Manipulation of the internal structure of starch by propionyl treatment and its diverse influence on digestion and in vitro fermentation characteristics.

High amylose maize starch (HAMS) and waxy maize starch (WMS) were modified by propionylation and their corresponding physicochemical characteristics, digestion and fermentation properties were studied. The results indicated that two new peaks related to methylene (2.20 ppm) and methyl (0.97 ppm) in the NMR spectrum were formed, indicating the occurrence of propionylation, and this was further confirmed by the formation of a characteristic absorption at 1747 cm-1 in the FTIR spectrum. The propionylation led the modified starch having a lower electron density contrast between the crystalline and amorphous flakes, resulting in the formation of a more compact structure following the increased degrees of substitution (DS). The propionylated starch also had a higher thermal stability and hydrophobicity. These structural changes increased the content of resistant starch (RS) and reduced the predicted glycemic index. More importantly, the gut microbiota fermentation properties indicated that the propionylation of the starch can not only increase the yield of propionate, but also increase the concentration of total short-chain fatty acids (SCFAs). This study highlights a new approach to significantly enhance the RS content in starch, together with an increased SCFA generation capacity.

Hitting the sweet spot: A systematic review of the bioactivity and health benefits of phenolic glycosides from medicinally used plants.

Phenolic acid and flavonoid glycosides form a varied class of naturally occurring compounds, characterised by high polarity-resulting from the glycone moiety-and the presence of multiple phenol functionalities, which often leads to strong antioxidant activity. Phenolic glycosides, and in particular flavonoid glycosides, may possess strong bioactive properties with broad spectrum activity. This systematic literature review provides a detailed overview of 28 studies examining the biological activity of phenolic and flavonoid glycosides from plant sources, highlighting the potential of these compounds as therapeutic agents. The activity of glycosides depends upon the biological activity type, identity of the aglycone and the identity and specific location of the glycone moiety. From studies reporting the activity of both glycosides and their respective aglycones, phenolic glycosides appear to generally be a storage/reserve pool of precursors of more bioactive compounds. The glycosylated compounds are likely to be more bioavailable compared to their aglycone forms, due to the presence of the sugar moieties. Hydrolysis of the glycoside in the in vivo environment would release the free aglycone, potentiating their biological activity. However, further high-quality studies are needed to firmly establish the clinical efficacy of glycosides from many of the plant species studied.

Phenolic Compounds with Antioxidant Properties from Canola Meal Extracts Inhibit Adipogenesis.

The extraction of phenolic compounds from canola meal produces functional health products and renders the canola meal a more digestible animal feed. The extracted phenolics may have novel bioactivity worth investigation. In this study, several solvents were evaluated for their ability to extract phenolic compounds from canola meal: water (WE) and various 80% organic solvent/water mixtures of methanol (ME), acetone (AE), ethanol (EE), butanol (BE), chloroform (CE) and hexane (HE). The in vitro antioxidant and anti-obesity properties of various extracts were investigated. Anti-obesity properties were studied using adipogenic differentiation inhibition of a murine mesenchymal stem cell line (C3H10T1/2) and a pancreatic lipase inhibition assay. AE, ME, and BE showed significant (p < 0.05) adipogenesis and pancreatic lipase inhibitory activities and may have more pharmacological properties. AE down-regulated the gene expression of the major adipogenic transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ), correlating to phenolic content in a dose-dependent manner. The chemical characterization of AE revealed the presence of sinapic acid, ferulic acid, and kaempferol derivatives as main bioactive phenols.

Abundance of Probiotics and Butyrate-Production Microbiome Manages Constipation via Short-Chain Fatty Acids Production and Hormones Secretion.

SCOPE: The characteristics of gut microbiota and host metabolism are hypothesized to be associated with constipation status, but the regulation mechanism is not fully understood. Thus, the current study investigates the effect of constipation symptoms on gut functionality following the modulation of gut microbiota and metabolites via dietary fiber intervention. METHODS AND RESULTS: Constipation causes a significantly reduced short-chain fatty acids (SCFAs) production and a higher level of iso-butyrate. The feces of constipated people are characterized with inhibited Faecalibacterium, Ruminococcaceae and Roseburia abundance. Desulfovibrionaceae is identified to be an important endotoxin producer in constipated patients, and a butyrate-enriched SCFAs profile achieved by dietary fiber supplement accelerates gastrointestinal transit and increases the thickness of the mucosal layer, possibly through triggering the secretion of colonic hormones and enhancing the expression of tight junction proteins for maintaining intestinal barrier integrity. More importantly, an interacting regulatory mechanism among SCFAs, in particular butyrate and propionate, may be involved in signaling between the microbiome and host cells in the colon. CONCLUSION: Gut microbiota, characterized with enriched butyrate-producing and depressed Desulfovibrionaceae bacteria, attenuates constipation symptoms through promoting intestinal hormones secretion and maintaining gut barrier integrity.

