Study finds daily d-mannose not effective in preventing recurrent UTIs

Recurrent urinary tract infection (UTI) is not reduced in primary care from daily d-mannose, according to a recent study published in JAMA Internal Medicine.¹

The lifetime risk of UTI is up to 50%, making it the most common bacterial infection among women in primary care. Recurrent UTI (rUTI) is defined as 2 UTIs in 6 months or 3 in a year. Patients’ quality of life is often adversely impacted, with over 200,000 UTI deaths reported worldwide in 2019.

Patients often administer daily antibiotics for rUTI prophylaxis, but this method increases resistant UTI and adverse effect risks. The food supplement d-Mannose may be an alternative to antibiotic prophylaxis in women with rUTI. However, high costs of d-mannose indicate a need to determine whether family physicians should advise purchase among patients.

To evaluate the efficacy of d-mannose against rUTI, investigators conducted a double-blind, placebo-controlled randomized clinical trial. Recruitment was performed across 99 primary care centers in 10 of 15 regions in England and 4 of 7 health boards in Wales.

Participants included women aged 18 years or older presenting to an ambulatory care system consistent with a UTI or resulting in a UTI-specific antibiotic prescription at least 3 times in the prior year or 2 times in the prior 6 months. Exclusion criteria included pregnancy, lactating, overactive bladder syndrome, and residing in a nursing home.

Participants were randomized to receive d-mannose or placebo, taking either 2 g of d-mannose or a similar scoop of fructose powder daily. Use of the study product continued when participants were symptomatic and when taking antibiotics.

UTI symptoms, over-the-counter medicine use, health care contacts, and EuroQol EQ-5D-5L instrument were recorded daily by patients in a symptom diary. Women with continuous, mild UTI also completed the diary when experiencing symptom flares. When the diary was not completed, data was obtained from a weekly questionnaire.

The proportion of women experiencing 1 or more additional UTI episode leading to ambulatory care was the primary outcome of the analysis. This outcome was recorded within 6 months of randomization.

The number of days with moderately bad or worse symptoms, time to next consultation, number of clinically suspected UTIs, number of microbiologically proven UTIs, antibiotic courses, defined daily dose, proportion of women with resistant uropathogens, and UTI hospital admissions were reported as secondary outcomes.

Data was available for 294 women receiving d-mannose and 289 receiving placebo. Of these women a further episode of clinically suspected UTI with ambulatory care was reported in 51% and 55.7%, respectively. This indicated a relative risk of 0.92, and a similar proportion was reported in the sensitivity analysis and subgroup analyses.

No difference was observed in moderately bad or worse UTI symptoms between groups. The time to next consultation and number of clinically suspected UTIs or microbiologically proven STIs also not differ from d-mannose vs placebo.

There was also no difference in the number of prescribed antibiotic courses between groups, but the median number of days prescribed antibiotics did differ. This number was higher in the placebo group with an adjusted median difference of -3.00. Antibiotic consumption was not decreased in the d-mannose group vs the placebo group.

Hospital admission rates related to UTIs were 2% in the d-mannose group and 1% in the placebo group. These groups experienced 20 and 8 serious adverse events, respectively.

These results indicated no improvement of rUTI from daily d-mannose use. Investigators concluded d-mannose should not be recommended to prevent clinically suspected UTI episodes.

Clinicians should also consider risks from d-mannose use among certain populations.² Insulin secretion from use may adversely impact patients with diabetes or insulin resistance. This indicates a need for further research about other potential prophylactic measures.

References

1. Hayward G, Mort S, Hay AD, et al. d-Mannose for prevention of recurrent urinary tract infection among women: A randomized clinical trial. JAMA Intern Med. 2024;184(6):619–628. doi:10.1001/jamainternmed.2024.0264
2. JAMA study demonstrates d-mannose should not be recommended to prevent UTIs in women. Solv Wellness. June 18, 2024. Accessed June 18, 2024. https://www.prnewswire.com/news-releases/jama-study-demonstrates-d-mannose-should-not-be-recommended-to-prevent-utis-in-women-302174818.html#:~:text=With%20no%20significant%20difference%20in,for%20women%20with%20recurrent%20UTIs.