To engraft or not to engraft: an ecological framework for gut microbiome modulation with live microbes

- Microbiome-modulation through live microbes has enormous potential to improve health.
- Recent studies have provided new insights into the impact of live microbes on gut microbiomes.
- Ecological theory can help reach a conceptual understanding on the impact of microbiome-modulating interventions.
- An ecological perspective will be essential to improve currently available strategies and develop novel ones.

Strategies aimed at modulating the gut microbiota by using live microbes range from single strains (probiotics or live biotherapeutics) to whole non-defined fecal transplants. Although often clinically efficacious, our understanding on how microbial-based strategies modulate gut microbiome composition and function is vastly incomplete. In this review, we present a framework based on ecological theory that provides mechanistic explanations for the findings obtained in studies that attempted to modulate the gut microbiota of humans and animals using live microbes. We argue that an ecological perspective grounded in theory is necessary to interpret and predict the impact of microbiome-modulating strategies and thus advance our ability to develop improved and targeted approaches with enhanced therapeutic efficiency.

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