The effects of cereal ß-glucans on cardiovascular risk factors and the role of the gut microbiome.

The human gut microbiome has emerged as a key influencer of human health and disease, particularly through interactions with dietary fiber. However, national dietary guidelines worldwide are only beginning to capitalize on the potential of microbiome research, which has established the vital role of host-microbe interactions in mediating the physiological effects of diet on overall health and disease. ß-glucans have been demonstrated to modulate the composition of the gut microbiota, leading to improved outcomes in cardiovascular disease (CVD). Raised serum cholesterol and blood pressure are important modifiable risk factors in the development of CVD and emerging evidence highlights the role of the gut microbiota in ameliorating such biomarkers and clinical characteristics of the disease. The proposed mechanism of action of ß-glucans on the pathophysiological mechanisms of disease have yet to be elucidated. Validating gaps in the literature may substantiate ß-glucans as a potential novel dietary therapy against modifiable risk factors for CVD and would further support the public health significance of including a habitual fiber-rich diet.

Transcriptomic analysis of turbot (Scophthalmus maximus) treated with zymosan a reveals that lncRNAs and inflammation-related genes mediate the protection conferred against Aeromonas salmonicida.

Aeromonas salmonicida is one of the most harmful pathogens in finfish aquaculture worldwide. Immunostimulants such as ß-glucans are used to enhance the immunity of cultured fish. However, their effects on fish physiology are not completely understood. In the present work, we evaluated the effect of a single intraperitoneal (ip) injection of zymosan A on fish survival against A. salmonicida infection. A single administration of this compound protected fish against A. salmonicida challenge and reduce the bacterial load in the head kidney one week after its administration. Transcriptome analyses of head kidney samples revealed several molecular mechanisms involved in the protection conferred by zymosan A and their regulation by long noncoding RNAs. The transcriptome profile of turbot exposed only to zymosan A was practically unaltered one week after ip injection. However, the administration of this immunostimulant induced significant transcriptomic changes once the fish were in contact with the bacteria and increased the survival of the infected turbot. Our results suggest that the restraint of the infection-induced inflammatory response, the management of apoptotic cell death, cell plasticity and cellular processes involving cytoskeleton dynamics support the protective effects of zymosan A. All this information provides insights on the cellular and molecular mechanisms involved in the protective effects of this widely used immunostimulant.

Effect of ß-glucans on rainbow trout (Oncorhynchus mykiss) IgM+ B cells.

ß-glucans are carbohydrates present in the cell wall of many fungi, which are often used as immunostimulants in feeds for farmed species. Their capacity to activate innate immune responses directly acting on innate cell populations has been widely documented in fish. However, whether they can affect the functionality of adaptive immune cells has been scarcely explored. In this context, in the current work, we have determined the effects of ß-glucans on rainbow trout blood IgM+ B cells in the presence or absence of 2,4,6-trinitrophenyl hapten conjugated to lipopolysaccharide (TNP-LPS), a model antigen. For this, rainbow trout peripheral blood leukocytes were incubated with different doses of ß-glucans or media alone in the presence or absence of TNP-LPS for 48 h. The size, levels of expression of surface MHC II, antigen processing and phagocytic capacities and proliferation of IgM+ B cells were then studied by flow cytometry. The number of IgM-secreting cells in the cultures was also estimated by ELISpot. ß-glucans significantly decreased the levels of surface MHC II expression and the antigen processing capacities of these cells, especially in the presence of TNP-LPS, while they increased their phagocytic activity. On their own, ß-glucans slightly activated the proliferation of IgM+ B cells but reduced that induced by TNP-LPS. In contrast, ß-glucans significantly increased the number of cells secreting IgM in the cultures. This effect of ß-glucans on the IgM-secreting capacity of B cells was also confirmed through a feeding experiment, in which the IgM-secreting capacity of blood leukocytes obtained from fish fed a ß-glucan-supplemented diet for one month was compared to that of leukocytes obtained from fish fed a control diet. Altogether, these findings contribute to increase our knowledge regarding the effects of ß-glucans on fish adaptive responses.

