Species Characteristics of and Interactions Between Large Herbivore Nemabiomes, Microbiomes, and Diets

Abstract

The relationship between host microbes and nematodes is just beginning to be understood; with, in some cases, nematodes appearing to exert antimicrobial activity and, in others, potentially causing bacterial disease to be worsened. Most of these studies are done in two ways: 1) studying the effects of one nematode on one pathogenic microbe or the microbiome as a whole or 2) treating all nematodes as equal and broadly studying the affects of nematodes on pathogenic disease or microbiome. Both of these methodologies are inherently limiting and do not allow for interactions between multiple nematodes and multiple pathogenic microbes or don’t account for differences across difference species of nematodes. In this study, full community sequencing of nemabiome and microbiome is utilized in order to understand what species characteristics may drive differences in nemabiome and microbiome (body size, water dependence, gut anatomy, and digestive system type) and how nemabiome and microbiome may be interacting with each other. Additionally, focus on nematode size as a potential modulator of interactions between nemabiome and microbiome is brought to the table. In this analysis, host species with larger sized nematodes were observed to have less diverse microbiomes. Further, individual hosts with larger nematodes were observed to have pathogenic microbes take up a larger proportion of their gut. With species characteristics, no correlation between host size and average nematode size was observed, preliminary evidence that domestication status and gut anatomy may correlate with average nematode size was shown. Further, an exploration of whether a connection between diet composition and nemabiome. Is formed, and in particular, if a proportion of grass in diet affects alpha-diversity metrics of nemabiome. Evidence for a connection between diet composition and nemabiome was found; however, no correlation between grass consumption and alpha-diversity metrics of nemabiome was observed. Finally, an exploration of the current landscape of surveillance is performed, arguing for integration of multi-host microbiome and nemabiome monitoring into the paradigm of surveillance.