A standard calibration method based on a symmetric resistance network matrix for galvanic logging instruments.

An increasing number of measurement electrodes have been designed to satisfy the demand for high-resolution detection using galvanic logging technology in complex formations. The forward modeling response analysis of logging tools has important guiding significance in the design of galvanic logging tools. Based on a three-dimensional finite element numerical simulation method, we established a forward model of galvanic multi-electrodes in a complex formation. We also designed a symmetrical resistance network model of the formation with equivalent resistance between two electrodes. A symmetrical resistance network was derived using the balanced bridge method. The asymmetrical admittance matrix was extended to a symmetrical extended admittance matrix to realize a convenient calculation of the equivalent symmetrical resistance network in complex formations. Verification of the microcolumn-focused logging tool, with nine electrodes in a simulated standard well, and an evaluation of the degree of invasion in an actual oil well indicate that this calibration method can improve the measurement accuracy of galvanic logging instruments.

Study on the thermal behaviour of spontaneous combustion of open-pit minerals.

To study thermal behaviour during spontaneous combustion of an open-pit coal mine, mixed slag (coal, oil shale, and coal gangue) was taken as the research object. Laser thermal conductivity analyser and differential scanning calorimetry were used to test thermophysical parameters and heat release characteristics of the minerals. The parameters can be employed to calculate the apparent activation energy using the Arrhenius equation and evaluate the thermal behaviour of open-pit mixed slag. The results indicate that thermophysical parameters have stage characteristics. Thermal diffusivity and thermal conductivity of minerals, especially mixed slag, have a strong correlation with temperature. Heat flow of minerals exhibits five characteristic stages, and heat flow of the samples is consistent with the change in heating rate. During the heating process, thermal diffusivity and heat flow of the mixed slag are between those of a single mineral. Except for the mixed slag at 15 and 20 °C/min, the initial exothermic temperature of the other samples is mainly concentrated at 50-80 °C. Thermal energy release of the sample is mainly concentrated in the accelerated exothermic stage and rapid exothermic stage. Thermal energy release of mixed slag in rapid exothermic stage is always greater than that in accelerated exothermic stage, and the proportion of thermal energy release in these two stages exceeds 98 %. The apparent activation energy during the accelerated exothermic stage is lower, making it easier to release heat, and rapid exothermic stage is relatively high, which can readily lead to heat accumulation. Thermal analysis reveals that the thermal behaviour of mixed slag is significantly different from that of a single mineral. Its unique exothermic characteristics can provide a more accurate theoretical basis for the prevention and control of environmental pollution caused by slag spontaneous combustion.

The correlation between flavor formation and microbial community dynamics during the fermentation of zha cai.

BACKGROUND: Zha cai, a pickled vegetable with unique flavors, is produced by fermenting fresh mustard tubers. In this study, the main physicochemical indices and volatile flavor compounds were determined in three fermentation periods. The bacterial and fungal communities in the three fermentation periods of zha cai were also monitored using high-throughput sequencing. Key microbial communities were identified based on significant correlations with flavor substances. RESULTS: Firmicutes and Proteobacteria were the main bacterial phyla found within the three fermentation periods. Lactic acid bacteria, namely Lactobacillus, was the predominant bacteria found at the genus level. Ascomycetes and Stenotrophomonas were the major fungal phyla found in the three fermentation periods. Yeast, namely Debaryomyces, was the predominant fungus found at the genus level. A total of 42 bacterial genera were negatively correlated with volatile flavor substances of zha cai, and 37 bacterial genera were positively correlated. Meanwhile, a total of 47 genera of fungi were negatively correlated with the volatile flavor substances of zha cai, while 50 genera were positively correlated. Several microbial genera were significantly correlated with volatile flavor compounds, including Lactobacillus, Halomonas, Rhodococcus, and Debaryomyces. CONCLUSION: This study identified the microbial classes that positively regulate the flavor of zha cai which could provide valuable help for flavor modulation in zha cai production. © 2024 Society of Chemical Industry.

Mechanisms of probiotic modulation of ovarian sex hormone production and metabolism: a review.

