Pterostilbene, 3′,5′-dimethoxy-4-hydroxystilbene, is a resveratrol analogue and has been reported to have similar and often potent health-promoting properties. Pterostilbene has been shown to reduce ...weight gain, liver fat, plasma cholesterol, adiposity, inflammatory biomarkers, blood glucose, and other physiological characteristics of metabolic diseases in animal models. Studies on pterostilbene suggest that it may improve risk factors associated with diabetes, cardiovascular disease, fatty liver diseases, Alzheimer’s disease, and other neurodegenerative diseases. Many of the extensive studies on the potential health benefits of pterostilbene were conducted by Dr. Agnes Rimando, a scientist with the United States Department of Agriculture, in collaboration with many U.S. and other international research groups. This review highlights the pterostilbene research of Dr. Rimando.
Scope
Kefir consumption inhibits the development of obesity and non‐alcoholic fatty liver disease (NALFD) in mice fed 60% high‐fat diet (HFD). To identify the key contributor of this effect, we ...isolated lactic acid bacteria (LAB) from kefir and examined their anti‐obesity properties from in vitro screening and in vivo validation.
Methods and results
Thirteen kefir LAB isolates were subjected to survivability test using artificial gastrointestinal environment and cholesterol‐reducing assay. Lactobacillus kefiri DH5 showed 100% survivability in gastrointestinal environments and reduced 51.6% of cholesterol; thus, this strain was selected for in vivo experiment. Compared to the HFD‐saline group, the HFD‐DH5 group showed significantly lower body weight (34.68 versus 31.10 g; p < 0.001), epididymal adipose tissue weight (1.39 versus 1.05 g; p < 0.001), blood triglyceride (38.2 versus 31.0 mg/dL; p < 0.01) and LDL‐cholesterol levels (19.4 versus 15.7 mg/dL; p < 0.01). In addition, L. kefiri DH5 administration significantly modulated gut microbiota of HFD‐fed mice. The hepatic steatosis was significantly milder (Lesion score, 2.1 versus 1.2; p < 0.001) and adipocyte diameter was significantly smaller (65.1 versus 42.2 μm; p < 0.001) in the HFD‐DH5 group. L. kefiri DH5 upregulated PPAR‐α, FABP4, and CPT1 expression in the epididymal adipose tissues (2.29‐, 1.77‐, and 2.05‐fold change, respectively), suggesting a reduction in adiposity by stimulating fatty acid oxidation.
Conclusion
L. kefiri DH5 exerts anti‐obesity effects by direct reduction of cholesterol in the lumen and upregulation of PPAR‐α gene in adipose tissues.
The proposed dual mechanism underlying the anti‐obesity and anti‐non‐alcoholic fatty liver disease (NAFLD) effects of L. kefiri DH5 in high‐fat diet (HFD)‐fed mice was explored. A large proportion of the orally administered L. kefiri DH5 remains active and viable in the gastrointestinal tract and exerts potent anti‐obesity effects in HFD‐fed mice via a dual mechanism: (i) direct reduction of excessive cholesterol in the lumen to decrease overall fat influx, and (ii) upregulation of genes encoding PPAR‐α, CPT1, and FABP4 in adipose tissue to increase fatty acid oxidation.
The synergistic anti-obesity effect of paraprobiotic heat-killed lactic acid bacteria (HLAB) and prebiotics has not been studied. To determine the anti-obesity properties of prebiotic polyphenol-rich ...wine grape seed flour (GSF) and paraprobiotic HLAB, C57BL/6J mice were administered a high-fat and high-fructose diet (HFFrD) with 5% microcrystalline cellulose (CON), HFFrD supplemented with 2.5% GSF, HFFrD with orally administered HLAB, or HFFrD with a combination of GSF and orally administered HLAB (GSF+HLAB) for 8 weeks. Compared with the CON group, the GSF and HLAB groups both showed significant reductions in HFFrD-induced body weight gain and adipose tissue weights (
< 0.05). Interestingly, combined supplementation with GSF and HLAB revealed statistically significant synergistic effects on body weight gain, visceral adiposity, and plasma triacylglycerol concentrations (
< 0.05). The synergistic action was significantly related to a decreased adipocyte gene expression in fatty acid synthesis and inflammation metabolism. In conclusion, the combination of prebiotic GSF and paraprobiotic kefir HLAB is potentially useful, as natural food ingredients, in the prevention of obesity and obesity-related diseases, especially for immunocompromised individuals.
