Abstract:

Objective To intervene in mice with artificially synthesized sweetener aspartame，explore its effects on the intestinal barrier and intestinal microflora of mice，and provide a basis for the health effects of additives. Methods The mice were randomly divided into a solvent control（Ctrl） group and an aspartame（Asp） group，with 10 mice in each group. Asp group mice were administered orally at a dose of 80 mg/（kg·d），while Ctrl group mice were given an equal amount of distilled water once a day. After 2 months，HE staining was used to detect the pathological changes in mouse colon tissues. Western blot was used to detect the expression levels of tight junction proteins in mouse colon tissue，including occludin and ZO-1.The effects of aspartame on mouse intestinal microflora were analyzed using high-throughput sequencing of the 16S rRNA gene. Results The HE staining results showed that the colon tissue of Asp group mice showed erosion，incomplete mucosal epithelium，and a small amount of connective tissue proliferation，accompanied by scattered granulocyte infiltration，and a small amount of mucosal epithelial cell watery degeneration，and swelling of mucosal epithelial cells. The results of Western blot showed that compared with the Ctrl group，the expression levels of occludin and ZO-1 in the Asp group mice were reduced. The analysis of gut microbiota showed that aspartame reduced the α-diversity and β-diversity of gut microbiota. At the phylum level，compared with the Ctrl group，the relative abundance of Actinobacteriota in the Asp group mice increased，while the relative abundance of Verrucomimicrobiota decreased. At the family level，the relative abundance of Streptococcaceae increased in the Asp group mice，while the relative abundance of Clostridia_UCG-014，Akkermansiaceae，and Ruminococcaceae_UCG-010 decreased. At the genus level，the relative abundance of Peptostreptococcaceae in the intestines of Asp group mice increased，while the relative abundance of Clostridi_UCG-014，Akkermansia，and Ruminococcaceae_UCG-010 decreased. Compared with the Ctrl group，the Asp group mice showed a decrease in the gut microbiota health index and an increase in the gut microbiota dysbiosis index. Conclusion Aspartame can cause damage to the intestinal barrier，and alter the intestinal microflora.

Key words: Aspartame, Intestinal barrier, Intestinal microflora, Tight junction proteins, Gut microbiota health index, Gut microbiota dysbiosis index