Impact of the environment on gut microbiome and allergy

Early life is a critical window for colonization and immune system development. This colonization, especially in the gut, are parallels in local and systemic immune development. However, with rapid urbanization and global diversity loss, individuals have had less contact with the natural environment, and have consumed less traditional foods. At the same time, caesarian section (CS) deliveries have also increased, and has been associated with the risk of allergies, given the gut microbiome alterations. Randomized clinical trials (RCTs) using microbiome seeding after CS deliveries are now being explored for its possible potential effects in the child’s microbiome, and immune and metabolic programming. At the same time RCTs using prebiotics and probiotics for prevention of allergic diseases (primarily eczema), as well as to test the biodiversity hypothesis, led to shifts in the skin and gut bacterial communities and increases in immunoregulatory biomarkers. Generally, exposure to appropriate health-supporting microbes in early life may curb the epidemic rise in allergic diseases, however, considerably more research is needed before this can be translated into specific practice guidelines.