Environmental influences on childhood allergies and asthma — The Farm effect

Abstract

Asthma and allergic diseases are major health problems with substantially high healthcare costs. Atopy typically first manifests as atopic dermatitis, and food allergies usually appear in the first two years of life. 1,2 As children grow older, allergic airway diseases, such as allergic rhinitis or asthma, may develop, following the so-called atopic march. Approximately, 10 to 20% of the children suffer from asthma and 30 to 40% from allergic rhinitis in industrialized countries in modern times. 1,3 Furthermore, children with allergic rhinitis have an increased risk to develop asthma.Several epidemiological studies worldwide have shown that children growing up on farms have a lower incidence of allergic diseases and asthma. 4 Lifestyle at farms, like early exposure to the environmental factors and nutrition and the parallel development of the gut microbiome and metabolome, influence the immune homeostasis of children. More and more data show that the cross-talk between the intestinal microbiota and the lung, termed as gut-lung axis, might

From maternal breath to infant's cells: Impact of maternal respiratory infections on infants ‘immune responses

“…Previous research in the field of allergy and chronic maternal infections have highlighted the impact of maternal exposure to specific microbial respiratory environment and immune modulation related to chronic infections on infant's immune responses. Susceptibility toward infection and response to vaccines in infancy are modulated after exposure to chronic maternal infection, without vertical transmission while susceptibility toward immune-mediated diseases (asthma, atopic dermatitis) is impacted by the respiratory maternal environment ( 2 , 8 , 19 ).…”

“…Exposure to a farming environment, contaminated by mold and bacteria species, during pregnancy has been associated with differential expression of Toll-like receptors (TLR) genes at birth ( 18 ). Children born to mothers living in farm environments have decreased risk of asthma and atopic dermatitis during childhood as compared to children born to mothers not living in such environment ( 19 ).…”

“…The factors associated with farm exposure and modulation susceptibility to atopic disease is likely multifactorial ( 19 ). Animal models suggest that microbial exposure through the maternal respiratory tract likely contribute to both immune and clinical risk modifications.…”

Editorial to the special issue “Environmental influences on childhood asthma”

“…Another extensively studied environmental factor that is associated with childhood as is the so called "farm effect". Frei et al (11) have summarized the current knowledge on how "farm effect" influences the immune homeostasis during the intrauterine period and in childhood with a focus on immune mechanisms induced by environmental microbial diversity and microbial components. Farming lifestyle factors including nutrition influence the immune homeostasis either by regulating the innate immune system or by induction of regulatory T cells or TH1.…”

Editorial to the special issue “Environmental influences on childhood asthma”

“…Another extensively studied environmental factor that is associated with childhood is the so called “farm effect.” Frei et al 11 have summarized the current knowledge on how “farm effect” influences the immune homeostasis during the intrauterine period and in childhood with a focus on immune mechanisms induced by environmental microbial diversity and microbial components. Farming lifestyle factors including nutrition influence the immune homeostasis either by regulating the innate immune system or by induction of regulatory T cells or TH1.…”