There is a long established link between Inflammatory Bowel Disease and Diabetes; however, cause and effect evidence has been slow to accumulate in human studies. We know that sweeteners and other food additives can disrupt the gut fauna, which can lead to dysbiosis and symptoms associated with both inflammatory bowel disease and irritable bowel syndrome, which in turn also may increase the risk of type 2 diabetes. It is safe to say that some sweeteners can cause symptoms of Irritable bowel syndrome, in specific circumstances, among many other factors.
What is Inflammatory Bowel Disease (IBD)
Inflammatory bowel disease (IBD) as a term refers to two specific conditions (Crohn's disease and Ulcerative Colitis) which have similar symptoms, primarily related to the chronic inflammation of the gastrointestinal (GI) tract. An extended period of inflammation damages the GI tract.
What is Irritable bowel syndrome (IBS)
A Frontiers in Microbiology article published in 2019 offers the most apt description of IBS, reflecting where we are in terms of understanding.
“Irritable bowel syndrome (IBS) is a functional disorder that affects a large proportion of the population globally. The precise etiology of IBS is still unknown, although consensus understanding proposes IBS to be of multifactorial origin with yet undefined subtypes. Genetic and epigenetic factors, stress-related nervous and endocrine systems, immune dysregulation, and the brain-gut axis seem to be contributing factors that predispose individuals to IBS. In addition to food hypersensitivity, toxins, and adverse life events, chronic infections and dysbiotic gut microbiota have been suggested to trigger IBS symptoms in tandem with the predisposing factors.”
It is common for people who suffer from Diabetes to also suffer from IBD and IBS, making it extremely difficult to treat.
Sweeteners and other food additives Cause Dysbiosis
The virtue of sweeteners is that far less is needed for the same/similar sugary taste. Amid an obesity pandemic, zero-calorie options have health merits. Also as a diabetic, it’s not always easy to keep the blood sugar levels in range, so using sweeteners could be useful in that sense as well. That being said, in the case of both sugar and sweeteners, less is better, which is perhaps not how sweeteners are being used, but rather as a direct alternative. The best is to have a balanced diet, relying on whole foods, and consuming these types of foods containing added sugar or artificial sweeteners only occasionally or as treats.
Unfortunately, for diabetics, it's not as simple as naming a specific sugar or sweetener or other substance and then banning it. This is because the links between IBD as a cause of type 2 diabetes have an intermediary, - the human gut and the gut fauna (bacteria living within the gut). In addition, there are other causes of IBS and IBD that are not directly sugar- or sweetener-related.
One way to manage these illnesses when they occur together is through food tracking through the use of a smartphone food diary app. For example DiabTrend has an extensive food database available for free with their DiaVital plan where foods can be searched for easily with autosuggest, or with the DiaPremium plan the app taps into your camera enabling AI based food and portion recognition. One benefit of detailed tracking is that it enables blood glucose level prediction, but most importantly, over time it enables you to determine what works best for your diet.
What is the evidence for a link between IBD and Type 2 Diabetes?
There are still not enough human studies on this subject, however, there are several very convincing ones, one from Denmark and one from Korea, this is beside the many animal studies that indicate considerable changes are caused in gut fauna with the consumption of sweeteners over time, the dysfunction that can lead to insulin resistance and type 2 diabetes. The diagram below demonstrates this to the left side of the diagram.
Effects of exposure of some artificial food additives on gut microbiota and gut barrier. These main findings are based on in vivo studies detailed within (also image source) this paper. Abbreviations: CMC, carboxymethyl cellulose; HFD, high-fat diet; IL, interleukin; LPS, lipopolysaccharide; P80, polysorbate 80; ROS, reactive oxygen species; SCFA, short-chain fatty acid; TLR, Toll-like receptor; TNF, tumor necrosis factor.
Food additives, including sweeteners are one of the many factors that could potentially trigger IBD, some other causes are to the center and right of the image above. Different food colorants, food preservatives, and artificial emulsifiers can also have adverse effects on the gut fauna.
No two gut fauna are the same; therefore, how your particular gut fauna reacts to a particular additive (sugar/sweetener or other additives) will determine whether you will have IBD or IBS symptoms or not.
Is there a link between IBS and IBD?
