Characterization of the gastrointestinal microbiome of the Syrian hamster (Mesocricetus auratus) and comparison to data from mice

Syrian hamsters (Mesocricetus auratus) have been increasingly used as rodent
models in recent years, especially for SARS-CoV-2 since the pandemic.
However, the physiology of this animal model is not yet well-understood,
even less when considering the digestive tract. Generally, the gastrointestinal
microbiome influences the immune system, drug metabolism, and vaccination
efficacy. However, a detailed understanding of the gastrointestinal microbiome
of hamsters is missing. Therefore, we analyzed 10 healthy 11-week-old
RjHan:AURA hamsters fed a pelleted standard diet. Their gastrointestinal
content was sampled (i.e., forestomach, glandular stomach, ileum, cecum,
and colon) and analyzed using 16S rRNA gene amplicon sequencing. Results
displayed a distinct difference in the bacterial community before and after
the cecum, possibly due to the available nutrients and digestive functions.
Next, we compared hamsters with the literature data of young-adult
C57BL/6J mice, another important animal model. We sampled the same gastrointestinal
regions and analyzed the differences in the microbiome between
both rodents. Surprisingly, we found strong differences in their specific gastrointestinal
bacterial communities. For instance, Lactobacillaceae were more
abundant in hamsters’ forestomach and ileum, while Muribaculaceae dominated
in the mouse forestomach and ileum. Similarly, in mouse cecum and
colon, Muribaculaceae were dominant, while in hamsters, Lachnospiraceae
and Erysipelotrichaceae dominated the bacterial community. Molecular
strains of Muribaculaceae in both rodent species displayed some species specificity.
This comparison allows a better understanding of the suitability of
the Syrian hamster as an animal model, especially regarding its comparability
to other rodent models. Thereby, this work contributes to the characterization
of the hamster model and allows better experimental planning.