GRIN2B and Salmonella Infections: We found no significant differences in miR-23a/b and NR2B expression between the subgroups of patients with PI-IBS-D with a history of Campylobacter infection (n = 14), Salmonella infection (n = 3), or Shiga toxin–producing E. coli infection (n = 4) (Supplemental Figures 9 and 10).