Oral administration of palatinose vs sucrose improves hyperglycemia in normal C57BL/6J mice

Safety of isomaltulose syrup (dried) as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on isomaltulose syrup (dried) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF consists of a mixture of mono- and disaccharides in powder form, mainly composed of isomaltulose (≥ 75%) and trehalulose (< 13%). The applicant intends to use the NF as a replacement for sucrose already on the market. The information provided on the manufacturing process, composition and specifications of the NF is sufficient and does not raise safety concerns. No absorption, distribution, metabolism and excretion (ADME) or toxicological data were provided for the NF. Instead, the safety of the NF was assessed based on literature data available on isomaltulose and mixtures of isomaltulose and trehalulose. In addition, considering the nature, compositional characterisation and production process of the NF, the Panel considered that such data were sufficient to conclude that the NF is as safe as sucrose.

Conditioned preference and avoidance induced in mice by the rare sugars isomaltulose and allulose

Isomaltulose, a slowly digested isocaloric analog of sucrose, and allulose, a noncaloric fructose analog, are promoted as "healthful" sugar alternatives in human food products. Here we investigated the appetite and preference conditioning actions of these sugar analogs in inbred mouse strains. In brief-access lick tests (Experiment 1), C57BL/6 (B6) mice showed similar concentration dependent increases in licking for allulose and fructose, but less pronounced concentration-dependent increases in licking for isomaltulose than sucrose. In Experiment 2, B6 male were given one-bottle training with a CS+ flavor (e.g., grape) mixed with 8% isomaltulose or allulose and a CS- flavor (e.g., cherry) mixed in water followed by two-bottle CS flavor tests. The isomaltulose mice showed only a weak CS+ flavor preference but a strong preference for the sugar over water. The allulose mice strongly preferred the CS- flavor and water over the sugar. The allulose avoidance may be due to gut discomfort as reported in humans consuming high amounts of the sugar. Experiment 3 found that the preference for 8% sucrose over 8% isomaltulose could be reversed or blocked by adding different concentrations of a noncaloric sweetener mixture (sucralose + saccharin, SS) to the isomaltulose. Experiment 4 revealed that the preference of B6 or FVB/N mice for isomaltulose+0.01%SS or sucrose over 0.1%SS increased after separate experience with the sugars and SS. This indicates that isomaltulose, like sucrose, has postoral appetition effects that enhances the appetite for the sugar. In Experiments 5 and 6, the appetition actions of the two sugars were directly compared by giving mice isomaltulose+0.05%SS vs. sucrose choice tests before and after separate experience with the two sugars. In general, the initial preference the mice displayed for isomaltulose+0.05%SS was reduced or reversed after separate experience with the two sugars although some strain and sex differences were obtained. This indicates that isomaltulose has weaker postoral appetition effects than sucrose.

Acute effect of fructose, sucrose, and isomaltulose on uric acid metabolism in healthy participants

Fructose is associated with hyperuricemia and gout development. Focusing on fructose and fructose-containing disaccharides, we investigated the effects of three different types of carbohydrates (fructose, sucrose, and isomaltulose) on uric acid metabolism and gene expression profiling in peripheral white blood cells. In a randomized crossover study, ten healthy participants ingested test drinks of fructose, sucrose, and isomaltulose, each containing 25 g of fructose. Plasma glucose, serum and urine uric acid, and xanthine/hypoxanthine concentrations were measured. Microarray analysis in peripheral white blood cells and real-time reverse transcription polymerase chain reaction were examined at 0 and 120 in after the intake of test drinks. Serum uric acid concentrations for group fructose were significantly higher than group sucrose at 30-120 min and were significantly higher than those for group isomaltulose at 30-240 min. Several genes involved in the "nuclear factor-kappa B signaling pathway" were markedly changed in group fructose. No significant differences in the mRNA expression levels of tumor necrosis factor, nuclear factor-kappa B, interleukin-1β, and interleukin-18 were noted. This study indicated that fructose intake (monosaccharide) elevated serum uric acid concentrations compared with disaccharide intake. Differences in the quality of carbohydrates might reduce the rapid increase of postprandial serum uric acid concentrations.

Toxic mechanism of the Mongolian medicine "Hunqile-7" based on metabonomics and the metabolism of intestinal flora

The traditional Mongolian medicine Hunqile-7 (HQL-7), which is mainly used to relieve pain in clinic, has certain toxicity. Therefore, toxicological investigation of HQL-7 is of great significance to its safety assessment. In this study, the toxic mechanism of HQL-7 was explored based on a combination of metabolomics and intestinal flora metabolism. UHPLC-MS was used to analyze the serum, liver and kidney samples of rats after intragastric administration of HQL-7. The decision tree and K Nearest Neighbor (KNN) model were established based on the bootstrap aggregation (bagging) algorithm to classify the omics data. After samples were extracted from rat feces, the high-throughput sequencing platform was used to analyze the 16s rRNA V3-V4 region of bacteria. The experimental results confirm that the bagging algorithm improved the classification accuracy. The toxic dose, toxic intensity, and toxic target organ of HQL-7 were determined in toxicity tests. Seventeen biomarkers were identified and the metabolism dysregulation of these biomarkers may be responsible for the toxicity of HQL-7 in vivo. Several kinds of bacteria was demonstrated to be closely related to the physiological indices of renal and liver function, indicating liver and kidney damage induced by HQL-7 may be related to the disturbance of these intestinal bacteria. Overall, the toxic mechanism of HQL-7 was revealed in vivo, which not only provides a scientific basis for the safe and rational clinical use of HQL-7, but also opens up a new field of research on big data for Mongolian medicine.

