Are Artificial Sweeteners Good for Your Gut? (Waistlines and Intestines)

Are Artificial Sweeteners Good for Your Gut? (Waistlines and Intestines)

Artificial sweeteners have been a staple in the diet of diabetics and in diets of people trying to lose weight by cutting back on sugar.  Artificial sweeteners provide a fix for the sweet tooth without consuming the added calories of sugar.  In a study done on both mice and human subjects, researchers looked at what effect artificial sweeteners have on our health: not only on our waistlines, but to our glucose metabolism and how gut microbiota mediate these effects.  Artificial sweeteners pass through the GI tract of the human without being digested.  This directly affects the microbiota of the gut.  It was found that consuming artificial sweeteners impaired glucose intolerance, similar to a person with diabetes.  Artificial sweeteners might actually be causing and exacerbating the symptoms of a disease in the people they were designed to help.

The researchers took 10 week old mice and added saccharin, sucralose and aspartame to their drinking water.  What they found is that all three groups of mice consuming the artificial sweeteners showed marked glucose intolerance (P < 0.001).  Saccharin had the most pronounced effect, so the researchers fed the mice either a high fat diet or a standard normal chow diet to compare obese and lean mice.  They found similar effects on glucose intolerance (P < 0.03) after just 5 weeks on the HFD.  The researchers then added antibiotics to the drinking water of both the lean and obese mice.  After 4 weeks of treatment, the mice were equal in glucose tolerance.  These results suggest that even while drinking artificial sweeteners, having a healthy microbiome can mediate the negative effects on glucose tolerance.  To further examine these results, researchers transplanted fecal matter from mice consuming saccharine on the normal chow diet into the guts of healthy mice.  They found that the mice who received the fecal transplant displayed glucose intolerance 6 days after implantation (P < 0.03).  To study the effects on humans, the researchers took food-frequency questionnaires from 381 non-diabetic individuals (44% males and 56% females) and found associations between artificial sweetener consumption and increased waist to hip ratio, higher fasting blood glucose, higher glycosylated hemoglobin and glucose tolerance test. 1

The results of this study suggest a strong association between consuming artificial sweeteners and glucose intolerance regardless of whether the diet is a high fat diet or a standard normal diet.  It also suggested the importance of having a healthy gut microbiome.  This study was primarily focused on mice, so the results on humans are not well known.  In order for this study to change dietary recommendations for humans, more studies would need to be done.

At this time, The Academy of Nutrition and Dietetics (AND) state that “consumers can safely enjoy a range of nutritive and nonnutritive sweeteners…”2  Results from a meta-analysis showed that consuming these artificial sweeteners reduced body weight, BMI, and waist circumference.3  There are conflicting opinions.  One of the main sources of artificial sweeteners is diet soda.  At least daily consumption of diet soda can lead to a 36% greater risk of metabolic syndrome and a 67% greater risk of type 2 diabetes.4  If consuming artificial sweeteners is better than glucose for a person with diabetes, the negative effects on glucose tolerance could possibly be mediated through the use of antibiotics. Antibiotics cannot be used long term, but scientists could take this research and create a probiotic to facilitate a healthier gut microbiome.

There is not enough research conducted on human subjects to draw a certain conclusion right now.  It is reasonable to suggest that artificial sweeteners are safe to consume in small doses when incorporated into a diet following the dietary recommendations for adults in the U.S.  This topic will likely be looked into further as preliminary research has been done.  We will have to wait and see whether they come out with another, safer kind of sweetener or a treatment to mediate the effects of what we are currently using.






  1. Suez, J. et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature. 514: 181-186 (2014).
  2. Academy of Nutrition and Dietetics. Use of nutritive and nonnutritive sweeteners. Eat Right Pro. 112: 5; 739-758 (2012).
  3. Miller P, Perez V. Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies. Am J Clin Nutr.  100:3; 765-777 (2014).
  4. Nettleton, J. A. et al. Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA). Diabetes Care 32: 688–694 (2009).


Ranking: Five green apples

Reviewed by Viktoriya Wolff

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