IL17A and susceptibility to pneumonia measurement: In this study, we established a standardized Kp-induced Gram-negative bacterial pneumonia complicating ICH model with the following characteristics (1): severe neurological deficits, brain damage, BBB disruption and neuroinflammation in the lesions; (2) lung injury and pneumonia, especially intense infiltration and activation of neutrophils; (3) disruptions of the intestinal structure and gut barrier and downregulations of protective intestinal IL-17A-producing γδT cells; and (4) profound alterations in the fecal microbial community composition and metabolic profile.