Is IBS caused by Inflammation?
IBS is a common digestive condition that affects approximately 12% of the global population. It is characterised by a specific set of symptoms such as bloating, abdominal pain and altered bowel patterns such as constipation or diarrhoea.
For IBS to be diagnosed, other digestive conditions need to be ruled out. This means that conditions such as Crohn’s disease, coeliac disease and bowel cancer are not present.
In the absence of these conditions, a set of IBS symptoms are required for a diagnosis of IBS. These symptoms of IBS are outlined in the ROME IV criteria. This indicates that abdominal pain needs to be present on average, at least 1 day per week in the last 3 months and this gut pain also needs to be associated with two or more of the following IBS symptoms:
- The pain is related to defecation (a bowel movement)
- There is an association with a change in the frequency of stool
- These symptoms are associated with a change in the appearance of stool [Source: Pubmed]
Instead of there being an exact cause of IBS, several factors are known to influence and contribute to IBS symptoms.
These factors include:
- Alterations in the gut-brain connection
- Food sensitivities
- Gut bacteria imbalances
- Low-grade inflammation
- Increases sensitivity in the nerves in the gut [Source: MDPI, Pubmed]
Long-term and low-level inflammation is understood to contribute to the ongoing nature of symptoms in IBS. This can result from cases of food poisoning or events of gastroenteritis and it is possible for this inflammation to contribute to further imbalances in the gut microbiome, increasing the sensitivity of nerves in the gut and altering gut immune function. [Source: Pubmed]
Inflammation in the Gut
The lining of the digestive tract is host to a high concentration of immune cells. The central role of these immune cells is to protect the individual from harmful invaders. The immune response, even in its balanced state can be inflammatory and is triggered by exposure to food, bacteria, parasites and viruses. Once the trigger has been and gone, the immune system and the inflammatory response can then reset.
However, when compared to people without IBS, IBS patients have been found to have a higher concentration of immune cells in the gut lining which may lead to an increased immune and inflammatory reaction to these triggers. This can be considered an overreaction of the inflammatory response. [Source: Pubmed]
IBS patients have also been shown to have reduced levels of certain compounds with anti-inflammatory properties. This means that IBS patients may be more able to produce inflammation in the gut and less able at reducing that inflammation. [Source: Pubmed, Pubmed].
Certain types of immune cells called mast cells have also been found in high levels within the gut lining of those with IBS. These types of immune cells are involved in inflammatory processes which can contribute to the chronic, low-level inflammatory response in IBS. Approaches to calm mast cells have shown promise in treating IBS. [Source: Pubmed]
In addition to the findings from the samples taken from the gut lining, blood samples have also indicated changes in inflammation in IBS patients. These blood samples from IBS patients have shown a higher frequency of additional immune cells (CD4+ and CD8+ cells). These types of increases in these immune cells suggest an increased immune activation within the gut of those with IBS. [Source: Pubmed]
What does IBS inflammation feel like?
Inflammation in the gut can contribute to many of the symptoms commonly seen in IBS.
These symptoms of IBS include:
- Bloating
- Abdominal pain
- Diarrhoea
- Constipation
Another symptom that can indicate the presence of inflammation is called visceral hypersensitivity. This is where the nerves along the gut lining are more sensitive which can lead to increased pain. This is present in up to 65% of those with IBS. [Source: Pubmed]
As mentioned already, the increased presence of mast cells in the gut of those with IBS can contribute to this increased sensitivity. When these cells are activated, they can release compounds such as histamine and cytokines which then stimulate an inflammatory response and contribute to IBS inflammation. [Source: Pubmed]
Visceral hypersensitivity can be seen in a similar way to sunburn. In sunburn, the impact on the nerves in the skin leaves them with increased sensitivity. This means that the same amount of pressure applied to the skin before sunburn feels different to the same pressure applied after sunburn.
This increased sensitivity can also happen in the gut as the result of an inflammatory or immunological response. Some of our patients have even described this feeling of sensitivity as ‘internal sunburn’ while others describe how the increased sensitivity means they can feel the food passing through the gut, rubbing along the sensitive nerves at the travels. [Source: Pubmed]
Calming the immune response by focusing on mast cell health as well as reducing the inflammatory process can help reduce symptoms of visceral hypersensitivity. [Source: Pubmed, Pubmed]
Postinfectious IBS
Postinfectious IBS is IBS that starts after a gut infection or food poisoning. It has been found that up to 10% of those who have a case of gastroenteritis or food poisoning will go on to develop postinfectious IBS. [Source: Pubmed]
When compared, the risk of developing postinfectious IBS appears to be higher in those with bacterial gastroenteritis than in those with viral gastroenteritis. [Source: Pubmed]
In those who do develop postinfectious IBS, samples taken from the lining of the digestive tract show an increased level of a cytokine called IL-1β. This is a chemical messenger of the immune system that contributes to inflammation. This was not increased in those who experienced gastroenteritis but did not go on to develop postinfectious IBS.
