Circadian disruption-induced metabolic syndrome in mice is ameliorated by oat ß-glucan mediated by gut microbiota.

Circadian disruption-induced metabolic syndrome (CDIMS) involves body weight gain, changes in blood profile and gut microbiota. In this study, CDIMS was induced by shifted light dark cycle (SLDC) in C57BL/6J mice. Dietary intervention by oral administration of oat ß-glucan (a polymeric prebiotic) alleviated CDIMS when compared to chicory inulin/fructan (an oligomeric prebiotic) and melatonin (a chronobiotic). Oat ß-glucan reversed the increase in body weight, liver weight-to-body weight ratio and plasma leptin concentration as well as restored glucose tolerance. In altering gut microbiota, oat ß-glucan increased the species richness, reversed the populations of 7 bacterial genera and increased butyrate producers including Ruminococcaceae and Lachnospiraceae which enhance gut barrier protection and regulate glucose homeostasis. Correlation analysis demonstrated the linking of the alleviation of CDIMS by prebiotics and melatonin with different microbial metabolic pathways involved in energy metabolism, biosynthesis of metabolites, metabolism of cofactors and vitamins and endocrine synthesis.

Prebiotic supplementation (beta-glucan and inulin) attenuates circadian misalignment induced by shifted light-dark cycle in mice by modulating circadian gene expression.

Circadian rhythm governs multiple behavioural and physiological processes and its disruption is closely associated with various pathological conditions. In this study, the effects of dietary intervention by prebiotics including beta-glucan and inulin on attenuating circadian desynchrony in C57BL/6J mice subjected to weekly shifted light-dark cycle under a high fat diet was investigated. Using RT-qPCR and rhythmicity analysis, our study revealed that beta-glucan (0.2 g/day) and inulin (0.2 g/day) modulated the expression and phase of circadian-clock genes, explicitly reversed the phase delay of Period 1 and Period 3 in the hypothalamus, and reversed the phase delay of Period 2 in the liver of the mice. In the shifted mouse group, inulin also exhibited its reversal effects on the phase advance of Brain and muscle-Arnt-like 1 in the hypothalamus. These findings indicated that prebiotic supplementation can be a novel dietary approach for attenuating circadian misalignment.

Research on a Specialty Mushroom (Pleurotus tuber-regium) as a Functional Food: Chemical Composition and Biological Activities.

Pleurotus tuber-regium (PTR) is an edible specialty mushroom that has attracted growing interest recently because of its sensory attributes, high nutritional values, and important medicinal properties. PTR is rich in bioactive polysaccharides, proteins with essential amino acids, essential fatty acids, dietary fiber, minerals, and vitamins. Current studies have shown that the nutrients and bioactive ingredients of PTR contribute to their antitumor, antihypercholesterolemic, antihypertensive, antiobesity, hepatic-protective, antimicrobial, antioxidant, and prebiotic activities, indicating that PTR is a promising functional food and nutraceutical. In this review, the chemical constituents and physiological functions of PTR are summarized, which provide the scientific basis to support the further research and development of its application in the food and pharmaceutical industries.

pH-sensitive PEG-coated hyper-branched ß-d-glucan derivative as carrier for CpG oligodeoxynucleotide delivery.

ß-d-glucan is a natural non-digestible polysaccharide that can be selectively recognized by recognition receptors such as Dectin-1 receptors, resulting in an emerging interest on exploring its capacity for carrying biological information to desired organs or cells. CpG oligodeoxynucleotide (ODN) has the potentiality to initiate an immune-stimulatory cascade via activating B cells inducing proinflammatory cytokines, which is conducive to immunotherapy and nucleic acid vaccine. Herein, we developed a pH-sensitive delivery system loading with CpG ODN by introducing poly-ethylenimine (PEI) to a hyperbranched ß-d-glucan (HBB) and coating with poly-ethylene glycol (PEG) shell via acidic liable Schiff bond. This delivery system exhibited a favorable biocompatibility and facilitated the cellular uptake of CpG ODN at pH 6.8 with the possibility of having higher accumulation in acidic cancer microenvironment. Furthermore, this carrier together with class B CpG ODN could enhance the secretion of cytokines including interleukin-6 and interferon-α as well as capable of interferon-α induction.

Framework as a Service, FaaS: Personalized Prebiotic Development for Infants with the Elements of Time and Parametric Modelling of in vitro Fermentation.

We proposed a framework with parametric modeling to obtain biological relevant parameters from the total probiotic growth pattern and metabolite production curves. The lag phase, maximum increase rate, and maximum capacity were obtained via a 205-h exploratory in vitro fermentation of a library of 13 structural-characterized prebiotic candidates against an exclusively breastfed infant fecal inoculum. We also conducted 16S rRNA amplicon sequencing of the infant fecal inoculum. Moreover, we introduce a robust composite metabolite-based indicator that reflects the eubiosis/dysbiosis of microbiota to complement the conventional microbial markers. In terms of short-chain fatty acid, we discovered that polymeric beta-glucans from barley demonstrated potential as prebiotic candidates, while alpha-glucans as glycogen showed the least dissolved ammonia production. In terms of total probiotic, beta-glucans from oat and mushroom sclerotia of Pleurotus tuber-regium showed comparable sustainability when compared to alpha-glucans after 48 h. Being classical prebiotic, galacto-oligosaccharides gave the second-highest metabolite-based indicator, followed by lactose. While limited improvement could be made to lactose and oligosaccharides, polymeric beta-glucans from barley avails more capacity for novel prebiotic development, such as structural modification. We anticipate that more similar parallel screening with the element of time and parametric modeling will provide more novel insights.

Carbohydrate-Based Prebiotics in Targeted Modulation of Gut Microbiome.

