Dietary fibre modification with or without antibiotics in the prevention of diverticulitis in adults with diverticular disease: A systematic literature review and mata-analysis

Background: The use of high dietary fibre intake and antibiotics have been hypothesised to play a role in the management of diverticular disease; however, dietary recommendations for the prevention of diverticulitis in those with diverticular disease are inconsistent and quality evidence is lacking. Therefore, this systematic review aimed to pool and appraise existing data to explore the effect of dietary fibre modifications with or without antibiotics on the development of acute diverticulitis, gastrointestinal symptoms and bowel habits in adults with diverticular disease. Methods: Five electronic databases were searched for studies from database inception until March 2017. Studies were critically appraised and pooled using meta-analysis. Results: 20 studies were included. Compared with placebo, ispaghula husk supplementation significantly increased daily stool weight by μ42g/day (95%CI:26-57g; P<0.00001); however, dietary fibre supplementation inconsistently improved gastrointestinal symptoms and transit times depending on baseline values, and no studies evaluated its role in preventing diverticulitis. Seven days to everyday per month for 12-24-months of dietary fibre supplementation had a 2.6 (95%CI:1.24-5.6; P=0.01) higher relative risk of diverticulitis compared to dietary fibre and poorly-absorbed antibiotic coadministration. Seven days every month for 12-24-months or 14 days of dietary fibre and poorly-absorbed antibiotic co-administration significantly decreased gastrointestinal symptoms compared with dietary fibre supplementation alone by a standardised mean of 1 point (scale of 0 to approximately 18) (95%CI:0.70-1.21; P<0.00001). Conclusions: Dietary fibre supplementation may improve bowel function and gastrointestinal symptoms in those with diverticular disease; but its role in the prevention of diverticulitis is unknown. Although co-administration with poorly-absorbed antibiotics appears to have superior effects compared to dietary fibre supplementation alone; recommendations for this are not supported due to the high risk of bias in existing research.