The Influence Of Feather In Diet On The Species Diversity And Richness Of Gut Microbiota In The Arctic Fox

Carnivores intake hair and feather of their prey species and the gut microbiota should have become adapted to the existence of hair and feather during their long evolution process. Hair and feather are constituted of keratins that are almost not digestible in the gut. This raises a question how hair and feather impact on the gut microbiota. This question has not yet been investigated up to now though it is critical to understand the adaptation and evolution of carnivores. We used farmed Arctic fox (Alopex lagopus) as experimental animal to compare the species diversity and abundance of gut microbiota before and after sterilized feather was added to their ration by using the terminal restriction fragment length polymorphism (T-RFLP) technique. The results indicated that, before the addition of feather,176 and 205 kinds of bacteria were detected by using enzymatic digestion of 16S rRNA gene respectively with combination of Rsa I and Bfa I and singly Bsl I. After the addition of feather, the number of bacterial kinds/species detected in the two enzymatic digestions became 366 and 406 respecitively. Moreover, when digested with Rsa I and Bfa I,65 kinds/speceis of bacteria were only detected before addition of feather, and 148 kinds/speceis were only detected after addition of feather,237 kinds/speceis were common to both before and after feather addition. When digested with Bsl I,85 kinds/speceis were only detected only before addition of feather, 135kinds/speceis were only detected after addition of feather, and 250 kinds/speceis were common to both before and after feather addition. Quantitative analysis showed that total abundance of gut bacteria had no substantial changes throughout the whole research. The change of bacterial species had significant individual specificity but no significant general trends. These results suggested the richness of gut microbiota reached its maximum capacity despite of influence of feather. However, the addition of feather resulted in equilibrium of relative abundance among all species of bacteria. i.e. bacteria with undetectable initial abundance became detectable due to the increment of abundance after feather addition. This implied that energetic flow paths of gut microbiota could be manifolded and altered, and such manifold and alteration could potentially improve the complexity and stability of the microecosystem, which has improved outcomes and sustainability of physiological functions. We further proposed that the individual specificity of such changes resulted from the influence of feather could be due to the variation of initial species and their abundance among individual foxes. This suggested different individual fox should have different process and outcomes (fitness) in adaptations in gut microbiota to a same environmental changes.