Comparison of the Gut Microbiome between Atopic and Healthy Dogs—Preliminary Data

Abstract

Human studies show that in addition to skin barrier and immune cell dysfunction, both the cutaneous and the gut microbiota can influence the pathogenesis of atopic diseases. There is currently no data on the gut-skin axis in allergic canines. Therefore, the aim of this study was to assess the bacterial diversity and composition of the gut microbiome in dogs with atopic dermatitis (AD). Stool samples from adult beagle dogs (n = 3) with spontaneous AD and a healthy control group (n = 4) were collected at Days 0 and 30. After the first sampling, allergic dogs were orally dosed on a daily basis with oclacitinib for 30 days, and then re-sampled. Sequencing of the V3–V4 region of the 16S rRNA gene was performed on the Illumina MiSeq platform and the data were analyzed using QIIME2. The atopic dogs had a significantly lower gut microbiota alpha-diversity than healthy dogs (p = 0.033). In healthy dogs, a higher abundance of the families Lachnospiraceae (p = 0.0006), Anaerovoracaceae (p = 0.006) and Oscillospiraceae (p = 0.021) and genera Lachnospira (p = 0.022), Ruminococcustorques group (p = 0.0001), Fusobacterium (p = 0.022) and Fecalibacterium (p = 0.045) was seen, when compared to allergic dogs. The abundance of Conchiformibius (p = 0.01), Catenibacterium spp. (p = 0.007), Ruminococcus gnavus group (p = 0.0574) and Megamonas (p = 0.0102) were higher in allergic dogs. The differences in alpha-diversity and on the compositional level remained the same after 1 month, adding to the robustness of the data. Additionally, we could also show that a 4-week treatment course with oclacitinib was not associated with changes in the gut microbiota diversity and composition in atopic dogs. This study suggests that alterations in the gut microbiota diversity and composition may be associated with canine AD. Large-scale studies preferably associated to a multi-omics approach and interventions targeting the gut microbiota are needed to confirm these results.

Distinct healthy and atopic canine gut microbiota is influenced by diet and antibiotics

“…Some allergy-associated gut microbial signatures have been identified in humans, either preceding the disease [49,50] or after the onset of the disease [51][52][53]. Information on how and which gut microbes are associated with allergy or atopy (AD) in dogs is scarce and from small samples [25,26].…”

“…Concurrently, allergy prevalence among dogs seems to be increasing [ 24 ]. The differences in the gut microbiota between atopic and healthy dogs are not widely studied [ 25 , 26 ], in particular considering the concurrent effect of diet. Similarly to humans [ 27 ], diet plays a dominant role in affecting gut microbial compositions also in pet dogs [ 28 ].…”

Bacterial composition changes in canine plaque over periodontal disease severity and daily care practices

“…They are known as multicellular longitudinal division species (MuLDi), where cells divide perpendicularly to the growth direction and remain interconnected. This unique evolution is likely to suit specific conditions in the oral cavity for the bacterium [36][37][38][39] . The reduced presence of Conchiformibius as PD worsened indicates that the genus may have difficulty adjusting to the environmental alterations brought by progression in PD.…”

Out with the old, in with the new: What's up with Simonsiella spp.?

“…10 In contrast, dogs with atopic dermatitis had a higher abundance of Conchiformibius in their feces than healthy controls. 11 Although Neisseriaceae found in osteoarticular infection in foals were closely related to Simonsiella and Alysiella, they were not reported to have MuLDi morphology. 12 Further studies are likely to reveal additional clinically relevant differences.…”