Abstract
Tetrodotoxin (TTX) is a potent marine neurotoxin found in pufferfish, causing severe poisoning or death if consumed improperly. Studies have indicated that intestinal symbiotic microbiota are associated with the production and accumulation of TTX in pufferfish. However, the specific symbiotic microorganisms involved in these processes and their respective functions remain unclear. This study explored differences in intestinal microbiota related to the TTX content between toxic and non-toxic tiger puffer Takifugu rubripes. We found that the dominant phyla exhibiting significant abundance differences between the two groups were Proteobacteria and Bacteroidota, with the core bacterial genera being Rikenella, Vibrio, Photobacterium, and Bacteroides. Moreover, the genera Marinimicrobium, Idomarina, Galbibacter, and Brumimicrobium were reported for the first time to be potentially associated with TTX bioaccumulation in T. rubripes. In addition, an integrated analysis with our previous study indicated that the "ABC transporters" pathway may play significant roles in the production and transport of TTX in both symbiotic microorganisms and T. rubripes. This study preliminarily investigated the intestinal symbiotic bacteria associated with the accumulation and metabolism of TTX in T. rubripes, as well as screening potential microbial biomarkers for assessing the safety of pufferfish.