Gut Health and Inflammatory Bowel Disease (IBD)


Key Points:

- An estimated 3 million adults in the United States suffer from Inflammatory Bowel Disease (IBD).

- The health of your gut and the gut microbiota has been shown to affect inflammation, which is the key feature of IBD.

- Dysbiosis has been observed in patients with IBD as compared to healthy individuals.

- The Anti-inflammatory Diet for IBD (IBD-AID), which includes the use of more prebiotic and probiotic foods to restore the healthy levels of gut microbiota, has been researched and studied as an adjunct therapy for IBD treatment.


Introduction

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease of the gut and bowels. The 2 conditions that are commonly associated with IBD are Crohn’s disease (CD) and ulcerative colitis (UC). The differences between CD and UC lie in the following [1]:

- Location: inflammation can affect any part of the gastrointestinal (GI) tract for CD; for UC, it is limited to the colon and the rectum - Type: damaged tissues appear in patches in CD, whereas the damaged areas are often continuous in UC - Extend: the extend of inflammation can affect multiple layers of the GI tract in CD, while inflammation is only often present in the innermost layer of the colon in UC.

An estimated 3 million adults from the United States (U.S.) suffer from IBD [2], with many more children under the age of 18 years old being diagnosed as well [3]. Common symptoms of IBD may resemble irritable bowel syndrome (IBS), but they are not the same condition. Some symptoms include abdominal pain, weight loss, and rectal bleeding.

The health of your gut and the gut microbiota (also called gut microbiome) has been shown to affect inflammation, which is the key feature of IBD [4]. Fiber intake may also have certain roles in the cause of IBD, which includes (but not limited to) its effects as a prebiotic for the gut microbiota.

World IBD Day falls on 19 May every year [5]. In conjunction with this day, find out how the health of your gut (including your gut microbiota) is related and associated with this autoimmune and inflammatory disease of the bowels!

Gut Health: What is the Gut Microbiota?

The human digestive system and health is greatly affected by the microorganisms harbored within the gut, which includes bacteria, virus, and fungi species. This is termed as the gut microbiota, with the number of bacterial cells estimated to be more than 10 times the number of human cells [6]. Its composition is unique to everyone, as several factors such as environmental and lifestyle contribute to the uniqueness of the gut microbiota composition [7].

Indications of an unhealthy digestive system can range from local (i.e., gut-related) such as digestive issues, to more systemic-related problems like skin health, mood swings, and even depression [8], and many of these effects may be contributed by the gut microbiota [9]. A change in the bacterial species and environment could happen because of drugs (e.g., antibiotics), toxins, and pathogens. This is called ‘dysbiosis’ [10].

How The Gut Microbiota affects IBD

There have been several published reports that studied the effects of the gut microbiota on IBD, mainly reflected by the gut microbiota’s effect on reducing inflammation.

Dysbiosis has been observed in patients with IBD as compared to healthy individuals [11]. As a healthy gut microbiota has been associated with anti-inflammatory effects on the gut, dysbiosis could have pro-inflammatory effects on the gut, leading to symptoms of IBD. An increase in the number of ‘bad’ bacteria in the gut also affects the gut in other ways, such as changing the permeability of the intestine walls [11]. This effect has also been shown in animal studies, where rats with gut microbiota changes induced by using antibiotics were associated with recurrent gut inflammation [12].

The gut microbiota also produces short-chain fatty acids (SCFAs) through the fermentation of prebiotics such as dietary fiber [9]. The concentrations of these SCFAs were also found to be lower in IBD patients, which may also play a part in inducing inflammation, leading to IBD and its respective symptoms [11].

How Can Dietary Changes Help with IBD?

Dietary changes that target gut microbiota may help to alleviate IBD symptoms [13]. The Anti-inflammatory Diet for IBD (IBD-AID) has been researched and studied as an adjunct therapy for IBD treatment [14]. The IBD-AID includes the use of more prebiotic and probiotic foods to restore the healthy levels of gut microbiota. According to the study, a 61.3% of patients on IBD-AID for 8 weeks reported a significant decrease in IBD symptoms [14]. IBD-AID also emphasize on the importance of using soluble fiber, which also promotes benefits such as SCFAs production by the gut microbiota, as mentioned above as well [15].