Regulation of hyperglycemia in diabetic mice by autolysates from ß-mannanase-treated brewer's yeast.

BACKGROUND: Diabetes mellitus is a serious chronic disease, characterized by hyperglycemia. This study administered either ß-mannanase-treated yeast cell autolysis supernatant (YCS) or yeast cell-wall residues after autolysis (YCR) to investigate their influence on the alleviation of diabetes in a diabetic mouse model. RESULTS: Application of either YCS or YCR led to body weight gain, blood glucose reduction, and an improvement in lipid composition in the diabetic mice. Administration of YCS was more effective in inhibiting oxidative stress than YCR. The expression of PPARα and CPT1α was enhanced, improving lipid biosynthesis, and Trx1 and HIF-1-α genes were downregulated due to the activation of thioredoxin following the interventions, indicating that the processes of lipid metabolism and oxidative stress were heavily involved in the reduction of diabetic characteristics following the interventions. The current study revealed that consumption of YCR also led to a reduction in hyperglycemia, this being associated with its richness in mineral elements, such as chromium and selenium. CONCLUSION: This study may highlight the potential of both YCS and YCR as functional ingredients in dietary formula for improving diabetic syndromes. © 2019 Society of Chemical Industry.

γ-Aminobutyric Acid Attenuates High-Fat Diet-Induced Cerebral Oxidative Impairment via Enhanced Synthesis of Hippocampal Sulfatides.

Long-term high-fat diet (HFD) in rats triggered cerebral oxidative stress, reflected by reactive oxygen species accumulation and antioxidant decline in peripheral and cerebral tissues, together with hippocampal lipid disturbance, particularly for triglyceride accumulation and sulfatide deficiency. Hippocampal formation and cerebral cortex also exhibited pathological changes, characterized by neurofibrillary tangle and reduced Nissl bodies. Sulfatides were noted to protect hippocampal neurons from oxidative damage through the clearance of ß-amyloid protein, with apolipoprotein E transporting and low-density lipoprotein receptor binding. Delightedly, we found γ-aminobutyric acid (GABA) supplement delivered by rice bran to rats significantly promoted hippocampal sulfatide synthesis and reversed the HFD-induced sulfatide deficiency and oxidative-triggered cerebral impairment. Elevated GABA concentration in hippocampus and the activation of GABA B-type receptors might be the primary contributors. This study demonstrated the potential of GABA-enriched rice bran as a novel dietary supplement to enhance a sulfatide-based therapeutic approach for neurodegenerative diseases in the early stages.

Gamma-aminobutyric Acid Enriched Rice Bran Diet Attenuates Insulin Resistance and Balances Energy Expenditure via Modification of Gut Microbiota and Short-Chain Fatty Acids.

In this study, gamma-aminobutyric acid (GABA) enriched rice bran (ERB) was supplemented to obese rats to investigate the attenuation of metabolic syndromes induced by high-fat diet. ERB-containing diet stimulated butyrate and propionate production by promoting Anaerostipes, Anaerostipes sp., and associated synthesizing enzymes. This altered short-chain fatty acid (SCFA) distribution further enhanced circulatory levels of leptin and glucagon-like peptide-1, controlling food intake by downregulating orexigenic factors. Together with the enhanced fatty acid ß-oxidation highlighted by Prkaa2, Ppara, and Scd1 expression via AMPK signaling pathway and nonalcoholic fatty liver disease pathway, energy expenditure was positively modulated. Serum lipid compositions showed ERB supplement exhibited a more efficient effect on lowering serum sphingolipids, which was closely associated with the status of insulin resistance. Consistently, genes of Ppp2r3b and Prkcg, involved in the function of ceramides in blocking insulin action, were also downregulated following ERB intervention. Enriched GABA and phenolic acids were supposed to be responsible for the health-beneficial effects.

Construction of local gene network for revealing different liver function of rats fed deep-fried oil with or without resistant starch.

To study the mechanism underlying the liver damage induced by deep-fried oil (DO) consumption and the beneficial effects from resistant starch (RS) supplement, differential gene expression and pathway network were analyzed based on RNA sequencing data from rats. The up/down regulated genes and corresponding signaling pathways were used to construct a novel local gene network (LGN). The topology of the network showed characteristics of small-world network, with some pathways demonstrating a high degree. Some changes in genes led to a larger probability occurrence of disease or infection with DO intake. More importantly, the main pathways were found to be almost the same between the two LGNs (30 pathways overlapped in total 48) with gene expression profile. This finding may indicate that RS supplement in DO-containing diet may mainly regulate the genes that related to DO damage, and RS in the diet may provide direct signals to the liver cells and modulate its effect through a network involving complex gene regulatory events. It is the first attempt to reveal the mechanism of the attenuation of liver dysfunction from RS supplement in the DO-containing diet using differential gene expression and pathway network.

Deep-fried oil consumption in rats impairs glycerolipid metabolism, gut histology and microbiota structure.

