During the 13th Probiotics, Prebiotics and New Foods Congress, Microbiomepost.com conducted an exclusive interview with Arthur Ouwehand, Technical Fellow at IFF Finland.

The intestinal barrier is essential for maintaining human health by separating the contents of the gut from the internal milieu of the body. In its strictest sense, this barrier consists of a single layer of epithelial cells with tightly regulated junctions. In a broader view, it also includes the overlying mucus layer, the resident gut microbiota, and the underlying immune system, which together form a dynamic interface between the host and the external environment. 

When epithelial cells or their tight junctions are damaged, luminal components can cross the barrier, activating the immune system, driving inflammation, and contributing to disease. This can create a self-perpetuating cycle, as seen for example in metabolic syndrome, where impaired barrier function promotes inflammation, which in turn further weakens the barrier.

Dietary strategies offer an opportunity to modulate and reinforce this barrier. Probiotics, often used alongside dietary fibers and prebiotics, can beneficially influence the gut microbiota and support barrier function. Certain probiotic strains have been shown to help reduce inflammation, promote epithelial repair, and restore or maintain a functional mucus layer, thereby improving overall barrier integrity. In this presentation, I discuss the components and vulnerabilities of the gut barrier, review how probiotics and related dietary interventions can support its structure and function, and explore the broader implications for health and disease prevention.