Characteristics of 767 patients from in-house cohort
| Characteristic | Antibiotic user | Non-antibiotic user |
| (n=133) | (n=634) | |
| Sex, no (%) | ||
| Male | 94 (70.7) | 472 (74.4) |
| Female | 39 (29.3) | 162 (25.6) |
| Median (IQR) age, years | 55 (47–65) | 55 (49–63) |
| Cancer type, no (%) | ||
| Lung cancer | 57 (42.9) | 283 (44.6) |
| Liver cancer | 14 (10.5) | 93 (14.7) |
| Esophageal cancer | 15 (11.3) | 48 (7.6) |
| Head and neck cancer | 7 (5.3) | 52 (8.2) |
| Cholangiocarcinoma | 6 (4.5) | 31 (4.9) |
| Cervical cancer | 10 (7.5) | 20 (3.2) |
| Lymphoma | 10 (7.5) | 13 (2.1) |
| Sarcoma | 3 (2.3) | 17 (2.7) |
| Other | 11 (8.3) | 77 (12.1) |
| irAEs, no (%) | ||
| Present | 43 (32.3) | 110 (17.4) |
| Absent | 90 (67.7) | 524 (82.6) |
| Drugs, no (%) | ||
| anti-PD-1 | 98 (73.7) | 474 (74.8) |
| anti-PD-L1 | 35 (26.3) | 160 (25.2) |
| Therapy, no (%) | ||
| ICI only | 69 (51.9) | 282 (44.5) |
| ICI +chemotherapy | 42 (31.6) | 261 (41.2) |
| ICI +target therapy | 22 (16.5) | 77 (12.1) |
| ICI +chemo+radiotherapy | 0 (0) | 14 (2.2) |
| Grade of irAEs, no (%) | ||
| Grade 1 | 24 (55.81) | 59 (50.43) |
| Grade 2 | 9 (20.93) | 33 (28.21) |
| Grade 3 | 4 (9.30) | 11 (9.40) |
| Grade 4 | 1 (2.33) | 0 (0.00) |
| Grade 5 | 1 (2.33) | 1 (0.85) |
| Unknown | 4 (9.30) | 13 (11.11) |
| Specified irAEs, no (%) | ||
| Thyroid irAEs | 16 (27.12) | 41 (29.71) |
| Vascular irAEs | 6 (10.17) | 15 (10.87) |
| Rash | 5 (8.47) | 14 (10.14) |
| Hepatic irAEs | 5 (8.47) | 13 (9.42) |
| Hematologic irAEs | 2 (3.39) | 11 (7.97) |
| Gastrointestinal irAEs | 4 (6.78) | 10 (7.25) |
| Others | 5 (8.47) | 8 (5.80) |
| Pneumonitis | 7 (11.86) | 7 (5.07) |
| Renal irAEs | 1 (1.69) | 4 (2.90) |
| Skin irAEs | 4 (6.78) | 3 (2.17) |
| Cardiac irAEs | 2 (3.39) | 3 (2.17) |
| Endocrine irAEs | 0 (0.00) | 3 (2.17) |
| Pancreatic irAEs | 0 (0.00) | 3 (2.17) |
| Eye irAEs | 1 (1.69) | 2 (1.45) |
| Musculoskeletal irAEs | 0 (0.00) | 1 (0.72) |
| Nervous system irAEs | 1 (1.69) | 0 (0.00) |
| Duration of treatment | ||
| ≤1 month | 9 (6.77) | 30 (4.73) |
| 1–3 months | 33 (24.81) | 119 (18.77) |
| 3–6 months | 28 (21.05) | 127 (20.03) |
| 6 months to 1 year | 30 (22.56) | 89 (14.04) |
| ≥1 year | 9 (6.77) | 20 (3.15) |
| Not available | 24 (18.05) | 249 (39.27) |
ICI, immune checkpoint inhibitor; irAEs, immune-related adverse events.