Extended Data Fig. 3. Tissue protease activity, gross morphology or histopathology of the high PA, low PA and healthy volunteer humanized mice.

a, In situ zymography for trypsin-like activity in mouse colonic tissue. No differences were observed between high PA and healthy humanized mice (n=6 mice/group, data presented as mean ±SD). b, Representative in situ zymography image of high PA and healthy mouse tissue. SYTOX Green Nuclear Stain (ThermoFisher, S7020) pseudocolored blue, N-p-Tosyl_Gly-Pro-Arg 7-amido-4-methylcoumarin hydrochloride cleavage pseudocolored green (Scale bar 50μm), c, Mouse weight, cecal weight and colonic length of humanized mice. Post-mortem weight was collected on humanized mice after which the gastrointestinal tract was removed and cecal weight was recorded. Colonic length measurements were done from proximal cecum to the distal rectum (n=6 human feces/phenotype, dots represent average). Boxplots: lower, middle and upper hinges correspond to 25^th, 50^th and 75^th percentiles. Upper and lower whiskers extend to the largest and smallest value no further than 1.5 * IQR from the respective hinge. d, Histological examination of the gastrointestinal tract of humanized mice. Distal small bowel and distal colon tissue sections were evaluated by a pathologist (RG) in blinded manner. No observed differences in inflammation and presence of immune cells between humanized mice (n= 6 mice scored/phenotype, Scale bar 50μm).