Diet, food components and the intestinal barrier

Abstract

The majority of dietary nutrient absorption occurs in the small intestine, with the intestinal epithelium acting as a barrier to the contents of the intestinal lumen. This barrier is maintained by intestinal epithelial cells, which support nutrient uptake but prevent translocation of bacteria, allergens and toxins. There is complex signalling and interaction between intestinal epithelia, macrophages, luminal contents and the microbiota which can modulate epithelial paracellular porosity. Intake of alcohol, fatty acids, pharmaceuticals and pathogenic bacteria has been reported to increase paracellular permeability, increase production of pro‐inflammatory cytokines and temporarily reorganise tight junctional proteins. Conversely, numerous probiotics, nutraceuticals and food‐derived bioactive components are promising due to reported restoration of intestinal barrier integrity by increasing production of anti‐inflammatory cytokines and increased expression of tight junctional proteins. In vitro co‐culture models exist and recent advances in microfluidic in vitro models are promising tools for investigating the complex effect of dietary components on the intestinal barrier. Temporarily perturbing the intestinal barrier may increase the oral bioavailability of therapeutic molecules. However, people with impaired intestinal integrity (e.g. those with Crohn's, coeliac or ulcerative colitis disease) should avoid foods which further perturb barrier integrity, while increasing intake of specific foods and possibly probiotics to promote intestinal barrier restoration.

Gelatin-Graphene Oxide Nanocomposite Hydrogels for Kluyveromyces lactis Encapsulation: Potential Applications in Probiotics and Bioreactor Packings

“…Such a physiological barrier poses a significant obstacle for absorption of administered compounds since the thickness varies from 30 to 300 µm, increasing from the intestine to the rectum [12]. Consequently, only a tiny fraction (tight junction proteins allow the exchange of molecules with molecular weight < 500 Da [13]) made it to the systemic circulation. For these reasons, it is of paramount importance to design encapsulating materials that not only can protect the cargoes but transiently maintain high levels of the bioactive compounds as they transit the lower portion of the GI tract.…”

The Gut–Liver Axis in Chronic Liver Disease: A Macrophage Perspective

“…Currently, modulation of intestinal microbiota and enhancing gut barrier integrity are being explored as therapeutic strategies in ALD [ 231 ]. In this regard, dietary intervention, either via pre- and/or probiotics, specific food intake, nutrient supplementation, or a combined approach [ 230 , 232 , 233 , 234 , 235 , 236 , 237 , 238 , 239 , 240 , 241 ], are the most extensively tested approaches thus far, both in ALD models and patients.…”

Recent Advancement in Chitosan-Based Nanoparticles for Improved Oral Bioavailability and Bioactivity of Phytochemicals: Challenges and Perspectives

“…Moreover, the oral bioavailability and bioactivity of phytochemicals can vary after processing, long-term storage, and oral intake due to modulation in the physicochemical properties [18,19]. In addition, the bioavailability and bioactivity of phytochemicals are greatly affected by quantity, composition, and other foods consumed with particular phytochemicals [20,21]. Furthermore, phytochemicals greatly vary from each other in terms of polarity, charge, functional groups, and molecular weights, which is also a reason for the significant differences in their solubilities in different solvents, partitioning, stability in different environmental conditions, and physical states [8].…”