The antiobesity action of nonviable probiotic lactic acid bacteria (PLAB) may be attributed to bacterial cellular components recognized by host cells. The anti-inflammation and antiobesity properties ...of surface layer proteins (SLPs) that are cellular components isolated from kefir PLAB were determined in macrophage RAW 264.7 cells and obese mice. Kefir SLPs significantly decreased secretion of IL-6 and production of NF-kB p65 protein by LPS-stimulated RAW 264.7 cells in a dose–response manner. C57BL/6J mice were fed a high-fat (HF) diet with oral administration of either saline (CON) or kefir SLPs for 6 weeks. SLPs significantly improved body weight gain and adipose tissue weight, plasma triglyceride concentrations, and insulin resistance. Profiling of adipocyte gene expression showed that the antiobesity effect was significantly related to the expression of genes associated with adipogenesis, autophagy, and inflammatory/immune response, and fatty acid oxidation. Taken together, SLPs are a novel bioactive component in kefir PLABs to target obesity and obesity-related disorders.
Kefir is a natural complex fermented milk product containing more than 50 species of probiotic bacteria and yeast, and has been demonstrated to have multiple properties conferring health benefits, ...including antiobesity, anti-hepatic steatosis, antioxidative, antiallergenic, antitumor, anti-inflammatory, cholesterol-lowering, constipation-alleviating, and antimicrobial properties. To better understand the underlying mechanisms of these benefits, we here review research on the effect of kefir (and kefir microorganisms) consumption to modulate the host gut microbiota. Owing to its excellent gastrointestinal resistance and colonization ability and wide ranges of microbial interaction, kefir has shown significant and wide-spectrum modulatory effects on the host gut microbiota. In particular, as a bacteria- and yeast-containing food, kefir can modulate both the gut microbiota and mycobiota. Since the association of this modulation with health benefit has only been addressed in a small number of recent studies thus far, further studies are needed to determine the precise mechanisms of the beneficial effects of kefir in relation to the modulation of the gut microbiota and mycobiota. Gaining this insight will surely help to take full advantage of this unique probiotic food.
We have reported that autophagy is crucial for clearance of amyloidogenic human IAPP (hIAPP) oligomer, suggesting that an autophagy enhancer could be a therapeutic modality against human diabetes ...with amyloid accumulation. Here, we show that a recently identified autophagy enhancer (MSL-7) reduces hIAPP oligomer accumulation in human induced pluripotent stem cell-derived β-cells (hiPSC-β-cells) and diminishes oligomer-mediated apoptosis of β-cells. Protective effects of MSL-7 against hIAPP oligomer accumulation and hIAPP oligomer-mediated β-cell death are significantly reduced in cells with knockout of MiTF/TFE family members such as Tfeb or Tfe3. MSL-7 improves glucose tolerance and β-cell function of hIAPP
mice on high-fat diet, accompanied by reduced hIAPP oligomer/amyloid accumulation and β-cell apoptosis. Protective effects of MSL-7 against hIAPP oligomer-mediated β-cell death and the development of diabetes are also significantly reduced by β-cell-specific knockout of Tfeb. These results suggest that an autophagy enhancer could have therapeutic potential against human diabetes characterized by islet amyloid accumulation.
Kefir is fermented milk produced by co-cultures of lactic and acetic acid bacteria and yeast that are encapsulated by an exopolysaccharide (EPS) called kefiran. Probiotic kefir provides many ...benefits, including antimicrobial effects against many pathogens. The mechanisms underlying these effects, however, are not yet completely understood. In this study, a total of 22 strains of lactic acid bacteria (LAB), including eight strains of Lactobacillus kefiranofaciens, two strains of Lactobacillus kefiri, seven strains of Lactococcus lactis, and five strains of Leuconostoc mesenteroides, were isolated from kefir and classified by 16S ribosomal RNA gene sequencing. The ability of each strain to produce EPS was determined, and Lactobacillus kefiranofaciens DN1 was found to have the highest EPS yield among all isolates. Lactobacillus kefiranofaciens DN1 produced EPS, using glucose and lactose, and EPS yield rose to 2.2 g/L in modified MRS broth (60 g/L glucose). The antimicrobial activities of the EPS produced by Lactobacillus kefiranofaciens DN1 (EPS_DN1) against Listeria monocytogenes and Salmonella Enteritidis were assessed by growth curve analysis. We found that EPS_DN1 at a concentration of at least 1% was able to exert bactericidal effects against both pathogens. Notably, results of high-performance size-exclusion chromatography (HPSEC) analysis indicated that EPS_DN1 was not kefiran, the major EPS of kefir grains, suggesting that EPS_DN1 represents a novel bioactive compound in kefir.
