What are the effects of nonnutritive sweeteners on the human gut microbiota?

In a recent study published in cellresearchers investigated the short-term effects of four nonnutritive sweeteners (NNS) on the human microbiome, glucose tolerance, and additional health parameters in a randomized controlled trial (RCT) in 120 healthy adults. We evaluated the impact.

Background

Dietary strategies for obese and hyperglycemic patients include replacing weight-producing dietary sugar with NNS. These strategies assume that NNS are metabolically inactive and unable to induce postprandial glycemic responses. popular, but efficacy of Such dietary strategies remain unclear.

Furthermore, there is a paucity of studies demonstrating how metabolically inactive substances affect human metabolism. Therefore, the use of NNS is still widely advocated by adult nutritionists worldwide. However, especially with children, a more cautious approach is required.

About research

In the current trial, researchers administered two sachets of each NNS supplement (aspartame, saccharin, sucralose, stevia) three times daily, with glucose as a bulking agent, at four doses corresponding to an Acceptable Daily Intake (ADI) of 8. It was characterized by flocks. %, 20%, 34%, and 75% respectively. The 5th arm participant she took 5 grams of glucose per day and the 6th arm took no supplements (NSC group).

This study had three different periods, from the first 7 days of baseline measurements of metabolic, metabolomics, and microbial parameters to 14 days of exposure to four NNSs. .

The researchers instructed all study participants between the ages of 18 and 70 to wear a continuous glucose monitor (CGM) for the duration of the 29-day trial, which was used in a prespecified study. A glucose tolerance test (GTT) was performed daily. For example, he self-performed anthropometric measurements and blood tests on days 0, 14, and 28 of the study. All participants performed his 9th GTT at home. CGM he recorded interstitial glucose every 15 minutes, and the data from that helped the researchers calculate the incremental area under the glucose curve (iAUC).

Additionally, the team used two linear mixed-effects models (LMMs) to assess the impact of NNS consumption over time for all GTTs. Similarly, researchers collected microbiome samples from the oral cavity and stool at predetermined time points. In addition, researchers asked all participants to record their food intake and physical activity in real time using a mobile application.

Study participants provided the frequency of NNS consumption (never, daily, weekly, monthly) based on consumption of NNS-containing products available in the Israeli market, such as carbonated diet drinks. sugar-free energy drinks; products labeled as diet/low/sugar-free;

Survey results

The researchers screened 1,375 people between 2018 and 2020, but 20 participants in each group (120 total) completed the trial and provided sufficient glucose readings for analysis. The median age of study participants was approximately 30 years and 65% were female.

Saccharin, sucralose, aspartame, and stevia significantly altered the human gut and oral microbiome. During his first week of exposure, normalized glycemic responses were significantly higher in the sucralose and saccharin groups than in the glucose vehicle and his NSC groups, as assessed by two-way analysis of variance (ANOVA). rice field. This elevated glycemic response persisted through the second week of exposure, but then returned to baseline during follow-up. The authors observed considerable interindividual heterogeneity ranging from 1,225 to 7,458 mg dL.⁻¹ minutes⁻¹ at each participant’s GTT-iAUC. However, baseline GTTs for the same individual were similar and correlated with each other, with a Spearman coefficient (r) of 0.44.

Interestingly, the authors also noted intersubject variability in fecal excretion. Sucralose is poorly absorbed. Thus, orally-supplemented sucralose reaches the colon and is excreted unchanged in the feces. Furthermore, exposure to sucralose decreased the abundance of nucleotide biosynthetic genes, whereas its supplementation increased the abundance of genes associated with the tricarboxylic acid (TCA) cycle.Plasma TCA metabolism during sucralose supplementation. Elevated levels suggested a microbiome contribution and impaired glycemic control.

Conclusion

This study revealed that NNS commonly ingested by humans may not be physiologically inert. In fact, it transforms the human gut microbiota into a responsive hub by affecting several different configurations. They experienced sluggish insulin secretion, leading to elevated blood sugar levels.

Future studies should reveal the molecular mechanisms and clinical consequences of NNS consumption on the human microbiome. In addition, these studies should investigate the effects of conjugation of NNS and carbohydrate moieties on insulin sensitivity compared to NNS alone. This data could be of great help in optimizing dietary recommendations for hyperglycemic and obese patients.