Microbiota Transfer Therapy for Children and Adults With Both Pitt Hopkins Syndrome and Gastrointestinal Disorders

For children 5-17 years old and adults 18-55 years old with Pitt-Hopkins Syndrome (PTHS) and Gastrointestinal (GI) problems who have attempted two standard-of-care (SOC) GI treatments with no alleviation of symptoms. This is a Phase 2 clinical trial that will evaluate the safety, tolerability, and efficacy of a powder version of Microbiota Transfer Therapy (MTT) called MTP-101P. The three parts of this trial are described below. Part 1: Placebo-Controlled Treatment (14 Weeks) The trial will begin with a randomized, double-blind, placebo-controlled trial which will include a 10-day treatment with oral vancomycin (or placebo), then 1 day of magnesium citrate to cleanse the bowel of vancomycin and bacteria/feces (all participants, since its bowel-emptying effect cannot be blinded), followed by 4 days of initial high dose of MTP-101P taken daily 5 minutes after antacid, and then 12 weeks of a lower maintenance dose of MTP-101P taken daily 5 minutes after an antacid. Group A: Real Treatment vs. Group B: Placebo vancomycin, real magnesium citrate, placebo MTP-101P, real antacid. Part 2: Open-Label Observation and Cross-Over (14 weeks) Group A: Observation over the next 14 weeks (no additional treatment). Group A completes the study at the end of part 2. Group B: They will receive the same treatment that Group A received in part 1. This includes 10 days of vancomycin, magnesium citrate, and an initial high dose of MTP-101P for 4 days taken daily 5 minutes after an antacid, and then a lower dose of MTP-101P for 12 weeks taken daily 5 minutes after antacid. Part 3: Follow Up Group B: There will be a follow-up evaluation 14 weeks post-treatment after the end of Part 2, to assess long-term efficacy and possible adverse effects.