Gut Microbiomes in HD

Eligibility criteria

* Inclusion Criteria:
  * 18 years or older
  * Provide informed consent
  * Able to read and speak English
  * Agree to comply with study procedures
* Inclusion criteria for the control group include:
  * CAG repeat length ≤ 26.
  * BMI 18.5-24.9
* Inclusion criteria for experimental group 1 include:
  * BMI \< 18.5 (underweight) or significant, involuntary weight loss within the past 12 months.
  * CAG repeat length 40 - 59.
  * Documentation of the Clinical Diagnosis of HD with a high level of certainty (>99% confidence) using the validated Unified Huntington's Disease Rating Scale (UHDRS).
  * Stage I-III on the Functional Assessment component of the UHDRS
* Inclusion criteria for experimental group 2 include:
  * BMI > 25.0 (overweight - obesity) or BMI ≤ 25.0 with significant, unexplained weight gain within the past 12 months
  * CAG repeat length 40 - 59.
  * Documentation of the Clinical Diagnosis of HD with a high level of certainty (>99% confidence) using the validated UHDRS.
  * Stage I-III on the Functional Assessment component of the UHDRS
* Exclusion Criteria:
  * CAG repeat length ≥ 60 to exclude participants with juvenile onset HD.
  * CAG repeat length 36 - 39 to exclude participants with reduced penetrance. As this is a pilot study, we are primarily interested in participants with typical HD characteristics.
  * UHDRS Functional Capacity stage ≥ 4 to exclude late-stage HD patients who may be institutionalized and receive nutrition through a feeding tube.
  * Use of any of the following drugs within the last 6 months:
    * System antibiotics, antifungals, antivirals, or anti-parasitics (intravenous, intramuscular, or oral)
    * Corticosteroids (intravenous, intramuscular, oral, nasal, or inhaled)
    * Cytokines
    * Methotrexate, immunosuppressive cytotoxic agents, or chemotherapy
    * Commercial probiotics ≥ 100 million CFU (fermented foods, yogurts, and other homeopathic probiotics and prebiotics do not apply)
  * Use of topical antibiotics or topical steroids within the last 7 days
  * History of active, uncontrolled gastrointestinal disorders or diseases, including:
    * Inflammatory bowel disease
    * Ulcerative colitis
    * Crohn's disease
    * Irritable bowel syndrome
    * Infectious gastroenteritis, colitis, or gastritis
    * Clostridium difficile or Helicobacter pylori infection
    * Persistent or chronic constipation or diarrhea
  * Acute illness with or without fever at time of sample collection
  * Positive for HIV, hepatitis B, or hepatitis C
  * Confirmed or suspected immunodeficient condition/state
  * Major surgery of the GI tract, excluding cholecystectomy and appendectomy
  * Unstable dietary history within the past month, such as elimination or significant increase of a major food group in the diet
  * Recent history of chronic, excessive alcohol consumption
  * Travel outside of the United States within the last 3 months

The sponsor's own eligibility wording, lightly reformatted. The study team makes the final eligibility decision — worth discussing with your doctor.

Eligibility criteria as of 2025-06-18