Consumption of the non-nutritive sweetener stevia for 12 weeks does not alter the composition of the gut microbiota

The use of non-nutritive sweeteners (NNS) as an alternative to caloric sugars has increased in recent years. Stevia is a NNS that has demonstrated beneficial effects on appetite and energy intake. However, the impact on the gut microbiome is not well understood. Therefore, we investigated how regular consumption of stevia, for up to 12 weeks, impacts upon the human gut microbiome. Healthy subjects with a normal body mass index participated in the study; the stevia group (n = 14) were asked to consume five drops of stevia, twice daily, compared against control participants (n = 13). Faecal samples collected before and after treatment were analysed by 16S sequencing. Stevia did not cause significant changes in the beta or alpha diversity when compared to the control groups. When relative abundances of taxa were investigated, no clear differences could be detected. Conversely, random forest analysis could correctly associate the gut microbiome with control and stevia groups with an average of 75% accuracy, suggesting that there are intrinsic patterns that could discriminate between control and stevia use. However, large-scale changes in the gut microbiome were not apparent in this study and therefore, our data suggest that stevia does not significantly impact the gut microbiome.