Sex hormones play a pivotal role in the growth and development of the skeletal, neurological, and reproductive systems. In women, the dysregulation of sex hormones can result in various health complications such as acne, hirsutism, and irregular menstruation. One of the most prevalent diseases associated with excess androgens is polycystic ovary syndrome with a hyperandrogenic phenotype. Probiotics have shown the potential to enhance the secretion of ovarian sex hormones. However, the underlying mechanism of action remains unclear. Furthermore, comprehensive reviews detailing how probiotics modulate ovarian sex hormones are scarce. This review seeks to shed light on the potential mechanisms through which probiotics influence the production of ovarian sex hormones. The role of probiotics across various biological axes, including the gut-ovarian, gut-brain-ovarian, gut-liver-ovarian, gut-pancreas-ovarian, and gut-fat-ovarian axes, with a focus on the direct impact of probiotics on the ovaries via the gut and their effects on brain gonadotropins is discussed. It is also proposed herein that probiotics can significantly influence the onset, progression, and complications of ovarian sex hormone abnormalities. In addition, this review provides a theoretical basis for the therapeutic application of probiotics in managing sex hormone-related health conditions.

Antibacterial activity and mechanism of cell-free supernatants of Lacticaseibacillus paracasei against Propionibacterium acnes.

Propionibacterium acnes (P. acnes) is an anaerobic and gram-positive bacterium involved in the pathogenesis and inflammation of acne vulgaris. This study particularly focuses on the antimicrobial effect of Lacticaseibacillus paracasei LPH01 against P. acnes, a bacterium that causes acne vulgaris. Fifty-seven Lactobacillus strains were tested for their ability to inhibit P. acnes growth employing the Oxford Cup and double dilution methods. The cell-free supernatant (CFS) of L. paracasei LPH01 demonstrated a strong inhibitory effect, with an inhibition zone diameter of 24.65 ± 0.27 mm and a minimum inhibitory concentration of 12.5 mg/mL. Among the CFS, the fraction over 10 kDa (CFS-10) revealed the best antibacterial effect. Confocal laser scanning microscopes and flow cytometry showed that CFS-10 could reduce cell metabolic activity and cell viability and destroy the integrity and permeability of the cell membrane. A scanning electron microscope revealed that bacterial cells exhibited obvious morphological and ultrastructural changes, which further confirmed the damage of CFS-10 to the cell membrane and cell wall. Findings demonstrated that CFS-10 inhibited the conversion of triglycerides, decreased the production of free fatty acids, and down-regulated the extracellular expression of the lipase gene. This study provides a theoretical basis for the metabolite of L. paracasei LPH01 as a potential antibiotic alternative in cosmeceutical skincare products.

Gut microbiome-based therapies for alleviating cognitive impairment: state of the field, limitations, and future perspectives.

Cognitive impairment (CI) is a multifaceted neurological condition that can trigger negative emotions and a range of concurrent symptoms, imposing significant public health and economic burdens on society. Therefore, it is imperative to discover a remedy for CI. Nevertheless, the mechanisms behind the onset of this disease are multifactorial, which makes the search for effective amelioration difficult and complex, hindering the search for effective measures. Intriguingly, preclinical research indicates that gut microbiota by influencing brain function, plays an important role in the progression of CI. Furthermore, numerous preclinical studies have highlighted the potential of probiotics, prebiotics, fecal microbiota transplantation (FMT), and diet in modulating the gut microbiota, thereby ameliorating CI symptoms. This review provides a comprehensive evaluation of CI pathogenesis, emphasizing the contribution of gut microbiota disorders to CI development. It also summarizes and discusses current strategies and mechanisms centered on the synergistic role of gut microbiota modulation in the microbiota-gut-brain axis in CI development. Finally, problems with existing approaches are contemplated and the development of microbial modulation strategies as therapeutic approaches to promote and restore brain cognition is discussed. Further research considerations and directions are highlighted to provide ideas for future CI prevention and treatment strategies.

Exosomal circRNAs in gastrointestinal cancer: Role in occurrence, development, diagnosis and clinical application (Review).

Gastrointestinal cancer is frequently detected at an advanced stage and has an undesirable prognosis due to the absence of efficient and precise biomarkers and therapeutic targets. Exosomes are small, living­cell­derived vesicles that serve a critical role in facilitating intercellular communication by transporting molecules from donor cells to receiver cells. circular RNAs (circRNAs) are mis­expressed in a variety of diseases, including gastrointestinal cancer, and are promising as diagnostic biomarkers and tumor therapeutic targets for gastrointestinal cancer. The main features of exosomes and circRNAs are discussed in the present review, along with research on the biological function of exosomal circRNAs in the development and progression of gastrointestinal cancer. It also assesses the advantages and disadvantages of implementing these findings in clinical applications.

