Probiotic-derived extracellular vesicles (PEVs) are functional nanovesicles secreted by various microbiota. As a novel class of microbial signals, they encapsulate proteins, nucleic acids, lipids, and microbial-associated molecular patterns, emerging as potent modulators of communication between gut microbiota and host immune cells, such as macrophages. Macrophages, as a crucial component of the innate immune system, rely heavily on specific metabolic reprogramming to execute their immune functions effectively. Recent evidence demonstrates the pivotal role of macrophage immunometabolism in orchestrating inflammatory responses and regulating systemic metabolic health. This review provides the first comprehensive synthesis of current evidence linking PEVs to the function and metabolic reprogramming of macrophages. We first conducted a detailed exploration of the release rationale, biosynthesis, composition, uptake by macrophages, and biological activity of PEVs. Subsequently, we elucidated how these vesicles and their cargo influence macrophage polarization through several metabolic pathways, including glycolysis, oxidative phosphorylation (OXPHOS), fatty acid oxidation (FAO), and amino acid metabolism. We further explore the implications of macrophage immunometabolism in chronic inflammation and metabolic disorders, including inflammatory bowel disease (IBD), neurodegenerative diseases, and atherosclerosis. Additionally, emerging evidence indicates that PEVs may be influenced by various factors, which in turn can affect host immunity and metabolism. Finally, we briefly discuss the limitations and future challenges in this field. This review highlights new research targets concerning the impact of gut microbiota on host immunity and metabolism.

BACKGROUND:Brucellosis poses a significant threat to animal and human health globally. However, how Brucella subverts the immune response to establish persistent infections remains unclear. METHODS:We utilized single-cell RNA sequencing (scRNA-seq) to decipher the immune landscape of mice infected with Brucella abortus. Flow cytometry, a transgenic cell line and mouse, and antibody blockage were utilized to explore the relevant mechanisms. RESULTS:Brucella infection induced significant changes in the composition and signaling pathways of immune cells, and flow cytometry analysis further confirmed the scRNA-seq data. An in-depth analysis of macrophages, the main target cell for Brucella, demonstrated activation of type I interferon (IFN) and type II IFN signaling, tumor necrosis factor production, diverse cell deaths, etc. Specifically, Vir-2308 Brucella infection induced IFN-β expression, primarily originating from macrophages. In vitro, a significantly lower level of intracellular Brucella survival was observed in ifnar1-/- macrophages. In vivo, ifnar1 genetic deficiency rendered the mice less susceptible to Brucella challenge resulting in a lower bacterial load and higher levels of macrophages and neutrophils. Interestingly, Brucella infection induced a dramatic reduction of NK cells along with the upregulation of CD94:NKG2A, one typical immune checkpoint module of NK cells. Further blockage of the NKG2A receptor in mice significantly reduced the bacterial load in the tissues, concurrent with a higher ratio of mature dendritic cells and a lower proportion of B cells. CONCLUSIONS:scRNA-seq revealed that Brucella infection significantly alters the immune microenvironment in mice, providing insight into a better understanding of brucellosis pathogenesis and the immune evasion strategies of this sophisticated pathogen.

