An Early Phase 1 interventional study of Gentamicin and Lactobacillus Rhamnosus GG in Spinal Cord Injury, Neurogenic Bladder (NB) and Neurogenic Lower Urinary Tract Dysfunction, sponsored by Medstar Health Research Institute. Not yet recruiting at 2 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Medstar Health Research Institute · Early Phase 1, Interventional, and Prevention
The main objective of the proposed research study is to determine in men and women with spinal cord injury/disease and neurogenic bladder whether the dose of coupled gentamicin \& Lactobacillus rhamnosus GG affects the recolonization of the bladder, and whether the rate of success differs by sex. Secondary objectives include determining whether that recolonization lasts 7, 14, or 28 days; and safety of the coupled gentamicin \& Lactobacillus instillations.
People with spinal cord injury/disease (SCI/D) experience, on average, 2.5 episodes of UTI annually. Since repeated exposures of bacteria to antibiotics leads to multi-drug resistant organisms (MDROs), it is likely that the frequent use of antibiotics for UTI is a driver of the increasing prevalence of infections with MDROs in the SCI/D population. This prevalence of MDROs among people with SCI/D represents a microcosm of the world-wide public health crisis of antibiotic resistance. As stated by the CDC, "antibiotic resistance is one of the biggest public health challenges of our time." In the US alone, 2.8M people annually develop infections with resistant microbes; of whom 35,000 die as a direct result. Infections with resistant organisms are associated with longer hospital lengths of stay, increased mortality, and higher health care costs. With UTI persistently being the leading reason for rehospitalizations among people with SCI/D, infections with resistant organisms represent a contributor to elevated health care costs as well as mortality risk. Additionally, the cost to treat a UTI due to an extended-spectrum beta-lactamase (ESBL) organism is estimated to be 1.5 times greater than treating a non-ESBL pathogen. Thus, not only are people with SCI/D and UTI at greater risk of mortality due to MDROs, they are also likely to have higher costs as a result of UTI. These costs can only be expected to increase, as the rate of antibiotic resistant UTIs increases. Moreover, individuals with SCI/D and NLUTD experience lower urinary tract symptoms (LUTS) frequently, and these may be treated with antibiotics whether they represent UTI or not.
As noted earlier, the standard of care for UTI treatment (systemic antibiotics, guided by standard urine culture (SUC)) is flawed and contributes to overtreatment and antimicrobial resistance. Use of intravesical therapeutics have been a part of clinical practice since the 1960's and intravesical antibiotics have been studied for nearly 30 years; however, use of intravesical antibiotics for UTI is typically only considered as a "last resort" (such as for recurrent UTI). Agents used include gentamicin, tobramycin, colistin, and neomycin/polymyxin. Gentamicin is the most commonly studied intravesical antibiotic and when administered intravesicularly, it has been shown to have little to no systemic absorption, nor nephro- or oto-toxicity (as with intravenous administration). Intravesical gentamicin has been shown to be safe, tolerated, and effective for recurrent UTI in people with NLUTD.
The investigators' team was first to compare the urobiomes of people with SCI/D and NLUTD to those of neurologically intact controls. This work verified the existence of the urobiome, showing that most control female urobiomes are predominated by Lactobacillus and some control male urobiomes contain Lactobacillus, but most do not. The investigators also showed that NLUTD urobiomes are dysbiotic, depleted in beneficial bacteria as most NLUTD females lacked or had reduced Lactobacillus levels, while most NLUTD males lacked the Streptococcus and/or Corynebacterium that was commonly observed in control males. These results support the investigators' hypothesis that NLUTD bladders of most females and at least some males could be colonized by LGG, and that LGG in the urobiome could improve urinary symptoms.
2,025 studies on the registry are indexed under Spinal Cord Injuries; 537 are open to participants now.
This study's planned enrollment of 48 is above the median of 24 across 1,633 interventional studies indexed under Spinal Cord Injuries.
Browse Spinal Cord Injuries studies →Medstar Health Research Institute is the lead sponsor of 161 studies on the registry; 31 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 7 (50%) have results posted.