The Human Microbiome Project has prompted unprecedented advancement in microbiome science. Personalized microbiome modulation with precision (PMMP) is one of the emerging yet challenging fields in microbiome research. Carbohydrate-based prebiotics (CBPs) have been shown to modulate the gut microbiome to various extents according to different structural characteristics, such as degree of polymerization, branching, glycosidic linkage, monosaccharide profile, and chemical modification. Subsequently, a targeted modulation of the microbiome might be achieved by using CBPs with a specific structure. A multidimensional database can be established based on the structure-microbiome and structure-microbial-marker relationships. Such relationships could facilitate the development of synbiotics and PMMP.

Role of intestinal microecology in the regulation of energy metabolism by dietary polyphenols and their metabolites.

BACKGROUND: Polyphenols are a class of plant secondary metabolites with a variety of physiological functions. Polyphenols and their intestinal metabolites could greatly affect host energy metabolism via multiple mechanisms. OBJECTIVE: The objective of this review was to elaborate the role of intestinal microecology in the regulatory effects of dietary polyphenols and their metabolites on energy metabolism. METHODS: In this review, we illustrated the potential mechanisms of energy metabolism regulated by the crosstalk between polyphenols and intestinal microecology including intestinal microbiota, intestinal epithelial cells, and mucosal immune system. RESULTS: Polyphenols can selectively regulate the growth of susceptible microorganisms (eg. reducing the ratio of Firmicutes to Bacteroides, promoting the growth of beneficial bacteria and inhibiting pathogenic bacteria) as well as alter bacterial enzyme activity. Moreover, polyphenols can influence the absorption and secretion of intestinal epithelial cells, and alter the intestinal mucosal immune system. CONCLUSION: The intestinal microecology play a crucial role for the regulation of energy metabolism by dietary polyphenols.

Chlorogenic acid alleviates obesity and modulates gut microbiota in high-fat-fed mice.

To evaluate the anti-obesity effects of chlorogenic acid (CGA), the mice were fed a high-fat diet (HFD) upon chlorogenic acid treatment for 6 weeks. The results showed administration of chlorogenic acid (150 mg per kg per day) remarkably promoted body loss, reduced lipid levels in plasma and altered mRNA expression of lipogenesis and lipolysis related genes in adipose tissue. Moreover, chlorogenic acid also reversed the HFD-induced gut microbiota dysbiosis, including significantly inhibiting the growth of Desulfovibrionaceae, Ruminococcaceae, Lachnospiraceae, Erysipelotrichaceae, and raising the growth of Bacteroidaceae, Lactobacillaceae. Overall, the amelioration of HFD-induced gut microbiota dysbiosis by chlorogenic acid may contribute, at least partially, to its beneficial effects on ameliorating HFD-induced obesity.

In Vitro Infant Faecal Fermentation of Low Viscosity Barley ß-Glucan and Its Acid Hydrolyzed Derivatives: Evaluation of Their Potential as Novel Prebiotics.

Barley contains high level of ß-1,3-1,4-glucans (BBGs) which can be fermented by microbes and are a potential prebiotic. In the present study, native BBG with low viscosity and a MW of 319 kDa was depolymerized by acid hydrolysis to produce a series of four structurally characterized fragments with MWs ranging from 6⁻104 kDa. In vitro fermentation of these BBG samples by infant faecal microbiome was evaluated using a validated deep-well plate protocol as parallel miniature bioreactors. Microbial taxa were identified using 16S amplicon sequencing after 40 h of anaerobic fermentation. Bioinformatics analysis including diversity indexes, predicted metagenomic KEGG functions and predicted phenotypes were performed on the sequenced data. Short chain fatty acids and dissolved ammonia were quantified and the SCFAs/NH3 ratio was used to evaluate the eubiosis/dysbiosis potential. Correlation analysis showed that most of the parameters investigated showed a parabolic function instead of a monotonous function with the BBG samples having different MWs. Among the five BBGs, it was concluded that BBG with an intermediate MW of 28 kDa is the most promising candidate to be developed as a novel prebiotic.

Low-Cost Method Generating In Situ Anaerobic Conditions on a 96-Well Plate for Microbial Fermentation in Food Research.

Commercial tools and instruments have been developed for a screening study of microbial fermentation, but they are expensive and mostly confined to aerobic fermentation only. There is little development on the generation of anaerobic conditions directly on a 96-well plate. This report proposed a simple and versatile microbial fermentation system known as OVAMO that makes use of Oxyrase, vacuum, and mineral oil to generate an in situ anaerobic environment on a 96-well plate for at least 48 h. The practicality of OVAMO in anaerobic fermentation experiments used for functional food research was validated by a prebiotic screening study of different carbohydrates by Bifidobacterium longum subsp. infantis. The OVAMO system provides a less expensive but effective way to conduct a microbial fermentation screening study that requires anaerobic conditions without the need for atmospheric control by external devices.

The diploid genome of the only sclerotia-forming wild-type species in the genus Pleurotus -Pleurotus tuber-regium - provides insights into the mechanism of its biomass conversion from lignocellulose substrates.

Pleurotus tuber-regium (Fr.) Singer, being a white-rot fungus, is widely used for food and medicine in the Asia-Pacific region. In this study, we sequenced and annotated the genome of a dikaryon P. tuber-regium wild strain to provide a better understanding of the carbohydrate-active enzymes (CAZymes) involved in the bio-conversion of lignocellulose to beta-glucan reserves in this sclerotia-forming Pleurotus mushroom with reference to enzyme participated in cellulosic compound breakdown and glucan reserve biosynthesis. The present genomic data provides new insights for lignocellulose bioconversion of white-rot fungus for the genus Pleurotus.