Slowly Digestible Carbohydrate Diet Ameliorates Hyperglycemia and Hyperlipidemia in High-Fat Diet/Streptozocin-Induced Diabetic Mice

Objective

Given that the prevalence rate of type 2 diabetes mellitus (T2DM) continues to increase, it is important to find an effective method to prevent or treat this disease. Previous studies have shown that dietary intervention with a slowly digestible carbohydrate (SDC) diet can improve T2DM with almost no side effects. However, the underlying mechanisms of SDC protect against T2DM remains to be elucidated.

Methods

The T2DM mice model was established with a high-fat diet and streptozocin injection. Then, SDC was administered for 6 weeks. Bodyweight, food intake, organ indices, fasting blood glucose (FBG), oral glucose tolerance test (OGTT), homeostasis model assessment for insulin resistance (HOMA-IR), and other biochemical parameters were measured. Histopathological and lipid accumulation analyses were performed, and the glucose metabolism-related gene expressions in the liver and skeletal muscle were determined. Lastly, colonic microbiota was also analyzed.

Results

SDC intervention alleviated the weight loss in the pancreas, lowered blood glucose and glycosylated hemoglobin levels, and improved glucose tolerance and HOMA-IR. SDC intervention improved serum lipid profile, adipocytokines levels, and lowered the lipid accumulation in the liver, subcutaneous adipose tissue, and epididymal visceral adipose tissue. In addition, SDC intervention increased the expression levels of IRS-2 and GLUT-2 in liver tissues and elevated GLUT-4 expression levels in skeletal muscle tissues. Notably, SDC intervention decreased the Bacteroidetes/Firmicutes ratio, increased Desulfovibrio and Lachnospiraceae genus levels, and inhibited the relative abundance of potentially pathogenic bacteria.

Conclusions

SDC intervention can improve hyperglycemia and hyperlipidemia status in diabetic mice, suggesting that this intervention might be beneficial for T2DM.

Isomaltulose Exhibits Prebiotic Activity, and Modulates Gut Microbiota, the Production of Short Chain Fatty Acids, and Secondary Bile Acids in Rats

In vitro experiments have indicated prebiotic activity of isomaltulose, which stimulates the growth of probiotics and the production of short chain fatty acids (SCFAs). However, the absence of in vivo trials undermines these results. This study aims to investigate the effect of isomaltulose on composition and functionality of gut microbiota in rats. Twelve Sprague–Dawley rats were divided into two groups: the IsoMTL group was given free access to water containing 10% isomaltulose (w/w), and the control group was treated with normal water for five weeks. Moreover, 16S rRNA sequencing showed that ingestion of isomaltulose increased the abundances of beneficial microbiota, such as Faecalibacterium and Phascolarctobacterium, and decreased levels of pathogens, including Shuttleworthia. Bacterial functional prediction showed that isomaltulose affected gut microbial functionalities, including secondary bile acid biosynthesis. Targeted metabolomics demonstrated that isomaltulose supplementation enhanced cholic acid concentration, and reduced levels of lithocholic acid, deoxycholic acid, dehydrocholic acid, and hyodeoxycholic acid. Moreover, the concentrations of propionate and butyrate were elevated in the rats administered with isomaltulose. This work suggests that isomaltulose modulates gut microbiota and the production of SCFAs and secondary bile acids in rats, which provides a scientific basis on the use of isomaltulose as a prebiotic.

Rapid HPLC Method for Determination of Isomaltulose in the Presence of Glucose, Sucrose, and Maltodextrins in Dietary Supplements

This paper presents a rapid HPLC method for the separation of isomaltulose (also known as Palatinose) from other common edible carbohydrates such as sucrose, glucose, and maltodextrins, which are commonly present in food and dietary supplements. This method was applied to determine isomaltulose in selected food supplements for special diets and athletic performance. Due to the selectivity of the separation system, this method can also be used for rapid profiling analysis of mono-, di-, and oligosaccharides in food.

Improved effect of palatinose syrup bioconverted from sucrose on hyperglycemia and regulation of hepatic lipogenesis in male C57BL/6J mice

In this study, we prepared palatinose-sucrose (PS) mixtures from sucrose by enzymatic bioconversion to improve the low sweetness of palatinose and to develop sweeteners that can lower blood sugar levels. We hypothesized that PS mixtures containing 30% or 50% palatinose might demonstrate improvement of hyperglycemia. The physiological changes in C57BL/6J mice fed with these concentrations of PS mixture were recorded. After feeding the mice the different diets for 5 weeks, the diet with a higher palatinose content was observed to have resulted in lower serum glucose levels. The expression levels of various genes and proteins related to hepatic lipogenesis and cholesterol homeostasis were measured. The diet containing the 50% PS mixture induced lower expression of HMGCR, CYP7A1, and PPARγ as compared to the diet containing the 30% PS mixture. In conclusion, the ingestion of palatinose resulted in lower lipid levels compared to that of sucrose; therefore, palatinose would be a good alternative to sucrose as a healthy sweetener. PRACTICAL APPLICATIONS: Palatinose (isomaltulose), along with tagatose, allulose, and allose, is a well-known sugar substitute. Many studies have reported that palatinose has various beneficial effects on postprandial glucose metabolism, such as glycemic index, fat accumulation, hyperglycemia, and hyperinsulinemia. Although there are many advantages, including desirable biological functions, palatinose has limitations as a complete alternative for sucrose because of higher production costs, lower solubility, and lower sweetness. Therefore, we aimed to investigate the possibility of developing a sucrose substitute by preparing PS mixtures bioconverted using α-glucosyltransferase from sucrose and to promote the industrial application of palatinose. Our results suggest that 50% palatinose syrup may be a new candidate as a sugar substitute for industrial application.