The abundance of Ruminococcus bromii is associated with faecal butyrate levels and atopic dermatitis in infancy

Background: Impaired microbial development and decreased levels of short chain fatty acids, particularly butyrate, is suggested to have a role in the development of atopic dermatitis (AD). Methods: Faecal microbiota composition, abundance of selected bacterial groups and fermentation metabolites were compared at 90, 180 and 360 days of life between 27 children who developed AD by age one (AD group), and 39 controls (non-AD group) among the CARE (Childhood AlleRgy, nutrition and Environment) study cohort. Results: Diversity within the Firmicutes and Bacteroidetes phylum in the faecal microbiota was lower in the AD group compared to the non-AD group. Longitudinal analysis showed multiple amplicon sequence variants (ASV) within the same bacterial family to be differentially abundant. Namely, Ruminococcus bromii, a keystone primary starch degrader, and Akkermansia muciniphila, a mucin-utilizer, had lower abundance among the AD group. Children with AD were less likely to have high levels of faecal butyrate at 360 days compared to those without AD (11.5% vs 34.2%). At 360 days, children with high abundance of R. bromii had higher level of butyrate as well as lower proportion of children with AD compared to children with low abundance of R. bromii (11.1-12.5% vs 44.4-52.5%), which was independent of the abundance of the major butyrate producers. Conclusion: Our results suggested that R. bromii and other primary degraders might play an important role in the differences in microbial cross-feeding and metabolite formation between children with and without AD, which may influence the risk of developing the disease. Keywords: atopic dermatitis; butyrate; microbiota; resistant starch; short chain fatty acid

Atopic dermatitis: Correlation of distinct risk factors with age of onset in adulthood compared to childhood

Background: Atopic dermatitis (AD) has long been regarded as a primarily pediatric disease. However, there is growing evidence for a high rate of adult-onset AD. We aimed to characterize factors associated with adult-onset versus childhood-onset AD and controls. Methods: We analyzed cross-sectional data of the CK-CARE-ProRaD cohorts Bonn, Augsburg, Davos, Zürich of 736 adult patients stratified by age of AD onset (childhood-onset <18 years: 76.4% (subsets: 0 to 2; ≥2 to 6; ≥7 to 11; ≥12 to 18); adult-onset ≥18 years: 23.6% (subsets: ≥18 to 40; ≥41 to 60; ≥61) and 167 controls (91 atopic, 76 non-atopic)). Results: We identified active smoking to be associated with adult-onset AD versus controls (adjusted Odds Ratio (aOR) = 5.54 [95% Confidence Interval: 1.06-29.01] vs. controls$^{non-atopic}$ , aOR = 4.03 [1.20-13.45] vs. controls$^{atopic}$ ). Conjunctivitis showed a negative association versus controls$^{atopic}$ (aOR = 0.36 [0.14-0.91]). Food allergy (aOR = 2.93 [1.44-5.96]), maternal food allergy (aOR = 9.43 [1.10-80.95]), palmar hyperlinearity (aOR = 2.11 [1.05-4.25]), and academic background (aOR = 2.14 [1.00-4.54]) increased the odds of childhood-onset AD versus controls$^{atopic}$. Shared AD-associated factors were maternal AD (4-34x), increased IgE (2-20x), atopic stigmata (2-3x) with varying effect sizes depending on AD onset and control group. Patients with adult-compared to childhood-onset had doubled odds of allergic rhinitis (aOR = 2.15 [1.12-4.13]), but reduced odds to feature multiple (3-4) atopic comorbidities (aOR = 0.34 [0.14-0.84]). Adult-onset AD, particularly onset ≥61 years, grouped mainly in clusters with low contributions of personal and familial atopy and high frequencies of physical inactivity, childhood-onset AD, particularly infant-onset, mainly in "high-atopic"-clusters. Conclusions: The identified associated factors suggest partly varying endo- and exogeneous mechanisms underlying adult-onset versus childhood-onset AD. Our findings might contribute to better assessment of the individual risk to develop AD throughout life and encourage prevention by non-smoking and physical activity as modifiable lifestyle factors

Allergieabklärung: wann und wie?

