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

Abstract

Background: High-altitude ecosystems are extreme environments that generate specific physiological, morphological, and behavioral adaptations in ectotherms. The shifts in gut microbiota of the ectothermic hosts as an adaptation to environmental changes are still largely unknown. We investigated the food ingested and the bacterial, fungal, and protistan communities in feces of the lizard Sceloporus grammicus inhabiting an altitudinal range using metabarcoding approaches. Results: The bacterial phyla Bacteroidetes and Firmicutes, and the genera Bacteroides and Parabacteroides dominated the core fecal bacteriome, while Zygomycota and Ascomycota, and the species Basidiobolus ranarum and Basidiobolus magnus dominated the core fecal mycobiome. The diet of S. grammicus included 29 invertebrate families belonging to Arachnida, Chilopoda, and Insecta. The diversity and abundance of its diet decreased sharply at high altitudes, while the abundance of plant material and Agaricomycetes was significantly higher at the highest site. The composition of the fecal microbiota of S. grammicus was different at the three altitudes, but not between females and males. Dietary restriction in S. grammicus at 4150 m might explain the high fecal abundance of Akkermansia and Oscillopira, bacteria characteristic of long fasting periods, while low temperature favored B. magnus. A high proportion of bacterial functions were digestive in S. grammicus at 2600 and 3100, while metabolism of aminoacids, vitamins, and key intermediates of metabolic pathways were higher at 4150 m. Different assemblages of fungal species in the lizard reflect differences in the environments at different elevations. Pathogens were more prevalent at high elevations than at the low ones. Conclusions: Limiting food resources at high elevations might oblige S. grammicus to exploit other food resources and its intestinal microbiota have degradative and detoxifying capacities. Sceloporus grammicus might have acquired B. ranarum from the insects infected by the fungus, but its commensal relationship might be established by the quitinolytic capacities of B. ranarum. The mycobiome participate mainly in digestive and degradative functions while the bacteriome in digestive and metabolic functions.

Fecal Microbiota Characterization of Seychelles Giant Tortoises (Aldabrachelys gigantea) Living in Both Wild and Controlled Environments

“…The findings of the current study revealed that Bacteroidetes and Firmicutes represented the two major phyla in Aldabra giant tortoises, as reported in studies on other herbivorous tortoises and herbivorous reptiles in general (Hong et al, 2011;Ahasan et al, 2018;Campos et al, 2018;Bloodgood et al, 2020;McDermid et al, 2020;Montoya-Ciriaco et al, 2020). However, the Bacteroidetes/Firmicutes ratio observed in the present study regarding giant tortoises was not in line with that reported by other authors who focused on herbivorous reptiles, specifically tortoises (Hong et al, 2011;Gaillard, 2014).…”

Crossing Kingdoms: How the Mycobiota and Fungal-Bacterial Interactions Impact Host Health and Disease

“…Amplicon sequencing uses fungal specific primers to amplify ITS or 18S regions of the rRNA gene locus, which contain hypervariable domains and allow for species discrimination ( 12 , 37 – 39 ), analogous to 16S bacterial sequencing. This method illuminated a diverse mycobiome in humans and virtually all other species analyzed, for example, mice ( 12 , 32 , 40 – 44 ), pigs ( 45 ), dogs ( 46 ), bees ( 47 ), and lizards ( 48 ). We will discuss the most frequently identified fungi of the human and mouse oral and gut mycobiomes in the following sections.…”

Microbial symbiosis and coevolution of an entire clade of ancient vertebrates: the gut microbiota of sea turtles and its relationship to their phylogenetic history

“…Investigations into the microbiota of reptiles, including sea turtles, are limited to studies describing microbial communities [16][17][18][19][20][21][22][23][24][25][26][27][28][29], factors that influence their composition [30][31][32][33][34][35][36][37][38][39][40][41][42][43], and how they affect host physiology [8,9,[44][45][46], but investigations into the influence of phylogenetic factors affecting microbiota composition in this taxon are rare. Irrespective of the potential host-phylogenetic signal in microbiota composition at a broad taxonomic level, it has been shown that at a more individual level, diet, captivity, geography, and feeding regime all influence the microbiota [9,17,32], and that fermenting bacteria are important for digestion in herbivorous species [47].…”