Sweeteners Alter Gut Microbiome to Promote Glucose Intolerance

I'll never forget when Ira Fritz, my doctoral committee chair, practically slapped a packet of artificial sweetener out of my hand as I was about to put it into my iced tea.  "That stuff will kill you!" he said as he extracted from me an oath to swear off the stuff.  I'm not sure I quite believed him, but to this day I still drink my iced tea unsweetened.

As usual, Ira was right.  Recently another brick has been added to the foundation of his concern about sugar substitutes. Researchers have found that sweeteners such as saccharine, sucralose, aspartame can alter the microbial ecosystem of our gut in a way that promotes the development of glucose intolerance.  Glucose intolerance is part of metabolic syndrome, one of the most significant epidemics of our (or any) era.

At least as interesting as this microbial mediation between our diet and our metabolic function is the fact that only those human subjects who were responders exhibited the changes observed.  This underscores our emerging view about the individualized nature of human nutrition and metabolism.

What can we use from this in teaching undergraduate A&P?

• We have yet another example to share regarding why and how the human microbial system plays such a vital role in our body.


• This may be an interesting story to bring up when discussing immunity in our A&P course, perhaps giving a preview of later topics on the gut microbiome and nutrition/metabolism.


• Nutrition and metabolism are not the same for everyone.  So the basic principles learned in an A&P course are likely to be generally true for humans, but not necessarily entirely true for every individual.


• Yet another example of the principle "you are what you eat."


• And here's another case of continued scientific research refining the story of what we know about human structure and function.  Consider mentioning it when you are explaining scientific methodology and it's relevance to A&P at the start of your course.  An interesting discussion may ensue after asking, "does this mean we should stop using sugar substitutes?"

Want to know more?

Artificial Sweeteners Linked to Glucose Intolerance

• Beth Skwarecki. Medscape Medical News. September 17, 2014
• Article summarizing the recent research.
• my-ap.us/1pkI645

Sugar Substitutes, Gut Bacteria, and Glucose Intolerance

• Anna Azvolinsky. TheScientist. September 17, 2014
• Another plain-English article covering how the consumption of artificial sweeteners results in glucose intolerance is mediated by changes in the gut microbiota in both mice and humans.
• my-ap.us/1qOBVvw

Artificial sweeteners induce glucose intolerance by altering the gut microbiota

• Jotham Suez, et al. Nature. doi:10.1038/nature13793 September 17, 2014
• Research article outlining the discovery of the sweetener-gut-glucose intolerance  link. Includes numerous illustrations.
• my-ap.us/1uLs0Hc

Metabolic Syndrome 

• S Wang, et al. Medscape. Updated 23 April 2014
• Detailed Medscap entry summarizing various aspects of metabolic syndrome.
• my-ap.us/1uLrNUE

Diet Sodas, as Well as Regular Ones, Raise Diabetes Risk

• Miriam E. Tucker. Medscape Medical News. February 14, 2013
• Article summarizing research showing that women who drink large amounts of diet soda are at increased risk of developing type 2 diabetes mellitus.
• my-ap.us/1uLrY20

Consumption of artificially and sugar-sweetened beverages and incident type 2 diabetes in the Etude Epidémiologique auprès des femmes de la Mutuelle Générale de l'Education Nationale–European Prospective Investigation into Cancer and Nutrition cohort

• Guy Fagherazzi, et al. American Journal of Clinical Nutrition. January 30, 2013. 
• Original research article about the diet soda-diabetes link.
• my-ap.us/1BQOTLP

Photo: S. Snodgrass