Allergic disease prevalence differs between urban and rural populations. We aimed to evaluate the relationships between environmental and dietary factors and allergic diseases in both urban and rural settings. The results showed that the alarming increase in the incidence and severity of allergic diseases coincided with environmental and lifestyle changes, such as global warming, extreme weather and dietary modifications. Higher greenhouse gas emissions, consumption of fast food and fried meat, use of pesticides, and less exposure to pets, greenery, and environmental microbes are associated with increased rates of urban allergic diseases. The living environment influenced the microbiota of rural and urban children. Changes in environments and lifestyles influence the commensal gut, skin, respiratory, and nasal microbiomes and their human hosts, contributing to the rising incidence of allergic diseases.