khalas. The ρ-coumaric acid contents in Umsellah and Khalas were 24.94 and 21.69 mg/ 100 g respectively. Total sugar in Umsellah (51.37 g of glucose equivalent / 100 g of dates) was found higher compared to Khalas (44.78 g of glucose equivalent / 100 g of dates). Among nutrients, potassium (K) level is very high (> 450 mg/100 g) in both the varieties with optimum range of other nutrients. For dietary fibers, Umsellah (81.17 g/100 g) reported higher proportion than Khalas (67.35 g/100 g). Overall findings inferred that Umsellah contained greater amount of beneficial individual phenolic and sugar compounds for the nourishment of health than Khalas. Therefore, as high antioxidant and nourished with several nutritional components, Umsellah and Khalas can be well adopted as organic and medicinal diets and can be used for various by-products irrespective of their market value.
Functional modulation of gut microbiota in diabetic rats following dietary intervention with pistachio nuts (Pistacia vera L.).
Background: Gut microbiota holds a key-role in numerous biological functions and has emerged as a driving force for the development of diabetes. Diet contributes to gut microbiota diversity and functionality providing a tool for the prevention and management of the disease. The study aimed to investigate the effect of a dietary intervention with pistachio nuts, a rich source of monounsaturated fatty acids, dietary fibers and phytochemicals on gut microbiota composition in the rat model of Type 1 Diabetes. Methods: Male Wistar rats were randomly assigned into four groups: healthy animals which received control diet (CD) or pistachio diet (PD), and diabetic animals which received control diet (DCD) or pistachio diet (DPD) for 4 weeks. Plasma biochemical parameters were determined and histological examination of liver and pancreas was performed at the end of the dietary intervention. Adherent intestinal microbiota populations in jejunum, ileum, caecum and colon were analyzed. Fecal microbiota populations at the beginning and the end of the study were determined by microbiological analysis and 16S rRNA sequencing. Results: Diabetic animals of both groups exhibited high plasma glucose and low insulin concentrations, as well as characteristic pancreatic lesions. Pistachio supplementation significantly increased lactobacilli and bifidobacteria populations in jejunum, ileum and caecum (p < 0.05) and normalized microbial flora in all examined intestinal regions of diabetic animals. After 4 weeks of supplementation, populations of bifidobacteria and lactobacilli were increased in feces of both healthy and diabetic animals, while enterococci levels were decreased (p < 0.05). Next Generation Sequencing of fecal samples revealed increased and decreased counts of Firmicutes and Bacteroidetes, respectively, in healthy animals that received the pistachio diet. Actinobacteria OTUs were higher in diabetic animals and increased over time in the pistachio treated groups, along with increased abundance of Bifidobacterium. Lactobacillus, Turicibacter and Romboutsia populations were elevated in healthy animals administered the pistachio nuts. Of note, relative abundance of Bacteroides was higher in healthy than in diabetic rats (p < 0.05). Conclusion: Dietary pistachio restored normal flora and enhanced the presence of beneficial microbes in the rat model of streptozotocin-induced diabetes.
The relationship between pistachio (Pistacia vera L) intake and adiposity: A systematic review and meta-analysis of randomized controlled trials.
Background: The aim of the study was to conduct a systematic review to comprehensively evaluate the relationship between pistachio intake and obesity. Methods: We searched 6 databases and acquired parameters from randomized controlled trials regarding obesity, including body weight, body mass index (BMI), and waist circumference. A fixed-effect model was applied to the meta-analysis for the weighted mean difference (WMD) between a diet with pistachios and a control diet. Results: Eleven trials including a total of 1593 subjects met the inclusion criteria. Compared to the group on a control diet, the pistachio diet group showed lower BMI values (WMD: -0.18 kg/m; 95% confidence interval [CI]: -0.26, -0.11 kg/m; I = 29.8%) and no differences in body weight (WMD: -0.22 kg; 95% CI: -0.50, 0.07 kg; I = 0.0%) or waist circumference (WMD: 0.76 cm; 95% CI: -0.11, 1.63 cm; I = 7.0%). Conclusion: A diet with pistachios reduced BMI and had no significant effects on body weight and waist circumference.
The effect of almond intake on anthropometric indices: a systematic review and meta-analysis.
This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize the effect of almond intake on anthropometric indices in adult subjects. We searched PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar databases until January 2020 to identify relevant RCTs. Data were reported as weighted mean differences (WMDs) and standard deviations (SDs) to show the magnitude of effects of almond on body weight (BW), body mass index (BMI), waist circumference (WC), fat mass (FM), and fat-free mass (FFM). Out of 2983 reports, 28 RCTs (37 arms) were eligible for including in our meta-analysis. The pooled results, obtained using a random-effects model, showed that almond intake significantly decreased BW (WMD: -0.38 kg, 95% CI: -0.65, -0.10, p = 0.007, I2 = 30.5%) and FM (WMD: -0.58 kg, 95% CI: -0.87, -0.28, p < 0.001, I2 = 4.9%). However, we found no significant effect of almond administration on BMI (WMD: -0.30 kg m-2, 95% CI: -0.67, 0.06, p = 0.101, I2 = 62.6%), WC (WMD: -0.60 cm, 95% CI: -1.28, 0.06, p = 0.078, I2 = 0.0%), and FFM (WMD: 0.23 kg, 95% CI: -0.04, 0.50, p = 0.097, I2 = 49.5%). Overall, the current meta-analysis demonstrated that resveratrol almond intake significantly reduced weight and FM, but did not affect BMI, WC, and FFM. Further studies are still required to confirm our results.