Files
Abstract
Despite wide use in our diet, the effects of artificial sweeteners on human health have been inconsistent, with both beneficial and adverse outcomes being reported. Maintaining the balance of gut microbiota and its metabolic functions is vital for human health. However, this balance can be disrupted by various external factors, including chemicals from the diet. Interestingly, it has been reported that artificial sweeteners, such as saccharin, could alter gut microbiota and induce dysbiosis. Inflammation is one of the most common physical conditions associated with the dysbiosis of gut microbiota, which is involved in several diseases, such as inflammatory bowel disease, diabetes, and obesity. Acesulfame-potassium (Ace-K), sucralose and saccharin are three commonly used artificial sweeteners that are found in many foods and beverages and are generally considered to be safe when consumed within the approved amounts. However, little is known about the functional impact of these artificial sweeteners on gut microbiota. In this dissertation, the effects of Ace-K, sucralose and saccharin on gut microbiota and the changes of fecal metabolic profiles were explored using metagenome sequencing and metabolomics technologies. Also, inflammatory signs were investigated after the consumption of artificial sweeteners. All of these three artificial sweeteners perturbed the gut microbiota and metabolites in mice and increased the bacterial genes that could induce inflammation. In addition, Ace-K consumption for four weeks increased body weight gain and enriched functional bacterial genes of energy metabolism in CD-1 mice with highly sex-specific effects. Consumption of sucralose and saccharin for six months elevated expression of pro-inflammatory genes in the livers of C57BL/6J male mice. Collectively, the results may provide novel understanding of the interaction between artificial sweeteners and gut microbiota, and their potential role in the development of inflammation.