Abstract
Numerous studies have demonstrated that food shapes the structure and composition of the host’s oral and gut microbiota. The disorder of oral and gut microbiota may trigger various host diseases. Here, we collected oral and gut samples from wild water monitor lizards (Varanus salvator) and their captive conspecifics fed with bullfrogs, eggs, and depilated chicken, aiming to examine dietary correlates of oral and gut microbiota. We used the 16S rRNA gene sequencing technology to analyze the composition of the microbiota. Proteobacteria and Bacteroidota were the dominant phyla in the oral microbiota, and so were in the gut microbiota. The alpha diversity of microbiota was significantly higher in the gut than in the oral cavity, and the alpha diversity of oral microbiota was higher in captive lizards than in wild conspecifics. Comparing the relative abundance of oral and gut bacteria and their gene functions, differences among different animal groups presumably resulted from human contact in artificial breeding environments and complex food processing. Differences in gene function might be related to the absolute number and/or the taxonomic abundance of oral and gut microorganisms in the wild and the water environment. This study provides not only basic information about the oral and gut microbiota of captive and wild water monitor lizards, but also an inference that feeding on frogs and aquatic products and reducing human exposure help water monitor lizards maintain a microbiota similar to that in the wild environment.
Highlights
Microbes affect many aspects of their host, including its life history (Videvall et al, 2019), immune regulation (Grice and Segre, 2011), healthy status (Alcaraz et al, 2012), and adaptability (Zhang et al, 2018b)
These 1,354 amplicon sequence variants (ASV) of oral and gut microbiota could be allocated to 23 phyla, 47 classes, 111 orders, 204 families, and 408 genera based on phylogenetic classification for the 50 microbial samples
Positions of the oral (Figure 3B) rather than the gut (Figure 3C) bacterial composition on a two-dimensional plane defined by the first two axes of principal coordinates analysis (PCoA) differed among animal groups, the relative abundance of the dominant bacteria in the gut microbiota differed among animal groups (Figures 4, 5)
Summary
Microbes affect many aspects of their host, including its life history (Videvall et al, 2019), immune regulation (Grice and Segre, 2011), healthy status (Alcaraz et al, 2012), and adaptability (Zhang et al, 2018b). The host has plenty of space for microbial colonization, including the body surface (Timm et al, 2020), oral cavity (Lu et al, 2019), and intestinal tract Microbial genomes from the gut encode more than 3.3 million genes, which are 10–100 times larger than their hosts (Qin et al, 2010). There are approximately 700 kinds of microorganisms in the human oral cavity (Lamont et al, 2018). With the development of sequencing technology, increasingly more attention has been paid to the evolution and functional role of host microorganisms (Lamont et al, 2018; Lavrinienko et al, 2018; Lu et al, 2019)
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