Gut Microbiomes Differ Among Dietary Types and Stool Consistency in the Captive Red Wolf (Canis rufus)

Abstract

Captive management of many wildlife species can be challenging, with individuals displaying health disorders that are not generally described in the wild population. Retrospective studies have identified gastrointestinal (GI) diseases, in particular inflammatory bowel disease (IBD), as the second leading cause of captive adult red wolf ( Canis rufus) mortality. Recent molecular studies show that imbalanced gut microbial composition is tightly linked to IBD in the domestic dog. The goal of the present study was to address two main questions: (1) how do red wolf gut microbiomes differ between animals with loose stool consistency, indicative of GI issues, and those with normal stool consistency and (2) how does dietary type relate to stool consistency and red wolf gut microbiomes? Fresh fecal samples were collected from 48 captive wolves housed in eight facilities in the United States and from two wild wolves living in Alligator River National Wildlife Refuge, NC, United States. For each individual, the stool consistency was categorized as loose or normal using a standardized protocol and their diet was categorized as either wild, whole meat, a mix of whole meat and kibble or kibble. We characterized gut microbiome structure using 16S rRNA gene amplicon sequencing. We found that red wolves with a loose stool consistency differed in composition than wolves with normal stool consistency, suggesting a link between GI health and microbiome composition. Diet was not related to stool consistency but did significantly impact gut microbiome composition; gut microbiome composition of wolves fed a kibble diet were significantly different than the gut microbiome composition of wolves fed a mixed, whole meat and wild diet. Findings from this study increase the understanding of the interplay between diet and GI health in the red wolf, a critical piece of information needed to maintain a healthy red wolf population ex situ .

Unveiling the Fecal Microbiota in Two Captive Mexican Wolf (Canis lupus baileyi) Populations Receiving Different Type of Diets

“…Significant difference was observed in the fecal microbiota between populations, where the Ocotal wolves showed greater specific richness, higher within samples diversity of OTUs, and more than twice bacterial genera in its core microbiota compared to Michilia wolves. Previous studies have documented that wolves and dogs fed with raw meat show Bacteroidetes (46.4%), Fusobacteria (30.5%), Firmicutes (13.4%), Proteobacteria (8.8%) and Actinobacteria (0.5%) as the most abundant fecal bacteria at phylum level [8][9][10]. These same phyla were recorded as part of the fecal microbiota in the two studied Mexican wolves' populations.…”

“…In this respect, providing an adequate diet to a large canine species is one of the most challenging aspects for conservation organizations, as most of the time it is far from the nutritional composition they obtain in their natural environment [7]. In several canine species (red wolf, gray wolf, and dogs), diet changes have shown microbiological diversity and abundance alterations due to the different type of available substrates to digest [8][9][10][11]. As the imbalance of the intestinal bacterial communities may, in some cases, be associated with severe negative health consequences for the host [12], conservation efforts for threatened species kept in captivity have included the analysis of the host's fecal microbiota to monitor their health and promote their survival [6,7,12].…”

Habitat Elevation Shapes Microbial Community Composition and Alter the Metabolic Functions in Wild Sable (Martes zibellina) Guts

“…The gut microbiota, a large, complex and diverse microbial community contained in animal gastrointestinal tracts, is widely recognized as a partner that forms coevolutionary association with its host [ 22 , 23 , 24 ]. Moreover, the microbiome in animal intestines also facilitates host’s nutritional acquisition, immune modulation and homeostasis in response to profound lifestyle changes [ 25 , 26 , 27 ].…”

Effect of Geography and Captivity on Scat Bacterial Communities in the Imperiled Channel Island Fox

“…Our results point to the influence that captivity can have on the fox immune system and subsequently the scat bacterial community. Reduced gut microbiome diversity can affect nutrient absorption and immune system function, ultimately affecting the overall health of the organism [4,29,90]. While there is some evidence that captive animals can gain back lost microbes upon release into the wild [30], carnivores have been shown to be more susceptible to losing microbial diversity in captivity [87] and there is evidence that it is more difficult to gain back wild microbes with an increasing number of generations in captivity [91,92].…”

“…This approach is burgeoning in the field of conservation biology, where anthropogenic effects such as habitat fragmentation [1] and increasing temperatures [2] have been shown to alter hostassociated microbial communities. Integrating microbiome research into conservation science is beneficial at multiple levels from health monitoring [3,4] to microbiome transplants in captive individuals [5,6]. Therefore, characterizing the current bacterial communities in endangered host species is crucial to identify future changes in microbial diversity.…”