It was also noted that levels of IL-1β were higher during the active infection in those who went on to develop postinfectious IBS when compared to those who did not. This indicates a greater susceptibility to inflammation in those who developed IBS after an infection. [Source: Pubmed]
The symptoms of postinfectious IBS are the same as what is typically seen in IBS. These symptoms include:
- Bloating
- Abdominal pain
- Diarrhoea
- Constipation
The rates of developing the diarrhoea subtype of IBS may be more common than constipation following an infection [Source: Pubmed]
Also Read: Methane SIBO & Constipation Guide
Gut Health and Inflammation
Postinfectious IBS can lead to changes and imbalances in the gut microbiome. The changes may then contribute to ongoing inflammation in the gut, creating an ongoing cycle.
One key finding was the reduction in microbial diversity in those with postinfectious IBS. Microbial diversity is understood to indicate the strength and stability of the gut microbiome. For example, the more diverse the gut microbiome is, the more stable it is and the less likely symptoms are to be present. While reduced diversity indicates a less stable microbiome and one that is more likely less resilient and less healthy. [Source: Pubmed]
Alterations in the balance of the gut bacteria have also been noted with increases in Bacteroides and Prevotella bacteria frequently reported. Due to the role of the gut microbiome in regulating the immune response and the inflammatory processes, gut bacteria imbalances (referred to as dysbiosis) can alter gut function. [Source: Pubmed]
Imbalances in the gut bacteria have been shown to:
- Promote inflammation
- Impair normal immune response
The combination of these factors can perpetuate ongoing and low-grade inflammation in the gut. [Source: Pubmed]
Research into probiotic supplements has been shown to alleviate symptoms of IBS. This is in part due to the ability of probiotics to stabilise and balance the gut microbiome as well as reduce inflammation. [Source: Pubmed, Pubmed]
Does Vaping Cause Inflammation in the Gut?
E-cigarettes and vaping have been shown to lead to damage to the gut. This has been shown by damaging the gut lining, leading to the gut being more susceptible to infections as well as increased inflammation. This appears to be the result of the ingredients in the e-cigarette’s liquid changing to more damaging compounds once heated and vapourised. [Source: Pubmed]
Studies have also shown that following repeated vaping of e-cigarettes exposure to E.Coli leads to higher infectivity as well as higher levels of inflammation.
Interestingly, nicotine itself has been found to have an anti-inflammatory effect. This further points to the ingredients in the vaping liquid (and how they’re altered when heated) being the culprits that lead to gut changes and inflammation with vaping. This was confirmed in studies that found nicotine and nicotine-free liquids to impact the gut to the same extent.
Vaping can often be seen as a healthy alternative to smoking cigarettes, however, from a gut perspective, it can have a damaging effect leading to increased levels of inflammation and increased susceptibility to infections. [Source: Pubmed]
Can Stress Cause Inflammation?
Various psychological factors are strongly linked with the development of IBS. This includes childhood abuse and PTSD, both of which are associated with the development of IBS in later life. [Source: Pubmed]
Stress has been shown to act in a way that increases inflammation. This is via stimulating proinflammatory signals in the gut. This is shown in research that linked mood disorders to ongoing inflammation. This inflammation can potentially be systemic (throughout the body) or located in the brain. [Source: Pubmed]
As mentioned, early-life abuse and PTSD have both been shown in increase inflammation and also dysregulate certain parts of the central nervous system and increase the rick of developing IBS. [Source: Pubmed, Pubmed]
Mindfulness and meditation practices have been studied for their ability to reduce inflammation. This calming practice has been shown to reduce levels of faecal calprotectin, a test that measures gut inflammation. This was understood to be due to the ability to calm the gut-brain connection and how that can improve the immune balance in the gut. [Source: Nature]
Inflammation and leaky gut
Leaky gut is also known as increased intestinal permeability. This refers to changes in the permeability of the gut lining. In some situations, such as during exercise, increased permeability of the gut lining is a normal and healthy response. However, in others, ongoing permeability can contribute to symptoms. [Source: Pubmed]
Increased inflammation in the lining of the digestive tract can increase the permeability of the gut lining which can alter how it functions. This can be an ongoing issue in the presence of inflammation. It has also been found that a sub-group of IBS patients have increased intestinal permeability.
