Systematic review of the association between short chain fatty acids and allergic diseases.

We performed a systematic review to investigate the current evidence on the association between allergic diseases and short chain fatty acids (SCFAs), which are microbially produced and suggested as one mechanism on how gut microbiome affects the risk of allergic diseases. Medline, Embase and Web of Science were searched from data inception until September 2022. We identified 37 papers, of which 17 investigated prenatal or early childhood SCFAs and the development of allergic diseases in childhood, and 20 assessed SCFAs in patients with pre-existing allergic diseases. Study design, study populations, outcome definition, analysis method and reporting of the results varied between papers. Overall, there was some evidence showing that the three main SCFAs (acetate, propionate and butyrate) in the first few years of life had a protective effect against allergic diseases, especially for atopic dermatitis, wheeze or asthma and IgE-mediated food allergy in childhood. The association between each SCFA and allergic disease appeared to be different by disease and the age of assessment. Further research that can determine the potentially timing specific effect of each SCFA will be useful to investigate how SCFAs can be used in treatment or in prevention against allergic diseases

The "experimental" dilemma

Sodobne pesniške tradicije sebe opredeljujejo kot eksperimentalne, kadar prelamljajo pravila bodisi realistične reprezentacije bodisi semantičnega realizma. Nekatere od teh tradicij so znane že iz sedemnajstega stoletja. Njihov vpliv se je širil po svetu, danes pa so del glavnega toka. Tudi v drugih tradicijah se poezija glavnega toka skuša na vsak način izogniti klišejem

Atopic dermatitis trajectories to age 8 years in the GUSTO cohort.

Background:The heterogeneity of childhood atopic dermatitis (AD) underscores the need to understand latent phenotypes that may inform risk stratification and disease prognostication.Objective:To identify AD trajectories across the first 8 years of life and investigate risk factors associated with each trajectory and their relationships with other comorbidities.Methods:Data were collected prospectively from 1152 mother-offspring dyads in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort from ages 3 months to 8 years. AD was defined based on parent-reported doctor's diagnosis. An unsupervised machine learning technique was used to determine AD trajectories.Results:Three AD trajectories were identified as follows: early-onset transient (6.3%), late-onset persistent (6.3%) and early-onset persistent (2.1%), alongside a no AD/reference group (85.2%). Early-onset transient AD was positively associated with male gender, family history of atopy, house dust mite sensitization and some measures of wheezing. Early-onset persistent AD was associated with antenatal/intrapartum antibiotic use, food sensitization and some measures of wheezing. Late-onset persistent AD was associated with a family history of atopy, some measures of house dust mite sensitization and some measures of allergic rhinitis and wheezing.Conclusion and Clinical Relevance:Three AD trajectories were identified in this birth cohort, with different risk factors and prognostic implications. Further work is needed to understand the molecular and immunological origins of these phenotypes.<br/

Atopic dermatitis trajectories to age 8 years in the GUSTO cohort.

Background:The heterogeneity of childhood atopic dermatitis (AD) underscores the need to understand latent phenotypes that may inform risk stratification and disease prognostication.Objective:To identify AD trajectories across the first 8 years of life and investigate risk factors associated with each trajectory and their relationships with other comorbidities.Methods:Data were collected prospectively from 1152 mother-offspring dyads in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort from ages 3 months to 8 years. AD was defined based on parent-reported doctor's diagnosis. An unsupervised machine learning technique was used to determine AD trajectories.Results:Three AD trajectories were identified as follows: early-onset transient (6.3%), late-onset persistent (6.3%) and early-onset persistent (2.1%), alongside a no AD/reference group (85.2%). Early-onset transient AD was positively associated with male gender, family history of atopy, house dust mite sensitization and some measures of wheezing. Early-onset persistent AD was associated with antenatal/intrapartum antibiotic use, food sensitization and some measures of wheezing. Late-onset persistent AD was associated with a family history of atopy, some measures of house dust mite sensitization and some measures of allergic rhinitis and wheezing.Conclusion and Clinical Relevance:Three AD trajectories were identified in this birth cohort, with different risk factors and prognostic implications. Further work is needed to understand the molecular and immunological origins of these phenotypes.<br/

Environmental and genetic determinants of vitamin D insufficiency in 12-month-old infants