Milk-derived extracellular vesicles (MEVs) modulate metabolic and immune processes. Donkey milk, given its compositional similarity to human milk and documented bioactivities-including antioxidant, anti-inflammatory, and anti-cancer properties-represents a promising source for therapeutically relevant EVs. However, standardized protocols for efficient donkey milk EVs isolation remain limited. This study compared two isolation methods for donkey milk EVs: conventional ultracentrifugation (UC) and the ultrafast isolation system EXODUS (DUS). We systematically evaluated MEV morphology, particle size distribution, and marker protein expression profiles. Subsequently, we performed comprehensive proteomic characterization using 4D label-free quantitative proteomics. Both isolation methods yielded MEVs with characteristic spherical or elliptical membrane structures. UC-isolated MEVs showed significantly higher particle concentrations compared to DUS-isolated vesicles; however, UC extraction introduced polymer precipitates and protein particle contaminants. Proteomic analysis identified 1220 proteins across both isolation methods. Gene Ontology annotation revealed distinct protein enrichment patterns: DUS-isolated MEVs showed enhanced representation of proteins associated with extracellular regions, extracellular matrix, and extracellular exosomes, while UC-isolated MEVs were enriched in proteins related to GTP binding, GTPase activity, and early endosome functions. These findings suggest that DUS extraction preserves greater MEV structural integrity. KEGG pathway enrichment analysis demonstrated that differentially expressed proteins from each extraction method exhibit distinct biological functionalities. These findings reveal that DUS extraction preserves superior structural integrity and functional capacity, while UC provides higher yield at the cost of increased contamination. This systematic framework enables researchers to align extraction strategy with specific applications, advancing both fundamental investigation of donkey milk bioactivities and industrial-scale production of therapeutically relevant EVs.

Bacterial extracellular vesicles (BEVs) are nanoscale, membrane-bound particles released constitutively by virtually all bacteria and serve as key mediators of host-microbiome communication. This review synthesizes current evidence on the biogenesis, molecular cargo, and functional roles of BEVs in the context of intestinal barrier regulation and gut-brain axis signaling, with emphasis on their contributions to neurodegenerative and metabolic diseases. We describe how BEVs from pathogenic bacteria disrupt intestinal barrier integrity by targeting tight junction proteins, activating pro-inflammatory PRR signaling, and inducing epithelial apoptosis, while BEVs from probiotic and commensal bacteria confer barrier protection, enhance mucin secretion, and promote immune homeostasis. Evidence is reviewed demonstrating that BEVs can traverse both the intestinal epithelium and the blood-brain barrier (BBB), delivering bioactive cargo—including LPS, bacterial amyloids, and regulatory RNAs—that promote neuroinflammation and aggregate pathology in Alzheimer's and Parkinson's disease models. Conversely, probiotic-derived BEVs exert neuroprotective effects through modulation of serotonergic signaling, BDNF expression, and anti-inflammatory pathways. The review further examines BEV roles in metabolic syndrome, MAFLD, and glucose homeostasis. Key translational challenges—including standardization of BEV isolation, large-scale production, and in vivo biosafety—are discussed alongside the promising therapeutic potential of engineered BEVs as vaccine platforms and drug delivery vehicles. A critical synthesis of evidence linking BEVs to specific neurological and metabolic disorders is provided, including a summary table of disease-specific findings to guide future mechanistic and clinical research.

Mastitis represents one of the most economically devastating diseases in dairy production, causing billions of dollars in annual losses through reduced milk quality and quantity. Recent advances in microbiome research have unveiled a critical gut–mammary axis that fundamentally influences mastitis susceptibility and pathogenesis in dairy cattle. Through comprehensive analysis of microbial communities across multiple anatomical sites, we demonstrate that mastitis development involves systematic disruption of both mammary and gastrointestinal microbiomes, characterized by reduced beneficial bacterial populations and increased pathogenic species. Healthy animals maintain balanced microbial ecosystems dominated by protective taxa including Firmicutes, Bacteroidetes, and beneficial Lactobacillus species, while mastitis-affected animals exhibit dysbiotic shifts toward Proteobacteria dominance, elevated Streptococcus and Staphylococcus populations, and compromised microbial diversity. Mechanistic investigations reveal that gut microbiota disruption compromises systemic immune competence, alters metabolite production including short-chain fatty acids and bile acids, and influences inflammatory mediators that circulate to mammary tissue. Therapeutic interventions targeting this axis, including probiotics, prebiotics, and plant-derived compounds, demonstrate significant efficacy in restoring microbiome homeostasis and reducing mastitis severity. These findings establish the gut–mammary axis as a fundamental regulatory mechanism in mastitis pathogenesis, opening new avenues for microbiome-based prevention and treatment strategies that could significantly enhance dairy health management while addressing antimicrobial resistance concerns.

