內(nèi)容: Cutaneous exposure to food allergens through a disrupted skin barrier is recognized as an important cause of food allergy, and the cutaneous sensitized mouse model has been established to investigate relevant allergic disorders. However, the role of different genetic backgrounds of mice on immune responses to food allergens upon epicutaneous sensitization is largely unknown. In this study, two strains of mice, i.e., the BALB/c and C57BL/6 mice, were epicutaneously sensitized with ovalbumin on atopic dermatitis (AD)-like skin lesions, followed by intragastric challenge to induce IgE-mediated food allergy. Allergic outcomes were measured as clinical signs, specific antibodies and cytokines, and immune cell subpopulations, as well as changes in intestinal barrier function and gut microbiota. Results showed that both strains of mice exhibited typical food-allergic symptoms with a Th2-skewed response. The C57BL/6 mice, rather than the BALB/c mice, were fitter for establishing an epicutaneously sensitized model of food allergy since a stronger Th2-biased response and severer disruptions in the intestinal barrier and gut homeostasis were observed. This study provides knowledge for selecting an appropriate mouse model to study food-allergic responses associated with AD-like skin lesions and highlights the role of genetic variations in the immune mechanism underlying pathogenesis of food allergy.

內(nèi)容: Gluten, known as the major allergen in wheat, has gained increasing concerns in industrialized countries, resulting in an urgent need for accurate, high-sensitive, and on-site detection of wheat gluten in complex food systems. Herein, we proposed a silver nanoparticles (AgNPs)/metal-organic framework (MOF) substrate-based surface-enhanced Raman scattering (SERS) sensor for the high-sensitive on-site detection of wheat gluten. The detection occurred on the newly in-situ synthesized AgNPs/MOF-modified SERS substrate, providing an enhancement factor (EF) of 1.89 × 105. Benefitting from the signal amplification function of AgNPs/MOF and the superiority of SERS, this sensor represented high sensitivity performance and a wide detection range from 1 × 10-15 mol/L to 2 × 10-6 mol/L with a detection limit of 1.16 × 10-16 mol/L, which allowed monitoring the trace of wheat gluten in complex food system without matrix interference. This reliable sandwich SERS sensor may provide a promising platform for high-sensitive, accurate, and on-site detection of allergens in the field of food safety.

內(nèi)容: Cellular senescence is the results of aging and age-related diseases, and the development of anti-aging methods may improve health and extend longevity. The natural flavonol fisetin has been shown to antagonize senescence in vitro and increases longevity in vivo, but has poor water solubility and limited bioavailability. In this study, a food-grade and senescent cell-targeted delivery system for fisetin was developed based on whey protein isolate-galactooligosaccharides (WPI-GOS) Maillard conjugate, which could recognize senescence associated β-galactosidase in senescent cells. The fisetin nanoparticles possessed a high encapsulation efficiency, excellent dispersibility in water, good storage stability and well biocompatibility. Moreover, they could effectively accumulate and retain in senescent cells with excellent senescent cell-targeting efficacy, and inhibit the oxidative stress-induced cellular senescence in vitro. Thus, this novel nanoparticle system based on WPI-GOS Maillard conjugate showed promise to deliver hydrophobic bioactive ingredients like fisetin to senescent cells to improve their bioavailability and anti-senescence effect.

內(nèi)容: Probiotics have great potential in regulating intestinal pain. In this study, the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome (IBS) rats were studied. The results showed that tryptase released after mast cell activation and degranulation plays a key role in visceral pain, and L. plantarum AR495 reduced the stimulation of colonic mast cells and the expression of protease-activated receptor 2 (PAR2) and TRPV1 in dorsal root ganglia. Research further showed that supplementation with L. plantarum AR495 increased the level of short-chain fatty acids (SCFAs) and enhanced the barrier function of the colon. In addition, the microbiota analysis of the colon indicated that L. plantarum AR495 promoted the proliferation of Bifidobacterium and inhibited the proliferation of Lachnospiraceae, which alleviated the imbalance of the intestinal microbiota caused by IBS to a certain extent. In total, L. plantarum AR495 might reduce visceral sensitivity through the Mast cell-PAR2-TRPV1 signaling pathway by maintaining the homeostasis of the intestinal barrier.

內(nèi)容: Blautia has attracted attention because of its potential efficacy in ameliorating host energy metabolism and inflammation. This study aims to investigate the influences of Blautia producta D4 on colitis induced by dextran sulfate sodium (DSS) and to reveal the underlying mechanisms. Results showed that B. producta D4 intervention significantly relieved body weight loss, and suppressed the elevation of pro-inflammatory cytokines (including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β)) and excessive oxidative stress (myeloperoxidease (MPO) activity, superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, and malondialdehyde (MDA) level) in colitis mice. Moreover, the concentrations of tight junction proteins (occludin, claudin-1, and ZO-1) related to the intestinal barrier were obviously elevated, and colitis-related TLR4/NF-κB pathway activation was remarkably inhibited after B. producta D4 intervention. The intestinal microbial disorder was evidently ameliorated by increasing the relative abundance of Clostridium sensu stricto 1, Bifidobacterium, GCA-900066225, Enterorhabdus, and reducing the relative abundance of Lachnospiraceae NK4A136 group. In conclusion, oral administration of B. producta D4 could ameliorate DSS-induced colitis by suppressing inflammatory responses, maintaining the intestinal barrier, inhibiting TLR4/NF-κB pathway, and regulating intestinal microbiota balance. These results are conducive to accelerate the development of B. producta D4 as a functional probiotic for colitis.