Prebiotics are substrates that are used and broken down by the gut microbiota to form metabolites such as SCFAs. Different forms of prebiotics include [16]:

- Resistant starches such as Fibrosol Prebiotic - Frutans - Galacto-oligosaccharides - Pectin

Conclusion

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease that can affect any part of the gastrointestinal system, depending on the type of IBD. The gut microbiota and alterations of the composition of it has been associated with IBD, as dysbiosis has been shown to be observed in patients with IBD as compared to healthy individuals. Dietary changes such as increasing the usage of prebiotic and soluble fiber may be useful in alleviating the symptoms of IBD.

This article is written in conjunction with World IBD Day, which falls on 19 May every year.

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References

  1. Centers for Disease Control and Prevention (CDC). Inflammatory bowel disease (IBD): What is IBD? 2018 March.
  2. Centers for Disease Control and Prevention (CDC). Inflammatory bowel disease (IBD): Data and Statistics. 2021 November.
  3. Pituch-Zdanowska A, Banaszkiewicz A, Albrecht P. The role of dietary fibre in inflammatory bowel disease. Prz Gastroenterol. 2015;10(3):135-141.
  4. National Institutes of Health (NIH). Changing gut bacteria in Crohn’s disease. 2017 December.
  5. World IBD Day. 2022.
  6. Thursby E, Juge N. Introduction to the human gut microbiota. Biochem J. 2017;474(11):1823-1836.
  7. Rutsch A, Kantsjö JB., Ronchi F. The Gut-Brain Axis: How Microbiota and Host Inflammasome Influence Brain Physiology and Pathology. Immunol. 2020;11.
  8. Digestive Health: An Introduction. 2022 April.
  9. What is the Gut Microbiota? 2021.
  10. Bourassa MW, Alim I, Bultman SJ, Ratan RR. Butyrate, neuroepigenetics and the gut microbiome: Can a high fiber diet improve brain health?. Neurosci Lett. 2016;625:56-63.
  11. Nishida A, Inoue R, Inatomi O, et al. Gut microbiota in the pathogenesis of inflammatory bowel disease. Clin J Gastroenterol. 2018 Feb;11(1):1-10.
  12. Schaubeck M, Clavel T, Calasan J, et al. Dysbiotic gut microbiota causes transmissible Crohn's disease-like ileitis independent of failure in antimicrobial defence. 2016;65:225-237.
  13. To Help IBD Symptoms, Target Your Microbiome with These Foods. 2020 January.
  14. Olendzki BC, Silverstein TD, Persuitte GM, et al. An anti-inflammatory diet as treatment for inflammatory bowel disease: a case series report. Nutr J. 2014 Jan 16;13:5.
  15. UMass Chan Medical School, Center for Applied Nutrition. Anti-Inflammatory Diet for IBD (IBD -AID).
  16. Overview of Prebiotics. 2021.


Key Points:

- It is found that about 11.2% of people worldwide suffer from Irritable Bowel Syndrome (IBS). 

- IBS is generally divided into 3 types, depending on the clinical presentation.

- One possible cause or risk factor of IBS could be the gut-brain axis interaction, which is also called functional gastrointestinal (GI) disorder, affecting the sensitivity of the gut.

- International guidelines have strongly recommended the use ofsoluble fiber (and not insoluble fiber) as an effective treatment for the global symptoms of IBS.


Introduction

Irritable bowel syndrome, or IBS for short, is also a condition known as ‘sensitive gut’. It is a relatively common long-term digestive system condition. It is found that about 11.2% of people worldwide suffer from IBS [1], although the prevalence may be different across different countries, with other studies citing a prevalence of about 4.4% to 4.8% in the United States, Canada and United Kingdom [2].

It is characterized with frequent abdominal pain coupled with symptoms of constipation and/or diarrhea. What are the other symptoms one with IBS will usually face, and how is it being managed and treated? Read on to find out more.

What are the different types of irritable bowel syndrome (IBS)?

IBS is generally divided into 3 types [3]:

- IBS-D (diarrhea) - IBS-C (constipation) - IBS-M (mixed), or also known as IBS-A (alternating)

Although there are no tests for IBS, doctors may do blood tests to rule out other possible conditions causing similar symptoms as IBS, including celiac diseases or inflammatory bowel diseases [4]. Your doctor may use a certain set of criteria called Rome IV diagnostic criteria, which evaluates based on the pattern and frequency of abdominal pain and its association with bowel movement, as well as whether there is a change in the frequency and consistency of your stools [5].

The doctors will then categorization based on the predominant stool consistency, based on the Bristol Stool Form Scale (BSFS) and the Rome IV criteria.

What are the causes and risk factors of irritable bowel syndrome (IBS)?

