The role that fibre plays on gut health

Fibre is an incredible macro-nutrient that doesn’t get the recognition that it deserves. Nutritionist Laura Bryan discusses the link between fibre and gut health.

Fibre is an incredible macronutrient that often doesn’t get the recognition that it deserves. Thankfully, the more we learn about the importance of gut health, the more fibre justifiably takes a step into the limelight of the health and wellbeing arena.

Starting with the basics, fibre is a type of carbohydrate that is often broken down into two different categories, soluble and insoluble fibre. Soluble fibre is found in foods such as: oats, nuts, beans and some fruit and veg. Soluble fibre dissolves in water and supports our wellbeing in a range of ways including, helping to keep us feeling fuller for longer, reducing cholesterol and feeding our beneficial bacteria in our gut.

Insoluble fibre on the other hand absorbs water and adds bulk to our stool helping us to go to the toilet daily. Insoluble fibre is found abundantly in wholegrains, fruits and vegetables and wheat bran.

It is recommended that we eat 30g of fibre daily but unfortunately as a Western Society, we generally don’t get enough, with the average fibre intake in the UK being around 18g (1).

A healthy microbiome

If you’re yet to hear about our ‘gut microbiome’, basically this is a term used for the trillions of different bacteria, viruses, fungus and protozoa cells (along with their genetic material) that are present in the gut.

The health and diversity of our gut microbiome is so important because we now know that this can not only impact gut related issues like constipation and irritable bowel syndrome (IBS), but is can even affect our:

• Mental wellbeing – as there is a strong connection between the gut and the brain through our vagus nerve. Additionally, even 90% of our happy hormone serotonin is created in the gut (2)
• Immune system – 70% of our immune system is held within the gut and is supported by our gut bacteria
• Energy levels – our gut bacteria is key for breaking down food in order for energy to be released and used by the body. Some bacteria even synthesise vitamins like B vitamins which have specific roles in energy production.
• Hormones – our ‘estrobolome’ is a collection of bacteria in the gut which is capable of metabolising and modulating oestrogen (3)

So how does fibre support our gut health?
Fibre can support our gut health in a number of ways, with the most obvious being the ability to support regular bowel movements. This is really important as if we aren’t going to the toilet daily, the toxins, metabolised hormones and waste we are looking to get rid of through our stools, are sat within our bowel for longer. This runs the risk that the waste products are re-absorbed into the bloodstream potentially increasing our risk of certain diseases like heart disease (4).

This can also create inflammation in the gut and other digestive symptoms, such as gas, bloating and pain.

Fibre is a type of carbohydrate that is broken down into soluble and insoluble categories.

Although being constipated could encourage the growth of harmful bacteria, fibre can support the growth of our beneficial bacteria which are associated with all the positive health impacts mentioned above. The reason for this is that the beneficial bacteria use fibre as their fuel and it allows them to thrive, creating
a diverse gut environment which is often correlated with good health (5).

Additionally, when beneficial bacteria ‘use’ fibre as their fuel, it goes through a fermentation process which creates short chain fatty acids (SCFAs). A common SCFA ‘Butyrate’ is essential for a healthy gut environment as it helps maintain the integrity of the gut wall which can prevent inflammation in the body by stopping unwanted material passing through the gut into the bloodstream.

Simple ways to increase your fibre intake
Now that we know how important fibre is for supporting our gut health, here’s some simple ways to increase your daily fibre intake:

• Eating the rainbow! This is really important as different types of bacteria within our gut use different types of fibre as their fuel, which is why it is so important to eat a wide variety of fruit and vegetables.
• Adding legumes like chickpeas, beans and lentils to meals. Hummus dolloped on the side of a salad, beans in a chilli or a nourishing, warming lentil dhal on a Winter’s evening are great options for increasing your fibre intake.
• Opting for wholegrain varieties of foods like bread, rice and pasta. One of the easiest swaps to make but if you aren’t too sure at first, maybe even just do ‘half and half’ with white and wholemeal
  versions whilst the family adjusts.
• Snacking on high fibre foods like nuts and seeds. These are great on their own, topped onto porridge or even as an alternative to croutons on soup!

If you are increasing your fibre intake, it is a good idea to increase it slowly as some people can experience slightly uncomfortable side effects like bloating, whilst their gut bacteria adjust to their added food sources. Making sure you drink plenty of water is also essential to ensure that your stools are easily passed when increasing fibre intake. Generally, though, as you can see, the extra effort to increase your fibre is definitely worth it in the long run for a happy and healthy gut!

Article written for Thrive Magazine Winter 2020 issue >>

References
1) NHS (2018). How To Get More Fibre Into Your Diet. https://www.nhs.uk/live-well/eat-well/how-to-get-more- fibre-into-your-diet 2) Jandhyala, S., 2015. Role of the normal gut microbiota. World Journal of Gastroenterology, 21(29), 3) Kwa et al.,(2016) The Intestinal Microbiome and Estrogen Receptor–Positive Female Breast Cancer, JNCI: Journal of the National Cancer Institute, Volume 108, Issue 8, djw029, 4) Salmoirago-Blotcher, et al (2011) “Constipation and risk of cardiovascular disease among postmenopausal women.” The American journal of medicine vol. 124,8 (2011): 714-23. doi:10.1016/j.amjmed.2011.03.026 5) Valdes et al., 2018. Role of the gut microbiota in nutrition and health. BMJ, p.k2179.