Assessing the proinflammatory potential of sterile fecal microbiome filtrate from ulcerative colitis patients using an intestine-on-chip platform and automated image analysis.
FMF from active ulcerative colitis patients can induce a strong pro-inflammatory response in an intestine-on-chip model, but the clinical implications remain to be fully understood.
Where it sits
this study against the rest of the melanotan i (mt-i) corpusSummary and findings
This study investigated the pro-inflammatory effects of sterile fecal microbiome filtrate (FMF) from ulcerative colitis (UC) patients using an intestine-on-chip model. The research involved 6 UC patients with active disease, 4 in remission, and 5 non-UC individuals. Significant increases in pro-inflammatory cytokines were observed in response to FMF from active UC patients.
Abstract
<h4>Background and aims</h4>Ulcerative colitis (UC) is characterized by disruptions of the gut microbiome and an exaggerated mucosal immune response in genetically susceptible individuals. Alterations in the composition of the intestinal metabolome associated with dysbiosis can trigger chronic inflammation. However, it remains unclear whether microbial dysbiosis is the cause or consequence of chronic mucosal inflammation. To address this gap, we aimed to investigate the potential pro-inflammatory effects of sterile fecal microbiome filtrate (FMF) using a microphysiological, immunocompetent intestine-on-chip (IoC) model.<h4>Methods</h4>Sterile FMF from UC patients with active disease (<i>n</i> = 6) or in remission (<i>n</i> = 4) and non-UC individuals (<i>n</i> = 5) were applied to IoC models. Cytokine responses of the epithelial and endothelial compartments were assessed after 24 h, 48 h, and 72 h of incubation, while barrier permeability was evaluated after a period of 72 h. An artificial intelligence-driven image analysis pipeline was developed to quantify structural alterations of the epithelial tissue, including damage and thickness, as well as endothelial and immune cell densities in the IoC model in response to FMF exposure.<h4>Results</h4>FMF from active UC patients significantly increased proinflammatory cytokines (IL-1β, IL-6, IL-8, IL-23, and MCP-1) in the vascular IoC compartment in a time-dependent manner. In contrast, FMF from non-UC or UC patients in remission had no significant impact on the proinflammatory cytokine response compared to untreated media control. Luminal-vascular permeability was increased following the FMF treatment regardless of its origin. Image-based analysis revealed increased epithelial tissue damage and reduced tissue thickness following FMF exposure, alongside decreased endothelial cell density and altered macrophage morphology, independent of UC disease activity.<h4>Conclusions</h4>FMF from UC patients with active disease induces a robust proinflammatory cytokine response in the IoC model, suggesting that UC-associated FMF-derived factors may contribute to the initiation of inflammatory processes relevant to UC pathogenesis. These findings are derived from a simplified intestinal barrier model and require further mechanistic and physiological validation. While image analysis revealed no significant microarchitectural differences among the three FMF groups, the pipelines established standardized metrics to evaluate the impact of FMF-derived factors on intestinal tissue integrity and immune responses, providing a framework for future IoC-based research in UC.
Background
Ulcerative colitis (UC) is associated with gut microbiome disruptions and an exaggerated immune response. Previous studies have linked dysbiosis to chronic inflammation, but the causal relationship remains unclear. This study aims to clarify whether microbial dysbiosis contributes to inflammation in UC by examining the effects of FMF from UC patients in an intestine-on-chip model.
Methods
The study utilized an intestine-on-chip (IoC) model to assess the effects of sterile FMF from 6 active UC patients, 4 UC patients in remission, and 5 non-UC individuals. The cytokine responses were measured after 24 h, 48 h, and 72 h of incubation, while barrier permeability was evaluated after 72 h. An AI-driven image analysis pipeline quantified structural changes in the epithelial tissue.
Results
FMF from active UC patients significantly increased pro-inflammatory cytokines in a time-dependent manner. In contrast, FMF from non-UC individuals or UC patients in remission did not significantly impact cytokine responses compared to controls. Increased epithelial damage and altered immune cell morphology were also observed.
Interpretation
The results suggest that FMF from active UC patients can induce a significant pro-inflammatory response, aligning with previous literature that highlights the role of the microbiome in UC pathogenesis. However, the clinical significance of these findings is uncertain due to the small sample sizes and the use of a simplified model. The study's limitations, including the lack of human data beyond the model, may affect the applicability of the results to clinical practice.
Key findings
- FMF from active UC patients significantly increased IL-1β, IL-6, IL-8, IL-23, and MCP-1 in the vascular IoC compartment.
- Cytokine responses were assessed at 24 h, 48 h, and 72 h of incubation.
- Luminal-vascular permeability was increased following FMF treatment regardless of its origin.
- Increased epithelial tissue damage and reduced tissue thickness were observed after FMF exposure.
- Decreased endothelial cell density and altered macrophage morphology were noted independent of UC disease activity.
Limitations
- small sample sizes (n=6 active, n=4 remission, n=5 non-UC)
- study based on a simplified intestinal barrier model
- requires further mechanistic and physiological validation
- no significant microarchitectural differences among FMF groups