Marine fauna provides a plentiful repository of peptides and bioactive proteins. Peptides and proteins isolated from marine animals have been studied and applied in the development of food supplements, drugs, and cosmeceutical products because of their special bioactivities, such as anti-inflammatory and antioxidant effects This study focused on exploring the alleviating effects of five major marine animal-derived peptides (Apostichopus japonicus, Acaudina leucoprocta, Melanogrammus aeglefinus, Phascolosoma esculenta and Rhopilema esculentum) on adjuvant-induced arthritis (AIA). The treatment with five marine animals-derived peptides downregulated the expression levels of pro-inflammatory cytokines of IL-1β, IL-17 and TNF-α in the bones of the mice with AIA and alleviated the rough surface of bone tissues significantly. A. japonicus-treatment ameliorates inflammation by restoring NF-κB pathway in AIA mice. High-throughput sequencing of the gut microbiota based on 16S rRNA sequencing revealed that A. japonicus peptide-treated AIA mice showed alterations and imbalance of intestinal flora and an increased abundance of Lactobacillus and Clostridium. Furthermore, metabolomic analysis showed that the level of SCFAs in the feces was enhanced to different degrees in mice treated with five major marine animal-derived peptides. Taken together, we propose that major marine animal-derived peptides can alleviate arthritis by improving the imbalance in the gut flora and increasing SCFA production to varying degrees.

Fructose consumption has risen dramatically in recent decades due to the use of sucrose and high fructose corn syrup in beverages and processed foods, contributing to rising rates of hyperuricemia. The purpose of this experiment was to explore the anti-hyperuricemia effects of an active oligopeptide (GPSGRP) derived from sea cucumber in fructose induced hyperuricemia mouse model, and to clarify the underlying mechanism in sight of gut microbiota and serum metabolites. Peptide GPSGRP treatment rebalanced uric acid metabolism and alleviated inflammatory response in mice. In addition, treatment with GPSGRP decreased the abundance of Bacteroides and Proteobacteria at the phylum level, Muribaculum, Prevotella and Bacteroides at the genus level, and inhibited the related pathways of purine metabolism and glycolysis/gluconeogenesis metabolism. Moreover, serum metabolites, including linoleic acid, indole and its derivatives, arachidonic acid and uridine, as well as related metabolic pathways, such as tricarboxylic acid cycle, ketone production and sugar production, were altered in response to GPSGRP treatment. This study provides a valuable reference for the application and development of marine biological peptides in uric acid management.