BACKGROUND: Deep frying in oil is a popular cooking method around the world. However, the safety of deep-fried edible oil, which is ingested with fried food, is a concern, because the oil is exposed continuously to be re-used at a high temperature, leading to a number of well-known chemical reactions. Thus, this study investigates the changes in energy metabolism, colon histology and gut microbiota in rats following deep-fried oil consumption and explores the mechanisms involved in above alterations. METHODS: Deep-fried oil was prepared following a published method. Adult male Wistar rats were randomly divided into three groups (n = 8/group). Group 1: basal diet without extra oil consumption (control group); Group 2: basal diet supplemented with non-heated canola oil (NEO group); Group 3: basal diet supplemented with deep-fried canola oil (DFEO group). One point five milliliters (1.5 mL) of non-heated or heated oil were fed by oral gavage using a feeding needle once daily for 6 consecutive weeks. Effect of DFEO on rats body weight, KEGG pathway regarding lipids metabolism, gut histology and gut microbiota were analyzed using techniques of RNA sequencing, HiSeq Illumina sequencing platform, etc. RESULTS: Among the three groups, DFEO diet resulted in a lowest rat body weight. Metabolic pathway analysis showed 13 significantly enriched KEGG pathways in Control versus NEO group, and the majority of these were linked to carbohydrate, lipid and amino acid metabolisms. Comparison of NEO group versus DFEO group, highlighted significantly enriched functional pathways were mainly associated with chronic diseases. Among them, only one metabolism pathway (i.e. glycerolipid metabolism pathway) was found to be significantly enriched, indicating that inhibition of this metabolism pathway (glycerolipid metabolism) may be a response to the reduction in energy metabolism in the rats of DFEO group. Related gene analysis indicated that the down-regulation of Lpin1 seems to be highly associated with the inhibition of glycerolipid metabolism pathway. Histological analysis of gastrointestinal tract demonstrated several changes induced by DFEO on intestinal mucosa with associated destruction of endocrine tissue and the evidence of inflammation. Microbiota data showed that rats in DFEO group had the lowest proportion of Prevotella and the highest proportion of Bacteroides among the three groups. In particular, rats in DFEO group were characterized with higher presence of Allobaculum (Firmicutes), but not in control and NEO groups. CONCLUSION: This study investigated the negative effect of DFEO on health, in which DFEO could impair glycerolipid metabolism, destroy gut histological structure and unbalance microbiota profile. More importantly, this is the first attempt to reveal the mechanism involved in these changes, which may provide the guideline for designing health diet.

Effect of Ganoderma lucidum spores intervention on glucose and lipid metabolism gene expression profiles in type 2 diabetic rats.

BACKGROUND: The fruiting body of Ganoderma lucidum has been used as a traditional herbal medicine for many years. However, to the date, there is no detailed study for describing the effect of G. lucidum spores on oxidative stress, blood glucose level and lipid compositions in animal models of type 2 diabetic rats, in particular the effect on the gene expression profiles associated with glucose and lipid metabolisms. METHODS: G. lucidum spores powder (GLSP) with a shell-broken rate >99.9 % was used. Adult male Sprague-Dawley rats were randomly divided into three groups (n = 8/group). Group 1: Normal control, normal rats with ordinary feed; Group 2: Model control, diabetic rats with ordinary feed without intervention; Group 3: GLSP, diabetic rats with ordinary feed, an intervention group utilizing GLSP of 1 g per day by oral gavages for 4 consecutive weeks. Type 2 diabetic rats were obtained by streptozocin (STZ) injection. The changes in the levels of glucose, triglycerides, total cholesterol and HDL-cholesterol in blood samples were analyzed after GLSP intervention. Meanwhile, gene expressions associated with the possible molecular mechanism of GLSP regulation were also investigated using a quantitative RT-PCR. RESULTS: The reduction of blood glucose level occurred within the first 2 weeks of GLSP intervention and the lipid synthesis in the diabetic rats of GLSP group was significantly decreased at 4 weeks compared to the model control group. Furthermore, it was also found that GLSP intervention greatly attenuated the level of oxidative stress in the diabetic rats. Quantitative RT-PCR analysis showed up-regulation of lipid metabolism related genes (Acox1, ACC, Insig-1 and Insig-2) and glycogen synthesis related genes (GS2 and GYG1) in GLSP group compared to model control group. Additionally, there were no significant changes in the expression of other genes, such as SREBP-1, Acly, Fas, Fads1, Gpam, Dgat1, PEPCK and G6PC1. CONCLUSION: This study might indicate that GLSP consumption could provide a beneficial effect in terms of lowering the blood glucose levels by promoting glycogen synthesis and inhibiting gluconeogenesis. Meanwhile, GLSP treatment was also associated with the improvement of blood lipid compositions through the regulation of cholesterol homeostasis in the type 2 diabetic rats.