This study investigated the effects of dietary mannan oligosaccharide (MOS) supplementation on growth performance, serum biochemistry, metabolomic profiles, and fecal microbiota in lactating Dezhou donkeys. Sixteen healthy jennies and their foals were randomly allocated to a control group (MCON), a group receiving no MOS, or an MOS-supplemented group (MMO; 0.5 g/kg diet) for 60 days. Compared with the MCON group, the MMO group showed a mitigation of lactational weight reduction, improved serum protein profiles, and favorable modulation of lipid metabolism. Furthermore, serum metabolomic analysis revealed 102 differentially abundant metabolites, which were enriched in 17 KEGG pathways involved in energy metabolism, bile secretion, and anti-inflammatory signaling. Key metabolites such as L-4-Chlorotryptophan, Gly-Trp, and cholylthreonine indicated enhanced nutrient metabolism and gut barrier function. Moreover, MOS supplementation significantly increased alpha diversity of the gut microbiota, altered community composition, and promoted the abundance of beneficial genera, including Clostridium and Bacteroides. Collectively, these results demonstrate that MOS supplementation improves metabolic health, modulates immune and antioxidant responses, and fosters a beneficial gut microbial ecosystem in lactating donkeys, suggesting its potential as an effective prebiotic in equine nutrition.

This review synthesizes research on nuclear factor erythroid 2-related factor 2 (Nrf2) in intestinal health across human, livestock, and mouse models. The Nrf2 signaling pathway serves as a master regulator of cellular antioxidant defenses and a key therapeutic target for intestinal inflammatory disorders, including ulcerative colitis and Crohn’s disease. The interplay between oxidative stress, Nrf2 signaling, and NF-κB inflammatory cascades represents a critical axis in the pathogenesis and resolution of intestinal inflammation. Under normal physiological conditions, Nrf2 remains sequestered in the cytoplasm by Kelch-like ECH-associated protein 1 (Keap1), which facilitates its ubiquitination and proteasomal degradation. However, during oxidative stress, reactive oxygen species (ROS) and electrophilic compounds modify critical cysteine residues on Keap1, disrupting the Keap1-Nrf2 interaction and enabling Nrf2 nuclear translocation. Once in the nucleus, Nrf2 binds to antioxidant response elements (ARE) in the promoter regions of genes encoding phase II detoxifying enzymes and antioxidant proteins, including heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), and glutamate-cysteine ligase. This comprehensive review synthesizes current evidence demonstrating that activation of Nrf2 signaling confers protection against intestinal inflammation through multiple interconnected mechanisms: suppression of NF-κB-mediated pro-inflammatory cascades, enhancement of cellular antioxidant capacity, restoration of intestinal barrier integrity, modulation of immune cell function, and favorable alteration of gut microbiota composition. We systematically examine a diverse array of therapeutic agents targeting Nrf2 signaling, including bioactive peptides, natural polyphenols, flavonoids, terpenoids, alkaloids, polysaccharides, probiotics, and synthetic compounds. The mechanistic insights and therapeutic evidence presented underscore the translational potential of Nrf2 pathway modulation as a multi-targeted strategy for managing intestinal inflammatory conditions and restoring mucosal homeostasis.

