ClinicalTrials.gg
CompletedNCT05556824Updated Jul 27, 2026

Multi-Center Study of Panosyl-Isomaltooligosaccharides Adjunctive to PPI Therapy to Treat GERD

A Phase 2 interventional study of MHS-1031 and Placebo in Gastroesophageal Reflux, sponsored by Microbiome Health Sciences. Completed at 18 sites in United States. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-07-27.

Sponsored by Microbiome Health Sciences · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
255
Allocation
Randomized
Ages
18 Years to 75 Years
Sex
All
01

Study summary

This study will be conducted as a multi-center, randomized, double-blind, placebo-controlled trial to evaluate the effect of MHS-1031 on heartburn-free days in subjects with GERD-related heartburn symptoms.

Read the detailed description

MHS-1031 is a specific proprietary digestion-resistant oligosaccharide carbohydrate that serves as a prebiotic.

This study will be conducted as a multi-center, randomized, double-blind, placebo-controlled trial to evaluate the effect of MHS-1031 adjunctive to PPI therapy on heartburn-free days in subjects with GERD-related heartburn symptoms who self-report improvement while on sustained daily PPI therapy. Heartburn-free days will be determined by subject report specific to any of the three questions ("burning feeling behind the breastbone" and/or "pain behind your breastbone" and/or "heartburn"; Questions 1, 2 \& 3 of the RESQ-eD). For purposes of this trial, heartburn-free days are defined as subject report of 'Did Not Have', or 'Very Mild' on each of the three RESQ-eD questions listed above.

All candidate subjects must self-report at least partial response to sustained daily PPI acid suppressive therapy (i.e. 'daily' defined as taking PPIs 5-7 days/week on average). Candidate subjects will be screened for medical history of chronic heartburn that may be associated with other medical conditions, and these subjects will be excluded. The entire study consists of three phases: Remote Screening Phase 2-Week Assessment (SP1), on-site Screening Phase Part 2 (SP2) and Treatment Phase (TP).

Efficacy will be assessed using patient reported outcome (PRO) questionnaires, concomitant medication assessments, and assessment of adverse events, from baseline (determined during Remote Screening Phase 2-Week Assessment) to Treatment Phase Weeks 1-4 and Weeks 5-8. The primary analyses will be conducted to assess the efficacy of MHS-1031 adjunctive to PPI therapy, and separately as monotherapy subsequent to combined PPI and MHS-1031 therapy, in randomized subjects with GERD-related heartburn as determined by the RESQ-eD validated questionnaire, validated for use online.

02

Conditions studied

  • Gastroesophageal Reflux

Keywords

  • GERD
  • microbiome
  • PIMO
  • PPI
  • Heartburn
  • Gastroesophageal Reflux
  • Prebiotic
03

In context

Gastroesophageal Reflux

1,211 studies on the registry are indexed under Gastroesophageal Reflux; 202 are open to participants now.

This study's enrollment of 255 is above the median of 68 across 796 interventional studies indexed under Gastroesophageal Reflux.

Browse Gastroesophageal Reflux studies →

Lead sponsor

Microbiome Health Sciences is the lead sponsor of 3 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • In the opinion of the investigator or sub-investigators, the subject is capable of understanding and complying with protocol requirements, including compliance with completing nightly online questionnaires in one of the IRB-approved languages.
  • Subject signs and dates an electronic (Screening Phase Part 1) and site-specific written form (ICF) and any required privacy authorization prior to the initiation of any study procedures.
  • Ability, during Remote Screening Phase 2-Week Assessment, to complete all required online nightly RESQ-eD questionnaires, medication questionnaires, 4-item Patient Health Questionnaire for Depression and Anxiety (PHQ-4) questionnaire and Participant Global Assessment questionnaire.
  • Access to a computer/tablet/phone with internet access and active email account in order to complete online questionnaires daily throughout study participation.
  • Males or females ≥18 and ≤75 years of age, with a ≥ 18 and \< 35 kg/m2.
  • Female subjects must be or surgically sterile or, if of , must agree to use a medically acceptable form of from the time of signing the informed consent form through completion of study. If only the barrier method is used, a single barrier or better is adequate. Postmenopausal women must have had ≥ 12 months of spontaneous amenorrhea. Surgically sterile women are defined as those who have had a hysterectomy, bilateral ovariectomy, or bilateral tubal ligation. All women of childbearing potential must have a negative pregnancy test result before administration of study drug.
  • Must be on stable doses of medications, if any, prescribed for chronic conditions other than GERD.
  • Subject must be taking daily PPI (defined as 5-7 days/week on average) for at least four (4) consecutive weeks with self-reported symptom improvement (frequency and/or severity) prior to the Screening Call selected from the following list of medications:
  • omeprazole
  • esomeprazole
  • lansoprazole
  • dexlansoprazole
  • pantoprazole
  • rabeprazole
  • Onset of GERD-related heartburn symptoms for a minimum of 3 months prior to Screening Call (i.e., "burning feeling behind the breastbone" and/or "pain behind your breastbone" and/or "heartburn" per questions 1, 2 or 3 of RESQ-eD).
  • Subject has maintained a stable diet and exercise regimen for ≥ 30 days prior to the Screening Call and is willing to maintain that diet and exercise regimen for the duration of the study (i.e., if subject is currently following diets including, but not limited to, Keto, FODMAP, Vegan, Vegetarian, s/he must be willing to continue this dietary lifestyle through end-of-study visit).

