Bowel Movement: Integrating Host Mobility and Microbial Transmission Across Host Taxa.

Arne Weinhold

doi:10.3389/fmicb.2022.826364

Abstract

The gut microbiota of animals displays a high degree of plasticity with respect to environmental or dietary adaptations and is shaped by factors like social interactions, diet diversity or the local environment. But the contribution of these drivers varies across host taxa and our ability to explain microbiome variability within wild populations remains limited. Terrestrial animals have divergent mobility ranges and can either crawl, walk or fly, from a couple of centimeters toward thousands of kilometers. Animal movement has been little regarded in host microbiota frameworks, though it can directly influence major drivers of the host microbiota: (1) Aggregation movement can enhance social transmissions, (2) foraging movement can extend range of diet diversity, and (3) dispersal movement determines the local environment of a host. Here, I would like to outline how movement behaviors of different host taxa matter for microbial acquisition across mammals, birds as well as insects. Host movement can have contrasting effects and either reduce or enlarge spatial scale. Increased dispersal movement could dissolve local effects of sampling location, while aggregation could enhance inter-host transmissions and uniformity among social groups. Host movement can also extend the boundaries of microbial dispersal limitations and connect habitat patches across plant-pollinator networks, while the microbiota of wild populations could converge toward a uniform pattern when mobility is interrupted in captivity or laboratory settings. Hence, the implementation of host movement would be a valuable addition to the metacommunity concept, to comprehend microbial dispersal within and across trophic levels.

Highlights

Microbial associations with animal hosts are ubiquitous and increasingly recognized as important factor for the understanding of host ecology and evolution (Shapira, 2016; Foster et al, 2017; Kolodny et al, 2020; Moeller and Sanders, 2020)
While insects have relatively simple and species poor gut microbiotas (Colman et al, 2012; Engel and Moran, 2013; Jones et al, 2013), most mammals are known for a highly diverse and host taxon specific gut microbiota, that often fits to the phylogenetic distance of the host (Groussin et al, 2017; Groussin et al, 2020; Kohl, 2020). Though this is believed to be the result of an adaptive evolution of mammalian clades for dietary specialization, such a framework does not fit well to the microbiota of birds or bats, which show high inter individual dissimilarity and little influence of host phylogeny (Davenport et al, 2017; Lutz et al, 2019; Song et al, 2020). With this manuscript I would like to highlight the role of host “movement” and mobility range as a neglected parameter explaining patterns in the microbiota of mammals, birds and insects and the potential transfer across host taxa
A major challenge in the investigation of the microbiota of wild animals is the lack of a clear framework of what can be expected when host species identity or geographic location are failing short to predict the observed variability within wild populations

Summary

Introduction

Microbial associations with animal hosts are ubiquitous and increasingly recognized as important factor for the understanding of host ecology and evolution (Shapira, 2016; Foster et al, 2017; Kolodny et al, 2020; Moeller and Sanders, 2020). Host aggregations reduces spatial scale and directly influence probability of inter-host transmissions, while host foraging movements could extend microbial acquisition range or increase microbial dispersal across different habitats. With this manuscript I would like to highlight the role of host “movement” and mobility range as a neglected parameter explaining patterns in the microbiota of mammals, birds and insects and the potential transfer across host taxa.

Results

Conclusion