Fructooligosaccharide supplementation improved blood antioxidative status in the constipated elderly subjects

Abstract

Fructooligosaccharide (FO) has been shown to stimulate the growth of bifidobacteria in men which may beneficially exert antioxidative effect. We have demonstrated FO supplementation promote fecal bifidobacteria population in constipated age population. This study further investigated effects of FO supplementation on blood antioxidative status in these subjects. Ten elderly adults (6 males) aged 74.0 ± 3.3 (mean ± SD) completed the single‐blind, placebo‐ and diet‐controlled study that consisted a 4‐wk placebo (3 g/d fructose syrup), a 4‐wk FO (10 g/d oligosaccharides) and a 4‐wk post period. Fasting bloods were collected at the end of each period for analysis of antioxidants, trolox equivalent antioxidant capacity (TEAC), thiobarbitituric acid‐reactive substances (TBARS) in the plasma. DNA strand breakage of whole blood, indicator of blood peroxidation, was determined using single‐cell electrophoresis (comet) assay. Results (means ± SDs) indicated that FO supplementation significantly increased plasma vitamin C level from 4.5 ± 1.1 to 11.9 ± 3.4 μM (P < 0.05 vs placebo) and tended to increase the plasma TEAC, vitamin E and GSH levels (P > 0.05). Plasma TBARS level was 13.1 ± 1.5 mM in the placebo period, which was significantly reduced to be 11.0 ± 1.6 mM in the FO period (by 16%, P < 0.05) and 10.3 ± 1.3 mM in post period (P < 0.05). The DNA strand breaks of whole blood was significantly reduced by 56% (P<0.05) with FO supplementation, and this effect lasted through the post period. Therefore, this study suggested that supplementation of FO exerted prolonged beneficial effects on plasma antioxidant capacity in constipated elderly subjects. This research was supported by the National Science Council 96‐2320‐B‐040‐031‐MY3, Taiwan.