[h=1]
Gut microbiome and innate immune response patterns in IgE‐associated eczema[/h] [h=2]Authors[/h]
- C. E. West ,
- P. Ryd?n ,
- D. Lundin ,
- L. Engstrand ,
- M. K. Tulic ,
- S. L. Prescott
- DOI: 10.1111/cea.12566
Provider: John Wiley & Sons, Ltd
[h=2]Summary[/h] [h=3]Background[/h] Gut microbiome patterns have been associated with predisposition to eczema potentially through modulation of innate immune signalling.
[h=3]Objective[/h] We examined gut microbiome development in the first year of life in relation to innate immune responses and onset of IgE-associated eczema over the first 2.5 years in predisposed children due to maternal atopy [
www.anzctr.org.au, trial ID ACTRN12606000280505].
[h=3]Methods[/h] Microbial composition and diversity were analysed with barcoded 16S rRNA 454 pyrosequencing in stool samples in pregnancy and at ages 1 week, 1 month and 12 months in infants (
n = 10) who developed IgE-associated eczema and infants who remained free of any allergic symptoms at 2.5 years of age (
n = 10). Microbiome data at 1 week and 1 month were analysed in relation to previously assessed immune responses to TLR 2 and 4 ligands at 6 months of age.
[h=3]Results[/h] The relative abundance of Gram-positive
Ruminococcaceae was lower at 1 week of age in infants developing IgE-associated eczema, compared with controls (
P = 0.0047). At that age, the relative abundance of
Ruminococcus was inversely associated with TLR2 induced IL-6 (−0.567,
P = 0.042) and TNF-α (−0.597,
P = 0.032); there was also an inverse association between the abundance of Proteobacteria (comprising Gram-negative taxa) and TLR4-induced TNF-α (rs = −0.629,
P = 0.024). This relationship persisted at 1 month, with inverse associations between the relative abundance of
Enterobacteriaceae (within the Proteobacteria phylum) and TLR4-induced TNF-α (rs = −0.697,
P = 0.038) and
Enterobacteriaceae and IL-6 (rs = −0.709,
P = 0.035). Mothers whose infants developed IgE-associated eczema had lower α-diversity of Bacteroidetes (
P = 0.04) although this was not seen later in their infants. At 1 year, α-diversity of Actinobacteria was lower in infants with IgE-associated eczema compared with controls (
P = 0.002).
[h=3]Conclusion and clinical relevance[/h] Our findings suggest that reduced relative abundance of potentially immunomodulatory gut bacteria is associated with exaggerated inflammatory cytokine responses to TLR-ligands and subsequent development of IgE-associated eczema.
