Fibre and IBS: what you need to know

Fibre and IBS: what you need to know

IBS is something we get asked about a lot. Despite affecting 10% of us in the UK, there remains a lot of confusion about how to keep symptoms at bay. This month we shine a light on IBS, and delve into the latest research on how dietary fibre can help restore gut health in the long-term.

 

What exactly is Irritable Bowel Syndrome (IBS)?

IBS is a condition that affects how the gut moves and functions, causing a range of symptoms like abdominal pain, bloating, excessive gas, and changes in bowel function – typically constipation, diarrhoea, or both. Less common symptoms include fatigue, “brain fog”, nausea, backaches, and bladder symptoms. The frequency and severity of symptoms varies a lot from person to person. But even the same person might experience very different symptoms from one day to the next.

For those interested, you can find the formal criteria for diagnosing IBS here

 

What is currently recommended for IBS?

Many people with IBS are recommended a low FODMAP diet. FODMAP is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (it’s a mouthful, we know). Broadly speaking, FODMAPs encompass a number of different foods, including wheat (fructans), dairy (lactose), certain fruits and vegetables (fructans, oligosaccharides, fructose, polyols), legumes and nuts (oligosaccharides), beverages (fructose), and artificially sweetened foods (polyols).  

 

FODMAPs are often problematic in IBS because they are poorly absorbed by the small intestine and instead, travel to the colon where they are rapidly fermented by our gut bacteria (producing large amounts of gas). People with IBS are thought to have more sensitive nerve endings in the gut. So while we all produce similar amounts of colonic gas in response to fermentable foods, people with IBS will experience uncomfortable wind and bloating. People with IBS also experience differences in absorption rates and transit time (that is, how quickly or slowly the contents of the digestive system move). These differences may contribute to either constipation, diarrhoea, or both.

 

What’s the problem with a low FODMAP diet?

The low FODMAP diet (like many diets) is quite restrictive, which means that there's a risk of missing out on important nutrients. Dietary fibre is a nutrient that's particularly at risk, largely because high-fibre foods like wheat, rye, legumes, oats, and vegetables, are also high in FODMAPs. 

 

Why do we need fibre?

Dietary fibre is a type of carbohydrate that cannot be broken down by the human body. Instead, fibre travels to the colon undigested where is it partially or completely broken down by our gut microbes. The trillions of microbes that reside in our gut (mostly in the colon) are collectively known as the gut microbiota. We keep our gut microbes healthy and thriving by feeding them with plenty of dietary fibre. In fact, it’s their favourite food. When our gut microbes ferment fibre, they produce Short Chain Fatty Acids (SCFAs). 

Consuming plenty of dietary fibre ( >30g/day) is the best thing we can do to help restore gut health in the long-term. So for someone with IBS, what are the best types of fibre to keep tricky symptoms at bay, while also restoring gut health?

 

The best types of fibre supplements for IBS

The latest research suggests that people with IBS may benefit from consuming specific types of fibre supplements that are slowly and gradually fermented in the colon (opposed to FODMAPs). Slowly fermented fibre:

  • Normalises bowel movements
  • Selectively feeds beneficial gut bacteria
  • Promotes SCFA production
  • Helps minimise wind, bloating, and abdominal discomfort
  • Provides a long-term solution for IBS

 

Below is a summary of the scientific evidence supporting the use of different fibre supplements for IBS:

 Fibre

Role in IBS

Partially Hydrolysed Guar Gum (PHGG)

Relieves symptoms   

 Feeds gut bacteria

 Anti-inflammatory

PHGG is derived from plant seeds called guar beans. PHGG is slowly fermented in the colon, producing less bloating and gas-related symptoms. PHGG can also help to relieve constipation and diarrhoea in IBS. PHGG is a prebiotic, and plays a role in selectively feeding beneficial gut bacteria, including Bifidobacteria and Streptococcus thermophilus – both known for their digestive and immune health benefits. 

Resistant Starch

Relieves symptoms   

 Feeds gut bacteria

 Anti-inflammatory

Similar to PHGG, resistant starches are slowly fermented along the entire length of the large intestine, producing less bloating and gas-related symptoms. Resistant starch has prebiotic properties (feeds the good gut bacteria).

Oat Fibre

 Relieves symptoms

 Oat fibre appears to be well tolerated in IBS, and may help to improve constipation, abdominal pain, and bloating.

Cellulose

 Relieves symptoms 

Cellulose forms a gel-like substance (viscous), helping to soften stool and relieve constipation in IBS. It is poorly fermented by gut bacteria and does not have prebiotic benefits for the gut microbiome.

Psyllium Husk

 Relieves symptoms 

Appears to be well tolerated by many (but not all) people with IBS, and is particularly effective at relieving constipation and diarrhoea. Psyllium husk is poorly fermented by gut bacteria and does not have prebiotic benefits for the gut microbiome.

Wheat bran, FOS, GOS, and inulin

 May exacerbate IBS  

 Feeds gut bacteria

 Anti-inflammatory

These fibres tend to promote a large amount of gas production in the colon in a short period of time. In large quantities, they may exacerbate IBS symptoms.

 

Where do I start?

Here at myota, we know that nurturing your gut microbiome with the right types of fibre has far-reaching benefits. We’ve spent a great deal of time and research finding high-quality fibres that both relieve IBS symptoms and restore long-term gut health. From this research, myota has created the Gut Regulator Fibre Mix.

We’ll be launching the Gut Regulator in April. For early access, enter your contact details here including the comment "Gut Regulator Launch".