Although we do not know the actual cause of why IBS occurs, there have been different postulations as to why IBS develops in some people. One possible issue could be with the gut-brain axis interaction, which is also called functional gastrointestinal (GI) disorder [6]. This occurs when there are issues with how your brain and gut works together, which affects the sensitivity of your gut. This interaction also affects the bowel muscles functions, which may explain the symptoms experienced by patients suffering from IBS.

Some conditions and diseases may also make someone more prone to getting IBS. You may be at higher risk of developing IBS if you have [6,7]:

- A family history of IBS - Emotional stressors, tensions, or anxiety - Bacterial infections of the gut - Intolerance to certain foods - Certain genetic composition

What are the signs and symptoms of irritable bowel syndrome (IBS)?

Patients suffering from IBS typically present with the following [8]:

- Abdominal pain and cramping - Bloating and passing of gas - Constipation - Diarrhea

Although patients may be classified as either IBS-C or IBS-D, over half of the patients are likely to change the subtype over a 1-year period [9], and hence presentations and symptoms may change for these patients, with some presenting with alternating constipation and diarrhea.

Some patients may also experience mucus in their stools and fatigue/ tiredness.

How to manage irritable bowel syndrome?

Several international guidelines have outlined the management of IBS depending on the subtypes of IBS. Such guidelines consist of both lifestyle advice and the different medications that can be used to manage and treat IBS. For this section, we will refer to guidelines on IBS management from both the American College of Gastroenterology (ACG) [10], as well as the British Society of Gastroenterology (BSG) [11].

Lifestyle – Fiber

Both guidelines have outlined the importance of using soluble fiber (and not insoluble fiber) as an effective treatment for the global symptoms of IBS. The guidelines have both recommended the use of soluble fiber for managing IBS symptoms after reviewing results from multiple clinical trials and found that soluble fiber intake was able to relief IBS symptoms significantly as compared to placebo. Insoluble fiber, on the other hand, may exacerbate symptoms such as bloating and pain.

Soluble fiber did not show any significant side effects as well, and hence the guidelines have provided a strong recommendation to the use soluble fiber as a reasonable first-line therapy in managing patients with IBS symptoms.

Other lifestyle changes

Frequent exercise may be able to help manage IBS as well, as recommended by the BSG guidelines. A reasonable 2nd-line management option can include the use of a low FODMAP diet. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, polyols. These substances lead to increase fermentation in the colon, producing short-chain fatty acids and gases, triggering symptoms of IBS in certain patients. Although potentially a viable option for the treatment of IBS, these guidelines believe that the complexity of implementing this diet means that patients should be under the supervision of trained dieticians.

Medications

If your condition is not sufficiently managed by lifestyle changes, your doctor may consider the use of certain medications, depending on the subtype of your IBS and severity of your IBS symptoms. The types of medications include:

- Loperamide - Lubiprostone - Linaclotide, plecanatide - Tegaserod - Rifaximin - Alosetron (for women) - Eluxadoline - Tricyclic antidepressants (e.g., amitriptyline, nortriptyline, imipramine) - Clidinium with chlordiazepoxide

Your doctor will decide which is the best treatment option for your IBS condition.

Conclusion

Irritable bowel syndrome (IBS) is a relatively common chronic gastrointestinal condition that affects about 10% of people worldwide. Typical symptoms include abdominal pain and constipation and/or diarrhea, which will determine the subtype of IBS, although the presentation may vary as the disease progresses. One of the first-line treatment of IBS recommended by international guidelines such as the ACG and BSG include the use of soluble fiber, which is especially helpful for patients who suffer from constipation symptoms from IBS. Other lifestyle changes also include regular exercise and possible use of low FODMAPs diet.

Article is written in conjunction with IBS Month every April.

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References

  1. Canavan C, West J, Card T. The epidemiology of irritable bowel syndrome. Clin Epidemiol. 2014;6:71-80.
  2. Palsson OS, Whitehead W, Törnblom H, et al. Prevalence of Rome IV Functional Bowel Disorders Among Adults in the United States, Canada, and the United Kingdom. Gastroenterology. 2020 Apr;158(5):1262-1273.e3.
  3. What is IBS-M? 2021 Apr.
  4. National Health System (NHS), United Kingdom (UK). Getting diagnosed: Irritable bowel syndrome (IBS). 2021 February.
  5. Lacy BE, Mearin F, Chang L, et al. Bowel disorders. Gastroenterology. 2016;150:1393–407.
  6. National Institutes of Health (NIH), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Symptoms & Causes of Irritable Bowel Syndrome. 2017 November.
  7. Cleveland Clinic. Irritable Bowel Syndrome (IBS). 2020 April.
  8. Everything You Want to Know About IBS. 2017 July.
  9. Palsson OS, Baggish JS, Turner MJ, Whitehead WE. IBS patients show frequent fluctuations between loose/watery and hard/lumpy stools: implications for treatment. Am J Gastroenterol. 2012 Feb;107(2):286-95.
  10. Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Am J Gastroenterol. 2021 Jan 1;116(1):17-44.
  11. Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. 2021;70:1214-1240.


