More Like this

1. The role of host traits and geography in shaping the gut microbiome of insectivorous bats

   https://doi.org/10.1128/msphere.00087-24  

   Dai, Wentao; Leng, Haixia; Li, Jun; Li, Aoqiang; Li, Zhongle; Zhu, Yue; Li, Xiaolin; Jin, Longru; Sun, Keping; Feng, Jiang (April 2024, mSphere)

   Suen, Garret (Ed.)

   ABSTRACT The gut microbiome is a symbiotic microbial community associated with the host and plays multiple important roles in host physiology, nutrition, and health. A number of factors have been shown to influence the gut microbiome, among which diet is considered to be one of the most important; however, the relationship between diet composition and gut microbiota in wild mammals is still not well recognized. Herein, we characterized the gut microbiota of bats and examined the effects of diet, host taxa, body size, gender, elevation, and latitude on the gut microbiota. The cytochrome C oxidase subunit I (COI) gene and 16S rRNA gene amplicons were sequenced from the feces of eight insectivorous bat species in southern China, includingMiniopterus fuliginosus,Aselliscus stoliczkanus,Myotis laniger,Rhinolophus episcopus,Rhinolophus osgoodi,Rhinolophus ferrumequinum,Rhinolophus affinis,andRhinolophus pusillus. The results showed that the composition of gut microbiome and diet exhibited significant differences among bat species. Diet composition and gut microbiota were significantly correlated at the order, family, genus, and operational taxonomic unit levels, while certain insects had a marked effect on the gut microbiome at specific taxonomic levels. In addition, elevation, latitude, body weight of bats, and host species had significant effects on the gut microbiome, but phylosymbiosis between host phylogeny and gut microbiome was lacking. These findings clarify the relationship between gut microbiome and diet and contribute to improving our understanding of host ecology and the evolution of the gut microbiome in wild mammals. IMPORTANCEThe gut microbiome is critical for the adaptation of wildlife to the dynamic environment. Bats are the second-largest group of mammals with short intestinal tract, yet their gut microbiome is still poorly studied. Herein, we explored the relationships between gut microbiome and food composition, host taxa, body size, gender, elevation, and latitude. We found a significant association between diet composition and gut microbiome in insectivorous bats, with certain insect species having major impacts on gut microbiome. Factors like species taxa, body weight, elevation, and latitude also affected the gut microbiome, but we failed to detect phylosymbiosis between the host phylogeny and the gut microbiome. Overall, our study presents novel insights into how multiple factors shape the bat’s gut microbiome together and provides a study case on host-microbe interactions in wildlife. 

   more » « less
2. Host phylogeny and host ecology structure the mammalian gut microbiota at different taxonomic scales

   https://doi.org/10.1186/s42523-021-00094-4  

   Rojas, Connie A.; Ramírez-Barahona, Santiago; Holekamp, Kay E.; Theis, Kevin R. (December 2021, Animal Microbiome)

   null (Ed.)

   Abstract The gut microbiota is critical for host function. Among mammals, host phylogenetic relatedness and diet are strong drivers of gut microbiota structure, but one factor may be more influential than the other. Here, we used 16S rRNA gene sequencing to determine the relative contributions of host phylogeny and host diet in structuring the gut microbiotas of 11 herbivore species from 5 families living sympatrically in southwest Kenya. Herbivore species were classified as grazers, browsers, or mixed-feeders and dietary data (% C4 grasses in diet) were compiled from previously published sources. We found that herbivore gut microbiotas were highly species-specific, and that host taxonomy accounted for more variation in the gut microbiota (30%) than did host dietary guild (10%) or sample month (8%). Overall, similarity in the gut microbiota increased with host phylogenetic relatedness ( r  = 0.74) across the 11 species of herbivores, but among 7 closely related Bovid species, dietary %C4 grass values more strongly predicted gut microbiota structure ( r  = 0.64). Additionally, within bovids, host dietary guild explained more of the variation in the gut microbiota (17%) than did host species (12%). Lastly, while we found that the gut microbiotas of herbivores residing in southwest Kenya converge with those of distinct populations of conspecifics from central Kenya, fine-scale differences in the abundances of bacterial amplicon sequence variants (ASVs) between individuals from the two regions were also observed. Overall, our findings suggest that host phylogeny and taxonomy strongly structure the gut microbiota across broad host taxonomic scales, but these gut microbiotas can be further modified by host ecology (i.e., diet, geography), especially among closely related host species. 

   more » « less
3. Covariation of diet and gut microbiome in African megafauna

   https://doi.org/10.1073/pnas.1905666116  

   Kartzinel, Tyler R.; Hsing, Julianna C.; Musili, Paul M.; Brown, Bianca R.; Pringle, Robert M. (November 2019, Proceedings of the National Academy of Sciences)

