The long-term safety of D-allulose administration in healthy dogs

Research Advances of d-allulose: An Overview of Physiological Functions, Enzymatic Biotransformation Technologies, and Production Processes

d-allulose has a significant application value as a sugar substitute, not only as a food ingredient and dietary supplement, but also with various physiological functions, such as improving insulin resistance, anti-obesity, and regulating glucolipid metabolism. Over the decades, the physiological functions of d-allulose and the corresponding mechanisms have been studied deeply, and this product has been applied to various foods to enhance food quality and prolong shelf life. In recent years, biotransformation technologies for the production of d-allulose using enzymatic approaches have gained more attention. However, there are few comprehensive reviews on this topic. This review focuses on the recent research advances of d-allulose, including (1) the physiological functions of d-allulose; (2) the major enzyme families used for the biotransformation of d-allulose and their microbial origins; (3) phylogenetic and structural characterization of d-allulose 3-epimerases, and the directed evolution methods for the enzymes; (4) heterologous expression of d-allulose ketose 3-epimerases and biotransformation techniques for d-allulose; and (5) production processes for biotransformation of d-allulose based on the characterized enzymes. Furthermore, the future trends on biosynthesis and applications of d-allulose in food and health industries are discussed and evaluated in this review.

A study of D-allulose-associated reproductive toxicity in rats

In this study, we assessed whether D-allulose was associated with reproductive toxicity in rats, assessing reproduction and offspring growth following gavage of parents with 0, 500, 1000, and 2000 mg/kg of this compound. Specifically, female rats were continuously dose from 2 weeks prior to mating until day 21 of lactation, while males were dose for the 10 weeks before mating. We did not observe any direct toxicity or mortality upon D-allulose administration, with no changes in body weight or eating behavior between study and control groups. We also did not observe any significant alterations in precoital time, copulation index, fertility index (male), or pregnancy index (male) between groups. Relative to controls, there was also no effect of D-allulose treatment on pregnancy rates, implantation, pregnancy length, gender ratios, viability indexes, lactation indexes, prenatal death rates, or number of live young at time of birth. Organ weights and indexes were also comparable between groups at time of sacrifice, and treatment was not linked to any obvious manifestations upon necropsy or histopathological examination. In the F1 offspring, the body weights of pups born to parents administered D-allulose (2000, 1000, and 500 mg/kg) were slightly higher on days 1-9 postnatally relative to controls (p < 0.05), however after day 9 these effects were no longer evident. Together, these results indicate a no-observed-adverse-effect level (NOAEL) of D-allulose of 2000 mg/kg, the highest dose tested, in parental animals and their offspring.