Effects of native chicory inulin on constipation in elderly people

Constipation is a common problem in the population and a major health problem in elderly people. Dietary fibre promotes laxation in healthy and constipated persons. This is a well established property of insoluble fibre; however the effect of soluble fibres is less well-known. Chicory inulin is a soluble prebiotic fibre. The aim of the present study is to evaluate the effect of native chicory inulin on bifidobacteria counts, bowel function parameters and quality of life of elderly constipated subjects. Two groups of 25 volunteers were asked to consume daily 15 g of chicory native inulin (Fibruline (R) Instant) or 15 g of placebo (maltodextrins) for four weeks. Stools were collected and stool frequency was evaluated at the beginning (V1) and after two (V2) and four weeks (V3) of treatment. Bifidobacteria counts were measured by PCR. Constipation improvement was assessed through a questionnaire and quality of life through visual analogue scale (VAS) at V1, V2 and V3. Bifidobacteria were significantly increased in the group consuming 15 g per day of chicory inulin between the beginning and the end of the study (P=0.0021) and compared to placebo at V3 (P=0.0003). A decrease in the occurrence of constipation was reported by the volunteers after four weeks of the inulin intake (with 47% less volunteers reporting no daily stools between the beginning and the end of the study, P=0.007). A trend for softer stools was reported in the inulin group between the beginning and the end of the study (with a score going from 1.32 to 1.64 after four weeks of intake, P=0.0555). A significant decrease in defecation difficulties after the four weeks of inulin intake was observed (P=0.0003). An increase in flatulence was also recorded but, more importantly, a rapid increase in digestive satisfaction (already after two weeks of the inulin intake) was observed. According to the results of this study, the daily intake of 15 g per day of chicory native inulin by elderly constipated persons, leads to an improvement of the bowel function and a modulation of the flora associated with a better quality of life.