Cytokine levels [pg mL-1, ng mL-1 for IL-8] (mean ± SE), in supernatants of mucosal colonic biopsies after 24 h microbial stimulation.

Footnote: Minimum detectable concentrations (pg/mL) for the assay according to the manufacturer are: IL-8 = 0.3; IL-10 = 0.5; IL-17 = 0.3; IL-1β = 0.7; IL-2 = 0.6; IL-13 = 0.9; IFN-γ = 0.3; TNFα = 0.1.The biopsies were either unstimulated or stimulated with the bacterial strains Bacteroides ovatus, Ruminococcus gnavus, Akkermansia muciniphila, Subdoligranulum variabile or Eubacterium limosum, respectively. The significance of the differences was calculated between PI-IBS patients (n = 11) and HC (n = 10) and denoted with a * = p 2 transformed data (see Statistical analysis).