Pyropia yezoensis porphyran alleviates metabolic disorders via modulating gut microbiota in high‐sucrose‐fed Drosophila melanogaster

Abstract BACKGROUND Prebiotics, such as algal polysaccharides, can be used to manage metabolic diseases by modulating gut microbiota. However, the effect of Pyropia yezoensis porphyran (PYP), a red algal polysaccharide, on gut microbiota has not been reported. Thus, the objective of this study was to determine effects of PYP on metabolic disorders caused by high sucrose (HS) and underlying mechanisms involved in such effects. RESULTS Biochemical analysis demonstrated that an HS diet increased triglyceride and circulating sugar contents (metabolic abnormalities) in Drosophila larvae. It also increased the relative abundance of harmful microbiota within the larvae as identified by 16S ribosomal DNA analysis. PYP supplementation at 25 and 50 g kg −1 equivalently reduced metabolic abnormalities in the HS group. Therefore, 25 g kg −1 PYP was selected to investigate its effects on the metabolic pathway and gut microbiota of larvae in the HS group. The activity of PYP in ameliorating metabolic abnormalities by reverse transcription quantitative real‐time polymerase chain reaction analysis was consistent with the expression trend of key factors involved in metabolism regulation. PYP reduced the relative abundance of bacteria causing metabolic abnormalities, such as Escherichia–Shigella and Fusobacterium , but increased the relative abundance of beneficial bacteria such as Bacillus and Akkermansia . However, PYP had no effect on triglyceride and circulating sugar contents in HS‐fed larvae treated with a mixture of antibiotics designed to remove gut microbiota. CONCLUSION PYP exhibits anti‐metabolic disorder activity by modulating gut microbiota, thereby supporting the development of PYP as a functional prebiotic derived from red algae food. Copyright © 2022 John Wiley & Sons, Ltd. © 2022 Society of Chemical Industry.