Artificial Sweeteners + Microbiome
In a recent study published in Nature, researchers measured effects of three artificial sweeteners on health of both humans and mice.1
When a group of mice were given saccharin, sucralose, or aspartame, a significant rise in blood sugar levels and weight gain was seen. This is surprising, as these sweeteners are all marketed as “zero calories,” and, therefore, should not affect blood sugar.
Researchers then measured effects on the microbiome from ingesting these three sweeteners and found that both the type and function of the gut microbes dramatically changed. Interestingly, certain bacteria grew in number while others decreased. More profoundly, levels of microbes linked to metabolism regulation (relating to blood sugar and weight) were severely compromised.1
But . . . It’s Zero-Calorie!
How could a zero-calorie substance raise blood sugar and weight? It’s related to dramatic changes in gut microbes that regulate blood sugar and metabolic pathways, linked to weight gain and other functions that govern cardiovascular health.1
To further evaluate effects of artificial sweeteners on blood sugar and the microbiome, researchers measured a large group. The group that regularly consumed artificial sweeteners showed the same changes in blood sugar and the microbiome as in the mice study.
Finally, they took a small group of human subjects and gave them the maximum safe dose of saccharin each day for one week. They monitored blood sugar every five minutes and the microbiome daily.1 Results showed that four out of seven subjects had significant changes in blood sugar and microbiome, similar to previous studies. They then took samples of fecal matter from the four human subjects sensitive to saccharin and inserted it into sterile mice. These mice developed the same blood sugar and metabolic symptoms as in previous findings. Then, researchers inserted a fecal matter sample from the three human subjects unaffected by saccharin into sterile mice and the mice showed no changes in blood sugar or weight. This strongly suggests that it was changes in gut microbes responsible for high blood sugar and weight gain.1
Artificial Sweeteners’ Effects on Weight
Science is beginning to identify many possible links between the sweet taste mechanism and our perception of satiation.2 Studies show men who drink tea with artificial sweeteners have an increased waistline of nearly two inches, while women who drink tea with artificial sweeteners have an increased waistline of an average of one inch.3 Both human and animal users of artificial sweeteners show to be significantly more likely to gain weight than non-user.4-6 Interestingly, animals exposed to aspartame prenatally were shown to consume more sweet foods as adults and be more susceptible to metabolic changes.7
Conclusion: Protect the Microbiome
While artificial sweeteners are marketed to have no effect on blood sugar and to be part of a weight loss strategy, the studies cited above strongly suggest they have a damaging influence on function of gut microbes, the body’s primary regulators of blood sugar, weight, and metabolism. (It should be said these studies did not include stevia or sugar alcohols, such as xylitol, sorbitol, and mannitol.)
Through these studies, we can become more aware of how sensitive the microbiome actually is, and that processed foods and sweeteners may wreak havoc on gut microbes fundamentally responsible for our longevity and well-being.
Stay tuned for my report on the new artificial sweeteners called sugar alcohols: sorbitol, mannitol, xylitol, maltitol, maltitol syrup, lactitol, erythritol, isomalt and hydrogenated starch hydrolysates.