Why is microbiome diversity good for your health?

New science provides intriguing clues.

Over the last decade, I've been telling people that having a diverse set of species in their gut microbiome is incredibly beneficial for their health. This community of trillions of microbes, archaea, fungi and parasites that inhabit our lower intestines is crucial in keeping us healthy. 

What evidence base is there for my advice? 

There are clear associations between the diversity of bacterial species and general health. We've seen these associations in virtually every study over the last decade, including my own research, such as the Twins UK study and the American and British Gut studies. And there are many more examples from other research groups. 

Yet, how we’ve measured diversity has been rather crude, essentially by counting the number of bacterial species. Generally, we’ve observed that the greater the number of species, the less likely you are to suffer from a range of common chronic diseases and infections. 

Photo by Henry Lorenzatto

When people ask me why this was – until now – I could only provide a rather general answer.