Steviol glycosides and gut bacteria in lab and animal studies
What it found
In lab tests and animal studies, stevia and its steviol glycosides had mixed effects on gut bacteria.
Some studies found more bacterial variety, others found changes in certain groups of bacteria.
What they found
Animal and lab studies
Bacterial growth in lab
In lab tests, stevia did not affect the growth of several pathogens or probiotics, but it reduced Staphylococcus aureus in a dose-dependent way. Another lab test found rebaudioside A stopped the growth of one E. coli strain but not another.
Animal studies on obesity
In obese lab animals, stevia did not protect against glucose intolerance or high-fat-diet changes. Some harmful effects on gut bacteria seemed to come from the high-fat diet rather than stevia.
Maternal stevia in animals
When pregnant animals were fed stevia, their offspring showed changes in gut bacteria that were linked to a higher risk of metabolic syndrome and type 2 diabetes. One study found memory loss and cognitive problems in adult male offspring.
Anti-inflammatory effects
In lab tests on colon cells and in mice with colitis, stevioside and steviol reduced inflammatory chemicals and blocked certain inflammation pathways.
Studies in people and animals
Gut bacteria diversity
Eight studies looked at alpha diversity, which is the variety of bacteria in one place. Four found higher diversity with stevia, three found no difference, and one found lower diversity during breastfeeding but no difference later.
Beta diversity unchanged
Three studies measured beta diversity, which compares bacteria between different samples. Stevia did not significantly change beta diversity in any of them.
What the authors conclude
“Although stevia may change the colonic microenvironment, this effect seems to depend on the amount, the frequency of intake, and the other dietary components of the food, a fact that could be confusing.”
Also in their conclusions
- They say that some studies show beneficial or no harmful effects of stevia on gut bacteria, while others show harmful effects, mostly in lab and animal models.
- They note that most studies had limitations such as different diets, small sample sizes, and doses lower than the acceptable daily intake, making it hard to compare results.
- They advise that further research is required to provide evidence of the role of stevia on the human gut microbiota.
How it was done
Stevia is a popular zero-calorie sweetener, and its breakdown depends on gut bacteria. The authors wanted to see whether eating stevia is good or bad for those bacteria.
The authors searched PubMed for English-language studies on stevia and gut bacteria. They found fourteen studies, all in lab dishes or laboratory animals, because no randomized clinical trials in humans have been done.
What it can’t tell you
- These studies were done in lab dishes or animals, not in people. They cannot show what happens in the human gut.
- The animal studies used different diets and doses, and the results may not apply to people eating stevia.
- No randomized clinical trials in humans have been done, so the effect of stevia on human gut bacteria is not known.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Attikon University General Hospital, Greece; Institute of Preventive Medicine Environmental and Occupational Health Prolepsis, Greece; University of Patras, Greece
The paper
- Title
- The Effects of Stevia Consumption on Gut Bacteria: Friend or Foe?
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Kasti AN, Nikolaki MD, Synodinou KD, et al (2022). The Effects of Stevia Consumption on Gut Bacteria: Friend or Foe?. Microorganisms. doi:10.3390/microorganisms10040744Free full textPubMed 35456796DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error