show Abstracthide AbstractRecent research has highlighted the importance of studying the composition of the microbiome of haematophagous ectoparasites such as bat flies, as they maintain complex relationships with the host and various pathogens. Analysis of the bat fly microbiome has revealed the presence of endosymbionts such as Wolbachia and Arsenophonus together with possible pathogenic bacteria such as Bartonella. This study aims to analyse the microbial composition of bat flies collected from Maghrebian mouse-eared bats in Algeria to gain insights into the dynamics of the microbiome of these vectors.The microbiome of bat flies of two genera (Nycteribia, Penicillidia) and three species (Nycteribia latreillii, Nycteribia vexata and Penicillidia duforii) was investigated using network analysis. In addition, the presence of endosymbionts (Arsenophonus, Wolbachia), commensals (Acinetobacter, Enterobacteriaceae) and possible pathogenic bacteria (Bartonella) in these bat ectoparasites, which have different feeding strategies (oligoxenous or polyxenous), was investigated and the network robustness in silico was evaluated.After the network analysis, a complex microbial community was identified in the bat fly genus Nycteribia, while analysis of the co-ocurence subnetworks of different bacteria showed that N. latreillii has the most intricate interaction pattern. Bartonella increases the robustness of the network in some cases, but decreases resilience in others, illustrating the complex interplay between different bacteria.