Host Age Affects the Development of Southern Catfish Gut Bacterial Community Divergent From That in the Food and Rearing Water

Abstract

Host development influences gut microbial assemblies that may be confounded partly by dietary shifts and the changing environmental microbiota during ontogenesis. However, little is known about microbial colonization by excluding dietary effects and compositional differences in microbiota between the gut and environment at different ontogenetic stages. Herein, a developmental gut microbial experiment under controlled laboratory conditions was conducted with carnivorous southern catfish Silurus meridionalis fed on an identical prey with commensal and abundant microbiota. In this study, we provided a long-term analysis of gut microbiota associated with host age at 8, 18, 35, 65, and 125 day post-fertilization (dpf) and explored microbial relationships among host, food and water environment at 8, 35, and 125 dpf. The results showed that gut microbial diversity in southern catfish tended to increase linearly as host aged. Gut microbiota underwent significant temporal shifts despite similar microbial communities in food and rearing water during the host development and dramatically differed from the environmental microbiota. At the compositional abundance, Tenericutes and Fusobacteria were enriched in the gut and markedly varied with host age, whereas Spirochaetes and Bacteroidetes detected were persistently the most abundant phyla in food and water, respectively. In addition to alterations in individual microbial taxa, the individual differences in gut microbiota were at a lower level at the early stages than at the late stages and in which gut microbiota reached a stable status, suggesting the course of microbial successions. These results indicate that host development fundamentally shapes a key transition in microbial community structure, which is independent of dietary effects. In addition, the dominant taxa residing in the gut do not share their niche habitats with the abundant microbiota in the surrounding environment. It's inferred that complex gut microbiota could not be simple reflections of environmental microbiota. The knowledge enhances the understanding of gut microbial establishment in the developing fish and provides a useful resource for such studies of fish- or egg-associated microbiota in aquaculture.

Spatiotemporal successions of shrimp gut microbial colonization: high consistency despite distinct species pool

“…Under these premises, discriminatory populations relating to life stage in shrimp gut are differed from these in rearing bacterioplankton communities. This pattern could be affected by, or attributed to, the effect of host selection, which supports the notion that host gut microbial community is not a simple mirror of their rearing environmental counterparts (Burns et al, 2016;Li et al, 2017;Zhang et al, 2018;Xiong et al, 2018a). Instead, shrimp selects specific bacteria (independent of their abundances in environmental pool) at a given life stage (Walke et al, 2014).…”

“…Intriguingly, a high stratification accuracy (95.5%) of shrimp life stages was achieved by using profiles of the top four gut age-discriminatory genera as independent variables (Figs. This pattern could be affected by, or attributed to, the effect of host selection, which supports the notion that host gut microbial community is not a simple mirror of their rearing environmental counterparts (Burns et al, 2016;Li et al, 2017;Zhang et al, 2018;Xiong et al, 2018a). By contrast, the four genera in water did not contribute comparable stratification accuracy for bacterioplankton communities.…”

Quantitative PCR Analysis of Gut Disease-Discriminatory Phyla for Determining Shrimp Disease Incidence

“…This assertion agrees with data from previous studies in which the gut microbial communities are distinct during shrimp ontogenesis (13,20,28) and from rearing water (8,9,11). Similarly, the gut microbiota of catfish undergoes significant temporal shifts, despite the fact that rearing water microbial communities remain constant during host development (26).…”

“…The gut bacterial communities exhibited high temporal dynamics as healthy shrimp aged (Fig. 1A), mirroring what has been observed in fishes (25)(26)(27). Additionally, the gut bacterial communities are markedly affected by the occurrences of shrimp disease (Fig.…”

Thermal processing of food reduces gut microbiota diversity of the host and triggers adaptation of the microbiota: evidence from two vertebrates

“…However, the downfall is intrinsic to thermal processing of food, and it occurs in sequencing based on microbial ecology studies. In general, small proportions of gut microbiota were derived from the microbiota present in food and other surrounding environments, which has been documented in some studies focusing on different animals [ 26 , 27 ]. This is also supported by dramatic differences in microbial abundances and compositions between the two animals’ gut and their foods in the present study.…”