If you were to list the top 5 most hyped areas of science right now, the microbiome would clearly be one. The collection of billions of microbes that live in our gut—and which are studied by collecting, er, “stool samples”—have been blamed for causing not just gastrointestinal symptoms, but even mental health disorders.

In this episode of The Studies Show, Tom and Stuart discuss the microbiome: what’s the evidence that it contributes to all our ills? Can it really be the case that we can transplant blended faeces from one person to another and improve their health? And, sorry to have to ask this, but what exactly is that smell?

The Studies Show is sponsored by Works in Progress, the online magazine about science, technology, and human progress. Their newest November 2023 issue is packed with data-driven, deeply-researched articles on the history and future of the science and tech that shapes our world. It’s all freely-available right here at this link.

Show notes

* 2007 Ben Goldacre Guardian article on “Dr.” Gillian McKeith, the Awful Poo Lady

* 2019 review of microbiome research and some of its methodological difficulties

* 2022 review of the mechanisms by which the microbiome might affect our health

* 2016 Science paper on population norms for the microbiome

* The “30 plants a week” claim, from the ZOE app website; from Tim Spector in the Guardian

* The “American Gut Project” study

* Stuart’s article on why “30 plants a week” is a silly claim

* 2020 meta-analysis of studies on faecal microbiome transplants for recurrent C. difficile infection

* Paper that’s critical of the evidence for faecal transplants for C. diff

* 2021 review of faecal transplants in Crohn’s disease

* 2019 review of the microbiome and mental health, including some of the history of the idea

* 2019 editorial speaking very highly of the power of the “gut-brain axis”

* 2023 KCL small-scale study on probiotics for depression

* 2023 review of observational studies of faecal transplants for autism

* Scott Alexander’s article “Against Against Autism Cures”

* Brain study on the apparent causal role of the microbiome in Alzheimer’s disease

* Stuart’s i article critiquing it

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.