Results Summary

What was the research about?

Spinal cord injuries, spina bifida, and multiple sclerosis are health problems that affect the spinal cord and may cause problems with urination. To manage these problems, many patients use an intermittent catheter, a tube placed and removed several times a day to drain urine. But using a catheter increases the risk of infection.

In this study, the research team wanted to learn whether a new approach to self-manage urinary symptoms that may warn of infection was safe for patients using an intermittent catheter. In this approach, patients insert a probiotic through the catheter when they have urinary symptoms such as cloudy or smelly urine. Probiotics are healthy bacteria that may treat or prevent illness.

What were the results?

During the study, 59 adults and 5 children used the probiotic in response to symptoms. The approach was safe and well-tolerated. The number of adverse events reported by patients, such as irritation or infection, didn’t increase after using the probiotic. Patients who used the probiotic had fewer symptoms, including pain, fever, and cloudy or smelly urine. Other symptoms, such as fatigue or blood in urine, didn’t change.

Patients who didn’t use the probiotic had no change in the number of symptoms during the study.

Who was in the study?

The study included 96 adults and 7 children from across the United States who had spinal cord injuries, spina bifida, or multiple sclerosis. Of adults, 74 percent were white, 19 percent were African American, 4 percent were Asian, 1 percent were American Indian, and 2 percent were more than one race; 6 percent did not report ethnicity and 2 percent were Hispanic. The average age was 43, and 63 percent were men.

What did the research team do?

To develop this new approach, the research team partnered with patients with spinal cord conditions or their parents. These partners also taught patients in the study about using the probiotic.

The research team looked at three 6-month study periods. During the first and last periods, patients didn’t use the probiotic. During the middle period, patients used the probiotic if they had urinary symptoms.

Patients or caregivers completed weekly surveys about urinary symptoms. Every six months, patients filled out a survey asking if they would seek out or pay for the probiotic if insurance didn’t pay for it. Patients also reported any adverse events. To see if the approach was well-tolerated, the team looked at whether having an adverse event affected how likely patients were to pay for the probiotic.

What were the limits of the study?

The number of adults and children who used the probiotic in the study was small. As a result, the research team can’t say for sure how well it improved symptoms.

Future research could test probiotics for urinary symptoms with more adults and children who use catheters.

How can people use the results?

Researchers can use the results to plan larger studies of this approach.

Final Research Report

View this project's final research report.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers asked why Lactobacillus rhamnosus GG was chosen as the probiotic since it is not known as a microorganism found in the bladder. The researchers explained that they chose this probiotic because it has been widely used, is easily obtained over the counter, and has a history of being safe, tolerated, and effective.
  • The reviewers asked why the researchers used a 10 percent reduction in symptoms as the cutoff to represent a clinically meaningful effect. The researchers said that the threshold has not been previously reported in scientific literature. Rather, the research team determined this level before starting the trial based on the experience and expertise of clinicians and patients.
  • The reviewers commented on the lack of dosing information and noted that the study did not show that Lactobacillus rhamnosus GG established itself in bladders. The researchers agreed that they did not provide dosing information in this pilot trial but said they plan to study dosing in a future study.
  • The reviewers asked why the researchers chose not to conduct a randomized trial or include a control group. The researchers said because of the preliminary nature of this work, it was best to treat participants as their own controls to have the greatest power of detecting any effect. The study also established safety and tolerability of the treatment. The researchers said this trial will inform future randomized trials. The researchers did acknowledge the limitations of a quasi-experimental design in the study limitations.

Conflict of Interest Disclosures

Project Information

Suzanne Groah, MD, MPH
MedStar Health Research Institute
The Impact of Self-Management with Probiotics on Urinary Symptoms and the Urine Microbiome in Individuals with Spinal Cord Injury and Spina Bifida

Key Dates

July 2014
August 2020

Study Registration Information


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Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
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Last updated: January 25, 2023