Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Resident gut bacteria are constantly influencing the immune system, yet the role of the immune system in shaping microbiota composition during an organism's life span has remained unclear. Experiments in mice have been inconclusive due to differences in husbandry schemes that led to conflicting results. We used Drosophila as a genetically tractable system with a simpler gut bacterial population structure streamlined genetic backgrounds and established cross schemes to address this issue. We found that, depending on their genetic background, young flies had microbiota of different diversities that converged with age to the same Acetobacteraceae-dominated pattern in healthy flies. This pattern was accelerated in immune-compromised flies with higher bacterial load and gut cell death. Nevertheless, immune-compromised flies resembled their genetic background, indicating that familial transmission was the main force regulating gut microbiota. In contrast, flies with a constitutively active immune system had microbiota readily distinguishable from their genetic background with the introduction and establishment of previously undetectable bacterial families. This indicated the influence of immunity over familial transmission. Moreover, hyperactive immunity and increased enterocyte death resulted in the highest bacterial load observed starting from early adulthood. Cohousing experiments showed that the microenvironment also played an important role in the structure of the microbiota where flies with constitutive immunity defined the gut microbiota of their cohabitants. Our data show that, in Drosophila, constitutively active immunity shapes the structure and density of gut microbiota.

Original publication

DOI

10.1534/genetics.116.190215

Type

Journal article

Journal

Genetics

Publication Date

06/2017

Volume

206

Pages

889 - 904

Addresses

Laboratory of Cell Biology, Development and Genetics, Department of Biochemistry, University of Oxford, OX1 3QU, United Kingdom.

Keywords

Immune System, Animals, Drosophila melanogaster, Bacteria, Acetobacteraceae, Gastrointestinal Microbiome