Exclusion criteria

Exclusion Criteria:

  • Current use of any mouthwash (e.g., Listerine, Scope, others) or unwilling to discontinue use for the duration of the study (requires 3-day prior to starting the Remote Screening Phase 2-Week Assessment)
  • Teeth whitening within 7 days of Screening Call or current use of teeth whitening substances (not including teeth whitening toothpaste) or unwilling to discontinue use for the duration of the study (requires 7-day washout prior to starting the Remote Screening Phase 2-Week Assessment).
  • Current use of histamine 2 receptor antagonists (H2RAs) (requires 7-day washout prior to starting the Remote Screening Phase 2-Week Assessment).
  • Surgical procedure requiring general anesthesia within 60 days of the Screening Call
  • Colonoscopy, high colonic, colonic cleanse or barium enema in the past 30 days, or scheduled for colonoscopy or barium enema at any time for the duration of the study, and unwilling to postpone until after study completion.
  • History of cancer diagnosis and/or treatment (other than basal cell carcinoma of the skin) within the preceding five (5) years.
  • Concomitant illness with potential to confound outcome assessments for this study, including, but not limited to:

    • History of untreated peptic or gastric ulcer, Zollinger-Ellison syndrome, or Helicobacter pylori (H. pylori) positivity without a history of successful treatment
    • History of ulcerative colitis or Crohn's disease.
    • Stomach ulcers, pancreaticobiliary disorder (e.g., gallstones bile duct stones, pancreatic stones, pancreatitis), diverticulitis symptomatic within the past 6 months.
  • Acute or chronic virus (HBV), virus (HCV), or (HIV) infection.
  • Significant current morbidity of the heart, kidney, liver or lung.
  • History of Long Syndrome
  • History of Torsades de pointes (TdP)
  • Current neurological or psychiatric disorder (e.g., Parkinson's, Huntington's chorea, schizophrenia, seizure, bi-polar disorder, major depressive disorder).
  • Known or suspected alcoholism, drug addiction, or significant drug abuse within 1 year of the Screening Call based on subject reporting and PI assessment.
  • Active history of tobacco or nicotine use (of any type) in the last 6 months averaging more than 1 cigar/cigarette per week. Vaping products and e-cigarettes that contain nicotine and/or tobacco are not allowed. Chewing tobacco and nicotine gum are prohibited at any level. Nicotine patches are NOT exclusionary.
  • Alcohol abuse (for alcohol defined as: > 14 drinks/week or 4 drinks/day for men, 7 drinks/week or 3 drinks/day for women).
  • Intake of acetylsalicylic acid (i.e., aspirin) at doses > 162 mg/day.
  • Non-steroidal anti-inflammatory pain relievers (NSAIDs) such as ibuprofen (Advil®, Motrin® IB, others) >/= 4 days/week on average not to exceed half the recommended maximum prescription daily dosing as listed in the Physician's Desk Reference.
  • Acetaminophen > 2,000 mg/day
  • Inhalation or ingestion of products containing delta-9-tetrahydrocannabinol (THC) > 2 days/week on average.
  • Any known medical condition, clinical signs and symptoms, vital signs, abnormal laboratory, or other testing that are not well controlled on stable dosing of medication for at least 90 days prior to the Screening Call or are considered by the Principal Investigator (PI), that could interfere with the subject's participation in and completion of the study. Examples of medical conditions including, but not limited to:
  • Uncontrolled hypertension
  • Uncontrolled diabetes
  • History of adrenal disease, diabetic nephropathy, or gastroparesis
  • Uncontrolled hypothyroidism
  • Untreated mental disorder
  • Paraplegia or Quadriplegia
  • Cerebrovascular event (stroke) or myocardial infarction (MI) within the last 6 months.
  • Structural abnormality of the GI tract, or disease or condition that can affect GI motility (e.g., achalasia, esophageal atresia), or defecation.
  • Planned travel outside the US during the study period or routine travel within the US during the study period that results in >2-hour time zone difference.
  • Cyclical work shift (e.g., routinely switching between day shifts and night shifts)
  • Any of the following current (within the past 6 months) symptomatic conditions:

