Certain nondigestible oligosaccharides can be selectively utilized by probiotics and reduce the risk of colon cancer. However, the inhibitory effects of xylooligosaccharides (XOS) on colon cancer are not well documented. This study evaluated the effects of xylooligosaccharides and fructooligosaccharides (FOS) on the alteration of cecal microbiota, cecal pH, cecal weight, and serum lipid levels, and also their inhibitory effect on precancerous colon lesions in male Sprague-Dawley rats. The rats were randomly assigned to 4 groups: control, treatment with 1,2-dimethylhydrazine (DMH) [15 mg/(kg body wt · wk) for 2 wk], treatment with DMH + 60 g XOS/kg diet, and treatment with DMH + 60 g FOS/kg diet. Rats were fed the experimental diets for 35 d, beginning 1wk after the second dose of DMH. Both XOS and FOS markedly decreased the cecal pH and serum triglyceride concentration, and increased the total cecal weight and bifidobacteria population. XOS had a greater effect on the bacterial population than did FOS. Moreover, both XOS and FOS markedly reduced the number of aberrant crypt foci in the colon of DMH-treated rats. These results suggest that XOS and FOS dietary supplementation may be beneficial to gastrointestinal health, and indicate that XOS is more effective than FOS.

Our aim was to investigate the effects of Spirulina on BV-2 microglial cell cytotoxicity and inflammatory genes expression. BV-2 microglial cells were treated with lipopolysaccharide (LPS) (1 µg/ml) and various concentrations of Spirulina platensis water extract or its active component (C-phycocyanin (C-PC)) for 24 hours. Cytotoxicity (lactate dehydrogenase (LDH) release) and expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) mRNAs were assayed. LPS increased LDH production and up-regulated expression of iNOS, COX-2, TNF-α, and IL-6 by BV-2 microglial cells. However, Spirulina platensis water extract and C-PC significantly reduced LPS-induced LDH release, and expression of iNOS, COX-2, TNF-α, and IL-6 mRNAs. Spirulina can reduce the cytotoxicity and inhibit expression of inflammation-related genes of LPS-stimulated BV-2 microglial cells.

The purpose of this study was to evaluate the effect of xylooligosaccharide (XOS) on the blood sugar, lipids and oxidative status in type 2 diabetes mellitus (DM). A total of 26 outpatient subjects of Taichung Veterans General Hospital, Taiwan, with HbA1c levels between 7.0 and 10.0% and triglyceride <400 mg/dL were enrolled in the present study. Subjects were supplemented with 4 g/d XOS (n=12) or a placebo (n=14) for 8 wk in a randomized double-blind clinical design. The results showed that the anthropometric values and nutrient intakes did not change during the experimental period. XOS supplementation not only reduced the glucose, HbA1c and fructosamine concentrations, but also decreased the levels of total cholesterol, low density lipoprotein (LDL) cholesterol, oxidized low density lipoprotein (ox-LDL) and apolipoprotein B. The activity of catalase of the erythrocyte sample decreased in the XOS group, but not the activities of superoxide dismutase and glutathione peroxidase. In conclusion, the dietary supplementation with XOS for 8 wk was effective in improving the blood sugar and lipids in type 2 diabetes, indicating that XOS-containing diets might be beneficial to DM subjects.