A Dose-Escalation Study to Evaluate Safety of a Novel β-1,3/1,6-Glucan from Ophiocordyceps dipterigena BCC 2073 Supplementation in Healthy Volunteers

Abstract

β-1,3/1,6-Glucan, a common functional ingredient in dietary supplements, is usually produced from left-over yeast in the bakery industry with low purity. Owing to gluten-free and high-purity advantages, new cost-effective biotechnology has recently manufactured β-glucan from fungi as an alternative. However, it is a novel food and the safety limit for human consumption is unknown. This dose-escalation study aimed to evaluate the safety and tolerability of β-1,3/1,6-glucan polysaccharides and oligosaccharides from Ophiocordyceps dipterigena BCC 2073 in healthy subjects and identify the maximum tolerated dose (MTD). In the single ascending dose phase, 12 participants consumed either β-glucan polysaccharides or oligosaccharides capsules (n = 6 each) one dose for one day in a stepwise dose escalation from 2 to 2,000 mg (total of 14 days). In the multiple ascending dose phase, 26 participants consumed either β-glucan polysaccharides (n = 12) or oligosaccharides (n = 14) one dose daily for 2 weeks in a stepwise escalation from 2 to 2,000 mg (total of 12 weeks). The safety and tolerability were assessed by using subject diaries and blood chemistry. Results show no serious adverse events in all participants throughout the study. More frequent defecation and liquid stool were found in the β-glucan polysaccharide (16%) than in the oligosaccharide group (7%). The average blood biochemical values are all in the normal range. This study suggests that the short-term maximum tolerated dose of β-glucan polysaccharide or oligosaccharide from O. dipterigena BCC 2073 is 2,000 mg per day. Further long-term safety trials are warranted.