Interplay Between Gut Microbiota and Adaptive Immunity in Amyotrophic Lateral Sclerosis: a Clinical Trial

The study will include 42 ALS patients with 2:1 allocation in 2 groups of subjects (28 FMT vs 14 placebo); computerized randomization will be stratified by progression rate (ΔFS) </≥0.7. Randomization time will last 18 months. Treatment will be double blinded to patients and physicians, and will be done at baseline and at month 6. FMT is regarded as the active treatment. Post-treatment follow up will be 6 months.

ALS patients will undergo upper GI endoscopy with small-intestine biopsies (n° 4 biopsies of small intestine, performed with a standard biopsy forces) at baseline and after 6 months. At baseline patients will be randomized (2:1) to either an allogenic (from donors) infusion of collected feces (fecal microbiota transplantation, FMT) (or no procedure in case of allocation to placebo) in the duodenum-jejunum. The infusion will be performed through a standard nasojejunal tube, that will be placed during endoscopy. Infusion of feces will be performed at time 0 and repeated at month 6. The patients allocated to placebo arm will not receive treatment, but will undergo intestinal biopsy.

Upper GI endoscopy 12 months after FMT will be performed only to identify specific microbioma and mucosal immunological evaluation. Fecal samples and small intestine biopsy samples (at baseline, before treatment, and at month 6 and 12) will be obtained from patients to perform the gut microbiota typing.

Every endoscopic procedure will be performed with sedation of the patient. Feces for FMT will be obtained by healthy donors for C. difficile infection. Procedures that are usually performed for the selection of donors for transplantation of feces are as follows. Potential donors stool will be chosen in healthy volunteers that will have given a questionnaire with questions about lifestyle, health status, current therapy, etc., significant clinical symptoms of gastrointestinal disease, etc.. Based on this questionnaire, the potential donor will be considered eligible if excluded: I) Habits of life and risk behaviors, II) Concomitant significant known disorders, III) chronic or recent use of concomitant medications that may interfere with the state of the intestinal microflora (eg, antibiotics), IV) Clinical symptoms indicative of gastrointestinal disease or other diseases of importance, V) Personal or family medical history known of neurodegenerative diseases or other autoimmune diseases.

Moreover, each suitable potential donor will be subjected to the following screening tests: I) Examination of stool for Clostridium difficile bacterial pathogens and protozoa and helminths of the small intestine and colon, Vancomycin-resistant Enterococci (VRE ), Methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative Multidrug-Resistant Organisms (MDR), II) Serological screening for hepatitis virus A,B and C, HIV 1-2, Treponema pallidum, H. pylori, blood count with differential, dose transaminasemia, creatinine and C-reactive protein.

Potential donors negative for this screening will be considered definitively suitable and will be invited to give a stool sample to prepare than for the fecal transplant. The donation will be made in the appropriate circles in the Department of Internal Medicine and Gastroenterology, and the preparation of faeces (manual homogenization in 500 mL of saline solution) for infusion will be performed at the Unit of Analysis 2 ° (Virology and Microbiology).

Analysis of T cell sub-populations will be performed both in peripheral blood and gut mucosa: especially the ratio T Regulatory cells (Tregs)/Th17 cells A Contract Research Organization (CRO) will be in charge for study monitoring.