Zusammenfassung. Allergien sind ein häufiges Problem im ärztlichen Alltag bei Atemwegsbeschwerden. Die wichtigsten Auslöser sind Pollen, Hausstaubmilben, Tierepithelien, Schimmelpilzporen und Substanzen im beruflichen Kontext. Die Anamnese ist für die Diagnosestellung zur Korrelation der Befunde und der klinischen Relevanz sehr wichtig, zumal eine hauttestmässig oder serologisch nachgewiesene Sensibilisierung zum Teil asymptomatisch bleibt. Therapeutisch sind nebst Verhaltensmassnahmen zur Allergenkarenz eine konsequente symptomatische medikamentöse Therapie und in gewissen Fällen eine allergenspezifische Immuntherapie (Desensibilisierung oder Hyposensibilisierung) die drei wichtigsten Behandlungspfeiler. = Abstract. Allergies are common in the clinical practice. The most important allergens are pollen, house dust mites, animal dander, mold and allergens attributable to a particular work environment. The medical history is a very important part for diagnosing an allergy, because sensitizations detected by skin prick tests and laboratory tests are common but not always symptomatic and therefore without clinical relevance. There are 3 options to manage allergic diseases: avoidance of allergens, symptomatic treatment and - in selected cases - a causal treatment like allergen-specific immunotherapy

Lung function improvement and airways inflammation reduction in asthmatic children after a rehabilitation program at moderate altitude

BACKGROUND: Rehabilitational programs at moderate altitude (1500-2500 m) showed improvement of lung function and reduction in airways inflammation in asthmatic adults. Allergen avoidance was postulated as the major cause of these improvements. METHODS: Spirometries of 344 and fractional exhaled nitric oxide measurements (FeNO) of 124 asthmatic children and adolescents, staying in a rehabilitation hospital in Davos (1590 m) with at least 14 days between admission and discharge, were analyzed in association with atopic sensitization (skin-prick testing and/or specific IgE), level of asthma control, and inhalative corticosteroid (ICS) dose. RESULTS: Pulmonary conditions improved significantly on average during the sojourn. Uncontrolled asthmatics benefited most with an absolute increase in predicted FEV1 , MEF25 , and MEF75 of 7.7%, 9.9%, and 12.7%, respectively (P < .001). FeNO decreased by 36.9 ppb for uncontrolled, by 26.9 ppb for partly controlled, and by 11.8 ppb for controlled asthmatics. In uncontrolled subjects, pulmonary improvement was comparable between patients with and without house dust mites (HDM) sensitization. Pulmonary improvements of pollen-sensitized patients were not dependent on the season of the sojourn. For the group with constant ICS level, the absolute increase in FEV1 was 4.9% (P < .001) with a FeNO decreased by 32.7 ppb (P < .001). When the ICS dose was elevated by one GINA level, the absolute increase in FEV1 was slightly higher (6.6%, P < .001), with a FeNO decrease of 31.4 ppb (P < .001). CONCLUSION: Inpatient rehabilitation at moderate altitude improved pulmonary conditions in asthmatic children and adolescents independent of sensitization status to HDM or pollen. A positive effect was also observed in patients without change in medication

The abundance of Ruminococcus bromii is associated with faecal butyrate levels and atopic dermatitis in infancy

