Gut Bacteria Food : how does the food we eat affect the bacteria in our gut?
How do our gut bacteria digest food?
Find out why the gut microbiota is vital to our health.
Why does our gut microbiome need a variety of high fibre (fiber) foods?
Gut Bacteria & Food
Our gut bacteria digest the food that our body can’t break down on its own to create chemicals vital to our health.
These chemicals include enzymes to break down food types that our body can’t digest itself, as well as vitamins and short chain fatty acids which help keep our immune systems working healthily.
Prebiotic fibre (fiber), are the indigestible parts of our food that our gut bacteria breakdown to feed themselves.
Eat a wide variety of high fibre (fiber) foods to encourage a diverse mix of bacteria in your gut.
How do our gut bacteria eat?
Our body breaks down the food we eat in stages, as it moves through our digestive system.
After chewing in the mouth, food travels down the oesophagus, to the stomach, then on to the small intestine and finally the large intestine, before any leftover waste is excreted.
Using acids & enzymes (like chemical scissors) that our body produce, the stomach breaks down large food particles into smaller molecules.
Once in the small intestine, bile & more enzymes break down more large food particles into smaller molecules of sugar & nutrients.
These are absorbed into the bloodstream and get reused for energy, building new cells.
Finally, leftover parts of the food, which our bodies can’t break down & absorb by itself, pass through into the large intestine.
Here our gut bacteria digest these larger food molecules to produce chemicals vital to our health & immune system.
Why are our gut bacteria vital to our health?
Scientists have only recently begun to understand the importance of the large intestine (the colon) & the gut bacteria, are to our overall health.
We used to think that the colon was for absorbing vitamins & water molecules & preparing waste products for excretion.
We now know that the bacteria in our gut break down the indigestible leftover food molecules (mostly fibre) that our body couldn’t digest & absorb in the small intestine.
Our bodies don’t produce the enzymes needed to breakdown fibre into useful calories or nutrients.
But our gut microbes have an estimated 6000+ enzymes (vs the 30 or so produced by the human body itself).
These enzymes are like chemical scissors and cut the indigestible fibre into smaller molecules, unlocking vital nutrients from the fibre which our gut bacteria feed on.
As part of this process, gut bacteria produce chemicals vital to our immune systems & overall health, like short chain fatty acids & vitamins.
Scientists are only just starting to uncover the different molecules our bacteria produce & beginning to understand their effects on our health.
Gut Bacteria Food : Eat a Varied High Fibre Diet for Diverse Gut Bacteria
Competition for food is fierce once it arrives in the gut.
Food molecules pass through swiftly and bacteria must work fast to digest any suitable food, for the energy they need to grow & reproduce.
Space on the gut wall is at a premium & bacteria must multiply fast to gain a foothold in the gut.
They will die off without the food they need, their places taken by other competing bacteria.
Different bacteria living in different parts of the colon feed on different types of prebiotics.
Studies show that people eating diets higher in fibre have a larger variety of bacteria in their guts. And importantly, lower rates of inflammatory diseases, bowel cancer and asthma.
A more varied mix of bacteria produces more helpful chemicals (including short chain fatty acids) which calm our immune systems & boost our overall health.
The Science Bit
The information I share on this site distills the research I’ve read on the microbiome, prebiotics & probiotics.
You’ll find links to the relevant research studies on each page.
I’m not a scientist / dietician / nutritionist. I’m a food lover & home cook, putting microbiome research findings into action in my kitchen.
Find out more about the scientists leading research into the microbiome on the FAQs page