   A major challenge in biology is to understand how phylogeny, diet, and environment shape the mammalian gut microbiome. Yet most studies of nonhuman microbiomes have relied on relatively coarse dietary categorizations and have focused either on individual wild populations or on captive animals that are sheltered from environmental pressures, which may obscure the effects of dietary and environmental variation on microbiome composition in diverse natural communities. We analyzed plant and bacterial DNA in fecal samples from an assemblage of 33 sympatric large-herbivore species (27 native, 6 domesticated) in a semiarid East African savanna, which enabled high-resolution assessment of seasonal variation in both diet and microbiome composition. Phylogenetic relatedness strongly predicted microbiome composition ( r = 0.91) and was weakly but significantly correlated with diet composition ( r = 0.20). Dietary diversity did not significantly predict microbiome diversity across species or within any species except kudu; however, diet composition was significantly correlated with microbiome composition both across and within most species. We found a spectrum of seasonal sensitivity at the diet−microbiome nexus: Seasonal changes in diet composition explained 25% of seasonal variation in microbiome composition across species. Species’ positions on (and deviations from) this spectrum were not obviously driven by phylogeny, body size, digestive strategy, or diet composition; however, domesticated species tended to exhibit greater diet−microbiome turnover than wildlife. Our results reveal marked differences in the influence of environment on the degree of diet−microbiome covariation in free-ranging African megafauna, and this variation is not well explained by canonical predictors of nutritional ecology. 

   more » « less
4. Understanding the factors regulating host–microbiome interactions using Caenorhabditis elegans

   https://doi.org/10.1098/rstb.2023.0059  

   Singh, Anupama; Luallen, Robert J (May 2024, Philosophical Transactions of the Royal Society B: Biological Sciences)

   The Human Microbiome Project was a research programme that successfully identified associations between microbial species and healthy or diseased individuals. However, a major challenge identified was the absence of model systems for studying host–microbiome interactions, which would increase our capacity to uncover molecular interactions, understand organ-specificity and discover new microbiome-altering health interventions.Caenorhabditis eleganshas been a pioneering model organism for over 70 years but was largely studied in the absence of a microbiome. Recently, ecological sampling of wild nematodes has uncovered a large amount of natural genetic diversity as well as a slew of associated microbiota. The field has now explored the interactions ofC. eleganswith its associated gut microbiome, a defined and non-random microbial community, highlighting its suitability for dissecting host–microbiome interactions. This core microbiome is being used to study the impact of host genetics, age and stressors on microbiome composition. Furthermore, single microbiome species are being used to dissect molecular interactions between microbes and the animal gut. Being amenable to health altering genetic and non-genetic interventions,C. eleganshas emerged as a promising system to generate and test new hypotheses regarding host–microbiome interactions, with the potential to uncover novel paradigms relevant to other systems. This article is part of the theme issue ‘Sculpting the microbiome: how host factors determine and respond to microbial colonization’. 

   more » « less
5. Disentangling the link between zebrafish diet, gut microbiome succession, and Mycobacterium chelonae infection

   https://doi.org/10.1186/s42523-023-00254-8  

   Sieler, Michael J; Al-Samarrie, Colleen E; Kasschau, Kristin D; Varga, Zoltan M; Kent, Michael L; Sharpton, Thomas J (December 2023, Animal Microbiome)

   Abstract BackgroundDespite the long-established importance of zebrafish (Danio rerio) as a model organism and their increasing use in microbiome-targeted studies, relatively little is known about how husbandry practices involving diet impact the zebrafish gut microbiome. Given the microbiome’s important role in mediating host physiology and the potential for diet to drive variation in microbiome composition, we sought to clarify how three different dietary formulations that are commonly used in zebrafish facilities impact the gut microbiome. We compared the composition of gut microbiomes in approximately 60 AB line adult (129- and 214-day-old) zebrafish fed each diet throughout their lifespan. ResultsOur analysis finds that diet has a substantial impact on the composition of the gut microbiome in adult fish, and that diet also impacts the developmental variation in the gut microbiome. We further evaluated how 214-day-old fish microbiome compositions respond to exposure of a common laboratory pathogen,Mycobacterium chelonae, and whether these responses differ as a function of diet. Our analysis finds that diet determines the manner in which the zebrafish gut microbiome responds toM. chelonaeexposure, especially for moderate and low abundance taxa. Moreover, histopathological analysis finds that male fish fed different diets are differentially infected byM. chelonae. ConclusionsOverall, our results indicate that diet drives the successional development of the gut microbiome as well as its sensitivity to exogenous exposure. Consequently, investigators should carefully consider the role of diet in their microbiome zebrafish investigations, especially when integrating results across studies that vary by diet. 

   more » « less