Banana Starch Nanoparticles Disrupt the Integrity of the Intestinal Barrier by Opening Tight Junctions in Mice

The banana-derived starch nanoparticles have been extensively used in food and biomedicine industries, due to their unique physicochemical properties and functional benefits. With their pervasive presence in food, people are significantly exposed to these nanoparticles, raising concerns about their potential health risks and impact on intestinal health. However, there is still limited understanding of the direct interaction between native banana starch nanoparticles (BSNs) and the intestinal systems. Here, it is demonstrated that BSNs can cause tight junctions to loosen, increase intestinal permeability, and disrupt the intestinal barrier. This increased permeability is closely linked to the size of BSNs, with smaller BSNs (d = 60 nm) having a stronger effect on permeation. Furthermore, the disruption of the intestinal barrier integrity caused by BSNs is connected to a reduced amount of tight junction proteins. Mechanistically, BSNs disrupt tight junctions by affecting mitochondrial function and activating myosin light chain kinase (MLCK) signaling pathway. These findings indicate that BSNs have the potential to pose health risks by compromising the integrity of the intestinal barrier, reminding the safety of food biopolymer nanoparticles in living organisms needs to be re-assessed.