Are artificial sweeteners hurting our ability to regulate blood sugar levels? Let's ask our microbiome

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What if artificial sweeteners and sugar-free snacks and drinks are actually causing our bodies to lose control of the ability to regulate blood sugar levels? What if these sweeteners are a part of the cause of our societal obesity epidemic and not part of the solution?

That is exactly what is being suggested in a landmark study published yesterday in Nature. Researchers at the Weizmann Institute in Israel demonstrated that giving mice water laced with the chemicals in Sweet’N Low, Splenda, or Equal caused the mice to become glucose intolerant, resulting in the inability to metabolize sugars, due to alterations to the gut microbiomes.

People often consume these sweeteners with the rationale that the fewer calories consumed, the more successful they will be in losing weight. This study has shown that these chemicals may be doing more harm than good by altering the composition of our microbiomes.

After the mice receiving artificial sweeteners became glucose intolerant, which is often seen as a precursor to adult onset diabetes and obesity among other metabolic diseases, the researchers treated the mice with antibiotics to eliminate their gut bacteria.  The scientists found that with antibiotic treatment, the glucose intolerance was reversed showing the sweeteners caused the glucose intolerance. The researchers went one step further and transplanted bacteria from the mice treated with sweeteners into germ-free mice. Shortly after receiving the bacteria, the previously healthy mice became glucose intolerant, again telling us that the gut bacteria caused the glucose intolerance. 

As this work was done in mice, the team of scientists conducted a smaller study with human subjects to learn whether if the mouse studies would translate to humans.  Seven individuals who did not usually consume artificially sweetened food and drinks were given a week-long diet consisting of high levels of artificial sweeteners.  In that short amount of time, four of the seven individuals began to develop glucose intolerance. They then took fecal samples from the four individuals whose blood sugar levels were disrupted and put them into healthy mice. The healthy mice after receiving the human's gut bacteria also became glucose intolerant. 

While the sample size of the human experiment was small, the overall study is quite compelling and demonstrates the important impact that diet has on our microbiome. This is not a call for the general public to stop using artificial sweeteners as further research needs to be conducted.

With that said, it will be very interesting to see how the general public reacts to this paper.  Numerous studies have shown correlations between the microbiome and disease, but few studies have shown how such a small change in one's dietary habits could potentially have a major impact on an individual's future health outcomes. This is a story that we look forward to reading more about. 

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