Effect of Oat Fiber Preparations with Different Contents of ß-Glucan on the Formation of Acrylamide in Dietary Bread (Rusks).

In the literature, there are few reports indicating hydrocolloids as a factor capable of reducing the amount of acrylamide formed in food. Therefore, the aim of the study was to examine the ability of soluble oat fiber to reduce the amount of acrylamide formed in the process of obtaining rusks. The effect of the concentration of ß-glucans in oat fiber preparations at 20% and 30% and the amount of preparations used at 10%, 15%, and 20% was investigated. On the basis of the obtained test results, it was shown that the most optimal concentration of oat fiber preparation in rusks recipe is at 15%, regardless of the content of ß-glucan in it. This concentration makes it possible to reduce the amount of acrylamide formed in baked goods and rusks by ~70% and ~60%, respectively, while maintaining the desired physical and chemical properties of the product. In addition, it was shown that the browning index and water activity strongly correlate with the content of acrylamide in rusks, which makes them good markers of this compound in rusks. The use of hydrocolloids in the form of oat fiber preparations with different contents of ß-glucan as a tool for reducing the amount of acrylamide in rusks, at the same time, offers the possibility of enriching these products with a soluble dietary fiber with health properties.

Effects of a ß-Glucan-Rich Blend of Medicinal Mushrooms and Botanicals on Innate Immune Cell Activation and Function Are Enhanced by a Very Low Dose of Bovine Colostrum Peptides.

Nutraceutical immune support offers potential for designing blends with complementary mechanisms of action for robust support of innate immune alertness. We documented enhanced immune activation when bovine colostrum peptides (BC-Pep) were added to an immune blend (IB) containing ß-glucans from yeast, shiitake, maitake, and botanical non-ß-glucan polysaccharides. Human peripheral blood mononuclear cells (PBMCs) were cultured with IB, BC-Pep, and IB + BC-Pep for 20 h, whereafter expression of the activation marker CD69 was evaluated on NK cells, NKT cells, and T cells. Cytokine levels were tested in culture supernatants. PBMCs were co-cultured with K562 target cells to evaluate T cell-mediated cytotoxicity. IB + BC-Pep triggered highly significant increases in IL-1ß, IL-6, and TNF-α, above that of cultures treated with matching doses of either IB or BC-Pep. NK cell and T cell activation was increased by IB + BC-Pep, reaching levels of CD69 expression several fold higher than either BC-Pep or IB alone. IB + BC-Pep significantly increased T cell-mediated cytotoxic killing of K562 target cells. This synergistic effect suggests unique amplification of signal transduction of NK cells and T cells due to modulation of IB-induced signaling pathways by BC-Pep and is of interest for further pre-clinical and clinical testing of immune defense activity against virally infected and transformed cells.

Rye Dietary Fiber Components upon the Influence of Fermentation Inoculated with Probiotic Microorganisms.

Rye flour is used as the main ingredient of sourdough bread, which has technological and gastronomic benefits and increased nutritional value. The transformations observed during fermentation and baking may enable the conversion or degradation of rye dietary fiber carbohydrates built mainly of arabinoxylans, fructans, and ß-glucans. This study aimed to determine the dynamics of the changes in the contents of complex carbohydrates in sourdoughs inoculated with potential probiotic microorganisms as well as the polysaccharide composition of the resulting bread. Sourdoughs were inoculated with the potential probiotic microorganisms Saccharomyces boulardii, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Bacillus coagulans, and spontaneous fermentation was performed as a control. Samples of the sourdoughs after 24 and 48 h of fermentation and of bread obtained with these sourdoughs were analyzed for the content of individual dietary fiber components. The present study demonstrated that the treatments applied contributed to an increased total content of arabinoxylans in the breads, and the inoculation of the sourdoughs with the potential probiotic strains improved their solubility in water. The use of the S.boulardii strain may seem prospective as it allowed for the greatest reduction in fructans in the rye bread. Rye sourdough bread is an attractive source of dietary fiber and can be modified for different nutritional needs.

