A Phase 2 interventional study of Resistant Potato Starch and Maltodextrin in Clostridium Infections, Methicillin-resistant Staphylococcus Aureus (MRSA) and Vancomycin-Resistant Enterococci, sponsored by VA Office of Research and Development. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-28.
Sponsored by VA Office of Research and Development · Phase 2, Interventional, and Treatment
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.
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.
251 studies on the registry are indexed under Clostridium Infections; 51 are open to participants now.
This study's planned enrollment of 120 is above the median of 64 across 185 interventional studies indexed under Clostridium Infections.
Browse Clostridium Infections studies →VA Office of Research and Development is the lead sponsor of 1,771 studies on the registry; 392 are open to participants now.
Of its 213 completed or terminated interventional studies of FDA-regulated products, 185 (87%) have results posted.
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Exclusion Criteria:
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.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
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Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
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Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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
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.
Also known as: MSPrebiotic
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.
Also known as: Starch placebo control
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)
Time frame: 3 years
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.
Time frame: 3 years
Gut microbiome composition
The gut microbiome will be assessed using next generation sequencing (shotgun metagenomics)
Time frame: 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.
Time frame: 3 years
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)
Time frame: 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.
Time frame: 3 years
Plan to share: Yes — 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.
Supporting information: Study protocol
Time frame: 3 years
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.
No publications or documents are linked to this record.
Start is estimated for Jan 2027; primary completion for Dec 2029, 35 months later.
Of 23 phase 2 interventional studies under Clostridium Infections, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 19 and three quarters within 39. This study's planned 35 months is above that.
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This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Resistant Potato Starch
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