Background:Some small secondary care studies have shown benefits from taking probiotics in diverticular disease. We investigated the feasibility of conducting a year-long probiotic study in primary care. Methods:Patients (n=21) with a past history of uncomplicated acute diverticulitis but not currently taking antibiotics were recruited from four general practices. Subjects were asked to take the daily probiotic drink YakultÒ. Probiotic effects were assessed by comparing clinically diagnosed diverticulitis attacks in the 6 months prior to probiotic intervention with the 0-6 and 6-12 month periods after probiotic intervention commenced. Effects on gastrointestinal symptoms were assessed by validated questionnaires at baseline, 6 and 12 months. Diet diaries were also completed. Results: Two thirds (14/21) of subjects who demonstrated good adherence in taking the daily probiotic improved symptomatically (p=0.025). Clinical presentations with diverticulitis were down 50% during the study period compared with the 12 months period before (7 vs 14 cases; p=0.021). The mean change in gastrointestinal symptom score improved significantly (p <0.001). Diverticulitis episodes did not correlate with body mass index (BMI), diabetic status or dietary fibre. Conclusions: Taking the daily probiotic was associated with a lower rate of clinical presentation with diverticulitis episodes and improvement in gastrointestinal symptoms. Sufficient information is presented to design a definitive trial. However, we recommend inclusion of a method to validate the diagnosis of diverticulitis. It is feasible to recruit and run a study that requires participants to take a daily probiotic drink for a year in a primary care setting. LACTOPRoD was registered at ClinicalTrials.gov: NCT01609751 in 2012.