For the study, researchers at Ben-Gurion University of the Negev tested the effects of a variety of stevia extracts on gut bacteria. Earlier research has found that stevia may have antimicrobial properties, after all. Since your health depends on maintaining the right balance of bacteria, investigating stevia’s impact on the gut makes good sense.
“Usually, gut bacteria and the host live in a commensal manner,” explains a 2015 review in the International Journal of Molecular Sciences. “However, gut bacteria can be potentially harmful when the ecosystem undergoes abnormal changes.”
Many other diseases are related to gut bacteria, such as inflammatory bowel diseases, obesity, diabetes, liver diseases, chronic heart diseases, cancers, HIV, and autism.
Subsequent research has also linked conditions like anxiety and depression to gut health, as well.
The good news is that the new study found that stevia wasn’t deadly to gut flora. The bad news is that it did seem to interfere with bacterial communication. Higher doses also seemed to upset the overall bacterial balance in the gut. As the Jerusalem Post reported,
The biological communication process between cells is known as quorum sensing. Several species of gut bacteria rely on it for a variety of functions, including synchronizing their activity or monitoring their environment.
“Bacteria are talking with a chemical language,” said Prof. Ariel Kushmaro of the department of biotechnology engineering at BGU, who supervised the study.
“What we saw in our research is that these [stevia] molecules are actually interfering with this communication and they can specifically bind to receptors that are related to this communication,” he said.
It’s important to note, though, that this research was done in a lab, not in human bodies. On its own, it’s far from definitive. It’s certainly not enough evidence to say “never, ever, ever consume stevia.” Much more research needs to be done.
But the study can be a reminder of the old adage “all things in moderation.” Too much of anything can be more harmful than helpful. And it also reminds that for as advanced as our scientific knowledge of human health is today, there’s still so much that we’re just beginning to know.