Factors shaping the gut microbiome of five species of lizards from different habitats

Abstract

Host-gut microbiota interactions are complex and can have a profound impact on the ecology and evolution of both counterparts. Several host traits such as systematics, diet and social behavior, and external factors such as prey availability and local environment are known to influence the composition and diversity of the gut microbiota. In this study, we investigate the influence of systematics, sex, host size, and locality/habitat on gut microbiota diversity in five lizard species from two different sites in Portugal: Podarcis bocagei and Podarcis lusitanicus, living in syntopy in a rural area in northern Portugal (Moledo); the invasive Podarcis siculus and the native Podarcis virescens, living in sympatry in urbanized environment (Lisbon); and the invasive Teira dugesii also living in an urban area (Lisbon). We also infer the potential microbial transmission occurring between species living in sympatry and syntopy. To accomplish these goals, we use a metabarcoding approach to characterize the bacterial communities from the cloaca of lizards, sequencing the V4 region of the 16S rRNA. Habitat/locality was an important factor explaining differences in gut bacterial composition and structure, with species from urbanized environments having higher bacterial diversity. Host systematics (i.e. species) influenced gut bacterial community structure only in lizards from the urbanized environment. We also detected a significant positive correlation between lizard size and gut bacterial alpha-diversity in the invasive species P. siculus, which could be due to its higher exploratory behavior. Moreover, estimates of bacterial transmission indicate that P. siculus may have acquired a high proportion of local microbiota after its introduction. These findings confirm that a diverse array of host and environmental factors can influence lizards gut microbiota.

Seasonal dietary changes relate to gut microbiota composition depending on the host species but do not correlate with gut microbiota diversity in arthropod‐eating lizards

“…In contrast, Vasconcelos et al. (2023) revealed that among five lizard species, the larger species showed a positive correlation between SVL and bacterial diversity, but this effect faded when the smallest individuals were removed. Similarly, SVL influenced the microbiota composition of Sceloporus virgatus (Bunker et al., 2022), but such effect may be driven by ontogenetic shifts since young and adult individuals were sampled in the cited study.…”

“…Quasi‐Poisson error distribution and a log link function were applied to account for overdispersion in bacterial diversity using the glm function in stats v.4.3.2 (Crawley, 2007). The models included the covariates SVL (mm) and elevation (m) of the sampling site of each individual, since larger lizards tend to harbour higher gut bacterial diversity (Vasconcelos et al., 2023) and bacterial richness varies with altitude (Hernández et al., 2022; Montoya‐Ciriaco et al., 2020). Sequencing depth (number of reads per sample) was also included as a covariate as it may affect diversity estimates (Alberdi et al., 2018).…”

“…While several studies attribute variation in gut microbiota composition to dietary shifts, most of them do not integrate dietary data in their analysis (see Bodawatta et al., 2022; Fan et al., 2022; Gao et al., 2023; Guo et al., 2021 for a few exceptions), limiting their conclusion about the influence of diet on gut microbiota variation. Importantly, seasonal variation in gut microbiota composition and its relationship with dietary changes may differ among lizard species (Gao et al., 2023), since life history features such as body size, reproductive season and modes (Bunker et al., 2022; Bunker & Weiss, 2022), feeding habits (Lankau et al., 2012; Vasconcelos et al., 2023) and geographical distribution (Härer et al., 2023) may affect both dietary and gut microbiota dynamics. Moreover, gut microbiota composition may be greatly affected by phylogenetic relatedness between vertebrate hosts (i.e.…”