Understanding Hyperuricemia: Pathogenesis, Potential Therapeutic Role of Bioactive Peptides, and Assessing Bioactive Peptide Advantages and Challenges.

Hyperuricemia is a medical condition characterized by an elevated level of serum uric acid, closely associated with other metabolic disorders, and its global incidence rate is increasing. Increased synthesis or decreased excretion of uric acid can lead to hyperuricemia. Protein peptides from various food sources have demonstrated potential in treating hyperuricemia, including marine organisms, ovalbumin, milk, nuts, rice, legumes, mushrooms, and protein-rich processing by-products. Through in vitro experiments and the establishment of cell or animal models, it has been proven that these peptides exhibit anti-hyperuricemia biological activities by inhibiting xanthine oxidase activity, downregulating key enzymes in purine metabolism, regulating the expression level of uric acid transporters, and restoring the composition of the intestinal flora. Protein peptides derived from food offer advantages such as a wide range of sources, significant therapeutic benefits, and minimal adverse effects. However, they also face challenges in terms of commercialization. The findings of this review contribute to a better understanding of hyperuricemia and peptides with hyperuricemia-alleviating activity. Furthermore, they provide a theoretical reference for developing new functional foods suitable for individuals with hyperuricemia.

Mechanochemical-Assisted Extraction and Biological Activity Research of Phenolic Compounds from Lotus Seedpod (Receptaculum Nelumbinis).

To explore the feasibility of the mechanochemical-assisted extraction (MCAE) of phenolic compounds from lotus seedpod (Receptaculum Nelumbinis), a single-factor experiment combined with response-surface methodology (RSM) was used to optimize the extraction process. The results showed the optimal extraction conditions as follows: Li2CO3 as a solid reagent (25%), an extraction time of 80 min, liquid/solid ratio of 42.8 mL/g, and extraction temperature of 80.7 °C; and the maximum value of total phenolic content (TPC) was 106.15 ± 1.44 gallic acid equivalents (GAE)/g dry weight (DW). Additionally, the 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) were 279.75 ± 18.71, 618.60 ± 2.70, and 634.14 ± 7.17 µmol TE/g, respectively. Ultra-high pressure liquid chromatography combined with triple-time-of-flight mass spectrophotometry (UPLC-Triple-TOF/MS) analysis identified eight phenolic compounds mainly consisting of polyphenols and flavonoids. Moreover, the phenolic compounds showed potent inhibitory effects on both α-amylase and α-glucosidase, with inhibition rates of over 80%. Furthermore, the results showed different degrees of inhibition activity against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli, among which the inhibitory effect on the growth of B. subtilis was the best. This paper shows that the phenolic compounds have good biological activities, which provides a reference for the further exploitation of LSP.

Intestinal organoid technology and applications in probiotics.

The impacts of probiotics on maintaining the host's intestinal health have been extensively confirmed. Organoid technology revolutionizes intestinal health research by providing a unique platform to study the effects of probiotics. It overcomes challenges posed by animal models and 2D cell models in accurately simulating the in vivo environment. This review summarizes the development of intestinal organoid technology and its potential applications in intestinal health research as well as highlights the regulatory mechanisms of probiotics on intestinal health, which have been revealed using intestinal organoid technology. Furthermore, an overview of its potential applications in probiotic research has also been provided. This review aims to improve the understanding of intestinal organoid technology's applications in this field as well as to contribute to its further development.

Enhancing the performance of aqueous zinc ion battery cathodes with a floral spherical V5O12·6H2O/V6O13/CNT nanocomposite.

Aqueous zinc ion batteries (AZIBs) offer a promising approach for electrical energy storage, combining cost-effectiveness and enhanced thermal safety. However, the cathode material, vanadium oxide, while known for its excellent theoretical specific capacity, faces a challenge in terms of its poor electronic conductance. In this study, we present a novel strategy to address this limitation by constructing the V5O12·6H2O/V6O13/CNT (VOH/CNT) nanocomposite, resulting in significantly improved electrochemical performance. This nanocomposite was synthesized through a facile solvothermal method, yielding a unique floral spherical structure featuring a central cluster and multiple smaller groupings. The integration of CNTs into the composite significantly enhanced its electronic conductance, effectively mitigating the electronic conductance issue associated with vanadium oxide. Moreover, the composite retains crystalline water within its structure, playing a crucial role in providing a favorable ion-conductive pathway. Consequently, the VOH/CNT nanocomposite exhibits an impressive reversible capacity of 201 mA h g-1 at 50 mA g-1, surpassing that of VOH (116 mA h g-1). Remarkably, even at a high current density, the VOH/CNT nanocomposite demonstrates an exceptional capacity retention, maintaining a capacity of 150 mA h g-1 over 500 cycles at 1 A g-1. Its outstanding electrochemical performance can be attributed to its distinctive structural arrangement, the conductive network facilitated by CNTs, and the introduced crystalline water component.

