魔芋葡甘低聚糖毒理学及肠道益生性评价

Toxicological and Prebiotic Evaluation of Konjac Oligosaccharides

目的:研究以半干法酶解制备的魔芋葡甘低聚糖(konjac oligosaccharides,KOS)的毒理学特性和肠道益生性。方法:以小鼠急性毒性实验,小鼠骨髓细胞微核实验和小鼠精子畸形实验对KOS急性毒性和遗传毒性进行研究、评价;通过小鼠盲肠内容物体外厌氧发酵评价KOS的肠道益生性。结果:KOS对雌、雄小鼠急性经口半致死量(LD50)均大于21 500 mg/kg,属无毒级;小鼠骨髓细胞微核实验及小鼠精子畸形实验均呈阴性;体外厌氧发酵实验表明KOS可被肠道菌群有效利用,明显增加肠道益生菌(双歧杆菌、乳酸菌)和短链脂肪酸的数量,而对大肠杆菌的增殖效果不明显。结论:KOS的安全性高,是一种功能显著的肠道益生元。

Objective: To evaluate the safety and prebiotic function of konjac oligosaccharides(KOS). Methods: Mouse acute toxicity test, mouse bone marrow cell micronucleus test and mouse sperm aberration test were used to evaluate the safety of KOS. The prebiotic function was evaluated by in vitro fermentation of mouse cecum contents. Results: Acute toxicity test showed that the LD50 of KOS was greater than 21 500 mg/kg body weight for both male and female mice, indicating that KOS is non-toxic. The results of genotoxicity tests, including mouse bone marrow cell micronucleus test and mouse sperm aberration test, were all negative. Fermentation in vitro showed that KOS could promote proliferation of beneficial bacteria, such as Bifidobacterium spp. and Lactobacillus/Enterococcus spp., but caused no significant effects on Escherichia coli. In addition, KOS significantly promoted the accumulation of acetic acid, propionic acid, butyric acid and valeric acid generated by gut microbes, and increased the total amount of short-chain fatty acid(SCFAs). Conclusion: KOS is highly safe and possesses an excellent prebiotic function.