Changes in intestinal microbiota across an altitudinal gradient in the lizard Phrynocephalus vlangalii

Abstract

High altitude is an important driving force in animal evolution. However, the effect of altitude on gut microbial communities in reptiles has not been examined in detail. Here, we investigated the intestinal microbiota of three populations of the lizard Phrynocephalus vlangalii living at different altitudes using 16S rRNA gene sequencing. Bacteroidetes, Firmicutes, and Proteobacteria were the most abundant phyla. Bacteroides, Odoribacter, and Parabacteroides were the most abundant genera. Significant differences in the intestinal microbiota composition were found among the three populations from different altitudes. The proportions of Verrucomicrobia and Akkermansia decreased, whereas Bacteroides increased significantly with altitude. Greater abundance of Bacteroides at higher altitude led to the fractional increase in the phylum Bacteroides relative to other phyla. Hypoxia may be the main factor that caused intestinal microbiota variation in P. vlangalii along the altitude gradient. Overall, our study suggested that the community composition and structure of intestinal microbiota of the lizard P. vlangalii varied along altitudes, and such differences likely play a certain role in highland adaptation. Our findings warrant a further study that would determine whether ambient and body temperatures play a key role in the modulation of intestinal microbiota in reptiles.

Dietary effects on gut microbiota of the mesquite lizard Sceloporus grammicus (Wiegmann, 1828) across different altitudes

“…In general, the vertebrates' gastrointestinal tract harbors a similar and conservative bacterial assemblage dominated by Firmicutes, Bacteroidetes, and Proteobacteria, with low relative abundances of other bacterial phyla [41]. The fecal microbiota of reptiles, such as herbivorous lizards, iguanas, and tortoises [42,43], the Burmese phyton (Python molurus) [44], and the lizards Phrynocephalus vlangalii [18], Liolaemus parvus, Liolaemus ruibali, and Phymaturus williamsi [45] are dominated also by Firmicutes and Bacteroidetes. However, it has been shown that the bacterial assemblages in the gut of squamates are affected by different parameters, such as diet, captivity, digestion of particular prey items, and periods of fasting [6,[45][46][47][48].…”

“…They speculated that Oscillospira degrade glycans of the host, such as fucose, sialic acids, and glucuronic acid. As such, it is more likely that dietary restriction enrich members of Oscillospira living at 4150 m instead of low O 2 pressure and low temperature as suggested by Zhang et al [18]. Additionally, the lizards at this high altitude were exposed to longer periods of lower temperatures than those at lower altitude, which promotes long periods of inactivity and fasting [15].…”

“…are mucin-degrading bacteria that live in the mucus layer of the intestine [63]. In other animal models, the proportion of Akkermansia decreases with altitude, for example in the lizard P. vlangalii [18] and in the wild house mice [64]. The Tibetan antelope (Pantholops hodgsonii), which is very well adapted to high altitudes, with a vegetarian diet low in calories and vitamins also contains large proportions of Akkermansia [65].…”

“…The gut mass of animals is proportional to the altitude reflecting an adaptation of digestive and absorptive functions [17]. Zhang et al [18] reported significant changes in the intestinal bacterial composition of the toad-headed lizard Phrynocephalus vlangalii from three different altitudes in the Tibetan Plateau.…”

Changes in the community structure of the symbiotic microbes of wild amphibians from the eastern edge of the Tibetan Plateau

“…Taken together, these studies show that an increased abundance of specific gut microorganisms improves the overall digestibility of nutrients in mammals living at high altitude (Li et al, ; Zhang et al, ; Zhao et al, ). The effect of altitude on the gut microbiome has also been investigated in other vertebrates, such as Tibetan chickens (Zhou et al, ) and lizards (Zhang et al, ).…”