DOI: https://doi.org/10.36347/sajb.2026.v14i10.004

Pages: 673-680

Recurrent urinary tract infection (rUTI) is managed with repeated, and often continuous, antimicrobial therapy. This review examines whether that strategy contributes to the condition it treats. We synthesise human volunteer and cohort studies of gut microbiota recovery after antibiotic exposure with the emerging evidence that butyrate-producing intestinal bacteria govern colonisation resistance against Enterobacteriaceae. Across controlled human studies, obligately anaerobic butyrate producers are among the taxa most consistently depleted and slowest to recover: community composition returns towards baseline within weeks to a few months, but individual species present in every participant before exposure can remain undetectable at 180 days, and compositional change has been documented between eight and 31 months after a single course. Recovery is not uniform across agents, and is modified by host diet and by repeat exposure. The functional consequence is relevant to urinary infection specifically, because depletion of these taxa reduces colonocyte oxidative metabolism and permits aerobic expansion of intestinal Escherichia coli, the reservoir from which most recurrences arise. Women with rUTI show depletion of butyrate producers, and intestinal E. coli blooms have been documented in the one to two weeks after antimicrobial treatment in patients colonised in the urinary tract. Together these observations describe a plausible iatrogenic loop. We assess what can and cannot be concluded, identify the agents least damaging to anaerobes, evaluate whether recovery can be accelerated, and propose a stewardship position for recurrent UTI that treats the intestinal anaerobic community as a tissue worth protecting. We place postbiotic and butyrate-precursor approaches within the set of candidate restoration strategies, and state what each would have to demonstrate before it could be offered to this population.