Toward effective probiotics for autism and other neurodevelopmental disorders

Abstract

Hsaio and colleagues link gut microbes to autism spectrum disorders (ASD) in a mouse model. They show that ASD symptoms are triggered by compositional and structural shifts of microbes and associated metabolites, but symptoms are relieved by a Bacteroides fragilis probiotic. Thus probiotics may provide therapeutic strategies for neurodevelopmental disorders.

Figure 1

Evolution of a pipeline for therapeutic strategies for mental disorders based on microbiome and metabolite profiling. Panel 1 (top): Experiments using mouse models with induced mental disorders (for example, an MIA mouse with ASD symptoms) and subsequent community profiling can provide a mechanistic understanding of the importance of specific gut microbes and their metabolites in triggering the illness process, especially when lead compounds or microbes are applied to germ-free mice. Panel 2 (middle): Potential treatments to restore the healthy state of the mouse model (replacements of the identified missing microbes and/or the differences in metabolites they cause) can be tested and validated in preclinical trials, including different strategies for altering the microbial community and/or metabolite profile. For example, introducing a beneficial microbe such as the probiotic strains of B. fragilis used by Hsaio et al. may decrease a harmful metabolite rather than increasing a beneficial one. Panel 3 (bottom): Formulation and application of analogous treatments in human trials may lead to new ways to treat human mental disorders. Careful clinical trials will be needed in humans, as the effects of a given microbe and metabolite may differ in different species.