An Update on the Pivotal Roles of Probiotics, Their Components, and Metabolites in Preventing Colon Cancer.

Diet, lifestyle, and gut microbiota composition are key risk factors for the progression of colon cancer. Probiotics are living microorganisms that can offer health benefits to the parasitifer when ingested in competent quantities. Several in vivo, in vitro, and clinical studies have demonstrated that probiotics can prevent and mitigate the development of colon cancer. The anti-colon cancer mechanisms of probiotics include the suppression of cell proliferation and the promotion of cancer cell apoptosis, immunomodulation, the modulation of intestinal microorganisms and their metabolism, strengthening the intestinal barrier, and antioxidant effects. This article describes the pathogenesis of colon cancer and the available therapeutic options. In addition, this paper reviews the mechanisms by which probiotics mitigate colon cancer as well as the mitigating effects of probiotic components and metabolites on colon cancer.

Non-coding RNAs' function in cancer development, diagnosis and therapy.

While previous research on cancer biology has focused on genes that code for proteins, in recent years it has been discovered that non-coding RNAs (ncRNAs)play key regulatory roles in cell biological functions. NcRNAs account for more than 95% of human transcripts and are an important entry point for the study of the mechanism of cancer development. An increasing number of studies have demonstrated that ncRNAs can act as tumor suppressor genes or oncogenes to regulate tumor development at the epigenetic level, transcriptional level, as well as post-transcriptional level. Because of the importance of ncRNAs in cancer, most clinical trials have focused on ncRNAs to explore whether ncRNAs can be used as new biomarkers or therapies. In this review, we focus on recent studies of ncRNAs including microRNAs (miRNAs), long ncRNAs (lncRNAs), circle RNAs (circRNAs), PIWI interacting RNAs (piRNAs), and tRNA in different types of cancer and explore the application of these ncRNAs in the development of cancer and the identification of relevant therapeutic targets and tumor biomarkers. Graphical abstract drawn by Fidraw.

Correlation between glycated hemoglobin A1c, urinary microalbumin, urinary creatinine, ß2 microglobulin, retinol binding protein and diabetic retinopathy.

BACKGROUND: Retinopathy is the most common microvascular disease of type 2 diabetes, and seriously threatens the life, health and quality of life of patients. It is worth noting that the development of diabetic retinopathy (DR) can be hidden, with few symptoms. Therefore, the preliminary screening of diabetic patients should identify DR as soon as possible, delay disease progression, and play a vital role in its diagnosis and treatment. AIM: To investigate the correlation between glycated hemoglobin A1c (HbA1c), urinary microalbumin (U-mALB), urinary creatinine (U-CR), mALB/U-CR ratio, ß2 microglobulin (ß2MG), retinol binding protein (RBP) and DR. METHODS: A total of 180 patients with type 2 diabetes mellitus attending the Second People's Hospital of Hefei from January 2022 to August 2022 were retrospectively enrolled by ophthalmologists. Based on whether they had combined retinopathy and its degree, 68 patients with diabetes mellitus without retinopathy (NDR) were assigned to the NDR group, 54 patients with non-proliferative DR (NPDR) to the NPDR group, and 58 patients with proliferative DR to the PDR group. General data, and HbA1c, mALB, ß2MG, RBP, mALB/U-CR and U-CR results were collected from the patients and compared among the groups. Pearson's correlation method was used to analyze the correlation between HbA1c, mALB, ß2MG, RBP, mALB/U-CR and U-CR indices, and multiple linear regression was applied to identify the risk factors for DR. Receiver operator characteristic (ROC) curves were also drawn. RESULTS: The differences in age, gender, systolic and diastolic blood pressure between the groups were not statistically significantly (P > 0.05), but the difference in disease duration was statistically significant (P < 0.05). The differences in fasting blood glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, and triglyceride between the groups were not statistically significant (P > 0.05). HbA1c in the PDR group was higher than that in the NPDR and NDR groups (P < 0.05). The levels of mALB, ß2MG, RBP, mALB/U-CR and U-CR in the PDR group were higher than those in the NPDR and NDR groups (P < 0.05). Multiple linear regression analysis showed that disease duration, HbA1c, mALB, ß2MG, RBP, mALB/U-CR and U-CR were risk factors for the development of DR. The ROC curve showed that the area under the curve (AUC) for the combination of indices (HbA1c + mALB + mALB/U-CR + U-CR + ß2MG + RBP) was 0.958, with a sensitivity of 94.83% and specificity of 96.72%, which was higher than the AUC for single index prediction (P < 0.05). CONCLUSION: HbA1c, mALB, mALB/U-CR, U-CR, ß2MG and RBP can reflect the development of DR and are risk factors affecting PDR, and the combination of these six indices has predictive value for PDR.

