Can Consuming Nonsugar Sweeteners Impact Gut Microbes and Inflammatory Markers?

A recent study conducted by researchers at Cedars-Sinai, Los Angeles, explored the effects of consuming nonsugar sweeteners (NSS) on the gut microbiome and inflammatory markers. The study analyzed samples from the REIMAGINE study and compared individuals consuming non-aspartame nonsugar sweeteners (NANS) and aspartame only (ASP) with a control group.

The findings revealed significant changes in both stool and duodenal microbial diversity and composition, as well as levels of circulating inflammatory markers. The duodenal alpha diversity was lower in NANS consumers compared to the control group. The relative abundance of Escherichia, Klebsiella, and Salmonella in the duodenum was lower in both NANS and ASP groups compared to the controls. However, the stool relative abundance of these Proteobacteria phylum was increased in both NANS and ASP groups.

The study also noted differences between NANS and ASP in their impact on predicted duodenal microbial metabolic pathways. NANS consumption affected polysaccharides biosynthesis and D-galactose degradation, while ASP significantly enriched the biosynthesis of cylindrospermopsin, a potential cancer-causing agent known to adversely affect the liver and nervous system.

Furthermore, the circulating levels of interleukin (IL)-1b, a pro-inflammatory cytokine, were significantly decreased in NANS consumers compared to the controls. In the ASP group, IL-6 and IL-10, two cytokines with protective properties, were decreased compared to the controls.

Considering the crucial role of small intestinal microbes in digestion, nutrient absorption, immune regulation, and endocrine functions, these findings have potential implications for metabolic and gastrointestinal health, especially considering the substantial prevalence of NSS consumption among US adults.

It is important to note that the study has some limitations. The study population may not be representative of healthy individuals, as they underwent upper endoscopy for various reasons. The duodenal sample size for the aspartame group was small, and samples were collected at a single timepoint, limiting the establishment of causal relationships.

This research was supported by various charitable trusts, and the authors declared no conflicts of interest. The study was published in iScience on November 22, 2023.