Mucin

Paracellular transport

Ecology

Amino acid

Biology

Permeability (electromagnetism)

Claudin

Skin barrier

Intestinal mucosa

Dermatology

Biochemistry

Indole test

Secretion

Caco-2

Immunology

Genetics

Transcellular

Membrane

Epithelium

Microbiology

Tryptophan

Internal medicine

Goblet cell

Mucus

Medicine

Chemistry

Occludin

Cell

Tight junction

Intestinal permeability

Journal of Agricultural and Food Chemistry

Destruction in intestinal barrier is concomitant with the intestinal diseases. There is growing evidence that tryptophan-derived intestinal bacterial metabolites play a critical role in maintaining the balance of intestinal mucosa. In this study, the Caco-2/HT29 coculture model was used to evaluate the effect of indole-3-propionic acid (IPA) on the intestinal barrier and explore its underlying mechanism. We found that IPA increased transepithelial electrical resistance and decreased paracellular permeability which was consistent with the increase in tight junction proteins (claudin-1, occludin, and ZO-1). Furthermore, IPA strengthened the mucus barrier by increasing mucins (MUC2 and MUC4) and goblet cell secretion products (TFF3 and RELMβ). Additionally, IPA weakened the expression of LPS-induced inflammatory factors. These discoveries provide new views for understanding the improvement of intestinal barrier by gut microbial metabolites of aromatic amino acids.

Indole-3-propionic Acid Improved the Intestinal Barrier by Enhancing Epithelial Barrier and Mucus Barrier