A Clinical Trial of Resistant Potato Starch for Gut MDRO Decolonization

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.

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