RETNLB and infection: Physical interactions, infection sites, changes in gut pH, competition for nutrients/ecological niches in the host gut, and secreted molecules from parasites or the host are likely to act in the interplay between helminths and microbiota and could at least partially affect the regarding compositions.50 Also, other AMPs derived from intestinal epithelium, such as Sprr2a and Retnlb, which are boosted by type 2-promoting cytokines, can affect the host microbiome, as has been reported for H. polygyrus51 and N. brasiliensis47 infection.