Experimental Manipulation Shows a Greater Influence of Population than Dietary Perturbation on the Microbiome of Tyrophagus putrescentiae.

is inhabited by bacteria that differ among mite populations (strains) and diets. Here, we investigated how the microbiome and fitness of are altered by dietary perturbations and mite populations. Four populations, referred to as dog, Koppert, laboratory, and Phillips, underwent a perturbation, i.e., a dietary switch from a rearing diet to two experimental diets. The microbiome was investigated by sequencing the V1-V3 portion of the 16S rRNA gene, and selected bacterial taxa were quantified by quantitative PCR (qPCR) using group/taxon-specific primers. The parameters observed were the changes in mite population growth and nutritional status, i.e., the total glycogen, lipid, saccharide, and protein contents in mites. The effect of diet perturbation on the variability of the microbiome composition and population growth was lower than the effect induced by mite population. In contrast, the diet perturbation showed a greater effect on nutritional status of mites than the mite population. The endosymbionts exhibited high variations among populations, including in the laboratory population, -like bacteria in the dog population, and in the dog and Phillips populations. -like and -like bacteria were present in the dog, Koppert, and Phillips populations in different proportions. The microbiome is dynamic and varies based on both the mite population and perturbation; however, the mites remain characterized by robust bacterial communities. Bacterial endosymbionts were found in all populations but represented a dominant portion of the microbiome in only some populations. We addressed the question of whether population origin or perturbation exerts a more significant influence on the bacterial community of the stored product mite The microbiomes of four populations of insects subjected to diet perturbation were compared. Based on our results, the bacterial community was more affected by the mite population than by diet perturbation. This result can be interpreted as indicating high stability of the putative intracellular symbionts in response to dietary perturbation. The changes in the absolute and relative numbers of , -like, -like, and bacteria in the populations can also be caused by neutral processes other than perturbation. When nutritional status is considered, the effect of population appeared less important than the perturbation. We hypothesize that differences in the proportions of the endosymbiotic bacteria result in changes in mite population growth.