Clinical trial to evaluate the safety and efficacy of cinnamon extracts on the improvement of bowel function and microflora

INTERVENTION: Dietary Supplement : On the screening visit, subject who voluntarily signs on the written informed consent is reviewed according to inclusion‐exclusion criteria. After one‐week run‐in period, selected subject is randomly allocated to either test or placebo group on visit 2(week 0). Subject takes test material or placebo for 8 weeks. Test food is composed of cinnamon extracts. Control food is included maltodextrin instead of cinnamon extracts. Each subject will consume 3 capsules two times a day. CONDITION: Diseases of the digestive system PRIMARY OUTCOME: bowel habit SECONDARY OUTCOME: fecal metabolites, fecal microbiota INCLUSION CRITERIA: 1) Subject who voluntarily agrees to participate and sign in informed consent form 2) Adults (20 years= Age) 3) Subject who has defecation difficulty by diarrhea ‐ According to Rome III criteria(functional diarrhea)