As an important functional protein resource in dairy products, milk protein has become a research hotspot due to its excellent nutritional value and multiple biological activities. Recent studies have made breakthrough progress in the preparation and functional analysis of milk protein-derived peptides. There are various bio-processing methods to precisely release bioactive peptides with specific functions from milk protein, such as directed enzymatic hydrolysis and controlled fermentation. These active components demonstrate significant health benefits in antioxidant defense, pathogen inhibition, immune homeostasis regulation, and blood pressure control. This paper systematically reviews the technologies for the preparation of milk protein-derived peptides, including enzymatic hydrolysis, microbial fermentation, chemical synthesis and computer simulation and prediction techniques, and conducts a comparative analysis the effectiveness and characteristics of these technologies. Furthermore, it elucidates the mechanisms by which milk protein-derived peptides exert their biological activities and their bioavailability, and evaluates their potential for application in functional foods and pharmaceutical formulations. By integrating existing research findings, this review provides a scientific basis for optimizing the production process of milk proteinderived peptides and expanding their application scenarios, thereby promoting their industrial development.

Marginal zinc deficiency (MZD) affects immunity, growth, and development in children. Therefore, effective interventions using food-derived functional components to enhance immunity are required. Although the immunomodulatory effects of bioactives, such as LF, colostrum, and yeast β-glycan have been previously established, their combined effects on MZD is unknown. Therefore, the systemic regulatory effects of a lactoferrin-based MZD formulation were investigated in this study. To establish a MZD model, weaned Sprague–Dawley rats were fed a diet containing 10 mg/kg zinc for 5 weeks. The rats were administered a lactoferrin-based formulation via oral gavage. Compared with the control group, zinc deficiency significantly affected body weight gain, femur development, organ index, NK cell activity, splenic lymphocyte proliferation, and cytokine levels. These indicators significantly improved after the lactoferrin-based formulation intervention. The high-concentration lactoferrin formulation (LFC_high) group showed the most significant recovery compared with that of the other groups. The NK cell activity increased from 12.25% in the Model group to 34.50% in the LFC_high group, and splenic lymphocyte proliferation increased from 9.30% in the Model group to 17.31% in the LFC_high group. Furthermore, the lactoferrin-based formulation effectively regulated the gut microbiota, increasing the abundance of beneficial bacteria and decreasing the relative abundance of harmful bacteria. These preclinical findings provide a foundation for exploring interventions to address MZD and future research on targeted nutritional strategies.

Functional proteins in milk, including α-lactalbumin, β-lactoglobulin, lactoferrin, lactoperoxidase, β-casein and milk fat globule membrane protein, have been reported to have important physiological functions and play important roles in human health and thus, they have attracted widespread attention from researchers and manufacturers. However, there is a bottleneck for the development of techniques for the separation of functional proteins from milk, which restricts their industrial production and practical application. In this paper, the mature techniques for the separation and purification of six functional proteins from milk are summarized, with special reference to their application conditions and experimental scale, in order to provide a basis the separation and purification of functional proteins from milk in laboratories and factories and the development of new functional milk protein products.

As the global population is aging, elderly individuals are increasingly facing significant health challenges, especially mental health issues such as emotional problems, sleep disturbance, and cognitive impairment. Probiotics, defined as live microorganisms that confer health benefits upon the host, have emerged as an effective means to improve the mental health of the elderly. Studies have shown that the gut microbiota regulates brain development and behavior in older adults through the gut-brain axis. This article focuses on summarizing the characteristics of the nervous system in the elderly and its connection to the gut microbiota, the characteristics of the gut microbiota in older individuals, and the mechanisms underlying the regulation of the nervous system in the elderly by the gut-brain axis. It also discusses recent advancements in understanding the role of probiotics in improving mental health conditions of the elderly, such as mild cognitive impairment, insomnia, depression, and Alzheimer’s disease, with the aim of providing a theoretical basis for the clinical application of probiotics and the management of mental health in older adults.

Ciprofloxacin (CIP) is an antibiotic used to treat infections caused by bacteria. In this experiment, key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4 was researched under CIP stress. The results showed that the activities of hexokinase, pyruvate kinase, β-galactosidase and Na⁺, K⁺-ATPase after 1/2 minimum bacteriostatic concentration (MIC) CIP treatment were significantly decreased (P < 0.01). Gas chromatography-mass spectrometry was used to analysis the changes of main metabolites in the cells and principal component analysis and partial least square model were constructed. The results indicated that CIP could cause changes in intracellular fatty acids, carbohydrates and amino acids, and the mechanism of amino acid metabolism under CIP stress was significantly inhibited. L. plantarum DNZ-4 made stress response to CIP by regulating the ratio of saturated fatty acids and unsaturated fats. This experiment revealed the changes of growth and metabolism mechanism of L. plantarum DNZ-4 under CIP stress, which help to provide technical means for the development of effective probiotics preparation products.