IBS and IBD during remission can have similar symptoms, but whether there is a link between IBS and IBD (specifically ulcerative colitis) it has yet to be identified, at least according to one study : “Irrespective of inflammation or IBS-like symptoms, systemic inflammatory protein (SIP) profiles differ between the two, suggesting that inflammatory mechanisms of the diseases are part of different spectrums.“
Food additives trigger IBD and IBS symptoms?
Sugar alcohol, sweeteners, emulsifiers, and other food additives are becoming ubiquitous in food, making it more difficult to avoid them; in addition, they often occur together in a single product and different sweeteners are being mixed, thus making it more difficult to isolate which sweetener or other food additives might have a role in the cause of the IBS and IBD symptoms when they occur.
Artificial sweeteners have been identified as a potential trigger of IBS or IBD symptoms, so have sugar-alcohols, such as sorbitol or xylitol, or even simple sugars, like the excess amount of fructose.
Further complicating the picture is the use of drugs in the control of Diabetes; drug regimes often have a dietary component to their use, making it more difficult to say definitively what the cause is in any particular case because drug side-effects can complicate the picture.
The first course of action used to determine the cause of IBS symptoms when the diet is suspected is food tracking. The simplest method is using a food diary and keeping track of everything you eat, and what the symptoms are after consuming them. This way you can easily identify the foods that could trigger IBS symptoms.
Little evidence exists for restricting particular foods. Large meals and certain foods may be poorly tolerated, such as excessive quantities of dietary fat, caffeine, lactose, fructose, sorbitol, and alcohol. This is especially true in patients with diarrhea-predominant IBS or mixed IBS.
A review of foods to avoid that may aggravate IBS symptoms should be covered during the initial nutrition consultation.
There is emerging research that a diet low in FODMAPs may be an effective therapy in the management of GI symptoms in patients with IBS. The term FODMAPs was coined by a group of Australian researchers who theorize that foods containing these forms of carbohydrates worsen the symptoms of some digestive disorders such as IBS and IBD.
The low FODMAPs diet limits foods that contain lactose, fructose, fructooligosaccharides (fructans), galactooligosaccharides (galactans), and polyols or sugar alcohols (sorbitol, xylitol, mannitol, isomaltase, and maltitol).
Problematic Artificial Sweeteners that could cause dysbiosis
There are around 40 natural and artificial sugar alternatives used in our lives, some are used more than others and for different purposes. Use varies from region to region and country to country, which helps in the process of elimination. Those listed below are commonly used as alternatives to refined sugar in food and an international brand example, but there are many others found in other household goods like toothpaste, some more common than others.
Each artificial sweetener affects the gut fauna differently as shown in profiles for Aspartame, Saccharin, Sucralose, Acesulfame potassium in the image above. And in another review from 2019, we can see stevia could also potentially alter the gut microbiome. In this 2019 review, they find no evidence that sugar-alcohols would change the gut fauna, but further research is needed on this subject. Even though sugar-alcohols might not change the gut fauna, they still could cause gastrointestinal problems in IBS and IBD, so be careful about them.
All of the sweeteners listed below are safe to consume in small quantities as both FDA (Food and Drug Administration) and EFSA (European Food Safety Authority) approved the use of them. However, a growing number of animal studies produced controversial results on how these nonnutritive sweeteners would affect the gut bacteria, gut barrier, and immune functions (which could worsen the condition of IBD). Hence we need to be mindful of their consumption and wait for further results from human studies.
Sucralose (Splenda) - 320-1000x times sweeter than sucrose
Sucralose (E-955) is a nonnutritive sweetener, meaning it has no caloric value. The acceptable daily intake (ADI) from it is 5 mg/kg body weight. Approximately 11-27% of ingested sucralose is absorbed from the gut and is excreted in the kidneys.
Sucralose is commonly used in cooking and baking as it’s stable over a wide range of temperatures and pH, and also soluble in water. The most common sweetener that contains sucralose is Splenda, which indeed contains carbohydrates (55g/100g), so be aware of that if you choose to use it.
A study with rats, where the dose was 100, 300, 500, 1000 mg/kg body weight found that the consumption of sucralose decreased the total anaerobes and aerobic bacteria, bifidobacteria, lactobacilli, Bacteroides, and clostridium. The decrease was >2-fold. (Note, that the recommended ADI is only 5 mg/kg body weight in humans!)
