Over the last couple of decades there has been a dramatic rise in the ‘0 calorie’ drinks. The sugar free gum. The myriad of products that are sold to us as healthy because they are ‘sugar free’. Well, the chickens are coming home to roost. It seems these miracle substances really are rather damaging after all. It seems that they causing havoc with our microbiome, and considering this system is such a key regulator of almost every other aspect of our physiology, disruptions here could have significant long term downstream effects.
So, let’s take a little look at what is going on and at the key detrimental ways in which artificial sweeteners can affect this vital ecosystem.
Alterations in Microbial Composition
You have probably heard me say many times that a broad range of microbial diversity in our gut is vital. This means that we need a varied microbiome made up of many different types of bacteria. Regular consumption of saccharin, sucralose, and aspartame have led to significant reductions in microbial diversity and rapid shifts in microbiome composition (Suez et al, 2014). These changes have been linked to reduced glucose tolerance, and exaggerated glucose responses. This was also shown to be the case in a study conducted by Palmnas et al (2014) who shoed metabolic changes associated with the consumption of these sweeteners induced glucose intolerance, suggesting a long term risk to metabolic health.
Risks to Barrier Function
When we refer to barrier function, we are talking about the mucous layer of the gut that the bacteria adhere to, and also something called the tight junction, which is a series of protein bands that pull enterocytes (cells of the gut wall) super tightly together to ensure that nothing gets through that isn't meant to.
The health of the barrier is regulated by substances called short chain fatty acids. These are byproducts of a process called saccharolytic fermentation, where the gut microbes will ferment and break down complex carbohydrates. The short chain fatty acid butyrate that is released during this process repairs and maintains the tight junction.
A study conducted by Uebanso et al (2017) showed a strong link between artificial sweetener consumption and a disruption of short chain fatty acid synthesis which led to impairments in barrier function over time.
Direct Effects Upon Bacteria
Artificial sweeteners have the potential to directly affect gut bacteria as they have antimicrobial properties which will stunt the growth of bacteria within the microbiome. An in vitro study by Bian et al (2017) found that sucralose and saccharin specifically had the ability to inhibit the growth of certain strains of gut bacteria, which suggests a direct impact upon microbiome composition.
Effects Related To Changes In Host Metabolism
We saw earlier that microbial changes instigated by sweeteners can influence host metabolism, such as triggering glucose intolerance. However, there seems to be a similar opposite influence too. Artificial sweeteners have often been linked to changes in Human metabolism, and these changes have been shown to have a knock on effect on the microbiome, it’s health and its composition too.
In Conclusion
The impact of artificial sweeteners on the gut microbiome is an emerging area of research with significant implications for human health. Current evidence suggests that these sweeteners can alter the composition and function of the gut microbiota, with potential consequences for metabolic health. However, more research, particularly in human populations, is needed to fully understand these effects and their implications for dietary recommendations.
References
Bian, X., Chi, L., Gao, B., Tu, P., Ru, H., & Lu, K. (2017). The artificial sweetener acesulfame potassium affects the gut microbiome and body weight gain in CD-1 mice. PloS one, 12(6), e0178426.
Food and Drug Administration (FDA). (2018). Additional Information about High-Intensity Sweeteners Permitted for use in Food in the United States.
Palmnäs, M. S., Cowan, T. E., Bomhof, M. R., Su, J., Reimer, R. A., Vogel, H. J., ... & Shearer, J. (2014). Low-dose aspartame consumption differentially affects gut microbiota-host metabolic interactions in the diet-induced obese rat. PloS one, 9(10), e109841.
Suez, J., Korem, T., Zeevi, D., Zilberman-Schapira, G., Thaiss, C. A., Maza, O., ... & Elinav, E. (2014). Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature, 514(7521), 181-186.
Turnbaugh, P. J., Ley, R. E., Hamady, M., Fraser-Liggett, C. M., Knight, R., & Gordon, J. I. (2007). The human microbiome project. Nature, 449(7164), 804-810.
Uebanso, T., Ohnishi, A., Kitayama, R., Yoshimoto, A., Nakahashi, M., Shimohata, T., ... & Takahashi, A. (2017). Effects of low-dose non-caloric sweetener consumption on gut microbiota in mice. Nutrients, 9(6), 560.
Valdes, A. M., Walter, J., Segal, E., & Spector, T. D. (2018). Role of the gut microbiota in nutrition and health. BMJ, 361, k2179.
