Lowered prevalence of infection with lactulose therapy in patients in long-term hospital care.

Over a 6-month, retrospective study period, regular lactulose therapy resulted in a significant reduction in the prevalence of UTIs when compared to a control group receiving no lactulose (P less than 0.005). The overall number of patients contracting infections was also reduced (P less than 0.25). There was a parallel reduction in the prescription of antibiotics (P less than 0.05) and in the number of patients requiring antibiotic therapy (P less than 0.005). There was no alteration in faecal continence with lactulose therapy and no urinary catheters were used in either group. In two additional groups of patients, low dose lactulose therapy for 6 months and a shorter duration of lactulose therapy for under 2 months, had no significant effect on the prevalence of UTIs. This study was retrospective and the results were both unexpected and do not explain the mode of action of lactulose. A controlled prospective study involving larger patient numbers is required before any realistic therapeutic recommendations can be made.