Are sugar substitutes harming your gut health?

Written By Taryn K White

Diet foods and sugar substitutes run rampant in our food culture today, and with so many products on the market, it’s easy to feel lost in a world of sugar substitutes.

Is stevia healthy? Are artificial sweeteners really better for your blood sugar than a sugar-laden drink or snack? 

Believe it or not, many sugar substitutes can actually substantially impact your gut microbiome. As insignificant as the microbes in your gut may seem, they have a huge impact on metabolic health, mental health, immune function, and so much more. Your gut microbiome alone weighs about 2.5 pounds! 

Let’s dive in and get to the bottom of sugar substitutes – what are they, how do they impact your gut and overall health, and which ones should you be consuming?

Coffee and sugar, artificial sweeteners

All sugar substitutes are NOT created equal.

Synthetic sweeteners: 

Synthetic sweeteners, AKA artificial, zero-calorie, and nonnutritive sweeteners, are even sweeter than sugar yet have lower calorie content per gram than caloric sweeteners. Here’s what they’re called on an ingredient label:

  • Acesulfame potassium (aka SweetOne or Sunett)

  • Aspartame (aka Nutrasweet or Equal)

  • Neotame (aka Newtame)

  • Saccharin (aka Sweet ‘N Low)

  • Sucralose (aka Splenda)

  • Advantame

NATURAL sweeteners: 

Natural sweeteners are made from plants versus being synthetically created. They are usually zero-calorie and around 200+ times sweeter than sugar. The most common ones include:

  • Stevia or Steviol glycosides (made from the leaves of the Stevia rebaudiana plant)

  • Monk fruit extract (from the Luo Han Guo plant)

  • Lucuma powder (from the lucuma fruit)

  • Allulose (found naturally in many foods but commercially produced from plants like corn or wheat)

SUGAR ALCOHOLS:

This type of sweetener has become quite popular because it’s converted to glucose more slowly than sugar, resulting in a lower insulin release and increase in blood sugar. Sugar alcohols are not the same as zero-calorie sweeteners and are commonly called low-calorie sweeteners. They have about 1.5-3 calories per gram, so they may be combined with synthetic sweeteners in food items to add extra sweetness with minimal calories. Sugar alcohols can be naturally occurring in some foods, such as sorbitol in apples, or mannitol in sweet potatoes, but these are different than commercially produced synthetic sugar alcohols that are added to foods and beverages. Our bodies also make small amounts of erthyritol during glucose (sugar) metabolism. Some of the most common sugar alcohols include:

  • Erythritol

  • Mannitol

  • Sorbitol

  • Xylitol

  • Lactitol

  • Isomalt

Diet soda, artificial sweetener

How do these sweeteners impact gut health?

Synthetic sweeteners can wreak havoc on the body.

While these zero-calorie sweeteners are often touted as superior, particularly for those with blood sugar dysregulation, they might not be the best for your metabolic and gut health. Studies have found that synthetic sweeteners, particularly in diet sodas, are associated with an increased risk of obesity, metabolic syndrome, and type 2 diabetes (Ruiz-Ojeda et al., 2019). While these sweeteners don’t contain sugar, they might still drive glucose intolerance through alterations to the gut microbiome (Ruiz-Ojeda et al., 2019). Saccharin and sucralose have been found to impair glucose tolerance, as well as induce alterations to microbiome composition and function (Suez et al., 2022). The latter was also found to be true of aspartame and stevia, although stevia is considered a natural sweetener, not synthetic (Suez et al., 2022).

Natural sweeteners likely do less harm than synthetic alternatives.

Many natural sweeteners have risen to the front stage in recent years, and it’s no surprise because they provide a great alternative to artificial sweeteners while remaining low–or zero-calorie. There is mixed data on stevia, with some studies observing that it does, in fact, induce shifts in microbiome function (Suez et al., 2022), while others have concluded that stevia has no such effects (Singh et al., 2024). On the other hand, monk fruit has been found to be very beneficial for the microbiome in animal studies, increasing the abundance of Akkermansia, Lactobacillus, and Bifidobacterium – all gut bacteria that are very beneficial for gut health (Ban et al., 2020).

Sugar alcohols have pros and cons. 

The big catch with sugar alcohols is that they’re metabolized differently than other sweeteners and are not completely absorbed in the small intestine. Sorbitol, for example, is a larger molecule that has a harder time being absorbed, while erythritol is smaller and absorbed more completely (Lenhart and Chey, 2017). When sugar alcohols aren’t absorbed completely, it can cause uncomfortable GI symptoms like bloating, diarrhea, and gas. If you frequently struggle with GI discomfort or have a condition like irritable bowel syndrome (IBS), you might be better off steering clear of sugar alcohols. 

However, these sweeteners aren’t all bad. Studies have shown that many sugar alcohols, including xylitol (Xiang et al., 2021), can increase short-chain fatty acids (SCFAs), such as propionate and butyrate. SCFAs are beneficial for gut and overall health and have been hypothesized to help regulate gut hormones and protect against obesity and insulin resistance (Lin et al., 2012).

 

What we recommend at GreenMind:

Opt for natural sweeteners 

Natural sweeteners are a great option to help promote blood sugar balance without harmful effects on gut health. Read more about why blood sugar balance matters here.

