Mouse Microbiota Models: Comparing Germ-Free Mice and Antibiotics Treatment as Tools for Modifying Gut Bacteria

Abstract

As the intestinal microbiota has become better appreciated as necessary for maintenance of physiologic homeostasis and also as a modulator of disease processes, there has been a corresponding increase in manipulation of the microbiota in mouse models. While germ-free mouse models are generally considered to be the gold standard for studies of the microbiota, many investigators turn to antibiotics treatment models as a rapid, inexpensive, and accessible alternative. Here we describe and compare these two approaches, detailing advantages and disadvantages to both. Further, we detail what is known about the effects of antibiotics treatment on cell populations, cytokines, and organs, and clarify how this compares to germ-free models. Finally, we briefly describe recent findings regarding microbiota regulation of infectious diseases and other immunologic challenges by the microbiota, and highlight important future directions and considerations for the use of antibiotics treatment in manipulation of the microbiota.

Keywords: antibiotics; gnotobiotic; immunity; microbiome; microbiota.

Figure 1

Comparison of the advantages and disadvantages of germ-free and antibiotics-treated mouse model systems.

Figure 2

Selected effects of microbiota depletion on cells in the gastrointestinal tract and spleen. Populations of different cell types are altered in association with depletion of the microbiota in both the gastrointestinal tract (Left) and the spleen (Right). Both secretory IgA (sIgA) and immune cell types are depleted in the intestine, while dendritic cells and neutrophils are depleted, but basophils are enriched, in the spleen. Please see Table 2 for more detailed findings by different groups and in other tissues.