We aimed to investigate the relationship between genetic and environmental exposure and vitamin D status at age one, stratified by ethnicity. This study included 563 12-month-old infants in the HealthNuts population-based study. DNA from participants\u27 blood samples was genotyped using Sequenom MassARRAY MALDI-TOF system on 28 single nucleotide polymorphisms (SNPs) in six genes. Using logistic regression, we examined associations between environmental exposure and SNPs in vitamin D pathway and filaggrin genes and vitamin D insufficiency (VDI). VDI, defined as serum 25-hydroxyvitamin D3(25(OH)D3) level &le;50 nmol/L, was measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Infants were stratified by ethnicity determined by parent\u27s country of birth. Infants formula fed at 12 months were associated with reduced odds of VDI compared to infants with no current formula use at 12 months. This association differed by ethnicity (P;bsubesub;= 0.01). The odds ratio (OR) of VDI was 0.29 for Caucasian infants (95% CI, 0.18-0.47) and 0.04 for Asian infants (95% CI, 0.006-0.23). Maternal vitamin D supplementation during pregnancy and/or breastfeeding were associated with increased odds of infants being VDI (OR, 2.39; 95% CI, 1.11-5.18 and OR, 2.5; 95% CI, 1.20-5.24 respectively). Presence of a minor allele for any GC SNP (rs17467825, rs1155563, rs2282679, rs3755967, rs4588, rs7041) was associated with increased odds of VDI. Caucasian infants homozygous (AA) for rs4588 had an OR of 2.49 of being associated with VDI (95% CI, 1.19-5.18). In a country without routine infant vitamin D supplementation or food chain fortification, formula use is strongly associated with a reduced risk of VDI regardless of ethnicity. There was borderline significance for an association between filaggrin mutations and VDI. However, polymorphisms in vitamin D pathway related genes were associated with increased likelihood of being VDI in infancy. &copy; 2014 Elsevier B.V. All rights reserved

Polymorphisms affecting vitamin D-binding protein modify the relationship between serum vitamin D (25[OH]D3) and food allergy.

BACKGROUND: There is evolving evidence that vitamin D insufficiency may contribute to food allergy, but findings vary between populations. Lower vitamin D-binding protein (DBP) levels increase the biological availability of serum vitamin D. Genetic polymorphisms explain almost 80% of the variation in binding protein levels. OBJECTIVE: We sought to investigate whether polymorphisms that lower the DBP could compensate for adverse effects of low serum vitamin D on food allergy risk. METHODS: From a population-based cohort study (n&nbsp;= 5276) we investigated the association between serum 25-hydroxyvitamin D3 (25[OH]D3) levels and food allergy at age 1 year (338 challenge-proven food-allergic and 269 control participants) and age 2 years (55 participants with persistent and 50 participants with resolved food allergy). 25(OH)D3 levels were measured using liquid chromatography-tandem mass spectrometry and adjusted for season of blood draw. Analyses were stratified by genotype at rs7041 as a proxy marker of DBP levels (low, the GT/TT genotype; high, the GG genotype). RESULTS: Low serum 25(OH)D3 level (&le;50 nM/L) at age 1 years was associated with food allergy, particularly among infants with the GG genotype (odds ratio [OR], 6.0; 95% CI, 0.9-38.9) but not in those with GT/TT genotypes (OR, 0.7; 95% CI, 0.2-2.0; P&nbsp;interaction&nbsp;= .014). Maternal antenatal vitamin D supplementation was associated with less food allergy, particularly in infants with the GT/TT genotype (OR, 0.10; 95% CI, 0.03-0.41). Persistent vitamin D insufficiency increased the likelihood of persistent food allergy (OR, 12.6; 95% CI, 1.5-106.6), particularly in those with the GG genotype. CONCLUSIONS: Polymorphisms associated with lower DBP level attenuated the association between low serum 25(OH)D3 level and food allergy, consistent with greater vitamin D bioavailability in those with a lower DBP level. This increases the biological plausibility of a role for vitamin D in the development of food allergy

Children of Asian ethnicity in Australia have higher risk of food allergy and early onset eczema than those in Singapore

Allerg

Children of Asian ethnicity in Australia have higher risk of food allergy and early onset eczema than those in Singapore

Background: in Western countries, Asian children have higher food allergy risk than Caucasian children. The early life environmental exposures for this discrepancy are unclear. We aimed to compare prevalence of food allergy and associated risk factors between Asian children in Singapore and Australia. Methods: we studied children in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort (n=878) and children of Asian ancestry in the HealthNuts cohort (n=314). Food allergy was defined as a positive SPT ≥ 3 mm to egg or peanut AND either a convincing history of IgE-mediated reaction at 18 months (GUSTO) or a positive oral food challenge at 14-18 months (HealthNuts). Eczema was defined as parent-reported doctor diagnosis. Results: food allergy prevalence was 1.1% in Singapore and 15.0% in Australia (p&lt;0.001). Egg introduction was more often delayed (&gt;10 months) in Singapore (63.5%) than Australia (16.3%; p&lt;0.001). Prevalence of early onset eczema (&lt;6 months) was lower in Singapore (8.4%) than Australia (30.5%) (p&lt;0.001). Children with early onset eczema were more likely to have food allergy than those without eczema in Australia [aOR 5.11 (2.34-11.14); p&lt;0.001] and Singapore [aOR 4.00 (0.62-25.8); p=0.145]. Conclusions: among Asian children, prevalence of early onset eczema and food allergy was higher in Australia than Singapore. Further research with larger sample sizes and harmonized definitions of food allergy between cohorts is required to confirm and extend these findings. Research on environmental factors influencing eczema onset in Australia and Singapore may aid understanding of food allergy pathogenesis in different parts of the world