Background Ruminococcus gnavus (R. gnavus) are mucin‐degrading gut bacteria that play a key role in the early colonization of the gut by serving as endogenous sources of nutrients. They can also influence immune development. We had previously reported a lower abundance of R. gnavus in infants with atopic dermatitis (AD) compared with that in healthy subjects. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of orally administered R. gnavus on antibiotic treatment‐induced gut dysbiosis (and the underlying mechanism) in a mouse model of AD. Methods Four‐week‐old female BALB/C mice were administered antibiotic cocktails for 2 weeks. R. gnavus was orally administered throughout the study duration. At 6 weeks of age, AD was induced by epidermal sensitization with ovalbumin. AD phenotypes and systemic and gut immune responses were investigated. Results Orally administered R. gnavus significantly reduced AD‐associated parameters (i.e., transepidermal water loss, clinical score, total serum immunoglobulin (Ig) E level, OVA‐specific IgE level, and skin inflammation). R. gnavus treatment also resulted in significant downregulation of T helper 2–related cytokine mRNA and upregulation of interleukin (IL)‐10 and Foxp3 in the skin. The population of CD4+FOXP3+ T cells in mesenteric‐ and skin‐draining lymph nodes and butyrate levels in the cecum increased in R. gnavus‐administered AD mice. Conclusions Immune modulation by orally administered R. gnavus may alleviate AD symptoms through the enhancement of regulatory T‐cell counts and short‐chain fatty acids production in AD mice.
<b><i>Background:</i></b> It is still debatable whether dog ownership during early childhood is a risk factor for the development of allergic diseases. <b><i>Objective:</i></b> We investigated the association of dog ownership in early life with sensitization and asthma in childhood. <b><i>Methods:</i></b> Data from the Cohort for Childhood Origin of Asthma and Allergic diseases were used to investigate the association between dog ownership at any time from pregnancy to 1 year of age and sensitization to aeroallergens at 3 and 7 years old, bronchial hyperresponsiveness (BHR), and asthma at 7 years old. We analyzed the cytokine levels in cord blood (CB) and indoor environmental measurement concentrations in the mother’s residence obtained at 36 weeks of pregnancy. <b><i>Results:</i></b> Sensitization to dogs at age 3 and 7 did not differ between dog ownership and nonownership, but dog ownership during early life decreased the risk of sensitization to aeroallergens at age 7 (aOR = 0.44, 95% CI 0.21–0.90). Dog ownership significantly increased the risk of nonatopic BHR (aOR = 2.86; 95% CI 1.32–6.21). In addition, dog ownership was associated with asthma, especially nonatopic asthma at 7 years old (aOR = 2.73, 95% CI 1.02–7.32; aOR = 7.05, 95% CI 1.85–26.90, respectively). There were no significant differences in the concentrations of IL-13 or interferon-γ in CB or indoor environmental measurements according to dog ownership during pregnancy. <b><i>Conclusion:</i></b> Early-life dog exposure in this birth cohort has been shown to reduce atopy but increase the risk of nonatopic BHR and nonatopic asthma at 7 years old.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.