Gut microbiome structure and adrenocortical activity in dogs with aggressive and phobic behavioral disorders

Abstract

Accompanying human beings since the Paleolithic period, dogs has been recently regarded as a reliable model for the study of the gut microbiome connections with health and disease. In order to provide some glimpses on the connections between the gut microbiome layout and host behavior, we profiled the phylogenetic composition and structure of the canine gut microbiome of dogs with aggressive (n ¼ 11), phobic (n ¼ 13) and normal behavior (n ¼ 18). Hormones' determination was made through Radio Immuno-Assay (RIA), and next generation sequencing of the V3-V4 gene region of the bacterial 16S rRNA was employed to determine gut microbiome composition. Our results did not evidence any significant differences of hormonal levels between the three groups. According to our findings, aggressive behavioral disorder was found to be characterized by a peculiar gut microbiome structure, with high biodiversity and enrichment in generally subdominant bacterial genera (i.e. Catenibacterium and Megamonas). On the other hand, phobic dogs were enriched in Lactobacillus, a bacterial genus with known probiotic and psychobiotic properties. Although further studies are needed to validate our findings, our work supports the intriguing opportunity that different behavioral phenotypes in dogs may be associated with peculiar gut microbiome layouts, suggesting possible connections between the gut microbiome and the central nervous system and indicating the possible adoption of probiotic interventions aimed at restoring a balanced host-symbiont interplay for mitigating behavioral disorders.

Fecal microbiota in client-owned obese dogs changes after weight loss with a high-fiber-high-protein diet

“…While a relationship between the gut microbiome and obesity has been observed, it remains unclear as to how the gut microbiome contributes to the development of obesity, but proposed mechanisms include the production of short chained fatty acids (SCFAs), monosaccharides, and other bioactive molecules. These bacterial products may lead to an increase in dietary energy harvest (Turnbaugh et al, 2006), changes in lipid metabolism (Ghazalpour et al, 2016), changes in fat storage regulation (Bäckhed et al, 2004;Bäckhed et al, 2007), altered satiety (Arora, Sharma & Frost, 2011), and an increase in systemic low-grade inflammation via the interaction with either the enteric nervous system (Schwartz, 2000;Tehrani et al, 2012;De Lartigue, De La Serre & Raybould, 2011), the endocrine system (Mondo et al, 2020;Kirchoff, Udell & Sharpton, 2019;Scarsella et al, 2020), or the immune system (Cani et al, 2007;Cani et al, 2012).…”

Interplay between Neuroendocrine Biomarkers and Gut Microbiota in Dogs Supplemented with Grape Proanthocyanidins: Results of Dietary Intervention Study

“…However, this consideration deserves further evaluations. According to Mondo et al (2020) [53], aggressive dogs show a shift of fecal microbiota, with a reduction of Paraprevotellaceae and Mogibacteriaceae. Aggressive dogs also showed an increase of Catenibacterium and Megamonas, but not significant differences in fecal cortisol and testosterone was reported.…”

Best Practices for Microbiome Study Design in Companion Animal Research

“…The microbiota consists of the assembly of microorganisms belonging to different kingdoms [Prokaryotes (Bacteria, Archaea), Eukaryotes (e.g., Protozoa, Fungi, and Algae)], while "their theater of activity" includes microbial structures, metabolites, mobile genetic elements (e.g., transposons, phages, and viruses), and relic DNA embedded in the environmental conditions of the habitat." Gut microbiota can play key roles in many areas of host health, including development, digestion, behavior, immune system function (3)(4)(5)(6). Alterations in the composition of the gut microbiome have also been associated with certain health conditions, including obesity (7,8), diabetes (9,10), kidney disease (11,12), skin disorders (13), chronic enteropathy (14-16), immune mediated disorders (17,18), and allergies (19).…”

“…Understanding the role of an intervention on gut microbial health can have a far-reaching impact from veterinary medicine, the pet food and supplement industry, to consumer choices. For example, the aforementioned microbiome-associated health problems can be expensive and difficult to treat in companion animals, as well as greatly compromise the performance of animals engaged in work or competition (6,(27)(28)(29)(30). Specialized interventions that target microbial taxa associated with specific disorders are a plausible method to prevent and more effectively treat the root cause of some of these conditions but require further study and development.…”