Abstract:

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.

Key words: konjac oligosaccharides (KOS), acute toxicity, genotoxicity, prebiotic function