Addition of ß-glucans in diets for tropical gar (Atractosteus tropicus) larvae: effects on growth, digestive enzymes and gene expression of intestinal epithelial integrity and immune system.

The effect of ß-glucans 1,3/1,6 from Saccharomyces cerevisiae yeast at different inclusion percentages (0.0, 0.2, 0.4, 0.6, and 0.8%) in the diet for tropical gar (Atractosteus tropicus) larvae was evaluated on growth, digestive enzyme activity and, relative expression of the immune system genes. The bioassay started on the third day after hatching (DAH) and lasted 21 days, using a total of 1500 larvae of 0.055 ± 0.008 g and, a total length of 2.46 ± 0.26 cm. Larviculture was carried out in a recirculation system with 15 tanks of 70 L using a density of 100 organisms per experimental unit. No significant differences in larval growth were observed by the inclusion of ß-glucans (p > 0.05). Digestive enzymes showed changes in lipase and trypsin activities, presenting higher values in fish fed 0.6% and 0.8% ß-glucans diets compared to the other treatments (p < 0.05). Leucine-aminopeptidase, chymotrypsin, acid phosphatase, and alkaline phosphatase activity showed higher activities in larvae fed with a 0.4% ß-glucan diet compared to the control group. The relative expression of intestinal membrane integrity (mucin 2) muc-2, (occludins) occ, (nucleotide-binding oligomerization domain) nod-2, and immune system lys (lysosome) genes showed over-expression in larvae fed the 0.4% ß-glucan diet to the rest of the treatments (p < 0.05). The inclusion of ß-glucans at 0.4-0.6% in diets for A. tropicus larvae could improve larviculture, as effects on the increase in the activity of several digestive enzymes and the expression of genes of the immune system.

The role of cereal soluble fiber in the beneficial modulation of glycometabolic gastrointestinal hormones.

According to cohort studies, cereal fiber, and whole-grain products might decrease risk for type 2 diabetes (T2DM), inflammatory processes, cancer, and cardiovascular diseases. These associations, mainly affect insoluble, but not soluble cereal fiber. In intervention studies, soluble fiber elicit anti-hyperglycemic and anti-inflammatory short-term effects, partially explained by fermentation to short-chain fatty acids, which acutely counteract insulin resistance and inflammation. ß-glucans lower cholesterol levels and possibly reduce liver fat. Long-term benefits are not yet shown, maybe caused by T2DM heterogeneity, as insulin resistance and fatty liver disease - the glycometabolic points of action of soluble cereal fiber - are not present in every patient. Thus, only some patients might be susceptive to fiber. Also, incretin action in response to fiber could be a relevant factor for variable effects. Thus, this review aims to summarize the current knowledge from human studies on the impact of soluble cereal fiber on glycometabolic gastrointestinal hormones. Effects on GLP-1 appear to be highly contradictory, while these fibers might lower GIP and ghrelin, and increase PYY and CCK. Even though previous results of specific trials support a glycometabolic benefit of soluble fiber, larger acute, and long-term mechanistic studies are needed in order to corroborate the results.

ß-glucan, "the knight of health sector": critical insights on physiochemical heterogeneities, action mechanisms and health implications.

ß-glucans, the class of biological response modifier has unceasing attention, not only for its immune stimulating but also for its role as prebiotics, modulator of physiological events etc. and is widely used in the treatment of cancer, diabetes, gastrointestinal disorders, cardiovascular diseases etc. However, ß-glucan with different physiochemical properties is found to have discrete clinical functions and thus careful selection of the types of ß-glucan plays pivotal role in providing significant and expected clinical outcome. Herein this review, we presented the factors responsible for diverse functional properties of ß-glucan, their distinct mode of actions in regulating human health etc. Further, clinical aspects of different ß-glucans toward the management of wound care, metabolic dysbiosis, fatty liver disorders and endurance training associated energy metabolism were compiled and exhibited in detail.

