Effect of Butyric Acid Treatment on Mucin Gene Expression in Caco-2 Cells and the Ability of Bacteria to Adhere to Intestinal Cells

This study examined the impact of a butyric acid treatment on mucin secretion and the expression of various mucin genes in a human colon-derived Caco-2 cell line, and bacteria adhesion.The Caco-2 cell line was treated with butyric acid at various concentrations, and mucin gene expression was analyzed using real-time polymerase chain reaction and the 2 -Ct method.An enzyme-linked immunosorbent assay was performed to quantify the mucin content, and immunohistological staining was used to examine mucin expression.In addition, the effects of butyric acid on the capacity of probiotics to adhere to Caco-2 cells and competition with Escherichia coli strains were also investigated.The expression levels of the MUC2, MUC5AC, and MUC12 genes increased significantly when butyric acid was added at concentrations above 4 mM.The administration of butyric acid at concentrations above 6 mM resulted in a significant increase in mucin levels compared to the control group.Immunohistochemical staining showed that Caco-2 cells treated with butyric acid at concentrations exceeding 6 mM showed a more intense staining pattern and markedly elevated the number of probiotics attached to Caco-2 cells.These findings suggest that butyric acid may impede the attachment of detrimental bacteria to intestinal cells by elevating the transcription of secretory mucin genes in intestinal cells, facilitating mucin secretion and enhancing the adherence of beneficial bacteria to intestinal cells.