BackgroundThe prevalence of allergic diseases, such as asthma, allergic rhinitis, eczema and food allergy, has been increasing worldwide, as shown in a large number of studies, including the International Study of Asthma and Allergies in Childhood (ISAAC). However, there is significant variation in the prevalence of these diseases in different regions, suggesting that there may be location-specific factors such as environment and microbial exposure affecting allergic disease prevalence. Hence, in this study we determine if there is a difference in microbiota composition and allergen concentration of household dust collected from the homes of non-allergic and allergic subjects from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort.MethodsFrom the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort, 25 allergic subjects and 25 non-allergic subjects were selected at the year 5.5 follow up. Definitions of allergic outcomes were standardized in the questionnaires administered at 3, 6, 9, 12, 15, 18, 24, 36, 48 and 60 months to ensure consistency during interviews and home visits. Allergen sensitization was determined by skin prick testing (SPT) at 18, 36 and 60 months. Dust samples were collected from the subject’s bed, sofa, and play area. DNA extraction was carried out and V3-V4 hypervariable regions of bacterial 16S rRNA gene were sequenced. Protein extraction was performed and allergens assayed by using multiplex assay and ELISA.ResultsThe most abundant phyla in house dust were Actinobacteria (29.8%), Firmicutes (27.7%), and Proteobacteria (22.4%). Although there were no differences in bacteria abundance and diversity between house dust samples of allergic and non-allergic subjects, the relative abundance of Anaplasmataceae, Bacteroidaceae, and Leptospiraceae were significantly higher in dust samples of allergic subjects as compared to non-allergic subjects in 2 or more locations. The concentration of Der p 1 was significantly lower in bed dust samples of allergic subjects (Median [Interquartile range], 174 ng/g [115–299 ng/g]) as compared to non-allergic subjects (309 ng/g [201–400 ng/g]; P < 0.05). The concentration of tropomyosin was significantly higher in sofa dust samples of allergic subjects (175 ng/g [145–284 ng/g] as compared to non-allergic subjects (116 ng/g [52.8–170 ng/g]; P < 0.05).ConclusionIn conclusion, we found a differential microbiota and allergen profile between homes of allergic and non-allergic subjects.Trial registrationNCT01174875 Registered 1 July 2010, retrospectively registered.Electronic supplementary materialThe online version of this article (10.1186/s40413-018-0212-5) contains supplementary material, which is available to authorized users.

BackgroundPeanut allergy is an increasing problem in Singapore and strict avoidance is difficult as peanut is ubiquitous in Asian cuisine.ObjectiveWe aimed to assess the efficacy and safety of peanut oral immunotherapy (OIT) in children with obvious peanut allergy in Singapore.MethodsThis was an open-label study of peanut OIT in children living in Singapore, with 2 weekly dose escalation until final maintenance dose of 3,000 mg of peanut protein and a maintenance phase of 12 months. An oral food challenge was performed at 6 months to assess for desensitisation and at 4 weeks after discontinuation of OIT having completed 12 months of maintenance therapy to assess for possible sustained unresponsiveness. The adverse events were monitored using the symptom diaries.ResultsNine subjects were started on OIT, with 7 managing to complete maintenance phase of therapy. Of these 7, all were able to tolerate at least 3,000 mg of peanut protein by 6 months of maintenance therapy, showing that the OIT was effective. Of these 7, 3 patients complied with the 4-week abstinence period after completion of OIT before another peanut challenge; 2 of the 3 subjects showed a significant decrease from the initial ability to tolerate 3,000 mg of peanut protein. Side effects were mainly gastrointestinal in nature and were more common during the updosing phase than the maintenance phase. No episodes of anaphylaxis were observed in this study.ConclusionPeanut OIT seemed to be effective and safe in our cohort of Singaporean children.