Probiotics have garnered escalating attention in the treatment and prevention of inflammatory disorders. In this study, Lactobacillus rhamnosus RL-H3-005 (RL5) and Pediococcus acidilactici RP-H3-006 (RP6), which possess anti-inflammatory effects and favorable probiotic attributes, were selected through the comparison of an RAW264.7 inflammatory cell model screening and in vitro probiotic properties. Subsequently, it was implemented in an animal model of dextran sulfate sodium (DSS)-induced colitis. The results demonstrated that RL5 and RP6 could inhibit the release of proinflammatory factors in RAW264.7 inflammatory cells and exhibited excellent environmental adaptability, adhesion, safety, and antibacterial activity. Additionally, RL5 and RP6 provided protective effects on the intestines of mice with acute colitis by reducing the levels of intestinal inflammation and oxidative stress. Concurrently, supplementation with RL5 and RP6 modulated the composition of the gut microbiota in mice. These discoveries suggest that RL5 and RP6 can be used as a novel probiotic for alleviating intestinal inflammation.

Atopic Dermatitis (AD) is a common inflammatory skin disease characterized primarily by its chronic and recurrent nature. This has a significant impact on productivity and human longevity. Dysbiosis of gut flora has been demonstrated to be significantly associated with the progression of AD. In our previous research, it was shown that Lactobacillus rhamnosus RL5-H3-005 (RL) and Pediococcus acidilactici RP-H3-006 (RP) have the ability to reduce the risk of disease in AD mice through the gut–mammary axis. Based on our previous work, this study aims to further investigate the effects of kynurenine (KYN), a metabolite of RL and RP, on AD mice induced by 2, 4-dinitrofluorobenzene (DNFB). In this study, we found that supplementing KYN in AD mice effectively alleviates the pathological symptoms of atopic dermatitis and further improves the levels of SCFAs in their intestines. Further research indicates that KYN’s therapeutic effects on AD are primarily manifested in the reduction of secretory immunoglobulin A (sIgA), immunoglobulin E (IgE), interleukin-4 (IL-4), IL-5, IL-13, and thymic stromal lymphopoietin (TSLP) levels in mice, while also repairing the intestinal barrier function of AD mice. Overall, the metabolites KYN of probiotics RL and RP can regulate the levels of SCFAs of mice, potentially improving the symptoms of AD mice through the gut–skin axis.

Atopic Dermatitis (AD) is a common inflammatory skin disease characterized primarily by its chronic and recurrent nature. This has a significant impact on productivity and human longevity. Dysbiosis of gut flora has been demonstrated to be significantly associated with the progression of AD. In our previous research, Lactobacillus rhamnosus RL5-H3-005 (RL) and Pediococcus acidilactici RP-H3-006 (RP) hold the potential to reduce the risk of AD in offspring via gut-mammary axis during the pregnancy and lactation period. Based on our previous work, this study aims to further investigate the effects of kynurenine (KYN), a metabolite of RL and RP, on AD mice induced by 2,4-dinitrofluorobenzene (DNFB). In this study, we discovered that supplementing KYN in AD mice effectively alleviates the pathological symptoms of atopic dermatitis and further improves the levels of SCFAs in their intestines. Further research indicates that KYN's therapeutic effects on AD are primarily manifested in the reduction of secretory immunoglobulin A (sIgA), immunoglobulin E (IgE), interleukin-4 (IL-4), IL-5, IL-13, and thymic stromal lymphopoietin (TSLP) levels in mice, while also repairing the intestinal barrier function of AD mice. Overall, the metabolites KYN of probiotics RL and RP can regulate the levels of SCFAs in mice, potentially improving the symptoms of AD mice through the gut-skin axis.

5-Fluorouracil (5-FU) is a first-line chemotherapeutic agent for solid tumors, but its clinical application is severely limited by dose-dependent intestinal injury that impairs patient quality of life and compromises therapeutic efficacy. Natural polysaccharides, especially marine-derived ones, have become safe and multi-targeted gut-protective candidates due to their excellent biocompatibility and prebiotic-like activities. Larimichthys crocea swim bladder is a characteristic marine biological resource, and its polysaccharides (CIPs) have shown potential bioactivities, yet their protective mechanism against 5-FU-induced intestinal injury remains unclear. Our study explored the protective effects of Larimichthys crocea swim bladder polysaccharides (CIPs) against 5-FU-induced intestinal injury in mice. Following 14-day preventive administration, CIPs alleviated 5-FU-induced body weight loss, diarrhea, colonic shortening, and mucosal injury, and restored goblet cell function. Mechanistically, CIPs enhanced intestinal barrier integrity by upregulating ZO-1, Occludin, and MUC2, suppressed the MyD88/NF-κB pathway to balance inflammatory cytokines, and ameliorated oxidative stress by regulating MDA, GSH, SOD, and CAT. CIPs also restored gut microbial diversity and the Firmicutes/Bacteroidota ratio, and modulated retinol and arginine metabolism. In vitro, CIPs reduced inflammation and oxidative damage in Caco-2 cells and promoted M2 macrophage polarization. Thus, CIPs alleviate 5-FU-induced intestinal injury via multi-targeted regulation of the gut–metabolic axis, showing great potential as a dietary intervention and gut health support agent in food science and oncology nutrition, and boosting the high-value utilization of marine resources.