    • pseudo-obstruction,
    • malignant polyps (requiring surgery),
    • abdominal adhesions confirmed via laparoscopy,
    • intestinal ischemia without colitis,
    • laxative or enema abuse.
  • History of ischemic colitis in the past 5 years.
  • Current COVID19 infection, or a history of a prior COVID19 infection with ongoing symptoms suggestive of "Long COVID".
  • Endoscopic evidence of any of the following:

    • Eosinophilic esophagitis, scleroderma, Barrett's esophagus, esophageal cancer, Candida esophagitis confirmed by histopathology.
    • LA grade B, C, or D erosive esophagitis, esophageal stricture or scarring.
    • History of surgery or endoscopic treatment including fundoplication and/or dilation for esophageal stricture.
  • History of fecal impaction that required hospitalization or emergency room treatment within 3 months of the Screening Call.
  • History of eating disorder within the last 2 years.
  • Symptomatic condition (e.g., polycystic kidney disease, endometriosis, ovarian cysts, etc.) during the 12 months prior to the Screening Call that required intervention (i.e., clinic or emergency room visit or hospitalization) that may be associated with chronic abdominal pain or discomfort and might confound the assessments in this study.
  • Surgical history that meets any of the following criteria:
  • Gastric bypass surgery or invasive procedure for the treatment of obesity or surgery to remove a segment of the GI tract at any time prior to the Screening Call
  • Gastric band present within the past 60 days
  • Open surgery of the abdomen, pelvis, or retroperitoneal structures within 6 months prior to the Screening Call
  • Laparoscopic appendectomy or cholecystectomy or other instrumentation of the bowel \< 60 days prior to the Screening Call. NOTE: Endoscopic removal of benign polyps is not exclusionary.
  • Prior use of the study medication MHS-1031 or ISOThrive Prebiotic Nectar.
  • Use of fructo-oligosaccharides (FOS) or inulin.
  • Symptomatic condition (e.g., angina, rumination, or other conditions involving the mouth and/or throat) during the 12 months prior to the Screening Call.
  • Use of any of the following medications that have not been stable dosing for at least 90 days at time of Screening Call:

    • Anticholinergics, such as oxybutynin (e.g., Ditropan XL®)
    • Theophylline (e.g., Elixophyllin®, Theochron)
    • Bisphosphonates taken orally, such as alendronate (Fosamax), ibandronate (Boniva) and risedronate (Actonel®, Atelvia®)
    • Quinidine
    • Anticoagulants (e.g., Coumadin, Heparin)
    • Iron supplement (other than contained in multi-vitamin)
    • Potassium supplements in pill form (Elixirs are NOT exclusionary)
    • Asthma medications
    • Prescription medication to control Irritable Bowel Syndrome or Chronic Idiopathic Constipation
  • Use of Nitrates within the last 12 months.
  • Medication for depression, anxiety, or sleep (e.g., benzodiazepines such as diazepam (Valium®) and temazepam (Restoril) with uncontrolled symptoms or medication dosing that has not been stable for at least 90 days at time of Screening Call.
  • Antibiotic use within 60 days of the Screening Call.
  • Narcotic (e.g., opiate) or illicit drug (i.e., illegal at both the Federal and State levels; e.g. Cocaine, Heroin, Methamphetamine) use within 60 days of the Screening Call.
  • Use of any product within 90 days prior to the Screening Call.
  • Use of GLP-1 agonists (e.g., Dulaglutide (Trulicity), Exenatide, Semaglutide (Ozempic/Wegovy), Liraglutide) or prescription medications used for weight loss within 6 months of Screening Call.

    * Current use of potassium-competitive acid blocker (PCAB). PCAB may not be used within one week of screening call.

