Bacteria and the Human Microbiome
Where do the bacteria that live in and on the human body come from?
We begin to colonise bacteria as soon as we’re born, getting our first of these microorganisms from our birth mothers.
As we grow, these bacteria types can change based on our diet and the foods we eat, what we’re exposed to (such as the individuals we meet / study / work with, pets, city or countryside living, the geographic locations, etc.), and various illnesses and life events.
How many bacteria do we have on our bodies?
There are more bacterial cells in and on our bodies than human cells, made up of over 1,000 species and 7,000 – 36,000 different strains. This includes both good bacteria (the kind that support our immune system and digestive functions) and bad (those which can harm these functions).
How much do the bacteria in your gut collectively weigh?
There are over 1 trillion bacteria in the gut, which covers the entire digestive tract, weighing in at over 1.5kg.
The different areas of the digestive tract offer different environments for bacteria to grow, meaning different bacteria will prefer to live in different parts. The majority of bacteria live in the large intestine.