Live probiotic bacteria administered in a pathomimetic Leaky Gut Chip ameliorate impaired epithelial barrier and mucosal inflammation

Abstract

Here, we report a pathomimetic Leaky Gut Chip that recapitulates increased epithelial permeability and intestinal inflammation to assess probiotic intervention as live biotherapeutics. We leveraged a mechanodynamic human gut-on-a-chip (Gut Chip) that recreates three-dimensional epithelial layers in a controlled oxygen gradient and biomechanical cues, where the addition of a cocktail of pro-inflammatory cytokines, TNF-α and IL-1β, reproducibly induced impaired epithelial barrier followed by intestinal inflammation. This inflamed leaky epithelium was not recovered for up to 3 days, although the cytokine treatment ceased. However, when probiotic bacteria, either Lactobacillus rhamnosus GG or a multi-species mixture (VSL#3), were respectively administered on the leaky epithelium, bacterial cells colonized mucosal surface and significantly improved barrier function, enhanced the localization of tight junction proteins such as ZO-1 and occludin, and elevated mucus production. In addition, inflammatory markers, including p65, pSTAT3, and MYD88, that were highly expressed in the germ-free control were significantly reduced when probiotic bacteria were co-cultured in a Leaky Gut Chip. Probiotic treatment also significantly reduced the production of secretory pro-inflammatory cytokines. Hence, our pathomimetic Leaky Gut Chip may offer a translational strategy to dissect the therapeutic mechanism of live biotherapeutic products and validate their clinical potential by incorporating patient-derived organoids.

Pathophysiology updates: gastroduodenal injury and repair mechanisms

“…Using this model, numerous studies were done to examine the role of microbiota and immune interactions in barrier function/dysfunction, cell death and matrix remodeling [14 ▪ ], which will greatly impact cell injury and subsequent repair mechanisms. In a second study, leaky gut syndrome was modeled in a gut-on-chip using cultured cells, matrix, luminal flow, an oxygen gradient, and peristalsis to recapitulate small intestinal function [15]. Leaky gut was accomplished by cytokine administration with different probiotic bacterial types tested for their efficacy in protection against cytokine-induced barrier dysfunction.…”

The Impact of Microbiome Interventions on the Progression and Severity of Inflammatory Bowel Disease: A Systematic Review

“…This technique is intended to normalize the dysbiotic intestinal environment. Probiotics are live beneficial bacteria that can potentially suppress proinflammatory responses and enhance the gut's barrier function [ 19 ]. Different strains may have varying effects on IBD activity.…”

“…Emerging evidence suggests that microbiome-directed therapies may reduce intestinal inflammation, restore microbial diversity, and induce remission in IBD [ 18 ]. Probiotics, live beneficial bacteria, have shown a potential to dampen proinflammatory responses and improve epithelial barrier integrity [ 19 ]. Prebiotics, dietary fibers promoting the growth of commensal bacteria, may also confer anti-inflammatory effects [ 20 ].…”

Microfluidic organotypic device to test intestinal mucosal barrier permeability ex vivo

“…2 Leaky gut has been associated with the pathogenesis of conditions such as inflammatory bowel diseases (IBD), [9][10][11] autoimmune diseases such as celiac disease, 2 neurodegenerative disorders such as Alzheimer's and Parkinson's disease, 12,13 and neurodevelopmental disorders such as autism spectrum disorder. 14 Generation of an intestinal model that maintains the complexity of intestinal anatomy, microenvironment, and barrier is necessary to better understand how alterations in barrier integrity may contribute to disease states.…”