The objective of this study was to evaluate the effects of cage size on the natural behavior, serum biochemistry, production performance and hypothalamic transcriptome profiles of laying hens. A total of 360 79-week-old hens were selected and randomly assigned to three groups (with five replicates each) with different cage sizes: large cages (LCs), medium cages (MCs), and small cages (SCs). The stocking density remained consistent across all groups throughout the experimental period. Behavioral expression was evaluated through observation of only six birds per group on a weekly basis. Compared to the SC group, the average frequencies of walking, wing-flapping, feather-pecking and drinking significantly increased in the LC and MC groups (P <0.05), whereas the average frequency of stereotypic behavior significantly decreased (P <0.05), indicating that cage size has positive effects on natural behavior. The average daily step count (DSC) was in the order LC > MC > SC (P <0.05), which suggested an improvement in exercise ability in larger cages. The serum levels of MDA, CORT, AST and T-CH were significantly lower in the LC and MC groups than in the SC group (P <0.05), whereas the serum activities of SOD and GSH-Px were significantly greater (P <0.05). Additionally, compared to the SC group, the laying rates were increased by 1.61% and 2.20% (P <0.05), and the feed conversion ratio (FCR) were improved by 1.35% and 2.25%, respectively (P <0.05) in the LC and MC groups, respectively. In total, 437 and 81 differentially expressed genes (DEGs) were identified in the hypothalamus of birds between the LC and SC groups and the MC and SC groups, respectively. A majority of these DEGs were involved primarily in neuroactive ligand‒receptor interactions, focal adhesion and calcium signaling pathways, which are associated with the regulation of behavioral patterns, the stress response and follicular development. Our results suggest that an appropriate increase in cage size is beneficial to the natural behavior expression, health status and production performance of laying hens.

The growing recognition of the role of milk-derived exosomes in metabolic and immunological processes has brought attention to the potential utility of donkey milk. However, the efficacy and bioactive components of donkey milk are underexplored. This study aimed to elucidate the proteomic profiles of exosomes isolated from donkey colostrum and mature milk using advanced four-dimensional (4D) label-free quantitative proteomics. A comprehensive analysis identified and quantified a total of 2293 exosomal proteins from donkey milk, including 276 differentially expressed exosomal proteins (DEEPs). The results revealed marked proteomic differences between colostrum and mature milk exosomes, particularly in proteins associated with immune responses and metabolic pathways. Exosomal proteins derived from colostrum were found to be enriched in immune-modulatory factors and glycan-related pathways, which may contribute to the enhancement in neonatal immune system development. In contrast, exosomal proteins from mature milk were predominantly associated with metabolic processes and cellular senescence. Protein-protein interaction (PPI) analysis further suggested that specific exosomal proteins highly expressed in colostrum could serve as nutraceutical components with potential health benefits for humans. In conclusion, this study underscores the distinct proteomic features and potential physiological roles of exosomes from donkey colostrum versus mature milk.

The CRISPR/Cas9 system enables precise and efficient modification of eukaryotic genomes. Among its various applications, homology-directed repair (HDR) mediated knock-in (KI) is crucial for creating human disease models, gene therapy, and agricultural genetic enhancements. Despite its potential, HDR-mediated knock-in efficiency remains relatively low. This study investigated the impact of 5′ end PEG10 modification on site-specific integration of the target gene. The HEK293 cell line is considered a highly attractive expression system for the production of recombinant proteins, with the construction of site-specific integration cell lines at the AAVS1 locus enabling stable protein expression. This study investigated the impact of the 5′ end PEG10 modification on the site-specific integration of the target gene at the AAVS1 locus in the 293T cell line. Utilizing this 5′ end PEG10 modification resulted in a 1.9-fold increase in knock-in efficiency for a 1.8 kb target fragment, improving efficiency from 26% to 49%. An optimized system was utilized to successfully establish a high-expression, site-specific integration 293T cell line for TAT-Cas9-EGFP, providing a reliable resource of seed cells for subsequent protein production.