This may be due to the breakdown of the tight junction proteins. These are the proteins that act to ‘bind’ the cells together along the gut lining, creating a strong surface. [Source: Pubmed]
This breakdown of the mucosal barrier (the gut lining) by inflammatory cytokines may then allow for the immune system to be in closer proximity to the foreign proteins travelling through the digestive tract. This includes food proteins as well as bacteria and viruses. This increase in the immune response in the gut lining may lead to some of the changes in bowel and impact it’s function leading to IBS symptoms. [Source: Pubmed]
Testing for Inflammation
Faecal calprotectin is a common test that is used to measure inflammation in the digestive tract. Calprotectin is produced in the gut at sites of inflammation. This is then transported out of the body in stool and levels are measured in a stool sample. This test for inflammation can help to differentiate between IBD (inflammatory bowel disease) and IBS.
Calprotectin can be elevated in some IBS patients, however, the levels are not high as in IBD. Calprotectin is also used to measure levels of inflammation in the gut of IBD patients to monitor response to treatment. It can also be used as a marker to predict an impending flare in IBD. [Source: Pubmed]
Levels of calprotectin can vary depending on the condition and the amount of inflammation present. In those without gut inflammation the levels are below 50ug/g. While in active inflammatory bowel disease, this may be as high as 1800ug/ug.
One study showed that approximately 36% of IBS patients had levels of calprotectin between 50 and 180ug/g. It was also noted that higher levels of inflammation were noted in the older participants of this study indicating that inflammation can increase with age. [Source: Pubmed]
What heals inflammation in the gut?
When the gut is inflamed there can often be increased sensitivity in the gut. Research into inflammatory bowel disease found that a Mediterranean diet was able to reduce inflammation in the gut. This was shown by a reduction in faecal calprotectin in those who followed the diet.
The focus of a Mediterranean diet is on a wide range of plant foods that include:
- Fruits
- Vegetables
- Whole grains
- Olive oil
This diet also limits the processed foods that are present in the Western diet. These foods include high amounts of fat, sugar and processed foods. Since the Western diet has been shown to contribute to bacterial imbalances (dysbiosis) in the gut as well as gut inflammation, the removal of these foods can support a healthy gut microbiome.
Additionally, the higher levels of nutrients, fibre and antioxidants within the Mediterranean diet can support a healthy gut microbiome as well as reduce inflammation in the gut. [Source: Pubmed]
The dietary approaches that can be considered for reducing inflammation partly depend on the underlying issue or the root cause.
The types of fibre found in fruits and vegetables are central to supporting a healthy gut environment and reducing inflammation. These fibres can be referred to as prebiotics as they act as a fuel source for the cells that line the gut.
Prebiotics support the gut in a number of ways:
- Preventing bacterial imbalances (dysbiosis)
- Decreasing colonic inflammation (inflammation in the gut)
- Supporting the health of the gut lining (preventing leaky gut)
- Supporting colonic mucus production (a healthy protective mucus along the gut wall) [Source: Pubmed]
Fructooligosaccharides (FOS) and Galactooligosaccharides (GOS) are 2 types of prebiotic fibres that are found in a range of foods. These include:
| FRUCTOOLIGOSACCHARIDES (FOS) | GALACTOOLIGOSACCHARIDES (GOS) |
| Asparagus Banana Barley Burdock (gobo) Chicory Dandelion Garlic Globe artichoke Jerusalem artichoke Leek Onion Rye Salsify Wheat Yacon |
Beetroot Beans (Borlotti, haricot, lima, red kidney, soy beans) Broccoli Chickpeas Fennel Lentils – green and red Lima Beans Oats Onion Radicchio Rye bread Split peas Wheat (wholemeal) |
However, prebiotic-rich foods may not be tolerated when there is a high level of inflammation or gut imbalances as they may lead to more gas and bloating.
In these cases, a very slow approach may be required with supplements also introduced to calm and rebalance the gut to then allow these foods to be tolerated. [Source: Pubmed]
Best gut supplements for inflammation
To support the gut and reduce inflammation both diet and stress levels as key factors that need to be addressed and supported.
In addition to this, there are certain supplements that have been shown in studies to reduce inflammation in the gut. The doses and brands of these supplements can however depend on gut symptoms, whether or not there is a specific diagnosis and the results of tests.
Gut supplements with research supporting their use to reduce gut inflammation include:
- Probiotics [Source: Pubmed]
- Fish oils [Source: Pubmed]
- Curcumin [Source: Pubmed]
- L-Glutamine [Source: OAMJMS]
- Boswellia [Source: Pubmed]
- Peppermint [Source: Pubmed]
- Oregano oil [Source: Pubmed]
Conclusion
Working to address inflammation in the gut can involve several factors which can involve dietary changes, lifestyle and evidence-based supplements. Depending on the underlying condition and imbalances in the gut, specific recommendations can be made.
Working with a gut health practitioner can help to take the guesswork out of approaching this yourself and help you to address the root cause of your gut health symptoms.
