The goal of this review is to look at recent research on the function of gut microbiota in allergic disorders and asthma. Experiment results show that a disrupted gut microbiota impacts the tendency to develop allergic symptoms, and that altering the gut microbiota during pregnancy may lower the risk of allergic airways disease and food allergy in the child. Clinical investigations have also looked at the gut microbiota in existing allergy illness and before disease development. One study found a substantial link between high levels of Faecalibacterium prausnitzii and lower levels of butyrate and propionate, as well as developed eczema. Ruminococcaceae relative abundance appears to be involved in food sensitivity and to precede the onset of atopic eczema. Reduced relative abundance of Lachnospira, Veillonella, Faecalibacterium, and Rothia in early infancy has been linked to an increased risk of asthma. Inoculation of germ-free mice with these bacteria reduced airway inflammation in their progeny, indicating that bacteria play a role in preventing allergic airway illness.

Gut microbiome research is a rapidly evolving subject. Although potential bacterial taxa have been identified, it is still unknown which bacteria, in what quantities and combinations, and when throughout the gut colonization process may help to avoid allergy disorders and asthma. There is still a demand for standardized techniques that will allow direct comparison of diverse investigations.