Project description:Background: More than 100 million Americans are living with metabolic syndrome, increasing their propensity to develop heart disease– the leading cause of death worldwide. A major contributing factor to this epidemic is caloric excess, often a result of consuming low cost, high calorie fast food. Several recent seminal studies have demonstrated the pivotal role of gut microbes contributing to cardiovascular disease in a diet-dependent manner. Given the central contributions of diet and gut microbiota to cardiometabolic disease, we hypothesized that novel microbial metabolites originating postprandially after fast food consumption may contribute to cardiometabolic disease progression. Methods: To test this hypothesis, we gave conventionally raised or antibiotic-treated mice a single oral gavage of a fast food slurry or a control rodent chow diet slurry and sacrificed the mice four hours later. Here, we coupled untargeted metabolomics in portal and peripheral blood, 16S rRNA gene sequencing, targeted liver metabolomics, and host liver RNA sequencing to identify novel fast food-derived microbial metabolites. Results: We successfully identified several metabolites that were enriched in portal blood, increased by fast food feeding, and essentially absent in antibiotic-treated mice. Strikingly, just four hours post-gavage, we found that fast food consumption resulted in rapid reorganization of the gut microbial community structure and drastically altered hepatic gene expression. Importantly, diet-driven reshaping of the microbiome and liver transcriptome was dependent on a non-antibiotic ablated gut microbial community. Conclusions: Collectively, these data suggest that single fast food meal is sufficient to reshape the gut microbial community yielding a unique signature of food-derived microbial metabolites. Future studies are warranted to determine if these metabolites are causally linked to cardiometabolic disease.
Project description:The parasitic amoeba, Neoparamoeba perurans is the causative agent of Amoebic Gill Disease in salmonids. The parasite has previously been reported to lose virulence during prolonged in vitro maintenance. In this study, the impact of prolonged culture on N. perurans virulence and its proteome was investigated. Three isolates of N. perurans maintained in culture for varying durations were compared. Two isolates, attenuated and virulent, had their virulence assessed in an experimental trial using Atlantic salmon smolts and their bacterial community composition was evaluated by 16S rRNA Illumina MiSeq sequencing. Soluble proteins were isolated from a newly acquired, virulent and attenuated N. perurans culture and were analysed using two-dimensional electrophoresis (2D PAGE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS). An experimental challenge trial using Atlantic salmon smolts confirmed a loss in virulence in an N. perurans culture that was maintained in vitro for 3 years. A greater diversity of bacterial communities was found in the microbiome of the virulent isolate harbouring predominant genera belonging to Pseudoaltermonas spp, Vibrio spp and Fluviicola spp. Microbial community richness was reduced in the attenuated microbiome, with a singular species, Thalassopira xiamenensis, representing a large proportion of its microbiome. A collated proteome database of N. perurans, Amoebozoa and four bacterial genera resulted in 24 proteins differentially expressed between the three cultures. The present LC-MS/MS results indicate protein synthesis, oxidative stress and the plausible occurrence of immunomodulation are ultimately upregulated in a newly acquired N. perurans culture and future studies may exploit these protein identifications for therapeutic purposes in infected farmed fish.