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At least 127 records · Page 7

Flaxseed oil ameliorates aging in d ‐galactose induced rats via altering gut microbiota and mitigating oxidative damage

Abstract BACKGROUND Aging causes decreased antioxidant capacity and chronic inflammation and may even elevate cancer risks. Previous studies reported that flaxseed oil (FO) can alleviate age‐related diseases, including improving alcoholic liver disease, atherosclerosis and diabetes. However, whether the intestinal microbiota accountable for this alleviation is still unknown. This study aims to study the antioxidant effects of FO in an aging rat model and the underlying mechanism between the intestinal microbiota and aging. RESULTS Our results presented that serum and liver antioxidant capacities in FO group were up‐regulated, and liver inflammation in FO group was reduced. The 16S rDNA sequencing showed that FO regulated the microbial community, including up‐regulation of four families of Lactobacillus and six families of Clostridium. In addition, FO had also adjusted the relative abundance of several genera such as Ruminococcaceae_UCG‐005 and Prevotella_9 , which may be the key bacteria associated with the aging process. Colonic transcriptome analysis showed that there were 1679 differentially expressed genes (DEGs) in the Model group and the FO group (134 up‐regulated and 1545 down‐regulated). Gene set enrichment analysis (GSEA) revealed FO down‐regulates the expression of the upstream genes Ptprc , Lck , Zap70 , Lat and Lcp2 in the T cell receptor signaling pathway. CONCLUSION In conclusion, FO improved antioxidant capacity and reduced intestinal microbial disturbances caused by aging damage, indicating that dietary FO has the potential to fight aging damage. This study provides a more comprehensive view of dietary intervention to improve aging. © 2022 Society of Chemical Industry.

Sun, Xiaoyan↗

Broccoli seed extract rich in polysaccharides and glucoraphanin ameliorates DSS ‐induced colitis via intestinal barrier protection and gut microbiota modulation in mice

Abstract BACKGROUND Broccoli has received widespread attention because of its anti‐inflammatory and antioxidant effects. The present study aimed to explore the composition of broccoli seed extract (BSE) and its effect on colitis induced by dextran sulfate sodium (DSS). RESULTS BSE mainly comprises glucoraphanin and polysaccharides composed of arabinose, galactose, glucose and mannose. Animal experiments suggested that BSE intervention effectively reversed body weight loss, suppressed the levels of proinflammatory interleukin‐6, tumor necrosis factor‐α and interleukin‐1β, and elevated the levels of anti‐inflammatory interleukin‐10 and the activities of superoxide dismutase and glutathione in DSS‐induced colitis mice. According to histopathologic and immunohistochemical analysis of colon tissue, BSE intervention may repair the intestinal barrier by upregulating mRNA levels and the expression of tight junction proteins (claudin‐1, occludin and zonula occludens‐1). Gas chromatography–mass spectrometry (MS) analysis demonstrated that cecal short‐chain fatty acids in mice with BSE administration were significantly increased compared with the model group. Sulforaphane and sulforaphane‐ N ‐acetylcysteine were only detected in BSE group mice by ultra‐performance liquid chromatography‐MS analysis. In addition, BSE intervention evidently increased the abundance of Alistipeds , Coriobacteriaceae UCG‐002 and Bifidobacterium and decreased the abundance of Escheichia‐Shinella , Lachnospiraceae others , Parabacteroides , Ruminococcaceae others and Turicibacter , which possibly promoted carbohydrate metabolism and short‐chain fatty acid production. CONCLUSION The present study aimed to elucidate the effect of BSE on colitis and found that BSE, as a novel food ingredient, has great potential for the improvement of colitis. © 2022 Society of Chemical Industry.

Wu, Jiaying↗

Plastic glut down a microbial gut

Enzymes sequestered from microbes have demonstrated the ability to readily digest amorphous regions of polyethylene terephthalate (PET) in ambient conditions. Although nascent, enzymatic depolymerization can soon vie for commercialization and provide monomeric feedstock at rates comparable to petrochemical feedstock for repolymerization, achieving the coveted goal of cradle-to-cradle recycling. © 2022 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

59 BASIC BIOLOGICAL SCIENCES↗

Towards natural and realistic E 7 GUTs in F-theory

We consider phenomenological aspects of a natural class of Standard Model-like supersymmetric F-theory vacua realized through flux breaking of rigid E 7 gauge factors. Three generations of Standard Model matter are realized in many of these vacua. We further find that many other Standard Model-like features are naturally compatible with these constructions. For example, dimension-4 and 5 terms associated with proton decay are ubiquitously suppressed. Many of these features are due to the group theoretical structure of E 7 and associated F-theory geometry. In particular, a set of approximate global symmetries descends from the E 7 group, leading to exponential suppression of undesired couplings.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Gauge symmetry breaking with fluxes and natural Standard Model structure from exceptional GUTs in F-theory

We give a general description of gauge symmetry breaking using vertical and remainder fluxes in 4D F-theory models. The fluxes can break a geometric gauge group to a smaller group and induce chiral matter, even when the larger group admits no chiral matter representations. We focus specifically on applications to realizations of the Standard Model gauge group and chiral matter spectrum through breaking of rigid exceptional gauge groups E 7 , E 6 , which are ubiquitous in the 4D F-theory landscape. Supplemented by an intermediate SU(5) group, these large classes of models give natural constructions of Standard Model-like theories with small numbers of generations of matter in F-theory.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

High fat intake sustains sorbitol intolerance after antibiotic-mediated Clostridia depletion from the gut microbiota

Carbohydrate intolerance, commonly linked to the consumption of lactose, fructose, or sorbitol, affects up to 30% of the population in high-income countries. Although sorbitol intolerance is attributed to malabsorption, the underlying mechanism remains unresolved. Here, we show that a history of antibiotic exposure combined with high fat intake triggered long-lasting sorbitol intolerance in mice by reducing Clostridia abundance, which impaired microbial sorbitol catabolism. The restoration of sorbitol catabolism by inoculation with probiotic Escherichia coli protected mice against sorbitol intolerance but did not restore Clostridia abundance. Inoculation with the butyrate producer Anaerostipes caccae restored a normal Clostridia abundance, which protected mice against sorbitol-induced diarrhea even when the probiotic was cleared. Butyrate restored Clostridia abundance by stimulating epithelial peroxisome proliferator-activated receptor-gamma (PPAR-γ) signaling to restore epithelial hypoxia in the colon. Collectively, these mechanistic insights identify microbial sorbitol catabolism as a potential target for approaches for the diagnosis, treatment, and prevention of sorbitol intolerance.

60 APPLIED LIFE SCIENCES↗