Safety and Gut Microbiota Analysis of an Oral Microbiotherapy in Patients With Amyotrophic Lateral Sclerosis (IASO)

Inclusion Criteria: Male or female subjects aged between18 and 80 years ALS meeting the revised El Escorial criteria for possible, probable, laboratory-supported probable, or definite ALS (familial or sporadic) Time since first motor deficit at screening: at least 6 months, up to 24 months Slope of progression of ALS Functional Rating Scale - revised (ALSFRS-R) from date of symptom onset to date of screening test (ΔFS/number of months) between [0.4 and 1.1] Able to swallow study treatments (including capsules without opening or chewing them) as per the investigator's assessment SVC (Slow Vital Capacity) equal to or greater than 70% of the predicted normal value for sex, height, and age at the screening visit If taking riluzole, subject must be on a stable dose for ≥30 days Signature of written informed consent by subject Exclusion Criteria: Subjects with a non-invasive ventilation, a tracheotomy and /or a gastrostomy Known autoimmune diseases, inflammatory disorders (SLE, Rheumatoid arthritis, connective tissue disorder) or chronic infections (HIV, hepatitis B, or C infection, Tuberculosis) Known hypersensitivity to rifaximin or macrogol or any of its components Known allergy or intolerance to trehalose, maltodextrin or Polyethylene Glycol (PEG) Documented hepatic impairment (Alanine Transaminase/ Aspartate Transaminase > 5N) Subject with white blood cells < 4000/ mm3; Polynuclear neutrophils < 1.5 G/ L Active infection requiring systemic antimicrobial therapy within 2-week prior to screening visit Active infection requiring systemic antimicrobial therapy between screening and baseline Medical condition requiring proton pump inhibitors (PPIs) Gastrointestinal obstruction or perforation Any gastro-intestinal bleeding in the past 3 months Gastric emptying disorders (gastroparesis) Toxic megacolon Severe forms of inflammation of the intestinal tract, including Crohn's disease and ulcerative colitis Severe vital organ dysfunctions unrelated to ALS and not compatible with experimental treatment, as per the investigator's assessment Subjects with negative IgG serology for Epstein Barr virus (EBV) Women of childbearing potential1 without effective contraceptive protection Nursing or pregnant women Any condition that, in the opinion of the investigator, may interfere with full participation in the study, including administration of study drug (and its preparation procedure) and attendance at required study visits; represent a significant risk to the subject; or interfere with the interpretation of study data Enrollment in another trial or expanded access program that may interfere with this study Guardianship/legal protection/curatorship of subjects Vulnerable subjects such as: persons deprived of liberty, persons in intensive care units unable to provide informed consent prior to the procedure