Key Points:

- Over 55 million people around the world are estimated to be living with dementia in 2020, and this number is likely to double in the next 20 years.

- Soluble dietary fibers are unable to be broken down by the human body and are then fermented by the gut bacteria, producing short-chain fatty acids (SCFAs).

- One study in Japan has shown that a high intake of fiber, especially soluble fiber, is linked to a lower risk of developing disabling dementia.

- The authors of the study have discussed several possibilities for this result: beneficial effects on several cardiovascular parameters and improved neuroinflammation via the effects on the gut microbiota.


The World Health Organization (WHO) estimates that by 2030, 1 in 6 people in the world will be aged 60 years or over [1]. With this silver tsunami looming large across the entire world, so does the incidence of dementia. Over 55 million people around the world are estimated to be living with dementia in 2020, and this number is likely to double in the next 20 years [2]. Are there simple ways that we can take to prevent dementia from setting in and developing? A recent Japanese study may have found an association between fiber and dementia. Read on more.

Evidence of fiber use and dementia incidence

You may have known of the importance of fibers more for their gut health and management of constipation. Several studies have also shown that a diet high in fiber can also help to decrease incidences of Type 2 diabetes and cardiovascular diseases [3]. However, did you know that an increased amount of fiber in our diet may be able to decrease the risk of developing dementia?

One study in Japan [4] has shown that a high intake of fiber, especially soluble fiber, is linked to a lower risk of developing disabling dementia. In this Japanese study, investigators conducted a dietary survey to over 3,700 healthy adults and collected data on what and how much was eaten during the 24 hours before the interview. These adults were subsequently followed through for the next 20 years to confirm incident dementia, including disabling dementia.

It was found that total fiber intake was ‘inversely and linearly associated’ with risk of incident dementia. This meant that a higher fiber intake was associated with a lower risk of developing dementia. The association remained even after the study adjusted for potential factors that might affect dementia onset, such as body mass index, blood pressure, antihypertensive medication us, serum total cholesterol, cholesterol-lowering medication, and diabetes.

One point to note is that this association was confined to dementia without a history of stroke. The study also found that this relationship was more evident for soluble fiber intake, and similar association was shown only for potatoes and not vegetables or fruits.

The authors did note several limitations of the study, which included the fact that the dietary habits may have changed over the course of the 20 years. Also, the type of dementia was not distinguished between Alzheimer's and non-Alzheimer's dementia.

How does it work in reducing dementia risk?

Although the actual mechanism about how this result occurs is currently unknown, the authors of the study have discussed several possibilities to this result. Firstly, the intake of fiber has been linked with beneficial effects on several cardiovascular parameters, including blood pressure, lipid levels, and blood glucose [5]. Consequently, this may have led to a potential decrease in the risk of developing dementia, particularly vascular-type dementia.

Another theory hypothesized by the authors is via the alteration of the gut microbiology by the soluble fibers. The composition of intestinal bacteria was found to be associated with prevalence of dementia [6]. Also, a diet high in soluble fibers has been shown to improved neuroinflammation in animal studies, via the regulation of gut bacteria [7]. This interaction between the brain and the intestinal environment (termed as ‘gut-brain interaction’) could potentially explain the results of this study.

What are fibers, and what are soluble fibers?

Fiber is classified under the category of carbohydrate which is an essential nutrient. It is a product that is naturally present in plants. Generally, most carbohydrates are broken down into simple sugar molecules by the body. However, dietary fibers are unable to be broken down by the human body, which makes it unable to be absorbed by the body. These undigested carbohydrates are then fermented by the gut bacteria, producing short-chain fatty acids (SCFAs), which have multiple benefits in keeping the colon healthy [8].

There are 2 types of fibers [8]:

- Insoluble fibers – this type of fiber does not dissolve readily in fluids. It adds bulk to fecal content and aids in constipation. This type of fiber is generally found in vegetables, wholegrain products, brown rice, and pasta. - Soluble fibers – this type of fiber dissolves readily in liquid. Apart from being fermented to form SCFAs, they also help to increase fecal bulk, soften the stool to aid in constipation. It is generally found in fruits, dried beans, and peas.

