Our human microbiome is in decline, which is likely to be contributing to the sharp rise in non-communicable diseases, health conditions that cannot be directly transmitted between people, such as cardiovascular disease and cancers. Josh Toussaint-Strauss talks to Dr James Kinross, colorectal surgeon and author of the book Dark Matter: The New Science of the Microbiome, about why the human microbiome is in decline, how modern life is impacting it and what we can do to look after it

James Kinross also appeared recently on the Guardian’s Science Weekly podcast, you can listen here:

• Your microbiome questions answered: part one

• Your microbiome questions answered: part two