Immune responses to prebiotics in farmed salmonid fish: How transcriptomic approaches help interpret responses.

Within aquaculture, prebiotics are composed of complex carbohydrate molecules that cannot be digested by the fish directly but are metabolised by the microbial communities within the host gut, with the desire that "healthy" bacterial species are promoted with subsequently improved performance of the fish, there are likely some direct responses of intestinal cells to these dietary components. The sources and processing of prebiotics, which fall under the overarching theme of "functional feeds" are highly varied between species and types of prebiotics administered. How these feeds exert their effect, and the host responses are hard to determine, but new technologies and the development of high-throughput technologies (omics) are enabling the mechanisms and methods of action to be further understood. The recent advances in the availability of 'omics' technologies with the transition from single gene assays to microarray and RNA-seq in fish health have enabled novel functional ingredients to be analysed. This review will focus on recent studies on targeted gene expression and 'omics' technologies to characterize immune responses. Comparisons between the immunomodulatory effect of different prebiotics have been made and specific examples of how transcriptomics techniques have been used to identify immune responses to prebiotics are given.

Fortifying a meal with oyster mushroom powder beneficially affects postprandial glucagon-like peptide-1, non-esterified free fatty acids and hunger sensation in adults with impaired glucose tolerance: a double-blind randomized controlled crossover trial.

PURPOSE: Impaired glucose tolerance (IGT) is a pathophysiological condition characterized by insulin resistance with known metabolic consequences such as postprandial hyperglycemia and hypertriglyceridemia. We hypothesized that fortifying a meal with mushrooms rich in ß-glucans may diminish glucose and triglyceride responses by improving postprandial gastrointestinal hormone release. METHODS: In a randomized controlled crossover study, 22 subjects with IGT ingested a meal either enriched with 20 g powder (8.1 g ß-glucans) of oven-dried Pleurotus ostreatus (enriched meal, EN) or without enrichment (control meal, CON). Blood was collected before and repeatedly within 4 h after the meal to determine AUC of glucose (primary outcome), insulin, triglycerides, non-esterified free fatty acids (NEFAs), glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP) and ghrelin. Appetite sensations (hunger, satiety, fullness, and desire to eat) were assessed before and after meal consumption by visual analog scales. RESULTS: Postprandial glucose, insulin, triglycerides, GIP and ghrelin concentrations as well as the corresponding AUCs did not differ between EN and CON. NEFAs-AUC was 14% lower (P = 0.026) and GLP-1-AUC 17% higher (P = 0.001) after EN compared to CON. Appetite ratings did not differ between treatments, except for hunger (AUC 22% lower after EN vs. CON; P = 0.031). CONCLUSION: The observed immediate postprandial metabolic changes indicate that an easily manageable fortification of a single meal with powder from dried oyster mushrooms as ß-glucan source may improve postprandial metabolism. If the effect is preserved long term, this measure can diminish the risk for further development of overweight/obesity and type 2 diabetes in subjects with IGT. CLINICAL TRIAL REGISTRATION: German Clinical Trial Register on 09/08/2018; trial-ID: DRKS00015244.

Antioxidant, anti-inflammatory and beneficial metabolic effects of botryosphaeran [(1→3)(1→6)-ß-d-glucan] are responsible for its anti-tumour activity in experimental non-obese and obese rats bearing Walker-256 tumours.

