A Clinical Trial of Resistant Potato Starch for Gut MDRO Decolonization (MDRO-Fiber)

Multidrug-resistant organisms (MDROs) cause serious infections that are difficult to treat, leading to increased morbidity and mortality, longer hospital stays, and increased healthcare costs. Many risk factors for MDRO infections are present in the Veteran population (such as older age, underlying medical conditions like diabetes, and stays in long-term healthcare settings). Some people can carry these organisms in their gut. Even without current symptoms, carrying these MDROs also increases risk of future infection. Effective, easy to use, and inexpensive interventions to reduce gut carriage of MDROs are needed to reduce risk of infection. Dietary fiber prebiotics have shown promise in improving the healthy gut microbiome, and the investigators have found that individuals with high fiber in their diets have reduced carriage of MDROs in the gut. The investigators propose a randomized controlled trial to test the effectiveness of a dietary fiber prebiotic intervention (resistant potato starch) in reducing gut MDRO carriage in Veterans with a history of MDRO carriage and/or infection. The investigators will also evaluate the effect on the gut microbiome as well as Veterans' experience with the fiber intervention.

Study Overview

• Status: Not yet recruiting
• Conditions: Clostridium Infections; Asymptomatic Infections; Vancomycin-Resistant Enterococci; Carbapenem-Resistant Enterobacteriaceae; Methicillin-resistant Staphylococcus Aureus (MRSA)
• Intervention / Treatment: Drug: Resistant Potato Starch; Drug: Maltodextrin

Detailed Description

Multidrug resistant organisms (MDROs) are resistant to antimicrobials and cause difficult to treat infections. MDRO infections thus lead to increased morbidity and mortality, increased length of stay, and higher medical costs. Colonization with an MDRO is also a risk factor for future infection. While decolonization of the skin is a straightforward and commonly used practice to prevent MDRO infections, gut colonization with MDROs is also a major risk factor but is much more difficult to modify. There is a critical gap in identification of effective, inexpensive, and easy to use interventions to reduce MDRO colonization and promote a healthy gut microbiome to reduce MDRO infections.

This project will address a novel approach to prevention: use of a dietary fiber prebiotic that is easily administered as a dietary supplement, inexpensive, and well-tolerated. While evidence suggests that prebiotics and dietary fiber have potential to promote healthy gut microbiomes and reduce MDRO colonization in the gut, there have not yet been any published studies in humans on the effect of dietary fiber prebiotic in reducing MDRO colonization.

The investigators will conduct a randomized, double-blind, placebo-controlled phase II clinical trial in 120 Veterans with a history of MDRO colonization and infection. Veterans will be randomized to a 5-week intervention period of either a dietary fiber intervention (resistant potato starch) or placebo. Participants will submit weekly stool samples during the intervention period, and one follow-up stool sample 3 months after completing treatment. Stool samples will be tested for presence of MDROs (primary outcome), and shotgun metagenomic sequencing and targeted metabolomics will be done to evaluate the gut microbiome (secondary outcomes: changes in metabolites and composition of the gut microbiome). Participants will also answer surveys about their experience with the intervention, including ease of use and tolerability.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Nasia Safdar, MD PhD; Phone Number: (608) 280-7007; Email: Nasia.Safdar@va.gov
• Study Contact Backup: Name: Julie A Keating, PhD; Phone Number: 12542 (608) 256-1901; Email: julie.keating@va.gov

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53705-2254
      • William S. Middleton Memorial Veterans Hospital, Madison, WI
      • Principal Investigator: Nasia Safdar, MD PhD
      • Contact: Nasia Safdar, MD PhD; Phone Number: (608) 280-7007; Email: Nasia.Safdar@va.gov

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Presence of C. difficile, Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococcus (VRE), and/or Multi-drug resistant Enterobacteriaceae (MDRE) in the gut as determined by a stool test
• Ambulatory/not hospitalized at time of enrollment

Exclusion Criteria:

