Effects of Xylooligosarcharide on Composition of the Human Colonic Microflora

Inclusion Criteria: 1. Age 20-50 years of age at screen. 2. In generally good health 3. Subjects must read and sign the Institutional Review Board-approved written informed consent prior to the initiation of any study specific procedures or enrollment. A subject will be excluded for any condition that might compromise the ability to give truly informed consent. Exclusion Criteria: 1. Any history of gastrointestinal disease except for appendectomy 2. No antibiotic, pre- or probiotic or laxative use during the 2 months before the study. 3. Any subject with a history of diabetes mellitus, or other serious medical condition, such as chronic hepatic or renal disease, bleeding disorder, congestive heart disease, chronic diarrhea disorders, myocardial infarction, coronary artery bypass graft, angioplasty within 6 months prior to screening, current diagnosis of uncontrolled hypertension (defined as systolic BP\>160mmHg, diastolic BP\>95mmHg), active or chronic gastrointestinal disorders, bulimia, anorexia, or endocrine diseases (except thyroid disease requiring medication) as indicated by medical history or routine physical examination. 4. Any subject with a screening laboratory value outside of the laboratory normal range that is considered clinically significant for study participation by the investigator. 5. Any subject who currently uses tobacco products. 6. Any subject who is pregnant or lactating, or becomes pregnant during the study. 7. Any subject who is unable or unwilling to comply with the study protocol.