Conclusion

As per every type of nutrients, moderation and balance is key. Much as such soluble dietary fibers can show benefits across many physiological functions and disease states such as dementia, taking the many different types of nutrients in moderation is still the key to having a well-balanced and healthy lifestyle.

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References

  1. World Health Organization (WHO). Ageing and Health. 2021 Oct.
  2. Alzheimer’s Disease International. Dementia Statistics.
  3. De Munter J.S.L. et al. Whole Grain, Bran, and Germ Intake and Risk of Type 2 Diabetes: A Prospective Cohort Study and Systematic Review. PLoS Med. 2007;4:e261.
  4. Kazumasa Yamagishi et al. Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study. Nutritional Neuroscience. 2022.
  5. Reynolds A, Mann J, Cummings J, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019;393(10170):434–45.
  6. Saji N, Hisada T, Tsuduki T, et al. Proportional changes in the gut microbiome: a risk factor for cardiovascular disease and dementia? Hypertens Res. 2019;42(7):1090–1.
  7. Matt SM, Allen JM, Lawson MA, et al. Butyrate and dietary soluble fiber improve neuroinflammation associated with aging in mice. Front Immunol. 2018;9(1832).
  8. Fibrosol. Fiber.

Dietary fiber is well-known to be beneficial for health. But did you know that other than the effects it has on your gut health, it also has a myriad of other benefits ranging from controlling blood sugar levels and cholesterol levels? How does dietary fiber help in improving them? Read on to find out more about the 4 health benefits of dietary fiber, and start your journey to maintain a healthy lifestyle!

1. Gut Health

Perhaps the most well-known function of dietary fiber is its role it plays in maintaining good digestive health. People with optimal digestive health usually experience fewer gastrointestinal symptoms, such as constipation and/or diarrhea.

There are 2 types of dietary fiber which help improve bowel movement in different ways:

- Insoluble fiber helps to increase bulk to promote regular bowel movement. - Soluble fiber absorbs water in the intestines, which helps softens the stool for smoother bowel movements.

2. Managing Satiety

Satiety is the feeling of fullness after eating. Studies have also shown that taking dietary fiber is associated with a lower body weight, and managing satiety (which in return leads to a reduction in energy and calorie intake) has been touted as a possible explanation for this [1].

Dietary fiber increases the time taken for food to move from your stomach into your intestine and this keeps you feeling full for a longer time, thus possibly reducing your appetite and energy intake. In addition, food with higher dietary fiber content takes a longer time to chew, thus slowing down your food intake [2].

3. Controlling Blood Sugar Level

Some studies have shown that even a small increase in intake of dietary fiber may help improve sugar level in the blood. Dietary fiber may delay the absorption of glucose into the bloodstream from the digestive tract. Hence, reducing sudden spikes of glucose in the blood and enabling the body to manage blood sugar level more efficiently [3]. Some soluble fiber may also form gel-like substance in the stomach, which can also slow down digestion [4].

4. Cholesterol levels

Cholesterol plays a role in bile production in the body. When dietary fiber is present in the diet, it hinders the reabsorption of bile and hence the body will be required to replace the unabsorbed bile salts. This increases the amount of cholesterol being removed from the blood for bile production [5]. Soluble fiber has been shown to be associated with a small but significant decrease in total cholesterol as well as low-density-lipoprotein (LDL) cholesterol (also often terms as the 'bad' cholesterol) [6].

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References

  1. Michelle J. Clark MS, J. Slavin. The Effect of Fiber on Satiety and Food Intake: A Systematic Review. Journal of the American College of Nutrition. 2013. 32:3, 200-211
  2. J. Slavin and H. Green. Dietary fibre and satiety. Nutrition Bulletin. 32: 32-42.
  3. Linda M Delahanty. Patient Education: Type 2 Diabetes and Diet. (Beyond the Basics). UpToDate 2021.
  4. Centres for Disease Control and Prevention (CDC). Fiber: The Carb That Helps You Manage Diabetes. 2022.
  5. Jovanovski E, Yashpal S, Komishon A, et al. Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr 2018; 108:922.
  6. Brown L, Rosner B, Willett WW, Sacks FM. Cholesterol-lowering effects of dietary fiber: a meta-analysis. Am J Clin Nutr. 1999 Jan;69(1):30-42.