Artificial Sweeteners and Gut Health: What You Need to Know
Artificial sweeteners and gut health may be related and causing your symptoms. Read the evidence and what it means for functional gut disorders like IBS.
·December 8th, 2021
Artificial sweeteners and gut health may be related, but the interaction between the two hasn’t been closely studied in humans.
Early studies on mice reveal points of potential concern in need of further study.
A nutritionist or dietitian can help you figure out if artificial sweeteners could be contributing to your gastrointestinal symptoms.
Bright Belly can help you find a nutritionist or dietitian who can work to find a diet that works for you.
Artificial sweeteners and gut health: is it an uneasy relationship? As we learn more about the risks of too much refined sugar, many people are turning to artificial sweeteners to satisfy their cravings for sweets. However, non-caloric artificial sweeteners may come with trade-offs you should know about.
What are artificial sweeteners?
There are two components to how artificial sweeteners work. The first is taste. In order for us to taste something sweet, a substance needs to bind to specific taste receptors in the tongue, like a puzzle piece locking into place.
Some artificial sweeteners do this even better than sugar does. For example, sucralose, sold under the brand name Splenda, is 600 times sweeter than sugar.
Artificial sweeteners are different from sugar because they aren’t broken down well by the body. Whereas our bodies turn sugar into energy, we can’t use artificial sweeteners in this way; they simply pass through our bodies undigested.
For people who are watching their weight, this can be great news. Because they don’t add calories to your diet, they may be useful in moderation for replacing sugar in your coffee.
That said, low-calorie sweeteners have some fairly notorious downsides. Sugar alcohols like sorbitol, for example, have been implicated in many case studies for causing chronic diarrhea. Sorbitol isn’t absorbed, so it brings water with it into the colon, causing diarrhea.
A review of a brand of sugar-free gummy bears on Amazon went viral discussing this exact phenomenon and its attendant embarrassment and discomfort.
It’s worth noting that natural sugars can cause similar problems in some people; lactose intolerance is one example. Further, sometimes these sweeteners get an undeserved bad rap. For example, saccharin, a common diet soda sweetener, was infamously banned in the early 1980s for causing cancer in rats, only to have the ban lifted when further study found a person would have to drink 800 sodas a day to reach dangerous levels.
This leads to the general medical view of these sweeteners: as long as you use them in moderation, they’re probably fine. However, even though humans can’t digest them, other organisms can, and that may be where the problem starts.
How are artificial sweeteners and gut health related?
Evidence points to microbiota of all sorts being able to eat artificial sweeteners. It would be more surprising if this weren’t the case, as over a thousand species can live in our gut. Just like anywhere else where many species share space, the quest for resources is constant.
If a potential resource is available and a species in the gut can exploit it, it will eventually evolve to do just that. In fact, when children switch from formula or breastmilk to solid food, their microbiota adapt within months to the new regimen.
That said, whether this is good for their host is irrelevant to the bacteria. They don’t have the ability to understand their impact on the environment they live in. They eat, excrete, and reproduce, and those three actions can potentially cause problems for their hosts.
Are artificial sweeteners feeding the wrong microbiota?
A survey of studies on the impact of a wide range of artificial sweeteners on gut bacteria was published in January 2019, and although it came to no definitive conclusions, it did bring up a few concerning issues.
First, the study found poorly understood prebiotic effects. Prebiotics can’t be digested by the gut but can be absorbed passively by the small intestine. Some can also reach the large intestine and feed probiotic species.
The research didn’t find this to be particularly harmful, but it’s potentially troubling because everyone’s gut is different. More research is needed to fully understand the implications.
Secondly, it found that some sweeteners reduced the populations of other microorganisms. Again, it’s unclear whether this is harmful or not, but more study is needed before any conclusions can be drawn.
Finally, and potentially most concerning, the study found evidence that the body treats some sweeteners like sugar, even if there is no sugar present.
This is especially concerning in light of evidence that artificial sweeteners may promote the development of glucose intolerance.
Do artificial sweeteners cause glucose intolerance?
“Glucose intolerance” is the medical term for what we generally call “high blood sugar.” People with prediabetes and diabetes have trouble digesting sugars. Since they have to go somewhere, these sugars often end up in the blood.
A 2014 study conducted by Israeli researchers found that a diet high in these sweeteners caused glucose intolerance in mice. When they performed fecal transplants into germ-free mice, these mice began showing similar symptoms.
This pairs with other troubling studies. For example, in a 2017 study, sucralose was found to potentially cause liver inflammation in germ-free mice.
There are some parallels between how we metabolize these non-nutritive sweeteners and how mice do. A human is very different from a mouse, though, and, so far, no studies have been conducted with humans to see if this is the case.
Are artificial sweeteners turning beneficial organisms into pathogens?
Another study published in 2021 showed potentially troubling results. The researchers exposed common microbiota to artificial sweeteners in the presence of human small intestine epithelial cells. They found that some sugar substitutes made it easier for these bacteria to form a biofilm and invade and kill epithelial cells.
By itself, this only raises the possibility of an issue. The human body is more than just its cells, and there would likely be an immune response by the body if formerly friendly residents of the digestive tract turned hostile. What’s more, other microbes might step in to protect their host.
Still, this understandably worries people, not least due to the state of the science. All of these studies have yet to be conducted at the scale and quality needed for confirmation.
How to manage your artificial sweetener consumption
If all this leaves you concerned, that’s reasonable. Yet you shouldn’t dump all your artificial sweeteners down the drain just yet. Remember, scientific opinion changes with what we learn, and if you’re only consuming small amounts of these sweeteners, it’s unlikely to provoke an issue.
Instead, take these steps with your doctor and nutritionist to protect your health and microbiota:
Look at how and why you use artificial sweeteners. Get a sense of how much of these you consume in a day, and why you consume them. If you need them to mitigate the taste of coffee, for example, you might consider switching to tea or using a small amount of natural sugar.
Inventory how and where you eat sugar substitutes. Unfortunately, there are many “hidden” sugars and substitutes in the foods we eat. Look for anything marked “syrup” or that has a name that ends in “ose” on the ingredients list of processed foods. If you see it, know that it’s sugar or a substitute.
Get a checkup. Now’s a good opportunity to talk to your doctor and get a sense of your overall health. Let your doctor know what your concerns are, especially if you have a family history of diabetes, metabolic diseases, or similar disorders.
Talk with a nutritionist about your options. Nutritionists can guide you to foods that support your gut health. They can help you find and reduce artificial sweeteners if you’re worried they may be contributing to digestive symptoms. A nutritional therapist can also help you develop a diet less reliant on these flavorings for sweetness.
Eat a gut-friendly diet. Again, a nutritionist can help you with the best foods to eat and food additives to avoid to minimize your gastrointestinal symptoms. A carefully balanced, mindful diet can help keep your gut happy.