Creation of a non-Western humanized gnotobiotic mouse model through the transplantation of rural African fecal microbiota
Authors: Van Den Ham Kristin M. , Little Morgan R. , Bednarski Olivia J. , Fusco Elizabeth M. , Mandal Rabindra K. , Mitra Riten , Li Shanping , Doumbo Safiatou , Doumtabe Didier , Kayentao Kassoum , Ongoiba Aissata , Traore Boubacar , Crompton Peter D. , Schmidt Nathan W. 
Published: October 2023

ABSTRACT
Gut microbiota are increasingly being recognized as a contributing factor in the etiology of numerous diseases and as a potential determinant in the immune response to various treatments. Recent work has suggested that the suboptimal immunogenic response to vaccination in low- and middle-income countries may be associated with differences in the gut microbiome, which are known to be substantially different between Western and non-Western countries. However, insufficient consideration has been given to the characterization of non-Western microbiomes and their relationship with well-being and immunity. Humanized gnotobiotic mouse models have been used to better understand the causal associations between the gut microbiota and health outcomes but have largely been limited to the study of Western microbiota. Thus, we were interested in determining the applicability of gavage strategies used to humanize germ-free mice with Western microbiota to the humanization of germ-free mice with rural African fecal samples. Here, we assessed the impact of the number and frequency of gavages and the effect of a donor-matched diet on the colonization of Malian fecal microbiota in germ-free mice. One gavage was insufficient to provide a stable establishment of the Malian microbiome, whereas four weekly gavages resulted in a more consistent colonization of the human donor taxa. Interestingly, the donor-matched diet did not improve colonization over the fixed-formula, grain-based mouse chow. Subsequent phenotypic studies using African gut microbiota-humanized gnotobiotic mouse models will allow for a better understanding of the interaction between African gut microbiota and well-being and potentially aid in developing improved treatments for microbiota-dependent diseases in non-Western populations.

IMPORTANCE
There is increasing evidence that microbes residing within the intestines (gut microbiota) play important roles in the well-being of humans. Yet, there are considerable challenges in determining the specific role of gut microbiota in human diseases owing to the complexity of diverse internal and environmental factors that can contribute to diseases. Mice devoid of all microorganisms (germ-free mice) can be colonized with human stool samples to examine the specific contribution of the gut microbiota to a disease. These approaches have been primarily focused on stool samples obtained from individuals in Western countries. Thus, there is limited understanding as to whether the same methods used to colonize germ-free mice with stool from Western individuals would apply to the colonization of germ-free mice with stool from non-Western individuals. Here, we report the results from colonizing germ-free mice with stool samples of Malian children.