Saccharin (Sweet'N Low) - 300-500x sweeter than sucrose
Saccharin or E-954 is also a nonnutritive sweetener which is one of the most commonly used sweeteners today. It’s also one of the oldest, used for well over 100 years (first synthesized in 1878 by Remson and Fahlberg). Saccharin is used as a tabletop refined sugar alternative in toothpaste, food products, and low sugar drinks as an alternative to refined sugar in soft drinks, but it can have an unpleasant bitter or metallic off-taste. Products that are marketed for weight loss often contain it.
Saccharin is excreted through urine and is not metabolized in the body, although it can cross the placenta and can be transferred through breast milk. Its consumption is not recommended for pregnant or breastfeeding women.
Over the years the FDA tried to ban it in 1977 because studies in rats showed that it causes bladder cancer, but many observational studies on humans showed no clear link between saccharin consumption and cancer risk. So today the biggest health authorities like WHO, FDA, and EFSA are all agreed that saccharin is safe for human consumption, although FDA limited its ADI to 5 mg/kg body weight. Also, there is a limitation on their use by manufacturers, for example, FDA restricts the use of saccharin and allows no more than 12 mg per fluid ounce (30 ml). Even though it’s probably not cancerous, there are other concerns around saccharin, like it has been shown to cause weight gain and obesity by interfering with the digestive system’s natural function and gut fauna. Saccharin did not alter the total numbers of anaerobic microbes but deleted a specific anaerobic microbe in the cecal contents.
Aspartame (NutraSweet) - 200x sweeter than sucrose
Aspartame (or E-951 as you can see in some food labels) is comprised of aspartic acid and phenylalanine, both of which occur naturally in the human body. It is used as a sugar alternative; it tastes like sugar but is 200x sweeter than sucrose. The ADI for aspartame is 40 mg/kg body weight.
There have been many studies looking at the effects of Aspartame on the body, because of its widespread use in diet soda drinks. Still, no direct links were found at the low doses consumed as a nonnutritive sweetener and gut dysbiosis. This compound is safe and without toxicity in gene mutations.
Other examples of food that commonly contain Aspartame include dairy products (light yoghurt, flavoured milk, sugar-free ice cream, etc.) sugar-free desserts, chewing gums, sauces, syrups, etc. Aspartame is also found in several low-calorie tabletop sweeteners.
Acesulfame potassium (Sunett)
Until recently, Acesulfame Potassium was considered safe; however, a 2021 study confirmed concerns that it might cause changes in the gut fauna in mice. The study published in the Journal of Gastroenterology and Hepatology concluded, “Acesulfame potassium induces dysbiosis and intestinal injury with enhanced lymphocyte migration to the intestinal mucosa. The massive use of non-caloric artificial sweeteners may not be as safe as we think.”
Acesulfame K (E950) is metabolized by the human body and has an ADI of 15 mg/kg body weight.
Steviol glycosides (Pure Via, Truvia) - 250x sweeter than sucrose
Even though the latest review doesn’t mention steviol glycosides, as it’s a natural and not synthetic sweetener, it’s good to know that a review in 2019 found that steviol glycosides could potentially change the gut microbiome as well.
Products based on Stevia are often blended with other sweeteners such as dextrose and maltodextrin, so while in purer forms, it is a great option for Diabetics (200-250x sweeter than sucrose), buyers must take care and read the product label fine print.
Although highly purified steviol glycosides are safe to use in foods in the EU, it is worth mentioning that consuming more than the ADI (4 mg/ kg body weight) is unsafe (EU regulation 1129/2011).
Whether you opt for using sweeteners vs. sugars or not, one thing is clear; less is better when it comes to sweetness.
While sweeteners require less to achieve the same level of sweetness, this does not necessarily make them better for you because sweeteners are less digestible, which can mean they are not tolerated well. The consequences include dysbiosis, IBD, and ultimately type 2 Diabetes with all the associated symptoms, and even IBS.
However, for Diabetics consumption of the above sweeteners is an important part of the management of their disorder, enabling the consumption of sweet things without the fear of big blood glucose spikes.
Sweeteners, as sugar alternatives, have been critically evaluated by the FDA, EFSA, and Codex Alimentarius and are considered safe and well-tolerated.
However, some long-term prospective studies raise the concern that the consumption of artificial sweeteners might actually contribute to the development of metabolic derangements that lead to obesity, type 2 diabetes, and cardiovascular disease. Also according to the evidence accumulating in animal studies suggest that the consumption of sweeteners is problematic for our gut health.
For safety, track consumption, monitor outcomes and maintain a food diary.