Changes of the intestinal microbiota along the gut of Japanese Eel ( Anguilla japonica )

Abstract

Fish intestine contains different types of microbiomes, and bacteria are the dominant microbiota in fishes. Studies have identified various core gut bacteria in fishes. However, little is known about the composition and their relative functions of gut microbial community along the intestine. To explore this, the current study investigated the microbial community distribution along the gut in Anguilla japonica. By 16S rRNA gene sequencing, we profiled the gut microbiota in eel along the three regions (anterior intestine (AI), the middle intestine (MI) and the posterior intestine (PI)). Results suggested that the three regions did not have significant differences on the observed species and diversities. The cluster tree analysis showed that the bacteria community in MI was closer to PI than the AI. The dominant bacteria in AI were the Proteobacteria, in which the majority was graduated replaced by Bacteroidetes along the gut to PI region. Through PICRUSt analysis, shifts in the bacterial community along the gut were found to affect the genetic information processing pathways. Higher levels of translation and transcriptional pathway activities were found in MI and PI than in AI. The dominant bacterial species were different among the regions and contributed to various biological functions along the gut.

Are fecal samples an appropriate proxy for amphibian intestinal microbiota?

“…The intestinal tract is a complex ecosystem that drastically differs across sections in terms of chemistry, physical structure, enzymatic activities, and immune system activity. As a result, a distinct microbiota inhabits each intestinal section, a phenomenon well documented in humans (Donaldson et al, 2016;Thursby & Juge, 2017;Vaga et al, 2020), other mammals (Anders et al, 2021;Gu et al, 2013;Kohl et al, 2018;Yang et al, 2020), fish (Zhu et al, 2021), birds (Choi et al, 2014), and reptiles (Kohl et al, 2017). Since the microbiota is heterogeneous along the intestinal tract, it is impossible for feces to mirror the microbiota of each section.…”

Impact of environmental micropollutants and diet composition on the gut microbiota of wild european eels (Anguilla anguilla)

“…marmorata (Lin et al, 2019), the Indonesian shortfin eel A. bicolor (Kusumawaty et al, 2020), and the Japanese eel A. japonica (Zhu et al, 2021).…”