The demand for functional foods is on the rise. These are food products that, besides providing energy and nutrients for life, provide additional health benefits. Xylitol, a five-carbon sugar alcohol, is a possible functional food, as well as a sugar replacement. The cost of xylitol has led manufacturers to add inulin, a nondigestible oligosaccharide, as an extender. Both xylitol and inulin have been suggested to provide added health benefits beyond being a reduced calorie replacement for sugar. We tested their impact on several human health parameters (fecal weight, fecal pH, fecal% Ill moisture, blood lipids, blood glucose, and fecal micro flora) with two age groups, "older" (62.3 ± 9.63 y, n= 17) and "younger" (23.3 ± 2.02 y, n= 18). Participants were given two different treatments: A, 7.5 g xylitol and B, 7.5 g of xylitol in combination with 7.5 g of inulin. Treatment schedules were as follows: 2 weeks with one treatment, followed by a 2-week washout period, and 2 weeks with the treatment they had not previously taken. Comparisons were then made between each treatment and the washout period. Due to the low number of participants, we were unable to obtain substantial significance on most observations, but important trends were detected. Treatment with xylitol by itself caused a decrease in stool mass compared to washout (control) values, while the addition of inulin reversed the decrease. This effect is important, as an increased stool mass is associated with a healthy gastrointestinal (GI) tract. Xylitol by itself or with added inulin provided for a more acidic colonic environment, which aids in mineral absorption and inhibition of pathogenic microbes. Both treatments were also noted to cause an increase the frequency of bowel movements compared to washout. As sugar replacements, it was observed that both treatments were associated with a decreased post-prandial blood sugar level from washout, indicating a benefit in blood glucose control. As for blood lipid values, xylitol caused a decrease, compared to washout, in triglycerides and VLDL levels while increasing HDL levels. However, the addition of inulin increased, from washout, the younger age group's serum triglycerides, but did not change xylitol 's effects on VLDL and HDL levels of either age group. In the fecal micro flora, it was seen that taking the xylitol treatment caused a decrease, from washout, in amounts of all microbes studied, while the addition of inulin increased the fecal Lactobacilli counts of the older age group. Interestingly, stool qualities responded differently by age. Both treatments made the older population's stool more firm, while the same treatments made the younger population's stool more loose. Despite the added benefits, there was an increase in flatulence-small with the xylitol treatment, but nearly a three-fold increase with the addition of inulin. In conclusion, xylitol alone or with the addition of inulin can be labeled as a functional food