Effect of chicory-derived inulin-type fructans on abundance of Bifidobacterium and on bowel function: a systematic review with meta-analyses

Inulin-type fructans are considered to stimulate the growth of beneficial microorganisms, like Bifidobacterium in the gut and support health. However, both the fructan source and chemical structure may modify these effects. A systematic review was conducted to assess the effects of chicory-derived inulin-type fructans consumed either in specific foods or as dietary supplements on abundance of Bifidobacterium in the gut and on health-related outcomes. Three electronic databases and two clinical trial registries were systematically searched until January 2021. Two authors independently selected randomized controlled trials that investigated with a protocol of minimum seven days supplementation the effect of chicory-derived inulin-type fructans on Bifidobacterium abundance in any population. Meta-analyses with random-effects model were conducted on Bifidobacterium abundance and bowel function parameters. We evaluated risk of bias using Cochrane RoB tool. Chicory-derived inulin-type fructans at a dose of 3-20 g/day significantly increased Bifidobacterium abundance in participants with an age range from 0 to 83 years (standardized mean difference: 0.83, 95% CI: 0.58-1.08; p < 0.01; 50 studies; 2525 participants). Significant bifidogenic effects were observed in healthy individuals and in populations with health impairments, except gastrointestinal disorders. Significant beneficial effects on bowel function parameters were observed in healthy subjects. Chicory-derived inulin-type fructans may have significant bifidogenic effects and may beneficially influence bowel function in healthy individuals. PROSPERO registration number CRD42020162892.