  • Lakanto and OLÜ Naturals are two brands of monk fruit sweeteners that we recommend (and you can find both in the GreenMind Amazon storefront). Lakanto brand monk fruit is made with erythritol, so be mindful of this if you’re sensitive to sugar alcohols.

  • With all sugar alcohols, be mindful of your intake and consume these in moderation to avoid GI upset.

Spice it up!

Spices and herbs are a great way to add more flavor and enhance natural sweetness. Try adding cinnamon, vanilla, or lavender when cooking and baking for extra flavor. Herbes de Provence is a common herb blend that includes lavender and is great on vegetables, meats, or any savory dish!

Choose foods/ingredients that are naturally sweet

Add applesauce or fruit when baking so you can reduce the amount of sugar needed. Plus, adding fruit increases the fiber content, which is beneficial for your GI system because fiber helps to feed the “good guys” in your gut microbiome. Keep in mind that some fruits and natural sweeteners can still be very high in sugar and spike blood sugar levels. Agave, for example, has a very high glycemic index.

Be mindful of hidden sources of synthetic sweeteners wreaking havoc on your gut health.

The following food and beverage products frequently have synthetic sweeteners added to them, so always read the label and keep your eye out for sneaky sources of artificial sweeteners in your diet.

  • Instead of synthetically sweetened gum, try mastic gum or PUR gum

  • Instead of diet soda, try Olipop soda

  • Instead of Dannon light or Yoplait light yogurt, try Greek yogurt with berries

  • Instead of “no sugar” pasta sauce, try Primal Kitchen marinara sauce, which has no sugar or sweeteners added

  • Instead of “light” bread, try Carbonaut or Base Culture breads

  • Instead of Quaker rice crisps, try LesserEvil Himalayan Pink Salt Popcorn

So, what’s our final verdict?

Synthetic, natural, or sugar alcohols? Your best bet is to stick to natural sweeteners – in moderation – while keeping sugar alcohols to a minimum and eliminating synthetic sweeteners from your diet. In a world where sugar substitutes are the craze, don’t forget that spices and fresh fruit can also be great flavor and sweetness enhancers, adding health-promoting phytochemicals and fiber to your diet! Consider occasionally resetting your taste buds by temporarily eliminating sweet and sugary foods to help reduce cravings and heighten your appreciation for naturally occurring flavors, supporting a more balanced approach to sweetness in your diet.

 

Sources

Ban, Q., Cheng, J., Sun, X., Jiang, Y., Zhao, S., Song, X., & Guo, M. (2020). Effects of a synbiotic yogurt using monk fruit extract as sweetener on glucose regulation and gut microbiota in rats with type 2 diabetes mellitus. Journal of Dairy Science, 103(4), 2956–2968. https://doi.org/10.3168/jds.2019-17700

Lenhart, A., & Chey, W. D. (2017). A systematic review of the effects of polyols on gastrointestinal health and irritable bowel syndrome. Advances in Nutrition, 8(4), 587–596. https://doi.org/10.3945/an.117.015560

Lin, H. V., Frassetto, A., Kowalik, E. J., Jr, Nawrocki, A. R., Lu, M. M., Kosinski, J. R., Hubert, J. A., Szeto, D., Yao, X., Forrest, G., & Marsh, D. J. (2012). Butyrate and propionate protect against diet-induced obesity and regulate gut hormones via free fatty acid receptor 3-independent mechanisms. PLOS One, 7(4), e35240. https://doi.org/10.1371/journal.pone.0035240

Ruiz-Ojeda, F. J., Plaza-Díaz, J., Sáez-Lara, M. J., & Gil, A. (2019). Effects of sweeteners on the gut microbiota: A review of experimental studies and clinical trials. Advances in Nutrition, 10. https://doi.org/10.1093/advances/nmy037

Yale New Haven Health. 2025. Eat any sugar alcohol lately? Yale New Haven Hospital. https://www.ynhh.org/services/nutrition/sugar-alcohol

Singh, G., McBain, A. J., McLaughlin, J. T., & Stamataki, N. S. (2024). Consumption of the Non-Nutritive Sweetener Stevia for 12 Weeks Does Not Alter the Composition of the Human Gut Microbiota. Nutrients, 16(2), 296. https://doi.org/10.3390/nu16020296

Suez, J., Cohen, Y., Valdés-Mas, R., Mor, U., Dori-Bachash, M., Federici, S., Zmora, N., Leshem, A., Heinemann, M., Linevsky, R., Zur, M., Ben-Zeev Brik, R., Bukimer, A., Eliyahu-Miller, S., Metz, A., Fischbein, R., Sharov, O., Malitsky, S., Itkin, M., Stettner, N., … Elinav, E. (2022). Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance. Cell, 185(18), 3307–3328. https://doi.org/10.1016/j.cell.2022.07.016

Xiang, S., Ye, K., Li, M., Ying, J., Wang, H., Han, J., Shi, L., Xiao, J., Shen, Y., Feng, X., Bao, X., Zheng, Y., Ge, Y., Zhang, Y., Liu, C., Chen, J., Chen, Y., Tian, S., & Zhu, X. (2021). Xylitol enhances synthesis of propionate in the colon via cross-feeding of gut microbiota. Microbiome, 9(1), 62. https://doi.org/10.1186/s40168-021-01029-6

Taryn K White
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