This review article highlights the surveillance of bacterial, viral, and parasitic diseases in donkey populations in China. Key findings highlight significant threats from Equine herpesviruses (EHV-8 and EHV-1), which cause encephalitis, abortion, and respiratory distress. Several parasitic infections including Giardia duodenalis, Cryptosporidium spp., Enterocytozoon bieneusi, and Toxoplasma gondii present important zoonotic concerns across multiple regions of China. Additionally, this review synthesizes current knowledge on donkey microbiota across various body sites and examines their functional significance in health and disease. The complex relationship between the microbiota and host health represents a critical area of research in donkeys. Recent molecular advancements have enhanced our understanding of the diverse microbial ecosystems inhabiting different body sites in donkeys and their profound impact on health outcomes. As single-stomach herbivores, donkeys possess complex microbial communities throughout their digestive tracts that are essential for intestinal homeostasis and nutritional processing. Significant variations in microbiota composition exist across different intestinal segments, with the hindgut displaying greater richness and diversity compared to the foregut. Beyond the digestive system, distinct microbial profiles have been characterized across various body sites including the skin, oral cavity, reproductive tract, and body secretions such as milk. The health implications of donkey microbiota extend to critical areas including nutrition, immune function, and disease susceptibility. Research demonstrates how dietary interventions, environmental stressors, and physiological states significantly alter microbial communities, correlating with changes in inflammatory markers, antioxidant responses, and metabolic functions. Additionally, specific microbial signatures associated with conditions like endometritis and respiratory disease suggest the potential for microbiota-based diagnostics and therapeutics. The identification of antibiotic-resistant strains of Proteus mirabilis and Klebsiella pneumoniae in donkey meat highlights food safety concerns requiring enhanced monitoring systems and standardized safety protocols. These findings provide a foundation for improved donkey healthcare management, including targeted disease surveillance, microbiota-based interventions, and protective measures for those working with donkeys or consuming donkey-derived products.

Macrophages are innate immune cells that extensively infiltrate and play a key role in the tumor microenvironment (TME). Tumor cell-secreted factors recruit monocytes into the TME, where they differentiate into tumor-associated macrophages (TAMs), which can polarize into distinct phenotypes: M1 and M2. M1 TAMs promote antitumor immunity through cytokine secretion and antigen presentation, whereas M2 TAMs support tumor progression by facilitating angiogenesis, invasion, and immune escape. Despite these dual roles, the specific mechanisms governing macrophage plasticity and polarization remain insufficiently understood. This review comprehensively summarizes the origin, polarization, and functional diversity of macrophages in the TME, with emphasis on pathways that regulate TAM-mediated immune responses. Furthermore, this article examines current TAM-targeted therapeutic strategies, including recruitment inhibition, phenotypic reprogramming, and the development of chimeric antigen receptor macrophages (CAR-Ms), as well as macrophage-based drug delivery and exosome therapy. By integrating recent advances in cell engineering and immunometabolism, this review highlights the translational potential of TAM-targeted therapies and their value in reshaping the immunosuppressive TME to enhance cancer immunotherapy.

Butyrate supplementation has gained considerable attention for its potential benefits in livestock, particularly concerning intestinal health and growth performance. This review synthesizes recent research on the diverse roles of butyrate, across various livestock species. As a short-chain fatty acid, butyrate is known for enhancing intestinal development, improving immune function, and modulating microbial diversity. Studies indicate that butyrate supports gut barrier integrity, reduces inflammation, and optimizes feed efficiency, especially during the critical weaning and post-weaning periods in calves, piglets, and lambs. Supplementation with butyrate in livestock has been shown to increase average daily gain (ADG), improve gut microbiota balance, promote growth, enhance gut health, boost antioxidant capacity, and reduce diarrhea. Additionally, butyrate plays a role in the epigenetic regulation of gene expression through histone acetylation, influencing tissue development and immune modulation. Its anti-inflammatory and antioxidant effects have been demonstrated across various species, positioning butyrate as a potential therapeutic agent in animal nutrition. This review suggests that optimizing butyrate supplementation strategies to meet the specific needs of each species may yield additional benefits, establishing butyrate as an important dietary additive for enhancing growth performance and health in livestock.

