D-mannose found to be ineffective for prevention of recurrent UTI

Taking daily D-mannose did not reduce the incidence of recurrent urinary tract infections (UTIs) in adult women compared with placebo, according to findings from a study recently published in JAMA Internal Medicine.¹

Participants in the study received 2 g of daily D-mannose powder or placebo with 6 months of follow-up.

"This study reinforces our role as physicians to guide patients away from costly supplements with little or no benefit," said Wai Lee, MD, in a news release on the findings.² Lee is the director of Female Pelvic Medicine and Reconstructive Surgery at the Smith Institute for Urology at North Shore University Hospital at Northwell Health.

For the study, 598 women were randomly assigned to receive D-mannose (n = 303) or placebo (n = 295). For the efficacy analysis, 294 and 289 women were included in each arm, respectively.

Of those, 150 women (51%) in the D-mannose cohort and 161 (55.7%) in the placebo cohort experienced a subsequent episode of clinically suspected UTI for which they contacted ambulatory care (relative risk [RR], 0.92; 95% CI, 0.80-1.05; P = .22; and unadjusted risk difference, −5%; 95% CI, −13% to 3%; P = .26). The proportions were also not significantly different in subgroup analyses comparing women with a history of more or less frequent UTIs and in pre- and post-menopausal women.

Regarding the study’s secondary end points, no significant difference was found between the 2 arms regarding the duration of moderately bad or worse symptoms of UTI (adjusted median difference: daily, 0.00; 95% CI, −0.36 to 0.36; P > .99; and weekly, 0.00; 95% CI, −0.37 to 0.37; P > .99). Similarly, there were no significant differences between the 2 groups in the time to next consultation with a clinically suspected UTI nor in the number of clinically suspected UTIs or microbiologically proven UTIs.

The findings also showed a higher median number of days on prescribed antibiotics among women in the placebo group (adjusted median difference, −3.00; 95% CI, −4.40 to −1.60; P < .001), although the findings were skewed by a small number of women who had a high antibiotic consumption during the follow-up period. With this taken into account, the investigators found no significant differences between the number of prescribed antibiotic courses between the study arms, with a mean number of days of 4.7 in the D-mannose group vs 5.1 days in the placebo group (adjusted median difference, 0.00; 95% CI, −1.40 to 1.40; P > .99).

Additionally, no significant differences were observed regarding the proportion of women with resistant uropathogens cultured during an episode nor in the number of hospital admissions related to UTIs.

Overall, the double-blind, randomized, placebo-controlled trial enrolled women with recurrent UTI between March 2019 and January 2020 across 99 primary care centers in the UK. The average age of participants was 58.6 years in the D-mannose cohort and 57.3 years in the placebo cohort. Participants in the study received 2 g of daily D-mannose powder or placebo with 6 months of follow-up.

The primary outcome for the study was the proportion of women with recurrent UTI who experienced a subsequent UTI for which they contacted ambulatory care, assessed at the 6-month time point. Secondary outcome measures for the study included the number of days of moderately bad or worse UTI symptoms, time to next consultation with a clinically suspected UTI, the number of clinically suspected UTIs or microbiologically proven UTIs, and the number and consumption of antibiotic courses for UTI.

Based on the findings, the authors concluded, “Daily D-mannose should not be recommended to prevent future episodes of clinically suspected UTI in women with rUTI in primary care.”¹

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 Jun 1;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. News release. Solv Wellness. June 18, 2024. Accessed June 19, 2024. https://www.prnewswire.com/news-releases/jama-study-demonstrates-d-mannose-should-not-be-recommended-to-prevent-utis-in-women-302174818.html