Background Impaired microbial development and decreased levels of short-chain fatty acids, particularly butyrate, is suggested to have a role in the development of atopic dermatitis (AD). Methods Faecal microbiota composition, abundance of selected bacterial groups and fermentation metabolites were compared at 90, 180 and 360 days of life between 27 children who developed AD by age one (AD group), and 39 controls (non-AD group) among the CARE (Childhood AlleRgy, nutrition and Environment) study cohort. Results Diversity within the Firmicutes and Bacteroidetes phyla in the faecal microbiota was lower in the AD group compared with the non-AD group. Longitudinal analysis showed multiple amplicon sequence variants (ASV) within the same bacterial family to be differentially abundant. Namely, Ruminococcus bromii, a keystone primary starch degrader, and Akkermansia muciniphila, a mucin-utilizer, had lower abundance among the AD group. Children with AD were less likely to have high levels of faecal butyrate at 360 days compared with those without AD (11.5% vs 34.2%). At 360 days, children with high abundance of R. bromii had higher level of butyrate as well as lower proportion of children with AD compared to children with low abundance of R. bromii (11.1-12.5% vs 44.4-52.5%), which was independent of the abundance of the major butyrate producers. Conclusion Our results suggested that R. bromii and other primary degraders might play an important role in the differences in microbial cross-feeding and metabolite formation between children with and without AD, which may influence the risk of developing the disease.ISSN:0105-4538ISSN:1398-999

The abundance of Ruminococcus bromii is associated with faecal butyrate levels and atopic dermatitis in infancy.

BACKGROUND Impaired microbial development and decreased levels of short chain fatty acids, particularly butyrate, is suggested to have a role in the development of atopic dermatitis (AD). METHODS Faecal microbiota composition, abundance of selected bacterial groups and fermentation metabolites were compared at 90, 180 and 360 days of life between 27 children who developed AD by age one (AD group), and 39 controls (non-AD group) among the CARE (Childhood AlleRgy, nutrition and Environment) study cohort. RESULTS Diversity within the Firmicutes and Bacteroidetes phylum in the faecal microbiota was lower in the AD group compared to the non-AD group. Longitudinal analysis showed multiple amplicon sequence variants (ASV) within the same bacterial family to be differentially abundant. Namely, Ruminococcus bromii, a keystone primary starch degrader, and Akkermansia muciniphila, a mucin-utilizer, had lower abundance among the AD group. Children with AD were less likely to have high levels of faecal butyrate at 360 days compared to those without AD (11.5% vs 34.2%). At 360 days, children with high abundance of R. bromii had higher level of butyrate as well as lower proportion of children with AD compared to children with low abundance of R. bromii (11.1-12.5% vs 44.4-52.5%), which was independent of the abundance of the major butyrate producers. CONCLUSION Our results suggested that R. bromii and other primary degraders might play an important role in the differences in microbial cross-feeding and metabolite formation between children with and without AD, which may influence the risk of developing the disease

Electrical impedance spectroscopy for the characterization of skin barrier in atopic dermatitis

Background Allergic disorders such as atopic dermatitis (AD) are strongly associated with an impairment of the epithelial barrier, in which tight junctions and/or filaggrin expression can be defective. Skin barrier assessment shows potential to be clinically useful for prediction of disease development, improved and earlier diagnosis, lesion follow-up, and therapy evaluation. This study aimed to establish a method to directly assess the in vivo status of epithelial barrier using electrical impedance spectroscopy (EIS). Methods Thirty-six patients with AD were followed during their 3-week hospitalization and compared with 28 controls. EIS and transepidermal water loss (TEWL) were measured in lesional and non-lesional skin. Targeted proteomics by proximity extension assay in serum and whole-genome sequence were performed. Results Electrical impedance spectroscopy was able to assess epithelial barrier integrity, differentiate between patients and controls without AD, and characterize lesional and non-lesional skin of patients. It showed a significant negative correlation with TEWL, but a higher sensitivity to discriminate non-lesional atopic skin from controls. During hospitalization, lesions reported a significant increase in EIS that correlated with healing, decreased SCORAD and itch scores. Additionally, EIS showed a significant inverse correlation with serum biomarkers associated with inflammatory pathways that may affect the epithelial barrier, particularly chemokines such as CCL13, CCL3, CCL7, and CXCL8 and other cytokines, such as IRAK1, IRAK4, and FG2, which were significantly high at admission. Furthermore, filaggrin copy numbers significantly correlated with EIS on non-lesional skin of patients. Conclusions Electrical impedance spectroscopy can be a useful tool to detect skin barrier dysfunction in vivo, valuable for the assessment of AD severity, progression, and therapy efficacy