Antibiotic treatment of urinary tract infection and its impact on the gut microbiota

Gut microbiota are considered to be the source of uropathogenic Enterobacterales that can colonise the periurethral space and ascend to the bladder, causing a urinary tract infection (UTI).1 Although broad-spectrum antibiotics are the cornerstone of UTI treatment, paradoxically, their use is a known risk factor for UTI by selecting uropathogens that can become resistant to common antibiotics.1,2 New UTI treatment strategies with less of an effect on the ecological balance of the gut microbiota than the antibiotics currently available are therefore needed, to reduce the risk of recurrent UTI and minimise the selection of antimicrobial resistance. [...]the clinical relevance of these findings at an individual patient level is less clear, since the difference between temocillin and cefotaxime in their effects on the gut microbiota diminished quickly, and the follow-up was too short to evaluate the effects of each antibiotic on risk of recurrent UTI or other features of a disrupted gut microbiota. [...]the primary endpoint focused on resistant Enterobacterales that could be grown on agar medium, ignoring the importance of commensal gut bacteria that do not grow on routine media. Data presented (n=139) Demographics Median age (IQR), years 39 (29–53) Sex Female 90 (65%)/139 Male 49 (35%)/139 Pregnant 11 (8%)/139 Uropathogen Escherichia coli 111 (90%)/123 Proteus spp 1 (1%)/123 Staphylococcus spp 3 (2%)/123 Streptococcus spp* 5 (4%)/123 Neisseria gonorrhoeae 2 (2%)/123 Other or mixed flora 1 (1%)/123 Treatment Antibiotics 0/130 Nephrectomy 7 (5%)/130 Renal lavage 47 (36%)/130 Nephrostomy or removal of renal stones 2 (2%)/130 Clinical outcome Duration of symptoms Several weeks† Mortality 4 (3%)/137 Clinical cure‡ 85 (69%)/124 Chronic relapsing course 39 (31%)/124 Table A case series to describe the course of acute pyelonephritis by Frank Kidd,11 published in 1920 (ie, the pre-antibiotic era)