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Objective: To explore the preventive effect of Lactobacillus paracasei FZU103 (LP-FZU103) on alcoholic liver injury (ALI). Methods: Altogether 36 specific pathogen free- (SPF-) grade ICR mice were randomly divided into three groups: control, model and experimental (LP-FZU103 intervention). After the six-week experiment, body mass, organ coefficients, serum and liver biochemical indexes, liver histopathology and inflammatory cytokines, the transcription of liver function-related genes and intestinal flora composition were measured. Results: Compared with the model group, intervention of LP-FZU103 improved the organ coefficients and pathological liver damage in ALI mice, significantly reduced the levels of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) as well as the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, increased the serum concentration of high-density lipoprotein cholesterol (HDL-C), significantly increased the activity of catalase (CAT) and superoxide dismutase (SOD) and the content of glutathione (GSH) in the liver, and decreased MDA content and interleukin-6 (IL-6), interferon-γ (IFN-γ) levels in the liver. Moreover, LP-FZU103 intervention significantly up-regulated the mRNA expression level of the lipid metabolism-related gene Ldlr and down-regulated the mRNA expression level of Acc1, Hmgcr and Cd36 as well as increased the relative abundance of beneficial bacteria such as Lactobacillus johnsonii, Lactobacillus reuteri and Lactobacillus paracasei in the gut of mice. Conclusion: LP-FZU103 intervention can prevent and control the occurrence of alcoholic liver injury in mice, which is closely related to the improved intestinal flora and liver metabolic function.

In this study, two common cereal polysaccharides, arabinoxylan (HBAX) and β-glucan (HBBG), were prepared from the bran and endosperm of highland barley, respectively. The inhibitory effects, modes and types of the two polysaccharides on pancreatic α-amylase and their interactions with the enzyme were investigated by enzymatic kinetics and fluorescence quenching analysis. The results showed that both HBAX and HBBG effectively inhibited the activity of pancreatic α-amylase, the former being significantly more effective. Their inhibitory effects were both reversible, but their inhibitory types were different. HBAX presented mixed competitive and non-competitive inhibition, indicating that it not only can bind to the active sites of the enzyme, but also can form an enzyme-starch-inhibitor complex to block the enzymatic reaction. HBBG exhibited a mixed type of anti-competitive and non-competitive inhibition, suggesting that HBBG could only bind to the inactive sites of the enzyme to form an enzyme-starch-inhibitor complex. The fluorescence quenching results revealed that both HBAX and HBBG could interact with pancreatic α-amylase and quench its endogenous fluorescence statically. However, HBAX showed significantly higher affinity to the enzyme than HBBG, and could affect the polarity of the internal hydrophobic environment of pancreatic α-amylase, and in turn affect its microstructure. In conclusion, the differences in the inhibitory effects of HBAX and HBBG on the activity of pancreatic α-amylase might be related to their different inhibitory types and affinities to the enzyme. This study will provide a theoretical basis for the application of highland barley polysaccharides in the regulation of starch digestion and in low glycemic index foods.

Erythritol, a natural sweetener, is widely used in the food, medicinal and chemical industries because of its advantages of low calorie, good stability and high food safety. Yarrowia lipolytica is widely used as an efficient fermentation strain for erythritol production. However, the current research on erythritol production by Yarrowia lipolytica concentrates on control of the fermentation process and metabolic pathway regulation and has bottlenecks in the yield of erythritol and the fermentation process. On this basis, this article reviews recent progress in research on erythritol production by Yarrowia lipolytica from three aspects: fermentation substrate utilization, fermentation process control and metabolic pathway modification by genetic engineering. This review is expected to provide a reference for breaking the bottlenecks in erythritol production by Yarrowia lipolytica.

As a phenotypically and phylogenetically diverse group, lactic acid bacteria are found in a variety of natural environments and play an important role in medicine, bioengineering, food fermentation and agriculture. Lactic acid bacteria have a long history of use in food and have been considered as suitable vehicles for the production and targeted delivery of health-promoting or therapeutic bioactive substances due to their safety and probiotic properties, and the operability of their genetic systems. This article summarizes the latest studies on lactic acid bacteria as delivery vehicles in vivo with a focus on gene expression systems of lactic acid bacteria, the expression forms of bioactive substances and the application of lactic acid bacteria as delivery vehicles in the treatment of various diseases. It is hoped that this review will provide a basis for subsequent research.

Previous studies have shown that Lactobacillus plantarum AR495 has good anti-inflammatory and anti-osteoporosis effects. In order to further explore the effect and mechanism of AR495 in alleviating osteoporosis (OA), a rat model of OA was established to investigate the effects of AR495 on OA markers, inflammatory factor levels and oxidative stress injury in OA rats and to verify the recovery of cartilage matrix and bone by pathological staining of joints and microtomography (micro-CT) imaging. The results showed that AR495 could significantly alleviate excessive body mass gain caused by decreased physical activity in OA rats (P < 0.05). Pathological analysis showed that AR495 could significantly reduce the level of tumor necrosis factor-α (TNF-α) in the joint tissue of OA rats, inhibit the production of matrix metalloproteinase-13 (MMP-13) and the production of C-telopeptide of type II collagen (CTX-II) as a degradation product of cartilage matrix, thereby alleviating the degradation of articular cartilage matrix in rats. Micro-CT imaging showed that AR495 could significantly alleviate bone loss in the joint of OA rats and effectively protect the integrity of cartilage and synovium of rats. In addition, AR495 could significantly increase the activity of superoxide dismutase (SOD) and reduce the concentration of malondialdehyde (MDA) in peripheral blood (P < 0.05). Quantitative real-time polymerase chain reaction (qPCR) analysis showed that AR495 could stimulate the expression of the mucin-2 (MUC-2) and occludin-1 genes in intestinal goblet cells and repair the intestinal barrier function. It can be seen that AR495 can alleviate OA inflammation level and create a beneficial internal environment for chondrocytes to exert their functions and produce collagen matrix, thereby alleviating and restoring joint injury and improving OA symptoms.

In order to investigate the key structural features of peach gum polysaccharide (PGP) responsible for its emulsifying function, partial acid hydrolysis of PGP with 0.1 mol/L trifluoroacetic acid was conducted, yielding hydrolysates 30P, 60P, 120P and 180P with different degrees of hydrolysis at different hydrolysis times. The effects of partial acid hydrolysis on the monosaccharide composition and molecular mass of PGP were analyzed by high performance anion-exchange chromatography (HPAEC) and high performance size-exclusion chromatography with a multi-angle laser light scattering detector (HPSEC-MALLS) and the effect of partial acid hydrolysis on the emulsifying function of PGP was investigated by using an oil in water (O/W) emulsion system. Results showed that PGP was an acidic arabinogalactan composed of arabinose, galactose, xylose, mannose, galacturonic acid and glucuronic acid conjugated with a small amount of protein. PGP, whose average molecular mass of 10 980 kU, presented a flexible coil-like chain in 0.1 mol/L NaNO3 solution. As acid hydrolysis progressed, the contents of uronic acid and protein in PGP gradually increased, the molecular mass and degree of branching gradually decreased, and the molecular conformation of the hydrolysates changed from a flexible coil-like to a rigid rod-like structure. The stability of the O/W emulsion prepared using 60P as an emulsifier was significantly improved compared to the other hydrolysates. It was speculated that 60P, whose molecular mass was 1 188 kU and which had reduced degree of branching and higher contents of glycuronic acid-protein conjugate and exhibited a flexible chain-like structure, may be the key structural feature responsible for of the emulsifying function PGP. This study will be helpful to further explain the mechanism action of PGP as an emulsifier.