Individuals' diet diversity influences gut microbial diversity in two freshwater fish (threespine stickleback and Eurasian perch).
Vertebrates' diets profoundly influence the composition of symbiotic gut microbial communities. Studies documenting diet-microbiota associations typically focus on univariate or categorical diet variables. However, in nature individuals often consume diverse combinations of foods. If diet components act independently, each providing distinct microbial colonists or nutrients, we expect a positive relationship between diet diversity and microbial diversity. We tested this prediction within each of two fish species (stickleback and perch), in which individuals vary in their propensity to eat littoral or pelagic invertebrates or mixtures of both prey. Unexpectedly, in most cases individuals with more generalised diets had less diverse microbiota than dietary specialists, in both natural and laboratory populations. This negative association between diet diversity and microbial diversity was small but significant, and most apparent after accounting for complex interactions between sex, size and diet. Our results suggest that multiple diet components can interact non-additively to influence gut microbial diversity.
Howard Hughes Medical Institute and Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA.
Daniel I
DI
Bolnick
Lisa K
LK
Snowberg
Philipp E
PE
Hirsch
Christian L
CL
Lauber
Rob
R
Knight
J Gregory
JG
Caporaso
Richard
R
Svanbäck
D000818:Animals; D044822:Biodiversity; D049628:Body Size; D004032:Diet / Q000662:veterinary*; D005260:Female; D005618:Fresh Water; D007422:Intestines / Q000382:microbiology*; D008297:Male; D010471:Perches / Q000382:microbiology*; D023701:Smegmamorpha / Q000382:microbiology*
Diet mixing; Gasterosteus aculeatus; Perca fluviatilis; generalist; individual specialisation; microbiota; perch; stable isotopes; threespine stickleback