Fecal Microbiota Transplantation With Immune Checkpoint Inhibitors in Lung Cancer

Patient (Recipient) Inclusion Criteria: 1. A histologically confirmed diagnosis of malignancy. 2. Patients over the age of 18. 3. Patients planning to be treated with chemotherapy, immune checkpoint inhibitors and/or targeted therapy. 4. Eastern Cooperative Oncology Group (ECOG) Performance Status 0-2 5. Able to provide written informed consent. Patient (Recipient) Exclusion Criteria: 1. Severe or life-threatening food allergy (e.g. nuts, seafood) 2. Allergy or other contraindication to omeprazole, investigational medicinal product. 3. Treatment with pre- or probiotics in the four weeks prior to randomization. 4. Severe immunodeficiency: * Systemic chemotherapy \<30 days from baseline * Known neutropenia with absolute neutrophils \<1.0x109 cells/µL * Prolonged treatment with corticosteroids (equivalent to prednisone \>60mg daily for \>30 days) within 8 weeks of randomization 5. Swallowing disorder, oral-motor discoordination, inability to swallow capsules 6. Pregnant or breastfeeding or expecting to conceive or father children within the trial's projected duration, starting from the pre-screening or screening visit through to 120 days after the last dose of trial treatment. Donor Inclusion Criteria: 1. A histologically confirmed diagnosis of malignancy. 2. Over the age of 18. 3. Treated with immune checkpoint inhibitors and with a full response. 4. Currently attending medical follow-ups Donor Exclusion Criteria: 1. Has not consumed any antimicrobials within the past 3 months 2. No prior exposure to HIV or viral hepatitis or suffering from tuberculosis/latent tuberculosis 3. No risk factors for blood-borne viruses, including high-risk sexual behavior, use of illicit drugs, any tattoo/body piercing/needlestick injury/blood transfusion/acupuncture, all within the past 6 months 4. No signs or symptoms consistent with Coronavirus disease 19 (COVID-19) or a nose/throat and/or stool sample with detectable Coronavirus disease 2 (CoV-2) 5. Has not received a live attenuated vaccine within the past 6 months 6. No underlying gastrointestinal conditions/symptoms (e.g., history of IBD, irritable bowel syndrome (IBS), chronic diarrhea, chronic constipation, coeliac disease, bowel resection or bariatric surgery) 7. No acute diarrhea/gastrointestinal symptoms within the 2 weeks prior to donating 8. No family history of any significant gastrointestinal conditions (e.g., family history of inflammatory bowel disease (IBD) or colorectal cancer) 9. No history of atopy (e.g., asthma, eosinophilic disorders) 10. Does not suffer from any systemic autoimmune conditions 11. Does not start any new treatment regimens within 2 weeks of fecal collection 12. No neurological or psychiatric conditions or known risk for prion disease 13. No history of chronic pain syndromes, including chronic fatigue syndrome and fibromyalgia 14. No history of receiving growth hormone, insulin from cows or clotting factor concentrates 15. Has not received an experimental drug or vaccine within the past 6 months 16. No history of travel to tropical countries within the past 6 months