Targeting microbiota to alleviate the harm caused by sleep deprivation.

Sleep deprivation has become a common health hazard, affecting 37-58% of the population and promoting the occurrence and development of many diseases. To date, effective treatment strategies are still elusive. Accumulating evidence indicates that modulating the intestinal microbiota harbors significant potential for alleviating the deleterious impacts of sleep deprivation. This paper first reviews the effects of sleep deprivation on gastrointestinal diseases, metabolic diseases, and neuropsychiatric diseases, discussing its specific mechanisms of influence. We then focus on summarizing existing interventions, including probiotics, melatonin, prebiotics, diet, and fecal microbiota transplantation (FMT). Finally, we have discussed the advantages and limitations of each strategy. Compared with other strategies, probiotics showed a high potential in alleviating sleep deprivation-related hazards due to their reduced risk and high security. We suggest that future research should focus on the specific mechanisms by which probiotics mitigate the harms of sleep deprivation, such insights may unveil novel pathways for treating diseases exacerbated by insufficient sleep.

Immunogenetic polymorphisms predict therapeutic efficacy and survival outcomes in tumor patients receiving PD-1/PD-L1 blockade.

BACKGROUND: While immune checkpoint inhibitors (ICIs) demonstrate remarkable clinical responses, only a small subset of patients obtains benefits. Genes linked to the tumor immune system are confirmed to be critical for the treatment of ICIs, and their polymorphisms can contribute to ICI efficacy. Here, we examined the potential of immunogenetic variations to predict the efficacy and survival of the PD-1/PD-L1 blockade. METHODS: Cancerous patients receiving PD-1/PD-L1 blockade were recruited and followed up. Pivotal genes related to tumor-immunity were filtered through a protein-protein interaction network and the degree algorithm in Cytoscape. Finally, 39 genetic variants were genotyped through multiplex genotyping assays. Association analyses between variants and ICI efficacy and progression-free survival (PFS) were performed. RESULTS: Overall, 318 patients were ultimately enrolled. Hence, three immunogenetic variants were identified as predictors of PD-1/PD-L1 blockade response. Mutant alleles from ATG7 rs7625881, CD274 rs2297136, and TLR4 rs1927911 were all at increased risk of tumor progression following ICI therapy (OR: 1.475, 1.641, 1.462, respectively; P value: 0.028, 0.017, 0.027, respectively). Significant immunogenetic variants also attained similar trends in the PD-1 blockade, lung cancer, or lung cancer using PD-1 blockade subgroups. Furthermore, the mutant genotypes of CD274 rs2297136 (GG as the reference: HR: 0.50 (95%CI: 0.29-0.88), P value: 0.015) and TLR4 rs1927911 (AA as the reference: HR: 0.65 (95%CI: 0.47-0.91), P value: 0.012) indicated poorer PFS and were both independent prognostic factors. CONCLUSION: Immunogenetic polymorphisms, including ATG7 rs7625881, CD274 rs2297136, and TLR4 rs1927911, were first identified as potential predictors of response to PD-1/PD-L1 blockade in tumor patients.

Edible insects as ingredients in food products: nutrition, functional properties, allergenicity of insect proteins, and processing modifications.