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Exclusion Criteria:
Gentamicin will be diluted in normal saline under sterile conditions by qualified pharmacy personnel to a concentration of 0.96mg/mL. 50cc (48 mg) of the resulting solution will be drawn up into a catheter tip syringe, which will then be capped and inserted into sterile packaging. Seven such syringes will be overnight mailed to each participant in temperature-controlled shipping containers. Once ready to begin instillations, the full contents of one syringe will then be instilled into the bladder after drainage of urine is complete by catheterization; the solution will be left indwelling until the next catheterization. This will be done six times. Low dose participants will wait 72 hours, then mix one capsule LGG into 45mL sterile saline and instill the resulting mixture in the same fashion as the gentamicin. Low dose participants will do this in once in the evening and again 12 hours later (the following morning). This mixture will remain in the bladder for at least 4 hours.
Drug: Gentamicin · Drug: Lactobacillus Rhamnosus GG
Gentamicin will be diluted in normal saline under sterile conditions by qualified pharmacy personnel to a concentration of 0.96mg/mL. 50cc (48 mg) of the resulting solution will be drawn up into a catheter tip syringe, which will then be capped and inserted into sterile packaging. Seven such syringes will be overnight mailed to each participant in temperature-controlled shipping containers. Once ready to begin instillations, the full contents of one syringe will then be instilled into the bladder after drainage of urine is complete by catheterization; the solution will be left indwelling until the next catheterization. This will be done six times. High dose participants will wait 72 hours, then mix one capsule LGG into 45mL sterile saline and instill the resulting mixture in the same fashion as the gentamicin. High dose participants will do this in once in the evening, and again every 12 hours until four doses are complete. This mixture will remain in the bladder for at least 4 hours.
Drug: Gentamicin · Drug: Lactobacillus Rhamnosus GG
Gentamicin will be diluted in normal saline under sterile conditions by qualified pharmacy personnel to a concentration of 0.96mg/mL. 50cc (48 mg) of the resulting solution will be drawn up into a catheter tip syringe, which will then be capped and inserted into sterile packaging. Seven such syringes will be overnight mailed to each participant in temperature-controlled shipping containers, with the extra syringe being included in case of damage or accidental dropping of one of the six instillations. Patients will be instructed to refrigerate all syringes immediately upon receipt. The first instillation will occur after the first catheterization of the morning. Once ready to begin instillations, the full contents of one syringe will then be instilled into the bladder after drainage of urine is complete by catheterization and the solution has reach room temperature; the solution will be left indwelling for at least four hours. This will be done every 12 hours for three days (6 doses).
Participants will be instructed to mix the contents of 1 LGG capsule into 45cc sterile 0.9% saline. After mixing, participants will draw up the 45cc liquid LGG mixture into a 60 cc syringe and instill the first dose via the intermittent catheter after the last catheterization prior to going to bed. Participants will receive 4 or 6 LGG capsules (2 additional capsules/participant, depending on randomization group) and will repeat this process every 12 hours until s/he has completed assigned dosing, according to randomization group. The first LGG instillation will occur 72 hours after the final dose of gentamicin.
Also known as: Lactobacillus RhamnosusGG
Level of Lactobacillus rhamnosus GG in Urine
Urine samples will be analyzed with qPCR to determine whether LGG is present and, if so, at what concentration. Concentration from 24 hours after final LGG instillation will be compared to that measured after final gentamicin instillation. An increase of 30% or greater from baseline will be considered successful recolonization if LGG is present at baseline, otherwise absolute increase will be used.
Time frame: 24 hours after final LGG instillation
Length of Recolonization
Urine samples collected at 7 days, 14 days, and 28 days after final Lactobacillus instillation will be analyzed with qPCR to determine if Lactobacillus is present, and if so, at what concentration. These values will be compared with the samples taken after gentamicin instillations and 24 hours after final LGG instillation to determine how long increased LGG values persist.
Time frame: 28 days after final Lactobacillus instillation
Start is estimated for Aug 2026; primary completion for Sep 2027, 13 months later.
Of 40 non-industry phase 1 interventional studies under Spinal Cord Injuries, half reached primary completion within 38 months of starting (the median), counting those still running; a quarter within 25 and three quarters within 55. This study's planned 13 months is below that.
Counting every sponsor, half of 51 studies reached it within 36 months; a quarter within 24 and three quarters within 55.
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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: Gentamicins
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