Botryosphaeran, a (1→3)(1→6)-ß-d-glucan, presents several beneficial activities, such as antiproliferative, hypoglycemic and antitumoural activities. This study evaluated the effects of botryosphaeran on oxidative stress, inflammation and metabolic activities in Walker-256 tumour-bearing non-obese and obese rats. Wistars rats were divided into four groups: control tumour (CT); control tumour + botryosphaeran (CTB); obese tumour (OT), and obese tumour + botryosphaeran (OTB). In ninth week, obese and non-obese rats were inoculated with 1 × 107 Walker-256 tumour cells and treated with botryosphaeran (30 mg/kg/d for 15 days). In 11th week, the following parameters were evaluated glycogen, glucose and lactate levels, pro-oxidant (TBARS) and antioxidant markers (superoxide dismutase [SOD]; catalase [CAT]; glutathione-S-transferase [GST]; reduced glutathione [GSH]; vitamin C) and cytokines. Obesity presented oxidative stress and inflammation, as demonstrated by high levels of TBARS, SOD and TNF-α, and lower levels of CAT, GSH and interleukin-10 (IL-10). Botryosphaeran significantly decreased TBARS and TNF-α and increased GST, GSH, vitamin C and IL-10 in the liver; increased SOD and vitamin C in tumour tissue; decreased TBARS in adipose tissue, and notably decreased the levels of glycogen and lactate in the tumour of CTB rats. Botryosphaeran promoted significant antioxidant, anti-inflammatory, and beneficial metabolic effects in Walker-256 tumour-bearing non-obese and obese rats, which contributed to its antitumour activity.

Revealing Candida glabrata biofilm matrix proteome: global characterization and pH response.

Candida glabrata is a clinically relevant human pathogen with the ability to form high recalcitrant biofilms that contribute to the establishment and persistence of infection. A defining trait of biofilms is the auto-produced matrix, which is suggested to have structural, virulent and protective roles. Thus, elucidation of matrix components, their function and modulation by the host environment is crucial to disclose their role in C. glabrata pathogenesis. As a major step toward this end, this study aimed to reveal, for the first time, the matrix proteome of C. glabrata biofilms, to characterize it with bioinformatic tools and to study its modulation by the environmental pH (acidic and neutral). The results showed the presence of several pH-specific matrix proteins (51 acidic- and 206 neutral-specific) and also proteins commonly found at both pH conditions (236). Of note, several proteins related to mannan and ß-glucan metabolism, which have a potential role in the delivery/organization of carbohydrates in the matrix, were found in both pH conditions but in much higher quantity under the neutral environment. Additionally, several virulence-related proteins, including epithelial adhesins, yapsins and moonlighting enzymes, were found among matrix proteins. Importantly, several proteins seem to have a non-canonical secretion pathway and Pdr1 was found to be a potential regulator of matrix proteome. Overall, this study indicates a relevant impact of environmental cues in the matrix proteome and provides a unique resource for further functional investigation of matrix proteins, contributing to the identification of potential targets for the development of new therapies against C. glabrata biofilms.

From Cancer Therapy to Winemaking: The Molecular Structure and Applications of ß-Glucans and ß-1, 3-Glucanases.

ß-glucans are a diverse group of polysaccharides composed of ß-1,3 or ß-(1,3-1,4) linked glucose monomers. They are mainly synthesized by fungi, plants, seaweed and bacteria, where they carry out structural, protective and energy storage roles. Because of their unique physicochemical properties, they have important applications in several industrial, biomedical and biotechnological processes. ß-glucans are also major bioactive molecules with marked immunomodulatory and metabolic properties. As such, they have been the focus of many studies attesting to their ability to, among other roles, fight cancer, reduce the risk of cardiovascular diseases and control diabetes. The physicochemical and functional profiles of ß-glucans are deeply influenced by their molecular structure. This structure governs ß-glucan interaction with multiple ß-glucan binding proteins, triggering myriad biological responses. It is then imperative to understand the structural properties of ß-glucans to fully reveal their biological roles and potential applications. The deconstruction of ß-glucans is a result of ß-glucanase activity. In addition to being invaluable tools for the study of ß-glucans, these enzymes have applications in numerous biotechnological and industrial processes, both alone and in conjunction with their natural substrates. Here, we review potential applications for ß-glucans and ß-glucanases, and explore how their functionalities are dictated by their structure.

