Mud crab, one of the aquatic organisms found in estuary areas, has become a significant economic source of seafood for communities due to its delectable taste. However, they face the threat of heavy metal contamination, which may adversely affect their biological traits. This study explored the comparison of the mud crabs collected from Setiu Wetland as a reference site, while Kuala Sepetang is an area that contains a higher concentration of heavy metals than Setiu Wetlands. Heavy metal levels were quantified using inductively coupled plasma mass spectrometry (ICP-MS), while proteomes were assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 1H nuclear magnetic resonance (NMR)-based metabolomics, respectively. Heavy metal contamination affects the proteome, metabolome, and putative molecular targets in mud crabs (Scylla olivacea), leading to oxidative stress. Mud crabs collected from the metal-polluted area of Kuala Sepetang in Perak had considerably elevated concentrations of nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), chromium (Cr), and cadmium (Cd) in comparison to the reference site of Setiu Wetlands in Terengganu. The proteome analysis revealed an upregulation of the stress-response protein Hsp70, which triggered superoxide dismutase (SOD) and increased arginine kinase expression (5.47 fold) in the muscle tissue, results in the alteration of metabolite regulation in the mud crab from Kuala Sepetang. Additionally, in the muscle tissues of mud crabs obtained from Kuala Sepetang, uncharacterized myosin-tail 1 domain proteins and sarcoplasmic calcium-binding proteins were downregulated. The metabolomic investigation identified changes in metabolites associated with energy metabolism and osmoregulation. Exploration of docking analysis suggests potential connections between methylarsonic acid and essential proteins in mud crabs. These findings suggest that the presence of heavy metals disrupts physiological processes and highlights potential molecular targets that warrant further investigation.
The fucoidan extract from Sargassum binderi, a brown algae-derived marine polysaccharide, is rich in fucose, and are a potent candidate for functional food, and nutraceutical applications. This study uniquely investigated the prebiotic potential of S. binderi fucoidan through in vitro simulated digestion and human fecal fermentation. The fucoidan extract demonstrated higher resistance to simulated upper gastrointestinal digestion (88.27 %) than inulin (81.13 %), allowing a substantial portion to reach the colon, which was metabolized by gut microbiota into beneficial metabolites. Fucoidan selectively modulated the gut microbiome by increasing the relative abundance of Megamonas and decreasing Bacteroides. Our current findings proved that the Megamonas enrichment, a carbohydrate-fermenting genus, contributed to a substantial rise in short-chain fatty acid (SCFA) production, including butyric acid (10.24-fold), acetic acid (5.89-fold), and propionic acid (4.92-fold), higher than those produced by inulin, indicating a strong butyrogenic effect. These microbiome shifts and enhanced SCFA production suggest that S. binderi fucoidan may help maintain gut microbiome balance. Overall, the current findings highlight the potential of S. binderi-derived fucoidan to formulate functional foods with a butyrogenic effect, for promoting gut health.