Hierarchical modelling of immunoglobulin coated bacteria in dogs with chronic enteropathy shows reduction in coating with disease remission but marked inter-individual and treatment-response variability.

Lina María Martínez-López,Andrew P Woodward,Caroline Mansfield,Aaron Jex,Nathalee Prakash,Elizabeth Ann Washington,Thurid Johnstone,Julien R S Dandrieux,Alexandra Jazmin Roth-Schulze,Alexis Perez-Gonzalez,Franck Carbonero

doi:10.1371/journal.pone.0255012

Abstract

Chronic enteropathies are a common problem in dogs, but many aspects of the pathogenesis remain unknown, making the therapeutic approach challenging in some cases. Environmental factors are intimately related to the development and perpetuation of gastrointestinal disease and the gut microbiome has been identified as a contributing factor. Previous studies have identified dysbiosis and reduced bacterial diversity in the gastrointestinal microbiota of dogs with chronic enteropathies. In this case-controlled study, we use flow cytometry and 16S rRNA sequencing to characterise bacteria highly coated with IgA or IgG in faecal samples from dogs with chronic enteropathy and evaluated their correlation with disease and resolution of the clinical signs. IgA and IgG-coated faecal bacterial counts were significantly higher during active disease compared to healthy dogs and decreased with the resolution of the clinical signs. Characterisation of taxa-specific coating of the intestinal microbiota with IgA and IgG showed marked variation between dogs and disease states, and different patterns of immunoglobulin enrichment were observed in dogs with chronic enteropathy, particularly for Erysipelotrichaceae, Clostridicaceae, Enterobacteriaceae, Prevotellaceae and Bacteroidaceae, families. Although, members of these bacterial groups have been associated with strong immunogenic properties and could potentially constitute important biomarkers of disease, their significance and role need to be further investigated.

Highlights

Chronic enteropathy (CE) in dogs constitutes a group of disorders that results in gastrointestinal (GI) tract inflammation and persistent or recurrent gastrointestinal clinical signs; CE is often termed inflammatory bowel disease (IBD) when immunosuppressive therapy is required [1, 2]
One animal withdrew from the study, and only provided samples during active disease (CE 3) (S1 Table)
It has been suggested that younger dogs with less severe disease, and a predominance of large intestinal signs, are more likely to respond to elimination diet alone [13, 31], we did not observe a clear pattern, possibly due to the number of dogs included in the study (Table 1)

Summary

Introduction

Chronic enteropathy (CE) in dogs constitutes a group of disorders that results in gastrointestinal (GI) tract inflammation and persistent or recurrent gastrointestinal clinical signs; CE is often termed inflammatory bowel disease (IBD) when immunosuppressive therapy is required [1, 2]. CE is considered to be a frequent cause of veterinary consultation, due to a lack of clinical specificity classification is made retrospectively based more on the response to treatment rather than based on the pathogenesis of the disease; leading to the administration of treatments that, in some cases, are lengthy or produce a short-term remission and relapse of the clinical signs [2, 3]. In CE, it is considered that the triad of host genetics- immune system- microenvironment, dietary antigens, and the gastrointestinal flora, are closely related to the development of gastrointestinal inflammation [4]. Intestinal IgA is the predominant Ig isotype produced in the intestine, other Igs such as IgM and IgG can be produced, and relative levels of bacteria coated with Igs may correlate with the magnitude of the inflammatory response triggered by specific intestinal bacterial species [7]

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Results

Discussion

Conclusion