The growing interest in functional foods has directed scientific attention toward alternative milk sources, particularly camel and donkey milk, which have been traditionally consumed for their purported health benefits across diverse cultures. These milk sources possess unique nutritional profiles and bioactive compositions that differ substantially from conventional bovine milk. This review examines the current scientific understanding of the anti-inflammatory and antioxidant bioactivities of camel and donkey milk, exploring their bioactive constituents and therapeutic potential. Camel and donkey milk demonstrate notable antioxidant and anti-inflammatory properties that may exceed those of conventional milk sources. Key bioactive compounds include lactoferrin, lysozyme, immunoglobulins, bioactive peptides, vitamins C and E, and polyunsaturated fatty acids. Mechanistic studies reveal that milk from donkeys and camels suppresses inflammatory pathways through NF-κB inhibition, cytokine modulation (reducing IL-6, IL-1β, and TNF-α while enhancing IL-10), and antioxidant pathway activation via Nrf2-ARE signaling. Donkey milk exhibits particularly high lysozyme content and demonstrates significant immunomodulatory effects, while camel milk shows remarkable therapeutic potential in diabetes management, nephroprotection, and hepatoprotection. Preclinical studies demonstrate efficacy in treating oxidative stress-related disorders, inflammatory conditions, metabolic dysfunction, and tissue injury models. Altogether, the published data show that camel and donkey milk represent promising functional foods with significant antioxidant and anti-inflammatory bioactivities mediated through multiple molecular pathways. Their unique bioactive profiles offer therapeutic potential for various health conditions, warranting further clinical investigation and development as nutraceutical interventions.

BACKGROUND:Milk extracellular vesicles (mEVs) are emerging as important mediators in gut pathology and cancer management. These stable nanoscale vesicles contain bioactive cargos including microRNAs, proteins, and lipids that facilitate intercellular communication and offer therapeutic opportunities. SCOPE AND APPROACH:This review examines mEVs' role in gut health and cancer therapy, synthesizing recent evidence from 2021 to 2025 across various milk sources (camel, bovine, equine, ovine, human). KEY FINDINGS AND CONCLUSIONS:mEVs significantly enhance intestinal health by strengthening epithelial barriers, modulating immune responses, and improving gut microbiota composition. In colitis models, they reduce inflammation, improve intestinal integrity, and restore microbial balance. Additionally, mEVs show promising cancer treatment applications, functioning as natural anticancer agents and efficient drug delivery vehicles. Their biocompatibility, tumor-targeting capabilities, and ability to enhance therapeutic efficacy while reducing toxicity address key limitations of conventional therapies. mEVs represent a promising frontier in preventive and therapeutic interventions for gastrointestinal disorders and cancer, positioning them as valuable candidates for future clinical applications in food-based therapeutics and precision medicine.

The clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 nuclease (CRISPR-Cas9) system have emerged as a powerful tool for the targeted and efficient modification of eukaryotic genomes, enabling deletion, insertion, and site-directed mutation. In the context of agricultural and biomedical applications, CRISPR/Cas9-mediated genome editing in sheep and goats holds significant potential. This chapter aims to provide a comprehensive overview of the current technical status, research and development progress, and future prospects of genome editing in sheep and goats. Furthermore, we present a systematic introduction to the technique process of CRISPR/Cas9-mediated genome editing in these species, serving as a valuable reference for researchers in this field.

The gut microbiota plays an important role in the digestion, absorption, and metabolism of nutrients, as well as in the immunity, health, and behavior of donkeys. While reference genomes and gut microbial gene catalogs have been helpful in understanding the composition of the donkey, there is still a significant gap in sequencing and understanding the functional aspects of donkey gut microbial genomes. In this study, we analyzed metagenomic sequencing data from 26 donkeys’ gut samples and successfully assembled 844 microbial metagenome-assembled genomes (MAGs). Surprisingly, 678 (80.33%) of these MAGs appear to belong to previously unidentified species. Our analysis further revealed a total of 292,980 predicted carbohydrate-active enzymes (CAZymes) and 257,893 polysaccharide utilization loci (PULs). Interestingly, these enzymes and loci displayed relatively low similarity matches in public databases. We found that the higher abundances of 36 MAGs in the cecum (such as Prevotella, Desulfovibrio, Alistipes, and Treponema_D) and 9 MAGs in the dorsal colon (such as Limimorpha, Saccharofermentans, and Lactobacillus) were associated with a diverse array of carbohydrate-degrading pathways. Network analysis identified Prevotella and Dysosmobacter as connectors, while Saccharofermentans and Akkermansia were shown as provincial hubs. This suggests their crucial roles in complex carbohydrate degradation and hindgut metabolism in donkeys. These findings underscore the complexity of hindgut metabolism in donkeys and expand our understanding of their gut microbiome. Overall, this study provides a comprehensive catalog of donkey gut microbial genes, revealing novel carbohydrate-degrading enzymes and offering new insights for future research on the donkey gut microbiome.