More Prominent Inflammatory Response to Pachyman than to Whole-Glucan Particle and Oat-ß-Glucans in Dextran Sulfate-Induced Mucositis Mice and Mouse Injection through Proinflammatory Macrophages.

(1→3)-ß-D-glucans (BG) (the glucose polymers) are recognized as pathogen motifs, and different forms of BGs are reported to have various effects. Here, different BGs, including Pachyman (BG with very few (1→6)-linkages), whole-glucan particles (BG with many (1→6)-glycosidic bonds), and Oat-BG (BG with (1→4)-linkages), were tested. In comparison with dextran sulfate solution (DSS) alone in mice, DSS with each of these BGs did not alter the weight loss, stool consistency, colon injury (histology and cytokines), endotoxemia, serum BG, and fecal microbiome but Pachyman-DSS-treated mice demonstrated the highest serum cytokine elicitation (TNF-α and IL-6). Likewise, a tail vein injection of Pachyman together with intraperitoneal lipopolysaccharide (LPS) induced the highest levels of these cytokines at 3 h post-injection than LPS alone or LPS with other BGs. With bone marrow-derived macrophages, BG induced only TNF-α (most prominent with Pachyman), while LPS with BG additively increased several cytokines (TNF-α, IL-6, and IL-10); inflammatory genes (iNOS, IL-1ß, Syk, and NF-κB); and cell energy alterations (extracellular flux analysis). In conclusion, Pachyman induced the highest LPS proinflammatory synergistic effect on macrophages, followed by WGP, possibly through Syk-associated interactions between the Dectin-1 and TLR-4 signal transduction pathways. Selection of the proper form of BGs for specific clinical conditions might be beneficial.

Health-Promoting Properties of Medicinal Mushrooms and Their Bioactive Compounds for the COVID-19 Era-An Appraisal: Do the Pro-Health Claims Measure Up?

Many mushroom species are consumed as food, while significant numbers are also utilised medicinally. Mushrooms are rich in nutrients and bioactive compounds. A growing body of in vitro, in vivo, and human research has revealed their therapeutic potentials, which include such properties as anti-pathogenic, antioxidant, anti-inflammatory, immunomodulatory, gut microbiota enhancement, and angiotensin-converting enzyme 2 specificity. The uses of medicinal mushrooms (MMs) as extracts in nutraceuticals and other functional food and health products are burgeoning. COVID-19 presents an opportunity to consider how, and if, specific MM compounds might be utilised therapeutically to mitigate associated risk factors, reduce disease severity, and support recovery. As vaccines become a mainstay, MMs may have the potential as an adjunct therapy to enhance immunity. In the context of COVID-19, this review explores current research about MMs to identify the key properties claimed to confer health benefits. Considered also are barriers or limitations that may impact general recommendations on MMs as therapy. It is contended that the extraction method used to isolate bioactive compounds must be a primary consideration for efficacious targeting of physiological endpoints. Mushrooms commonly available for culinary use and obtainable as a dietary supplement for medicinal purposes are included in this review. Specific properties related to these mushrooms have been considered due to their potential protective and mediating effects on human exposure to the SARS CoV-2 virus and the ensuing COVID-19 disease processes.

FT-IR Method Limitations for ß-Glucan Analysis.

ß-glucans are known as biological response modifiers. However, different sources can result in structural differences and as a result differences in their biological activity. The hot water extraction method allows to obtain, high molecular weight ß-glucans without altering their structure by using strong chemicals, such as alkalis or acids. Analysis of ß-glucans by FT-IR and NMR spectroscopy in solid state is superior to analysis in solution as it allows researchers to study the preserved structure of the extracted polysaccharides. FT-IR spectroscopy was used in this study to make side-by-side comparison analysis of hot water extracted ß-glucans from different yeast sources. NMR spectroscopy was used to confirm findings made by FT-IR spectroscopy. Extracted ß-glucans exhibit characteristic structure of ß-1,3/1,6-linked glucans with noticeable levels of proteins, possibly in a form of oligopeptides, chitin and other impurities. ß-glucans obtained from C. guilliermondii, P. pastoris and S. pastorianus exhibited higher protein content. Differences in mannan, chitin and α-glucan content were also observed; however, the species-specific structure of obtained ß-glucans could not be confirmed without additional studies. Structural analysis of high molecular weight ß-glucans in solid state by FT-IR spectroscopy is difficult or limited due to band intensity changes and overlapping originating from different molecules.