  • Pregnancy, lactation, planned pregnancy or planned ova donation during the study period.
  • Participation in another investigation (clinical trial) during the course of this study.
  • Any major lifestyle change, such as getting married, change in residence, change in job, or other highly stressful event planned during the study periods.
  • Sustained daily use of PPIs without self-report of improvement of heartburn symptoms.
  • Self or relative employed directly or indirectly by the Sponsor or relative or employee of investigator or investigator's staff.
  • Other conditions or situations that, in the Investigator's opinion, may put the subject at significant risk, may confound the study results, or may interfere significantly with the subject's participation in the study.
Terms in these criteria, in plain language(12)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Washout period

A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
255 participants (actual)

Study arms

  • Active comparator
    Drug Product

    Panosyl-isomaltooligosaccharide (PIMO) liquid 1 g (1.5 ml) per day for 8 weeks

    Drug: MHS-1031

  • Placebo comparator
    Placebo

    Placebo liquid (1.5 ml) per day for 8 weeks

    Other: Placebo

Interventions

  • DrugMHS-1031

    Study medication will be supplied as a syrup in individual sachets containing 1g (1.5 mL) of MHS-1031. Subjects will be randomized in 2:1 fashion to either study drug (2) or placebo (1)

    Also known as: Panosyl-isomaltooligosaccharide

  • OtherPlacebo

    Matching placebo is an oral solution formulated to have a degree of sweetness and acidity similar to the study medication and will be provided in equivalent sachets containing 1.5g (1.5 mL) of the oral placebo solution.

06

What researchers measure

Primary outcomes

  1. Heartburn-free days/week

    The difference between baseline weekly average heartburn-free days and weekly average heartburn-free days during Treatment Phase Weeks 1-4 and Weeks 5-8 (as measured using questions 1, 2 and 3 of the Reflux Symptom Questionnaire Electronic Diary) (RESQ-eD).

    Time frame: 4 and 8 weeks

Secondary outcomes

  1. Heartburn symptom severity

    The difference between baseline daily average heartburn symptom severity score and daily average heartburn symptom severity score during Treatment Phase Weeks 1-4 and Treatment Phase Weeks 5-8 (as measured using questions 1, 2 and 3 of the Reflux Symptom Questionnaire Electronic Diary) (RESQ-eD).

    Time frame: 4 and 8 weeks

  2. Heartburn-free day satisfaction

    Any increase between baseline weekly average heartburn-free days and heartburn-free days during Treatment Phase Weeks 1-4 and Weeks 5-8 where Patient Global Assessment Question 1 is ≥ baseline.

    Time frame: 4 and 8 weeks

  3. GERD-related severity satisfaction

    Any increase between baseline daily average heartburn severity and heartburn severity during Treatment Phase Weeks 1-4 and Weeks 5-8 where Patient Global Assessment Question 1 is ≥ baseline.

    Time frame: 4 and 8 weeks

07

Study locations

18 sites
  • Elite Clinical Studies LLC
    Phoenix, Arizona 85018, United States
  • Angel City Research
    Los Angeles, California 90010, United States
  • Wr-Msra, Llc
    Lake City, Florida 32055, United States
  • A Positive Clinical Research
    Miami, Florida 33186, United States
  • Advanced Gastroenterology Associates LLC
    Palm Harbor, Florida 34684, United States
  • Health Synergy Clinical Research
    West Palm Beach, Florida 33407, United States
  • West Palm Quality Research (WPQR)
    West Palm Beach, Florida 33407, United States
  • EmVenio-Georgia (EMGA)
    Atlanta, Georgia 30345, United States
  • WR-Mount Vernon Clinical Research (MVCR)
    Sandy Springs, Georgia 30328, United States
  • Gastroenterology Associates of Western Michigan PLC (WMCR)
    Wyoming, Michigan 49519, United States
  • M3 Wake Research (CPOR)
    Raleigh, North Carolina 27612, United States
  • Vanderbilt University Medical Center
    Nashville, Tennessee 37232, United States
  • SMS Clinical Research (SMSR)
    Mesquite, Texas 75149, United States
  • A and U Family Medicine (NCR)
    Sugar Land, Texas 77479, United States
  • University of Virginia Health System
    Charlottesville, Virginia 22908, United States
  • Charlottesville Medical Research Center
    Charlottesville, Virginia 22911, United States
  • Digestive Disease and Liver Specialists
    Norfolk, Virginia 23502, United States
  • GI Research Partners, LLC
    Richmond, Virginia 23236, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 27, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05556824
Lead sponsor
Microbiome Health Sciences
Collaborators
VBHRC Virginia Catalyst
Responsible party
Sponsor
First posted
Sep 27, 2022
Start date
Mar 3, 2023
Primary completion
May 27, 2026
Completion
May 27, 2026
Last update
Jul 27, 2026

Study contacts

Peter Swann, MD
principal investigator · Microbiome Health Sciences

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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