2. Histologically proven diagnosis of malignant melanoma and/or kidney cancer.
3. Treatment with any immune checkpoint inhibitor (Nivolumab, Pembrolizumab, Cemiplimab, Atezolizumab, Durvalumab, Avelumab, Ipilimumab), alone or in combination, within the last 8 weeks.
4. Grade 2 or higher CTCAE diarrhea, of which at least 3 stools are Bristol chart score 6-7.
5. Negative PCR for enteric pathogens including C. difficile, after the onset of diarrhea.
6. Signed written informed consent.
You may not be if
1. Diagnosed bacterial infection requiring antibiotic treatment at inclusion.
2. Pregnancy or breastfeeding. Pregnancy ruled out by male sex, postmenopausal women or a negative choriogonadotropin (hCG) urine test.
3. Primary diarrheal disease pre-existing to the immune checkpoint inhibitor treatment, including inflammatory bowel disease.
4. Unable to ingest capsules.
5. Unable to understand written or oral patient information.
