The primary objective of this study is to determine the 5-day tolerability of one commercially available prebiotic food ingredient, FOS, in healthy human subjects with and without diet control.

Inclusion Criteria:

1. Be able to give written informed consent;
2. Be male or female of any race, between 18 and 65 years of age;
3. Have a BMI > 20 & < 27 kg/m2;
4. Be willing to follow a controlled low fiber diet for a period of 11 days;

Exclusion Criteria:

1. Are less than 18 and greater than 65 years of age;
2. Are hypersensitive to any of the components of FOS;
3. Are currently taking probiotic or prebiotic supplements, or have taken them in the past 28 days;
4. Unwilling to avoid probiotics/prebiotics supplements for the duration of the study;
5. Have a significant acute or chronic, unstable and untreated disease or any condition which contraindicates, in the investigators judgment, entry to the study;
6. Subject is a smoker;
7. Subject has a history of drug and/or alcohol abuse at the time of enrollment;
8. Taken a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results;
9. Individuals who, in the opinion of the investigator, are considered to be poor attendees or unlikely for any reason to be able to comply with the trial;
10. Subjects may not be receiving treatment involving experimental drugs;
11. If the subject has been in a recent experimental trial, these must have been completed not less than 60 days prior to this study;