CCK and irritable bowel syndrome: In the PI-IBS subgroup, inverse correlations were found between Streptococcus sanguinis and thermophiles and the following: CgA (r = −0.94, P = 0.017), CCK (r = −0.89, P = 0.03), and serotonin (r = −0.89, P = 0.03) cells and between Actinobacteria and CgA (r = −0.89, P = 0.03), CCK (r = −0.94, P = 0.017) and serotonin (r = −0.94, P = 0.02) cells.