Microorganisms in the rumen play a crucial role in determining the most efficient utilization rate of nutrients. Among these microorganisms, Prevotella stands out as one of the most representative bacteria within the rumen biological system. Prevotella is a common strict anaerobic bacterium that is found in the gastrointestinal tract of livestock. Prevotella plays a crucial role in breaking down and metabolizing complex nutrients like cellulose and protein during food digestion. Moreover, it is capable of working together with other bacteria in the body’s digestive system. Several studies have shown a strong correlation between the abundance of Prevotella and livestock growth performance. This paper provides a comprehensive review of the current research on the function, mechanisms, and applications of Prevotella in the gastrointestinal tract. The insights provided in this review could serve as a theoretical basis for accurately classifying Prevotella, further investigating its effects and potential mechanisms on livestock growth performance, and exploring its practical applications.

Considerable evidence suggests that the skin microbiota is not only important and complex in humans and other mammals but also critical for maintaining health and skin homeostasis. To date, studies on the skin microorganisms of donkeys are surprisingly rare. To investigate the dynamic changes in commensal microbial communities on the skins of healthy donkeys throughout the growing period, skin and soil samples were collected from 30 healthy Dezhou donkeys (ranging from 1, 6, 12, 24 to 48 months of age) and their corresponding breeding sheds on the farm. All samples were analysed for high-throughput sequencing of the 16S rRNA and ITS to characterize the skin microbiota of healthy donkeys and compare the differences in skin microbiota among donkeys of different ages. There were notable differences in the proportions of various genera (including bacteria and fungi) between dorsal and abdominal skin with increasing age. The comparison of the skin microbial communities among these groups revealed that Staphylococcus was mainly enriched in the early growing stage (1 and 6 months), while the relative abundance of Streptococcus was higher in both the 1- and 48-month-old age groups. Moreover, some bacteria and commensal fungi, such as Staphylococcus and Trichosporon, were found to be positively correlated between the skin and the environment. This is the first study to investigate the dynamic changes in skin microbiota diversity and composition in donkeys of different ages and at different sites of the body. Furthermore, this study provides insights into the dynamic alterations in skin microbes during a donkey’s growth and characterizes the profiles of bacterial and fungal communities across a donkey’s body regions (dorsal and abdomen).

Introduction Aflatoxins (AFT) identified as a Group 1 human carcinogen naturally contaminate various types of food and could increase the risk of hepatocellular carcinoma (HCC) through dietary intake. Chongqing municipality is located in Southwest China with subtropical monsoon climate which is conducive to AFT contamination in crops. However, the burden of HCC caused by the dietary exposure of the population in Chongqing to AFT has not been quantified. Methods The burden of HCC was estimated in terms of Disability Adjusted Life Year (DALY) using FDA-iRISK software. Dietary exposure to AFT in three food categories including grain and its products, nuts and seeds, and spices was assessed. Results The lifetime average daily dose (LADD) of AFT exposure for the population ranged from 2.40 to 8.25 ng/kg bw/day and 9.51 to 15.10 ng/kg bw/day at the mean and heavy (P95) AFT contamination levels, respectively. Among the three food categories, grain and its products contributed most to AFT exposure of the population. The estimated DALYs related to HCC induced by AFT were 162,000–556,000 and 641,000-1,020,000; the DALY rates were 6.47–22.20 and 25.59–40.72 per 100,000 persons per year; and the population attribution fractions (PAF) were 1.68–5.78% and 6.66–10.60%. Discussion Although the burden of HCC caused by dietary AFT was estimated to be relatively low among the population, the overall health burden might be underestimated owing to the uncertainties of this dataset. Thus, the overall health burden associated with AFT intake should still be of concern in further studies.