• Allergy to any ingredient or source material in intervention or placebo product
• Severe gastrointestinal condition that may be exacerbated by high dietary fiber intake (history of bowel obstruction, intestinal strictures, diverticulitis, active inflammatory bowel disease with structuring, gastroparesis, and/or severe gastrointestinal motility disorders)
• Uncontrolled diabetes (hospitalized in previous 5 years due to diabetes)
• Dysphagia
• Fecal microbiome transplant in the last 30 days
• Intestinal surgery in the last 30 days
• Pregnancy or breastfeeding
• Immunosuppression, defined as history of solid organ transplant or as receipt of ablative chemotherapy, steroids at the equivalent of ≥5 mg/day prednisone, antimetabolites, anti-TNF agents, calcineurin inhibitors, or mycophenolate at time of enrollment
• Use of probiotics or fiber supplements in previous 30 days
• Already on a decolonization protocol
• Active infection requiring acute antibiotic treatment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Prebiotic; Participants assigned to this arm will consume resistant potato starch prebiotic fiber powder as part of their standard diet for 5 weeks. On days 1-4 they will consume 4 grams (g) of product, on days 5-7 they will consume 7g of product, on days 8-35 they will consume 10g of product.	Drug: Resistant Potato Starch; MSPrebiotic (MSPrebiotic Inc, Carberry, Manitoba, Canada). MSPrebiotic is an unmodified resistant starch derived from potatoes (Solanar tuberosum). It consists of 20% amylose and 80% amylopectin forming granules the stomach and small intestine are unable to digest allowing for absorption in the colon. MSPrebiotic is consumed by mixing 10g into cold or room temperature foods or beverages; it is not to be heated.; Other Names: MSPrebiotic
Placebo Comparator: Placebo; Participants assigned to this arm will consume placebo (maltodextrin) powder as part of their standard diet for 5 weeks. On days 1-4 they will consume 4 grams (g) of product, on days 5-7 they will consume 7g of product, on days 8-35 they will consume 10g of product.	Drug: Maltodextrin; The placebo will be 10 grams of digestible maltodextrin powder daily. Maltodextrin is a is a polysaccharide food additive and is white, tasteless, water-soluble powder making it a comparable placebo for the prebiotic. The placebo will be pharmaceutical grade and available over the counter.; Other Names: Starch placebo control

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Multidrug resistant organism (MDRO) Decolonization	Changes in prevalence of MDRO carriage with one or more MDRO of interest: C. difficile, Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and/or multi-drug resistant Enterobacteriaceae (MDRE)	3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Alpha-1-antitrypsin (AAT) levels	Changes in fecal AAT levels. AAT has been used successfully as a biomarker for intestinal permeability with higher concentrations of AAT in the gut indicating a leaky gut.	3 years
Gut microbiome composition	The gut microbiome will be assessed using next generation sequencing (shotgun metagenomics)	3 years
Changes in gut microbiome metabolites	Gut microbiome metabolites (short-chain fatty acids, secondary-bile acid producers) will be identified through next-generation sequencing technology and both targeted and untargeted metabolomics.	3 years

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Multidrug resistant organism (MDRO) Infections	Changes in infection rates with one or more of the MDROs of interest: C. difficile, Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and/or multi-drug resistant Enterobacteriaceae (MDRE)	3 years
Intervention acceptability	A written questionnaire will be given to assess participants' experience with the fiber products. The questionnaire will include statements where participants are asked to rate their agreement with the statement, with responses on a 5-point Likert scale (1-Strongly Disagree to 5-Strongly Agree). Higher scores will indicate higher acceptability of the product.	3 years

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Investigators: Principal Investigator: Nasia Safdar, MD PhD, William S. Middleton Memorial Veterans Hospital, Madison, WI

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): December 31, 2029
• Study Completion (Estimated): September 30, 2030

Study Registration Dates

• First Submitted: August 11, 2026
• First Submitted That Met QC Criteria: August 25, 2026
• First Posted (Actual): August 28, 2026

Study Record Updates

• Last Update Posted (Actual): August 28, 2026
• Last Update Submitted That Met QC Criteria: August 25, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Veterans; Dietary fiber; Prebiotics; Gastrointestinal microbiome; methicillin-resistant Staphylococcus aureus; Clostridioides; Drug resistance, multiple
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Asymptomatic Diseases; Pathological Conditions, Signs and Symptoms; Clostridium Infections; Asymptomatic Infections; maltodextrin
• Other Study ID Numbers: INFA-002-25F; I01RD001117-01-A1 (Other Grant/Funding Number: VA Office of Research and Development)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: A BioProject will be created with NCBI and sequencing data will be shared there with a limited, deidentified set of metadata from participants. Additional data can be obtained from the research team with permissions.
• IPD Sharing Time Frame: 3 years
• IPD Sharing Access Criteria: Written requests for access to the data will be accepted. Data and documentation will be available under a data use agreement (DUA) that provides a commitment to use data for research purposes only, not to attempt to identify participants, to secure data using appropriate computer technology, and to destroy/return data after analyses are complete.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No