The Road to Structurally Defined ß-Glucans.

ß-glucans are polymers of glucose that have been isolated from a variety of organisms. Isolated ß-glucans have been used for medical purposes for centuries; however, efforts to define the biological activities of ß-glucans experimentally were initiated in the 1940's. The diversity of structure associated with isolated ß-glucans has impeded said investigations, and efforts to leverage the biological activity of ß-glucans for clinical applications. In recognition of the need for defined ß-glucans that retain the biological activity of isolated ß-glucans, considerable investment has been made to facilitate the synthesis of structurally defined ß-glucans. Here, we review the different approaches that have been applied to prepare ß-glucans. In addition, we summarize the approaches that have been utilized to conjugate ß-glucans to proteins.

Enrichment of bread with beta-glucans or resistant starch induces similar glucose, insulin and appetite hormone responses in healthy adults.

PURPOSE: ß-Glucans (ßG) and resistant starch (RS) are known for their effects on the improvement of glucose tolerance and enhancement of insulin sensitivity. Enrichment of bread with ßG or RS was performed to examine potential postprandial benefits regarding gastrointestinal hormone responses. METHODS: Ten healthy normoglycaemic adults participated in the study and were provided with either a glucose solution (reference food, GS) or bread enriched with ß-glucans (ßGB) (3.6 g/30 g available CHO) or bread enriched with resistant starch (RSB) (15% of total starch), with 1-week intervals in amounts that yielded 50 g of available carbohydrates. Venous blood samples were collected before consumption and at 15, 30, 45, 60, 90, 120 and 180 min postprandially. Glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) responses as well as glycaemic index (GI) and subjective appetite ratings were evaluated. RESULTS: Ingestion of ßGB and RSB elicited lower incremental area under the curve (iAUC) for glycaemic response compared to GS (P < 0.05). Both breads demonstrated a low GI (ßGB: 48, RSB: 40). There were no significant differences in insulin response, ghrelin, GLP-1 or PYY between the two breads. A significantly lower desire to eat and higher fullness were detected 15 min after ßGB and RSB consumption and until 180 min (P < 0.05 compared to GS). CONCLUSION: Enrichment of bread with either ßG or RS produced a low GI product but the two breads were not significantly different in relation to insulin, ghrelin, GLP-1 and PYY responses. The development of bread products which cause improved metabolic effects is of great importance for the promotion of public health.

ß-Glucan phosphorylases in carbohydrate synthesis.

ß-Glucan phosphorylases are carbohydrate-active enzymes that catalyze the reversible degradation of ß-linked glucose polymers, with outstanding potential for the biocatalytic bottom-up synthesis of ß-glucans as major bioactive compounds. Their preference for sugar phosphates (rather than nucleotide sugars) as donor substrates further underlines their significance for the carbohydrate industry. Presently, they are classified in the glycoside hydrolase families 94, 149, and 161 ( www.cazy.org ). Since the discovery of ß-1,3-oligoglucan phosphorylase in 1963, several other specificities have been reported that differ in linkage type and/or degree of polymerization. Here, we present an overview of the progress that has been made in our understanding of ß-glucan and associated ß-glucobiose phosphorylases, with a special focus on their application in the synthesis of carbohydrates and related molecules. KEY POINTS: • Discovery, characteristics, and applications of ß-glucan phosphorylases. • ß-Glucan phosphorylases in the production of functional carbohydrates.