1. d Day 2Day 1Day 4Day 6 Day 1 Day 2 Day 4 Day 6 Biopsy Injury D0 D1 D2 D3 D4 D5 D6 Wound monitoring by endoscope & Intrarectal adminstration of LGG or HBSS Wild type, HBSS Wild type, LGG Supplementary Figure S1 En face image of the wound HBSS LGG Wound at Day 0 Wound at Day 2 d a Wound Adjacent crypts Transverse image of H&E staining of the wound bed b * Adjacent crypts c * % wound re-epithelialization 100 80 60 40 20 0

2. a 5005,00050Media 2.5  10 7 5  10 6 1.25  10 8 fMLF: (nM) LGG : (cfu/ml) fMLF (500nM) LGG (2.5  10 7 cfu/ml) LGG (2.5  10 7 cfu/ml) To-pro 3 (DNA) ROS (CM-H2DCF-DA) Supplementary Figure S2 LGG HBSS 15’30’60’ 5’ wound b

3. Supplementary Figure S2 (continued) 50 uM 500 nM Control 50 nM5 uM d FPR1 KO WT wound FPR1 KO Control 2.5 x 10 9 cfu2.5 x 10 10 cfu WT 2.5 x 10 8 cfu 2.5 x 10 7 cfu wound c

4. D ** % migration c Wild type Fpr1 -/- HBSS, 1hr HBSS 6hr LGG 6hr EdU (chase 6 hrs) DNA WT HBSS WT LGG Fpr1 -/- HBSS Fpr1 -/- LGG b Wound bed Adjacent crypts Adjacent crypts Wound Staining for EdU chase assay to detect cellular migration Day 0 1 2 4 Biopsy wound & labeling of cells by EdU P-FAK Actin WT, LGG P-paxillin 0 10 15 20 125 kDa 45 kDa 68 kDa Min a Supplementary Figure S3

5. WT, NAC + LGG Nox1 -/-IEC, LGG Fpr1 -/-, LGG P-ERK Actin WT, LGG WT, HBSS 15 min 60 min Supplementary Figure S4 0 10 15 20 LGG Min 45 kDa P-ERK Actin 44/42 kDa b a

6. I.P. injection of EdU 2hr prior to wound bed collection & EdU staining to detect proliferation Wound Adjacent crypts Adjacent crypts Adjacent crypts Adjacent crypts Wild Type, HBSS, Day 2 Wild Type, LGG, Day 2 Wild type, LGG Wound Wild type, HBSS Fpr1 -/-, LGG Ki67 (+) Nox1 -/-IEC, LGG Wound DNA EdU Wound Adjacent crypts Wound Adjacent crypts Wound Adjacent crypts Wild Type, Day 1Wild Type, Day 4Wild Type, Day 2 B a b c DNA EdU Biopsy injury Day 0 Day 1 Day2 Day4 DNA Supplementary Figure S5