How Trillions of Invisible Companions
Shape Who We Are
Your life is not yours alone, for from your first moments to your last, you are a living, breathing chorus of many voices, with most too small to see.
About the Book
Beneath the surface of our skin and within the winding corridors of our bodies, an invisible world hums with life. It is a city without streets, a forest without trees, and a galaxy without stars, yet it is every bit as vast. This is our microbiome, a living community made up of trillions of companions.
Microbial Self follows this hidden community from the moment of birth, when the first microbes stake their claim on our skin and gut, through the shifting landscapes of childhood, adulthood, and old age. Along the way, it introduces the individual organisms that define our inner ecology as characters in a living gallery, each with its own story, contradictions, and relationship to the host it inhabits.
Part popular science, part personal journey, part vision of medicine's next frontier, this book reveals that the most profound discovery in modern biology is not about leaving the body behind. It is about learning to listen to what it has been telling us all along.
"Your microbiome is an internal refinery-and-pharmacy, converting leftover dietary fibres into useful products, coaching the immune system with daily drills, and changing the way you absorb drugs."
From the Prologue
Microbial Portraits
To know ourselves, we must also know our companions. Within us lives a hidden crowd, trillions strong, each with its own story. Some are steady friends. Others are more mercurial. And then there are those that slip across boundaries, transforming from harmless neighbour to dangerous intruder.
Bifidobacterium
The Guardian of Beginnings
A pioneer of the newborn gut, drawn to the sugars of breast milk that few others can digest. By breaking down these complex sugars, it nourishes the infant and teaches the immune system the difference between friend and foe.
Escherichia coli
The Shapeshifter Neighbour
A quiet tenant in the colon, producing vitamin K and occupying space that might otherwise be seized by invaders. But through borrowed genes and subtle mutations, it can transform from benign neighbour into notorious disruptor.
Akkermansia muciniphila
The Keeper of the Gate
Living in the mucus lining, it performs a paradoxical task: feeding on mucus while stimulating its renewal, strengthening the wall that keeps the gut sealed and safe. A sentinel of metabolic health.
Faecalibacterium prausnitzii
The Peacemaker
A master producer of butyrate, calming inflammation and supporting the immune system. Where it thrives, harmony follows. Where it wanes, inflammation often rises. A quiet reminder that strength sometimes looks like steadiness.
Prevotella
The Forager's Legacy
Flourishing on plant-based diets rich in grains and legumes. Its presence speaks of lives close to the land, where meals are pulled from soil and field rather than packaged and processed.
Lactobacillus
The Quiet Caretaker
Best known for thriving in fermented foods like yoghurt, sauerkraut, and kimchi. Inside the body, it maintains acidic environments that ward off pathogens. Reliable yet restless, a reminder that context is everything.
"In an age of AI that increasingly frames the next step in human development as a departure from biology, the microbiome tells a different story. It suggests we have barely begun to understand the biology we already have."
From the Introduction
Inside the Book
From Beginnings to End
A Gallery of the Hidden Self
Investing in Our Microbial Self