•A new exopolysaccharide (EPS), EPS_DN1, was isolated from kefir-derived bacteria.•Lactobacillus kefiranofaciens DN1 was the best EPS producer among 22 kefir isolates.•Lb. kefiranofaciens DN1 produced EPS_DN1 in glucose concentration-dependent manner.•EPS_DN1 exerted bactericidal effects against S. Enteritidis and L. monocytogenes.•EPS_DN1 is a heteropolysaccharide composed of five kinds of monosaccharide.
A 9-year-old female mixed-breed dog presented with ascending flaccid tetraparesis, and a 5-year-old castrated male Poodle dog presented with ventroflexion of neck, dysphonia, and hindlimb weakness, ...which progressed to acute ascending tetraparesis. Both dogs were fed raw poultry for over 9 and 5 years, respectively. Blood examination and other test results were normal or unrelated to the present case. Fecal polymerase chain reaction analysis in the Poodle dog was positive for Clostridium perfringens and Campylobacter jejuni. Tetraparesis improved with supportive care in both dogs. Human IV immunoglobulin was only administered to the Poodle dog, which showed a shorter recovery (12 days compared to 34 days in the mixed-breed dog). Both dogs returned to normal conditions eventually.
The Bacillus cereus group of bacteria, which causes foodborne diseases, can be detected by culture on selective media. However, the presence of competing flora is the most common factor preventing ...the accurate enumeration of B. cereus on selective agars. In this study, we improved the selectivity of mannitol-yolk-polymyxin B agar (MYPA) and its modified version containing trimethoprim (mMYPA) developed in our previous study by supplementation with ceftazidime (16 μg/mL). Ceftazidime-supplemented MYPA (C-MYPA16) and mMYPA (C-mMYPA16) were evaluated for bacteria recovery and selectivity with three types of ready-to-eat vegetables. Four B. cereus and one Bacillus thuringiensis strains were mixed and artificially inoculated into vegetable salad, radish sprouts, and sprout mix and then recovered on MYPA, mMYPA, C-MYPA16, and C-mMYPA16. In all tested vegetables, mMYPA, C-MYPA16, and C-mMYPA16 culture resulted in similar recovery of B. cereus and B. thuringiensis (P > 0.05), whereas radish sprout and sprout mix colonies grown on MYPA were undistinguishable. C-mMYPA16 was the most selective medium because it eliminated most of the competing flora, especially that in sprouts, without negatively affecting the recovery of B. cereus and B. thuringiensis. Our results indicate that supplementation of mMYPA with ceftazidime may improve the selectivity of this medium for B. cereus and B. thuringiensis in food testing.
Scope
This study aims to determine the separate and combined effect of a prebiotic (catechin‐rich wine grapeseed flour, GSF) and a probiotic (newly isolated kefir lactic acid bacteria, LAB) on ...hepatic steatosis of obese mice.
Methods and results
High‐fat (HF)‐induced obese mice are fed a HF diet containing 6% microcrystalline cellulose (MCC, control), 10% GSF, orally administrated LAB, or a combination of GSF and LAB for 9 weeks. There is a significant reduction of body weight gain and liver weights, plasma insulin concentrations, and HOMA‐IR in all experimental groups compared to control. Total lipid content, triglyceride, and low‐density lipoprotein (LDL)‐cholesterol concentrations of the liver are also significantly lowered. The combination of GSF and LAB further significantly affects cecum propionate content, plasma aspartate aminotransferase (AST/GOT), and zonulin concentrations, which is significantly correlated with hepatic lipid content. Analysis of hepatic microarray data reveals that genes related to lipid synthesis, bile acid and cholesterol synthesis, antioxidant activities, oxidative stress, inflammation, and liver function are significantly modulated following the combination of GSF and LAB.
Conclusion
These data suggest that amelioration of HF‐induced hepatic steatosis after consumption of GSF and LAB is partially mediated via alteration of cecum propionate and intestinal permeability, which modulates hepatic gene expression.
Supplementation of flavonoid‐rich chardonnay grapeseed flour (GSF) and newly isolated kefir lactic acid bacteria (LAB) synergistically enhances cecum short‐chain fatty acid and intestinal barrier function, which alters expression of hepatic genes related to fatty acid synthesis; oxidative stress; inflammation; response to lipopolysaccharides, bile acid, and cholesterol synthesis; and liver function. Eventually, it ameliorates high‐fat‐induced insulin resistance, hepatic steatosis, and inflammation.
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