A study that investigated links between juvenile idiopathic arthritis (JIA) and gut microorganisms found that circulating anti-lipopolysaccharide (anti-LPS) antibody concentrations were higher in patients with new-onset JIA, with no substantial intergroup differences between those with polyarticular JIA (n = 22), oligoarticular JIA (n = 31) or spondyloarthropathies (n = 16), than in healthy controls (n = 34). Circulating concentrations of LPS-binding protein and α-1-acid glycoprotein were also increased in patients with JIA and correlated with C-reactive protein levels as well as juvenile arthritis disease activity score.