Peptide iron chelate is widely regarded as one of the best iron supplements for relieving iron deficiency. In this study, a new type of walnut peptide iron (WP-Fe) chelate was prepared using low molecular weight walnut peptides (WP) as raw materials. Under the conditions of this study, the chelation rate and iron content of the WP-Fe chelate were 71.87 ± 1.60% and 113.11 ± 2.52 mg/g, respectively. Fourier transform infrared spectroscopy (FTIR), zeta potential, amino acid composition, and other structural analysis showed that WP-Fe is formed by the combination of carboxyl, amino and carbonyl with Fe²⁺. The WP-Fe chelate exhibits a honeycomb-like bulk structure different from that of WP. In addition, we predicted and established the binding model of ferrous ion and WP by molecular docking technology. After chelation, the free radical scavenging ability of the WP-Fe chelate was significantly higher than that of the WP. Overall, the WP-Fe chelate has high iron-binding capacity and antioxidant activity. We believe that peptides from different sources also have better iron binding capacity, and peptide iron chelates are expected to become a promising source of iron supplement and antioxidant activities.

Probiotics, as live microbial agents, play a pivotal role in modulating host microbiota balance, enhancing immunity, and improving gastrointestinal health. However, their application is hindered by critical challenges, such as inactivation during processing, storage, and gastrointestinal delivery, as well as low colonization efficiency. This article comprehensively reviews recent advances in probiotic delivery systems, focusing on innovative technologies, including hydrogels, nanocoatings, emulsions, and core–shell microgels. It provides an in-depth analysis of natural polyphenol-based nanocoatings and metal–phenolic network (MPN) single-cell encapsulation strategies for enhancing bacterial survival rates while highlighting the unique potential of microalgae-based bio-carriers in targeted delivery. Research demonstrates that well-designed edible delivery systems can effectively preserve probiotic viability and enable controlled intestinal release, offering novel strategies to reshape a healthy gut microbiome. While these systems show promise in maintaining probiotic activity and gut colonization, challenges remain in safety, scalable production, and clinical translation. Overcoming these barriers is crucial to fully harnessing probiotics for human health.

The human gut microbiome plays a central role in regulating host health, serving as a core hub for systemic physiological interactions. Dysregulation of the gut microbiome is implicated in a wide spectrum of local and systemic diseases. Research has evolved from establishing associations to elucidating the mechanistic roles of gut microbes and developing targeted strategies for their modulation, with a growing emphasis on their bidirectional communication with other organ systems. This review aims to synthesize current knowledge on the composition and function of the gut microbiome, its functional crosstalk with the host, and its integral role in both health and disease. A major focus is placed on critically evaluating the mechanisms, efficacy, and applications of key microbiome-directed interventions-probiotics, prebiotics, synbiotics, and postbiotics-in maintaining or restoring gut-centric ecological balance. The gut microbiome acts as a dynamic microbial organ essential for digestion, immune maturation, and metabolic homeostasis. Dysbiosis, characterized by a loss of beneficial microbes and an overgrowth of potential pathogens, is a critical factor in the pathogenesis of gastrointestinal disorders, metabolic diseases, and other systemic conditions. The gut microbiome engages in continuous bidirectional communication with distant organs, including the oral cavity, lungs, skin, and urinary tract, via specific axes (e.g., gut-oral, gut-lung, gut-skin), thereby exerting widespread influence on host physiology. Probiotics, prebiotics, synbiotics, and postbiotics represent complementary strategies to counteract dysbiosis and reestablish gut ecological integrity, ranging from introducing live beneficial bacteria to utilizing inactivated microbial cells and their bioactive metabolites. Enhancing the translational potential of these interventions requires deeper mechanistic insights and robust clinical validation.