Does anybody have any suggestions for ways to prevent recurring Urinary Tract Infections?

I have a close relative who is constantly plagued with recurrent urinary tract infections. To treat the bacteria involved often E. coli but not always and symptoms she needs to take antibiotics but is not happy about doing so. While alternative products have been tried, nothing has been successful in the long term. She is looking for any suggestions as to prevention of the development of UTIs without resorting to a prophylactic course of low-dose antibiotics. Your response is eagerly awaited…