Comparison of Three Interventions for Antibiotic-Resistant Bacteria (ARB) Decolonization From the Gastrointestinal Tract

The aim of this research experiment is to evaluate the effectiveness of three interventions for decolonization of antibiotic-resistant bacteria (ARB) from the gastrointestinal tract of colonized patients. The interventions include fecal microbiota transplantation (FMT), multistrain probiotic therapy preceded by antibiotic pre-treatment and bowel cleansing, and an eubiotic gut microbiota boosting diet as an active comparator. This approach addresses the urgent global need to develop new strategies against antimicrobial resistance, a growing threat predicted to cause millions of deaths annually by 2050 and significant economic impact.

This is an open-label, randomized, controlled experiment with a 2:1:1 allocation ratio (FMT:probiotic:diet). The total planned recruitment is approximately 360 adult patients documented to be colonized with clinically significant antibiotic-resistant bacterial strains, including carbapenem-resistant Enterobacteriaceae, multidrug-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, vancomycin-resistant Enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA). Patients must meet defined inclusion and exclusion criteria ensuring safety and appropriateness for the interventions.

The FMT intervention involves administration of standardized fecal microbiota preparations in capsule form or via colonoscopy on specified days, preceded by a 5-day course of targeted antibiotics and bowel cleansing to reduce the existing gut microbial load. The probiotic arm receives a defined multi-strain probiotic preparation twice daily for 20 days following similar bowel cleansing. The diet arm follows a scientifically formulated diet designed to promote eubiosis, delivered daily for 38 days.

Study visits are conducted at screening, treatment initiation, and multiple follow-up points extending to six months post-intervention to monitor safety, efficacy, and long-term outcomes. Clinical assessments include medical history, physical examination, vital signs, and laboratory testing. Biological samples such as stool, urine, saliva, and blood are collected for microbiological and genomic analyses to evaluate colonization status and mechanisms of decolonization.

Sample size calculations, based on power analyses, aim to detect a clinically significant difference in decolonization rates among the groups, with 142 patients in the FMT arm and 71 patients in each comparator arm in the intention-to-treat population, accounting for anticipated dropout and screening failure rates.

This experiment is designed to provide robust data on the relative efficacy and safety of FMT, probiotic therapy, and dietary modulation in eradicating ARB colonization, potentially informing future clinical practices and public health policies to combat antibiotic resistance.