Background and aim: Diverticular disease represents the first most important gastrointestinal disease in Western countries. The vast ma- jority of patients experience symptomatic uncomplicated diverticular disease (SUDD), whose most frequent abdominal symptoms are pain and bloating. No specific standard treatment for SUDD is accepted, guidelines of the Am College Gastroent suggest a high–fibre diet in SUDD pts. A possi- ble role of gut microflora in determining symptoms related to SUDD is suggested, thus these pts may benefit from probiotics treatment. Aim: to assess the efficacy of Lactobacillus paracasei F19 in SUDD pts Material and methods: Multicentric randomized controlled study on 50SUDD pts, aged 47-78 years (18 M, 32 F) diagnosed by double contrast enema and biochemistry to exclude acute inflammation. SUDD was defined as: presence of abdominal symptoms (pain < 24h and bloating) for at least 6 months before enrollment. All pts had a validated detailed questionnaire for abdominal symptoms and functional dyspep- sia (FD) including a visual analogic scale (VAS). Exclusion criteria: complicated diverticular disease, previous colon surgery, antibiotics or laxatives 30 days before enrollment, use of NSAIDs. In all pts a daily intake of 30 g dietary fibre was recommended. Pts were randomly assigned to receive: 1 sachet b.i.d of L. paracasei F19 for 14 days/month for 6 months (Group A, n=16), only fibre diet (Group B, n=16) or 1 sachet once daily of L. paracasei F19 for 14 days/month for 6 months (Group C, n=18). Endpoint of the study was to evaluate the decrease of abdominal pain and bloating after 6 months of treatment. Results expressed as mean ± SD. Results: At baseline, 40 pts had both abdominal pain and bloating, whereas 10 pts had only bloating. 43 (86%) patients completed the study: 1 patient (Group A) was withdrawn for diarrhea and 6 patients (2 from Group A, 1 from Group B, 3 from Group C) were lost at follow-up. A significant decrease of bloating VAS was observed in group A and C whereas of pain VAS in group C. Conclusions: Six-months treatment with L. paracasei F19 significantly decreases the score of abdominal bloating in patients with SUDD. The higher dosage of probiotics is able to also reduce the score of abdominal pain. Thus, treatment with L. paracasei F19 is more efficacious than dietary fibres in controlling abdominal symptoms in SUDD patients.