Gut bacteria and IBD

What is the microbiome?

We have around 10 times more bacteria in our guts than cells in our body1 and it’s this bacteria (or microbes) that make up our microbiome. Most of these microbes live in our large intestine (colon) but every part of our body has microbes living in or on it (even our skin). Each of these separate colonies of microbes around our body are known as microbiota.

The majority of these microbes are beneficial and they help us to digest food, such as vegetables, which we wouldn’t be able to digest without them, provide energy for our metabolism, make essential vitamins and act as the first line of defence against germs.

Of course, there’s also some bad bacteria in our microbiome but the good bacteria in our bodies works to stop the bad ones from having ill effects on us.

Every day the bacteria in our microbiome looks slightly different as new bacteria enters our body and develops and others leave or die off. And, no two people’s microbiomes are the same - not even identical twins.

It is thought we have around 500-1000 different types of bacteria in our bodies - totalling trillions.

How does the microbiome develop?

Researchers are still figuring out exactly how our microbiome works and grows but it is believed that just before you are born your body is sterile. During the process of birth you pick up bacteria in the vaginal canal which populates your body and creates the microbiome. In your early days breastfeeding assists in helping your microbiome to grow.

But, a vaginal birth is not always possible and having a caesarian section exposes you to skin bacteria, creating a very different type of microbiome from a baby who is born vaginally2. Babies who are not breastfed are also exposed to a different set of bacteria to those who are.

As we grow and develop during our first few years we are exposed to a lot of different bacteria in our environments - around the house, outside of the home and from other people and animals. All of this bacteria assists in adding to your microbiome and it is the first few years of our lives in which it grows and develops the most3. Some people believe we now create an environment that is too sterile through over cleaning and steralising and children are not being exposed to the bacteria which gives them as diverse microbiome as they would have received just a few generations ago.

As you move from childhood to adolescence and then to adulthood your microbiome continues to develop - though the biggest development phase takes place in your early years.

There are also some things which are thought to negatively affect your microbiome - taking antibiotics, poor diet, stress, and other environmental factors are believed to contribute to damaging your microbiome. Scientists are now linking these changes to the develop of chronic diseases, other health conditions and changes in mental health.


What does the microbiome do?

The role the microbiome plays is wide-reaching and essential to our survival. We are only just beginning to really understand the roles it plays.

Some of its main functions include protecting us from bacteria that cause disease, regulating our immune system and breaking down our food to absorb nutrients. It also produces vitamins (including B12, thiamine, riboflavin and K) and has an influence over whether we are fat or thin, affects our overall health and contributes to our rate of ageing.

An imbalance of the gut microbiota is known as dysbiosis. Dysbiosis may play a role in causing and/or contributing to many disease, including some beyond the digestive system4. These diseases and conditions include irritable bowel syndrome, inflammatory bowel disease, neonatal necrotizing enterocolitis, gastrointestinal (GI) cancers, asthma, allergy, and infectious diseases, Parkinson’s Disease, Alzheimer’s disease, cancer, obesity and diabetes4.

What is the link between our microbiome and inflammatory bowel disease (IBD)?

The role gut health and our microbiome plays in IBD is an area being researched more and more. It is becoming increasingly accepted that intestinal dysbiosis (an imbalance of the gut microbiota) is found in people with IBD5, 6, 7.  However, it is not yet understood if this is a cause or a consequence of IBD and more research into this area is being carried out. These changes to the gut microbiota may be allowing disease-promoting bacteria to thrive instead. Again, this is an area that more research is being carried out into.

Recent research has found there to be some success in inducing remission in ulcerative colitis patients through the use of faecal microbiota transplants - or FMT transplants. In simple terms FMT is the process of taking faeces from a healthy donor, extracting the beneficial intestinal bacteria and yeasts from it and then transplanting it into the colon of a recipient. It is also sometimes referred to as a stool transplant. Read more about FMT.

How can we encourage the good bacteria to grow?

Our modern lifestyles mean that we often do things that damage our microbiome without even realising. Being more aware of some of these things means we can try to reduce them, and in turn reduce the harm to our microbiome. These include:

  • Use of antibiotics8, 9
  • Stress and anxiety
  • Poor diet - such as eating lots of sugar, fatty foods and little fruit and veg
  • Increased use of other medication such as mouthwashes, aspirin, antacids, painkillers, laxatives, antidepressants, sleeping pills and NSAIDs
  • Widespread use of antibacterial cleaners and personal products
  • Pesticide and herbicides on our foods
  • Colon cleansing and vaginal douches
  • Surgery
  • Mercury dental fillings

To help your microbiome you should look at limiting as much of the list above as possible. Some particularly good things you could do include cutting down on sugar, drinking plenty of water to stay hydrated, reducing stress, eating probiotic foods and/or taking probiotic supplements

This will help to limit the damage you are doing to your microbiome, giving it more of an opportunity to thrive.

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  1. Palmer C, Bik EM, DiGiulio DB, Relman DA, Brown PO. Development of the human infant intestinal microbiota. PLoS Biol. 2007;5:e177. [PMC free article] [PubMed]
  2. Dominguez-Bello MG, Costello EK, Contreras M, Magris M, Hidalgo G, Fierer N, Knight R. Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns. Proceedings of the National Academy of Sciences of the United States of America.2010;107:11971–11975. [PMC free article] [PubMed]
  3. Koenig JE, Spor A, Scalfone N, Fricker AD, Stombaugh J, Knight R, Angenent LT, Ley RE. Succession of microbial consortia in the developing infant gut microbiome. Proceedings of the National Academy of Science, USA. 2010 [PMC free article] [PubMed]
  4. Jun Sun , Eugene B. Chang.. Exploring gut microbes in human health and disease: Pushing the envelope. Genes & Diseases. Volume 1, Issue 2, December 2014, Pages 132–139.
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