A prospective microbiome-wide association study of food sensitization and food allergy in early childhood.

Alterations in the intestinal microbiome are prospectively associated with the development of asthma; less is known regarding the role of microbiome alterations in food allergy development. Intestinal microbiome samples were collected at age 3-6 months in children participating in the follow-up phase of an interventional trial of high-dose vitamin D given during pregnancy. At age 3, sensitization to foods (milk, egg, peanut, soy, wheat, walnut) was assessed. Food allergy was defined as caretaker report of healthcare provider-diagnosed allergy to the above foods prior to age 3 with evidence of IgE sensitization. Analysis was performed using Phyloseq and DESeq2; P-values were adjusted for multiple comparisons. Complete data were available for 225 children; there were 87 cases of food sensitization and 14 cases of food allergy. Microbial diversity measures did not differ between food sensitization and food allergy cases and controls. The genera Haemophilus (log2 fold change -2.15, P=.003), Dialister (log2 fold change -2.22, P=.009), Dorea (log2 fold change -1.65, P=.02), and Clostridium (log2 fold change -1.47, P=.002) were underrepresented among subjects with food sensitization. The genera Citrobacter (log2 fold change -3.41, P=.03), Oscillospira (log2 fold change -2.80, P=.03), Lactococcus (log2 fold change -3.19, P=.05), and Dorea (log2 fold change -3.00, P=.05) were underrepresented among subjects with food allergy. The temporal association between bacterial colonization and food sensitization and allergy suggests that the microbiome may have a causal role in the development of food allergy. Our findings have therapeutic implications for the prevention and treatment of food allergy.

Savage JH ，Lee-Sarwar KA ，Sordillo J ，Bunyavanich S ，Zhou Y ，O'Connor G ，Sandel M ，Bacharier LB ，Zeiger R ，Sodergren E ，Weinstock GM ，Gold DR ，Weiss ST ，Litonjua AA ... -  《-》

Early-life gut microbiome and egg allergy.

Gut microbiota may play a role in egg allergy. We sought to examine the association between early-life gut microbiota and egg allergy. We studied 141 children with egg allergy and controls from the multicenter Consortium of Food Allergy Research study. At enrollment (age 3 to 16 months), fecal samples were collected, and clinical evaluation, egg-specific IgE measurement, and egg skin prick test were performed. Gut microbiome was profiled by 16S rRNA sequencing. Analyses for the primary outcome of egg allergy at enrollment, and the secondary outcomes of egg sensitization at enrollment and resolution of egg allergy by age 8 years, were performed using Quantitative Insights into Microbial Ecology, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States, and Statistical Analysis of Metagenomic Profiles. Compared to controls, increased alpha diversity and distinct taxa (PERMANOVA P = 5.0 × 10-4 ) characterized the early-life gut microbiome of children with egg allergy. Genera from the Lachnospiraceae, Streptococcaceae, and Leuconostocaceae families were differentially abundant in children with egg allergy. Predicted metagenome functional analyses showed differential purine metabolism by the gut microbiota of egg-allergic subjects (Kruskal-Wallis Padj  = 0.021). Greater gut microbiome diversity and genera from Lachnospiraceae and Ruminococcaceae were associated with egg sensitization (PERMANOVA P = 5.0 × 10-4 ). Among those with egg allergy, there was no association between early-life gut microbiota and egg allergy resolution by age 8 years. The distinct early-life gut microbiota in egg-allergic and egg-sensitized children identified by our study may point to targets for preventive or therapeutic intervention.

Fazlollahi M ，Chun Y ，Grishin A ，Wood RA ，Burks AW ，Dawson P ，Jones SM ，Leung DYM ，Sampson HA ，Sicherer SH ，Bunyavanich S ... -  《-》

Sensitization to common food allergens is a risk factor for asthma in young Chinese children in Hong Kong.

Leung TF ，Lam CW ，Chan IH ，Li AM ，Tang NL ... -  《-》

Prevalence of food sensitization and probable food allergy among adults in India: the EuroPrevall INCO study.

Data are lacking regarding the prevalence of food sensitization and probable food allergy among general population in India. We report the prevalence of sensitization and probable food allergy to 24 common foods among adults from general population in Karnataka, South India. The study was conducted in two stages: a screening study and a case-control study. A total of 11 791 adults in age group 20-54 were randomly sampled from general population in South India and answered a screening questionnaire. A total of 588 subjects (236 cases and 352 controls) participated in the case-control study involving a detailed questionnaire and specific IgE estimation for 24 common foods. A high level of sensitization (26.5%) was observed for most of the foods in the general population, higher than that observed among adults in Europe, except for those foods that cross-react with birch pollen. Most of the sensitization was observed in subjects who had total IgE above the median IgE level. A high level of cross-reactivity was observed among different pollens and foods and among foods. The prevalence of probable food allergy (self-reports of adverse symptoms after the consumption of food and specific IgE to the same food) was 1.2%, which was mainly accounted for cow's milk (0.5%) and apple (0.5%). Very high levels of sensitization were observed for most foods, including those not commonly consumed in the general population. For the levels of sensitization, the prevalence of probable food allergy was low. This disassociation needs to be further explored in future studies.

Mahesh PA ，Wong GW ，Ogorodova L ，Potts J ，Leung TF ，Fedorova O ，Holla AD ，Fernandez-Rivas M ，Clare Mills EN ，Kummeling I ，Versteeg SA ，van Ree R ，Yazdanbakhsh M ，Burney P ... -  《-》

The age-specific microbiome of children with milk, egg, and peanut allergy.

Immune regulation by gut microbiota is affected by dysbiosis and may precede food allergy onset. Prior studies lacked comparisons stratified by age and clinical phenotype. To assess the microbiome of children with food allergy (<3 years, 3-18 years) compared with similar aged children without food allergy. A real-world prospective cross-sectional study performed from 2014 to 2019 recruited children highly likely to have milk, egg, or peanut allergy defined by history and serum IgE or confirmed by food challenge. 16S ribosomal RNA sequencing identified stool microbial DNA. Alpha and beta diversity was compared between groups with food allergy and healthy controls stratified by age. Differential abundance for non a priori taxa was accepted at absolute fold-change greater than 2 and q value less than 0.05. A total of 70 patients were included (56 with food allergy and 14 healthy controls). Groups were not significantly different in age, gender at birth, race, mode of delivery, breastfeeding duration, or antibiotic exposure. Younger children with food allergy had similar alpha diversity compared with controls. Beta diversity was significantly different by age (P = .001). There was differential abundance of several a priori (P < .05) taxa (including Clostridia) only in younger children. Both a priori (including Coprococcus and Clostridia) and non a priori (q < 0.05) Acidobacteria_Gp15, Aestuariispira, Tindallia, and Desulfitispora were significant in older children with food allergy, especially with peanut allergy. Dysbiosis associates with food allergy, most prominent in older children with peanut allergy. Younger children with and without food allergy have fewer differences in gut microbiota. This correlates with clinical observations of persistence of peanut allergy and improved efficacy and safety of oral immunotherapy in younger children. Age younger than 3 years should be considered when initiating therapeutic interventions.

Ponda P ，Cerise JE ，Navetta-Modrov B ，Kiehm J ，Covelli GM ，Weiss J ，Lee AT ... -  《-》