內(nèi)容: Probiotics exert beneficial effects on the host. This study aimed to investigate whether maternally ingested Lacticaseibacillus rhamnosus Probio-M9 during pregnancy could access and colonize the infant gut. This study recruited one pregnant woman, who ingested Probio-M9 daily from 35 weeks of gestation to delivery. Feces of the mother-infant pair were regularly collected from one month before delivery to 6 months of infant’s age for metagenomic sequencing. Probio-M9 genomes were mappable to all infant fecal samples, suggesting the ingested probiotics could be vertically transmitted from mother to infant. Infant- or mother-specific differential metabolic pathways were found between the maternal and infant’s gut microbiome, implicating apparent differences in the intestinal metagenomic potential/function between the mother and the infant. In conclusion, maternal ingestion of Probio-M9 during the final weeks of gestation could deliver to the infant gut. The findings provided novel insights into shaping infant’s gut microbiota.

內(nèi)容: Multidrug-resistant (MDR) Enterobacteriaceae critically threaten duck farming and public health. The phenotypes, genotypes, and associated mobile genetic elements (MGEs) of MDR Enterobacteriaceae isolated from 6 duck farms in Zhejiang Province, China, were investigated. A total of 215 isolates were identified as Escherichia coli (64.65%), Klebsiella pneumoniae (12.09%), Proteus mirabilis (10.23%), Salmonella (8.84%), and Enterobacter cloacae (4.19%). Meanwhile, all isolates were resistant to at least two antibiotics. Most isolates carried tet(A) (85.12%), blaTEM (78.60%) and sul1 (67.44%) resistance genes. Gene co-occurrence analysis showed that the resistance genes were associated with IS26 and integrons. A conjugative IncFII plasmid pSDM004 containing all the above MGEs was detected in Proteus mirabilis isolate SDM004. This isolate was resistant to 18 antibiotics and carried the blaNDM-5 gene. MGEs, especially plasmids, are the primary antibiotic resistance gene transmission route in duck farms. These findings provide a theoretical basis for the rational use of antibiotics in farms which are substantial for evaluating public health and food safety.

內(nèi)容: Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans. The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E. coli O157:H7 than using either alone. This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level. The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E. coli O157:H7 found that acid resistance systems in kojic acid were activated, and the cell membrane and genomic DNA were destructed in the cells, resulting in “oxygen starvation”. The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP, which affected the bacteria's life metabolic process. Interestingly, we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA, respiration, tricarboxylic acid cycle. The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E. coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.

內(nèi)容: The interaction between host circadian rhythm and gut microbes through the gut-brain axis provides new clues for tea polyphenols to improve host health. Our present research showed that oolong tea polyphenols (OTP) improved the structural disorder of the intestinal flora caused by continuous darkness, thereby modulating the production of metabolites related to pyruvate metabolism, glycolysis/gluconeogenesis, and tryptophan metabolism to alleviate the steady-state imbalance. After fecal microbiota transplantation from the OTP group, the single-cell transcriptomic analysis revealed that OTP significantly increased the number of hypothalamus cell clusters, up-regulated the number of astrocytes and fibroblasts, and enhanced the expression of circadian rhythm genes Cry2, Per3, Bhlhe41, Nr1d1, Nr1d2, Dbp and Rorb in hypothalamic cells. Our results confirmed that OTP can actively improve the intestinal environmental state as well as internal/peripheral circadian rhythm disorders and cognitive impairment, with potential prebiotic functional characteristics to notably contribute to host health.

內(nèi)容: Lipid metabolism disorders commonly occur during menopause. Estrogen deficiency has been shown to lead to excessive energy intake and abnormal lipid metabolism in ovariectomized rats, resulting in obesity. Probiotics exhibit anti-obesity properties, and their underlying mechanism has been widely reported. In this study, we demonstrated the metabolic benefits of Lactobacillus plantarum CCFM1180 in suppressing appetite, controlling body weight, correcting obesity-induced abnormalities, enhancing liver lipid metabolism, and protecting liver function in estrogen-deficient rats. The mechanisms associated with the anti-obesity and anti-dyslipidemia effects of CCFM1180 on estrogen-deficient rats were clarified. The results showed that CCFM1180 dramatically reduced food intake by activating the expression of estrogen receptor alpha (ERα) and increasing the level of leptin in abdominal adipose tissue. These changes, combined with the increased butyrate concentration and recovered bile acid structure, helped enhance lipid metabolism. Additionally, CCFM1180 treatment was found to be safer than exogenous estrogen supplementation. Thus, L. plantarum CCFM1180 could be considered a new therapeutic strategy for preventing and alleviating menopausal lipid abnormalities.