Microbiome and Asthma: What Have Experimental Models Already Taught Us?

Table 1

Microbial exposures and asthma.

Exposure	Microbial exposure assessment	Effect	Endpoint	References
Environment	Exposure to animals (dogs, cats, and farm animals)	Decrease	Allergy or asthma	[51–56]
	Raw milk consumption	Decrease	Atopy or asthma in childhood	[57]
	Antibiotic use during pregnancy or first year of life	Increase	Risk of asthma	[42]
	Gram-negative bacteria’s endotoxin levels in mattress dust	Inverse relation	Atopic asthma and sensitization in children	[58]
	Prenatal microbial exposure	Increase	Cord blood; Treg cell counts; FOXP3 expression	[59]
		Decrease	TH2 cytokine secretion
Digestive tract	Bifidobacterium bifidum	More prevalent	Stool samples of nonallergic infants	[47]
	Bifidobacterium adolescentis and B. longum	More prevalent	Stool samples of allergic infants
	Bacteroides fragilis	High prevalence	Stool samples of children with positive prediction for asthma	[48]
	Bacterial diversity	Inverse association	Allergic sensitization	[38]
Respiratory tract	Bronchial infection by Chlamydophila pneumonia	Association	Asthma development	[40]
	Microbiota species in lower respiratory tract	Different	Asthmatic versus healthy subjects	[43, 44, 63]
	Haemophilus spp. in airways	More frequent	Subjects with airway diseases	[63]
	Prevotella spp.in airways	More frequent	Healthy subjects
	Enterobacteriaceae and Neisseriaceae	More frequent	Asthmatic patients	[63]
	Malassezia pachydermatis	Frequent	Asthmatic patients	[65]