ABSTRACT
A high-fat diet (HFD) easily contributes to the pathogenesis of obesity and insulin resistance. Obesity and insulin resistance have been clinical and public health challenges all over the world. Probiotic-fermented yogurt is one type of popular and functional beverage in people's daily lives. This study mainly explored the lipid- and glucose-lowering effects of Lactobacillus acidophilus NX2-6-fermented yogurt (LA-Y) in HFD-fed mice. The results showed that LA-Y administration improved the lipid profile in the serum and liver, reduced fasting blood glucose levels, and enhanced insulin sensitivity. Protein analysis showed that LA-Y treatment promoted fatty acid oxidation and suppressed de novo lipogenesis in the adipose tissue and liver. LA-Y effectively alleviated glucose metabolism disorders by activating the insulin signaling pathway, suppressing gluconeogenesis in the liver and muscle, reducing the concentration of pro-inflammatory cytokines in the serum, and promoting glycolysis and gluconeogenesis in the small intestine. LA-Y supplementation also promoted fat browning via the adiponectin/AMPKα/PGC-1α/UCP1 pathway and enhanced mitochondrial biogenesis in the liver and muscle by activating the adiponectin/AdipoR1/APPL1/AMPKα/PGC-1α pathway, leading to increased energy expenditure. Therefore, LA-Y may be a functional dairy food for preventing and alleviating diet-induced metabolic disorders.
Subject(s)
Insulin Resistance , Probiotics , Mice , Animals , Diet, High-Fat/adverse effects , Adiponectin/metabolism , Yogurt , Obesity/drug therapy , Obesity/etiology , Lipid Metabolism , Insulin/metabolism , Lipids , Mice, Inbred C57BL , Adaptor Proteins, Signal Transducing/metabolismABSTRACT
The rapid emergence and prevalence of multidrug-resistant salmonellosis lack effective therapies, which causes epidemic health problems and stimulates the development of antimicrobials with novel modes of action. In this research, 10 short symmetrical ß-hairpin peptides are synthesized by combining the ß-turn of Leucocin-A with recurring hydrophobic and cationic amino acid sequences. Those designed peptides exhibited potent antibacterial activities against drug-susceptible and drug-resistant Salmonella. One of the 10 peptides, WK2 ((WK)2CTKSGC(KW)2), displayed best cell selectivity towards Salmonella cells over macrophages and erythrocytes in a co-culture model. Fluorescent measurements and microscopic observations reflected that WK2 exerted its antimicrobial activity through a membrane-lytic mechanism. Moreover, the ß-hairpin peptides can bind to endotoxin (LPS) and suppress the production of LPS-induced proinflammatory cytokines in RAW264.7 cells, indicating as a potent anti-inflammatory activity. The preliminary in vivo studies can also demonstrate that WK2 decreased loads of Salmonella in the liver and spleen, mitigated Salmonella-caused inflammation and maintained the integrity of intestinal mucosal surfaces. Ultimately, the results highlight that WK2 is a promising therapeutic agent to prevent multidrug-resistant S. Typhimurium infections in humans and animals.
Subject(s)
Salmonella Infections , Salmonella typhimurium , Animals , Humans , Lipopolysaccharides/pharmacology , Salmonella Infections/drug therapy , Salmonella Infections/microbiology , Anti-Bacterial Agents/chemistry , Peptides/pharmacologyABSTRACT
Diet-induced obesity is one of the major public health concerns all over the world, and obesity also contributes to the development of other chronic diseases such as non-alcoholic fatty acid liver disease, type 2 diabetes mellitus and cardiovascular diseases. Evidence shows that the pathogenesis of obesity and obesity-associated chronic diseases are closely related to dysregulation of lipid metabolism, glucose metabolism and cholesterol metabolism, and oxidative stress, endoplasmic reticulum stress, abnormal gut microbiome and chronic low-grade inflammation. Recently, in view of potential effects on lipid metabolism, glucose metabolism, cholesterol metabolism and intestinal microbiome, as well as anti-oxidative and anti-inflammatory activities, natural probiotics, including live and dead probiotics, and probiotic components and metabolites, have attracted increasing attention and are considered as novel strategies for preventing and ameliorating obesity and obesity-related chronic diseases. Specifically, this review is presented on the anti-obesity effects of probiotics and underlying molecular mechanisms, which will provide a theoretical basis of anti-obesity probiotics for the development of functional foods.
Subject(s)
Diabetes Mellitus, Type 2 , Gastrointestinal Microbiome , Probiotics , Diet , Humans , Obesity/prevention & controlABSTRACT
AIMS: To identify the main spoilage bacterium on fresh-cut leafy vegetables and establish a multiplex PCR assay. METHODS AND RESULTS: Based on physiological-biochemical, molecular identification, and artificial contamination tests, the main bacterium to spoil fresh-cut leafy vegetables was identified as Exiguobacterium spp. and Exiguobacterium acetylicum. Comparative genomics showed that P401_RS0117025 and oxi_50,582,462 genes are specific to Exiguobacterium spp. and E. acetylicum. Based on this, three pairs of primer sets to EaG-291, EaS-2B, and Ea16S-12 genes were designed and used to develop a multiplex PCR assay, which exhibited 100% specificity among 16 Exiguobacterium and 10 non-Exiguobacterium strains. Finally, 84 fresh-cut leafy vegetable samples were analyzed by multiplex PCR assay and standard physiological-biochemical experiments, the results showed multiplex PCR assay reached a detection rate of 96%. CONCLUSIONS: The main spoilage bacterium was identified as Exiguobacterium spp. and E. acetylicum on fresh-cut leafy vegetables based on the novel specific genes explored in this study. SIGNIFICANCE AND IMPACT OF STUDY: A rapid, specific, and sensitive PCR assay was developed for the detection of Exiguobacterium spp. and E. acetylicum.