Elevated zonulin levels, associated with impaired mucosal barrier functions, have been described in non-celiac gluten sensitivity (NCGD) [126], irritable bowel syndrome (IBS) [127,128], inflammatory bowel diseases (IBD) [34,46,129], necrotizing enterocolitis [130], neonatal gastrointestinal abnormalities [75,131], and environmental enteric dysfunction [132,133]. Here, HP is linked to irritable bowel syndrome.