Edible insect products contain high-quality protein and other nutrients, including minerals and fatty acids. The consumption of insect food products is considered a future trend and a potential strategy that could greatly contribute to meeting food needs worldwide. However, insect proteins have the potential to be allergenic to insect consumers. In this review, the nutritional value and allergy risk of insect-derived foods, and the immune responses elicited by insect allergens are summarized and discussed. Tropomyosin and arginine kinase are the most important and widely known insect allergens, which induce Th2-biased immune responses and reduced the activity of CD4+T regulatory cells. Besides, food processing methods have been effectively improving the nutrients and characteristics of insect products. However, limited reviews systematically address the immune reactions to allergens present in edible insect proteins following treatment with food processing technologies. The conventional/novel food processing techniques and recent advances in reducing the allergenicity of insect proteins are discussed in this review, focusing on the structural changes of allergens and immune regulation.

Metabolomics reveals the role of Lactobacillus plantarum SHY130 in hepatic metabolic regulation in a mouse model of type 2 diabetes.

BACKGROUND: Among type 2 diabetes (T2D) patients, the incidence rate of liver metabolic disorders is much higher than that in healthy subjects. It was observed in our previous research that diabetic symptoms were improved by Lactobacillus plantarum SHY130 (LPSHY130) isolated from yak yogurt in a murine model of T2D. This study sought to investigate the LPSHY130-mediated hepatic metabolic regulation in a murine model of T2D. RESULTS: Treatment with LPSHY130 improved liver function and pathological damage in diabetic mice. Untargeted metabolome analysis revealed that T2D-induced changes in 11 metabolites were regulated after LPSHY130 treatment, mainly involving purine metabolism, amino acid metabolism, and choline metabolism and pantothenate and coenzyme A biosynthesis pathways. In addition, correlation analysis indicated that hepatic metabolic changes can be adjusted by the intestinal microbiota. CONCLUSION: Overall, this study suggests that treatment with LPSHY130 relieves liver injury and regulates liver metabolism in a murine model of T2D, thus providing a theoretical basis for the use of probiotics as dietary supplements to regulate hepatic metabolic disorders associated with T2D. © 2023 Society of Chemical Industry.

Genome-wide association study of tuberculosis in the western Chinese Han and Tibetan population.

Tuberculosis (TB) remains a serious global public health threat. Accumulated evidence has demonstrated that human susceptibility to TB has a strong genetic basis. And different susceptibility single nucleotide polymorphisms (SNP) have been reported in different studies. To gain greater insight into the host susceptibility to TB, we perform a two-stage genome-wide association study to identify the susceptible loci of TB. In the discovery stage, 3116 (1532 TB patients and 1584 healthy controls) and 439 (211 TB patients and 228 healthy controls) individuals were genome-wide genotyped from a western Chinese Han and Tibetan population, respectively. Based on the additive genetic model, we discovered 14 and three independent loci that had potential associations with TB susceptibility in the Chinese Han and Tibetan populations, respectively (p < 1 × 10-5). Furthermore, we conducted an imputation-based meta-analysis on another two East Asia cohorts to replicate our findings. We identified one independent locus harbored by the human leukocyte antigen (HLA) class II genes that was genome-wide significantly associated with TB (lead SNP rs111875628 with a p-value of 2.20 × 10-9). Our findings suggest a novel mechanism of the interaction with the HLA class II genes and reinforce the importance of the HLA class II alleles in response to TB.

Identification and molecular mechanism of action of antibacterial peptides from Flavourzyme-hydrolyzed yak casein against Staphylococcus aureus.

Antibacterial peptides can be released from yak milk casein. To date, the amino acid sequences and mechanism of action of yak casein-derived antibacterial peptides remain unknown. The current study identified antibacterial peptides from yak casein and their molecular mechanism of action. Our results showed that yak α-casein, ß-casein, and κ-casein could be effectively hydrolyzed by Flavourzyme (Solarbio Science and Technology Co. Ltd.), and the 2-h hydrolysate showed the highest antibacterial rate of 43.07 ± 2.59% against Staphylococcus aureus. The 1,000 to 3,000 Da fraction accounted for 23.61% of the 2-h hydrolysate and had an antibacterial rate of 62.64 ± 4.40%. Three novel peptides with antibacterial activity were identified from this fraction, and the ß-casein-derived peptide APKHKEMPFPKYP showed the strongest antibacterial effect (half-maximal inhibitory concentration = 0.397 mg/mL). Molecular docking predicted that APKHKEMPFPKYP interacted with 2 important enzymes of Staph. aureus, dihydrofolate reductase and DNA gyrase, through hydrophobic, hydrogen bonding, salt bridge, and π-π stacking interactions. Our findings suggest that the yak casein-derived peptides may serve as a potential source of natural preservatives to inhibit Staph. aureus.