Harboring various proteins, lipids, and RNAs, the extracellular vesicles (EVs) in milk exert vital tissue-specific immune-protective functions in neonates via these bioactive cargos. This study aims to explore the anti-inflammatory effects of bovine milk-derived EVs on a dextran sulfate sodium (DSS)-induced colitis model and to determine the underlying molecular mechanisms. Sixty C57BL/6 mice were divided into the NC group (normal control), DSS group (DSS + PBS), DSS + LOW group (DSS + 1.5 × 10⁸ p/g EVs), DSS + MID group (DSS + 1.5 × 10⁹ p/g EVs), and DSS + HIG group (DSS + 1.0 × 10¹⁰ p/g EVs). Histopathological sections, the gut microbiota, and intestinal tissue RNA-Seq were used to comprehensively evaluate the beneficial functions in mitigating colitis. The morphology exhibited that the milk-derived EVs contributed to the integrity of the superficial epithelial structure in the intestine. Additionally, the concentrations of IL-6 and TNF-α in the colon tissues were significantly decreased in the EVs-treated mice. The abundances of the Dubosiella, Bifidobacterium, UCG-007, Lachnoclostridium, and Lachnospiraceae genera were increased in the gut after treatment with the milk-derived EVs. Additionally, the butyrate and acetate production were enriched in feces. In addition, 1659 genes were significantly down-regulated and 1981 genes were significantly up-regulated in the EVs-treated group. Meanwhile, 82 lncRNAs and 6 circRNAs were also differentially expressed. Overall, the milk-derived EVs could attenuate colitis through optimizing gut microbiota abundance and by manipulating intestinal gene expression, implying their application potential for colitis prevention.

Milk extracellular vesicles (EVs) are rich in abundant bioactive macromolecules, such as glycoconjugates, proteins, lipids and nucleic acids, and these vesicles might transmit signals to human consumers. However, it remains to be determined whether milk EVs import new pathogens to humans or are beneficial for human health. Here, C57BL/6 female and male mice were randomly divided into 4 EV dose levels (0, 1.5 × 10⁹ p g⁻¹, 1.0 × 10¹⁰ p g⁻¹ and 1.5 × 10¹⁰ p g⁻¹). Based on the alterations in body weight, the control group (0 p g⁻¹, PBS) and the middle treatment group (1.0 × 10¹⁰ p g⁻¹) were chosen for further analysis of the effects of EVs on the gut microbiota and blood metabolites in mice, by 16S rRNA gene sequencing and untargeted metabolomics, respectively. We found that milk EVs increased the abundance of “beneficial” microbes such as Akkermansia, Muribaculum and Turicibacter, while decreased the level of “harmful” bacteria Desulfovibrio. Serum metabolites showed that EVs mainly changed the lipid and amino acid metabolism, and especially increased several serum anti-inflammatory factors, which might be beneficial for inflammation and other metabolic diseases. The results of KEGG analysis suggested that the enriched pathways were the intestinal immune network for IgA production, retinol metabolism, and D-glutamine and D-glutamate metabolism. Taken together, the positive effect of milk EVs on serum nutrient metabolism without promoting “harmful” bacterial colonization in female and male mice may indicate that they are safe bioactive molecules, and some of the changes they induce may provide protection against certain diseases.

Inflammatory bowel disease (IBD) is a global health problem in which metabolite alteration plays an important pathogenic role. Bovine milk-derived extracellular vesicles (mEVs) have been shown to regulate nutrient metabolism in healthy animal models. This study investigated the effect of oral mEVs on metabolite changes in DSS-induced murine colitis. We performed metabolomic profiling on plasma samples and measured the concentrations of lipids and amino acids in both fecal samples and colonic tissues. Plasma metabolome analysis found that mEVs significantly upregulated 148 metabolite levels and downregulated 44 metabolite concentrations (VIP > 1, and p < 0.05). In the fecal samples, mEVs significantly increased the contents of acetate and butyrate and decreased the levels of tridecanoic acid (C13:0), methyl cis-10-pentadecenoate (C15:1) and cis-11-eicosenoic acid (C20:1). Moreover, the concentrations of eicosadienoic acid (C20:2), eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6) were decreased in colonic tissues with mEV supplementation. In addition, compared with the DSS group, mEVs significantly increased the content of L-arginine, decreased the level of L-valine in the fecal samples, and also decreased the levels of L-serine and L-glutamate in the colonic tissues. Collectively, our findings demonstrated that mEVs could recover the metabolic abnormalities caused by inflammation and provided novel insights into mEVs as a potential modulator for metabolites to prevent and treat IBD.

Evidence shows that effective nutritional intervention can prevent or mitigate the risk and morbidity of inflammatory bowel disease (IBD). Bovine milk extracellular vesicles (mEVs), a major bioactive constituent of milk, play an important role in maintaining intestinal health. The aims of this study were to assess the effects of mEV pre-supplementation on the colonic transcriptome and proteome in dextran sulphate sodium (DSS)-induced acute colitis, in order to understand the underlying molecular mechanisms of mEV protection against acute colitis. Our results revealed that dietary mEV supplementation alleviated the severity of acute colitis, as evidenced by the reduced disease activity index scores, histological damage, and infiltration of inflammatory cells. In addition, transcriptome profiling analysis found that oral mEVs significantly reduced the expression of pro-inflammatory cytokines (IL-1β, IL-6, IL-17A and IL-33), chemokine ligands (CXCL1, CXCL2, CXCL3, CXCL5, CCL3 and CCL11) and chemokine receptors (CXCR2 and CCR3). Moreover, oral mEVs up-regulated 109 proteins and down-regulated 150 proteins in the DSS-induced murine model, which were involved in modulating amino acid metabolism and lipid metabolism. Collectively, this study might provide new insights for identifying potential targets for the therapeutic effects of mEVs on colitis.

Wheat straw is considered an abundant lignocellulosic biomass source in China. However, its recalcitrance hinders the degradation of wheat straw by enzymes and microbes. In this study, we investigated the optimum steam explosion conditions of pretreated wheat straw by response surface methodology to improve its nutrition level as a feedstuff for the ruminant industry or as a feedstock for biofuel production. The highest volatile fatty acid (VFA) yield (30.50 mmol L⁻¹) was obtained at 2.3 MPa, 90 s and a moisture content of 36.46%. Under optimal conditions, steam explosion significantly altered the fermentation parameters in vitro. Ionic chromatography showed that pretreating wheat straw could improve the production of fermentable sugar, which was ascribed to the degradation of cellulose and hemicellulose. In addition, high throughput 16S rRNA amplicon sequencing analysis revealed that steam explosion changed the microbial community and enhanced the colonization of cellulolytic bacteria. Our findings demonstrated that steam explosion pretreatment could greatly improve the digestibility of wheat straw by facilitating sugar production and microbial colonization.

Plastic pollution has become one of the major environmental problems facing human beings in the world today. Plastic waste accumulated in the environment forms plastic particles of different sizes due to farming activities, climate change, ultraviolet light, microbial degradation, and animal chewing. The pollution caused by microplastics has become a major environmental problem in recent years, and it is also a research hotspot in the field of ecological environment. More and more studies have found that ruminants are exposed to microplastics for a long time, which seriously threaten their healthy growth. This paper introduces the current situation of plastic pollution; the properties of microplastics and their effects on the ecological environment, human beings, and animals; summarizes the types and toxicity mechanisms of microplastics; and concludes the main ways that microplastics enter ruminants and their harm to them. In addition, the shortcomings and future development of microplastics in ruminants research are summarized and prospected to provide theoretical reference for the related research on alleviating the influence of microplastics on ruminant production.