低聚果糖对慢性应激小鼠抑郁样行为及 肠道菌群的影响

目的探讨低聚果糖(FOS)对慢性应激小鼠的抑郁样行为及肠道菌群的影响。方法选取8周龄健康雄性ICR小鼠随机分成3组,C组小鼠每天给予正常护理,S组和SF组小鼠每天随机给予1～2种应激源,持续8周,SF组小鼠在应激造模的同时经食物补充FOS。在造模4周和8周后,分别通过强迫游泳、蔗糖偏好试验评估各组小鼠抑郁样行为。造模结束后通过Western blot试验检测小鼠大脑皮层内糖皮质激素受体(GR)的表达,并收集结肠内容物进行16SrDNA扩增子测序分析。结果应激造模8周后,C、S和SF三组小鼠的肠道菌群组成存在明显差异;与C组相比,S组小鼠强迫游泳的不动时间显著增加(t=3.970,P=0.0009),蔗糖偏好率显著降低(t=3.890,P=0.0011),脑内GR的表达显著降低(t=4.311,P=0.0125);与S组相比,SF组小鼠强迫游泳的不动时间显著缩短(t=3.495,P=0.0026),蔗糖偏好率和脑内GR表达有增加趋势。结论益生元FOS可调节肠道菌群,改善慢性应激诱发的精神情绪异常。

Effects of fructooligosaccharides on depression-like behavior and gut flora in chronic stress mice

Abstract: Objective To explore the effects of fructooligosaccharides (FOSs) on the depression-like behavior and intestinal flora in chronic stress mice. Methods 8-week-old healthy male ICR mice were randomly allocated to three groups. The mice in group C received normal daily care, while those in groups S and SF were given one or two random stressor every day for eight weeks. The mice in group SF were fed with food supplemented with FOS during stress modelling. After 4 and 8 weeks of stress modelling, the depression-like behavior of mice in each group was respectively evaluated by using forced swim test and sucrose preference test. By the end of modelling, the expression of glucocorticoid receptor (GR) in cerebral cortex of mice was detected with Western blot, and the composition of colonic flora was analyzed with amplicon sequencing of the 16S rDNA. Results The composition of colonic flora presented significant difference between groups. Compared with group C, the mice in group S showed increased immobility time (t=3.970, P=0.0009) and decreased sucrose preference (t=3.890, P=0.0011), and GR expression in brain was down-regulated (t=4.311, P=0.0125). Compared with group S, the mice in group SF showed decreased immobility time (t=3.495, P=0.0026), increased tendency in sucrose preference and increased cortex GR expression. Conclusion FOS, as a prebiotic, can regulate gut flora and improve mental state of chronic stress mice.