Endoscopic laser endomicroscopy and “leaky gut” in patients with functional gastrointestinal symptoms and food intolerance

Abstract

Background Intestinal epithelial barrier dysfunction (“leaky gut syndrome”, LGS) is thought to play a major role in the pathogenesis of disorders of the gut brain axis. Endoscopic confocal laser endomicroscopy (eCLE) is an objective measure to test duodenal permeability. We applied this technique in patients with functional gastrointestinal symptoms and food intolerance to characterize the proportion of patients with LGS.

Material and Methods In an observational study, we evaluated 85 patients with functional gastrointestinal symptoms and food intolerance. Gastrointestinal symptoms were classified according to Rom IV into functional abdominal pain (FAP), irritable bowel syndrome (IBS), irritable bowel syndrome diarrhea dominant (IBS-D), irritable bowel syndrome constipation dominant (IBS-C), irritable bowel syndrome with mixed stool (IBS-M), functional abdominal bloating (FAB), functional diarrhea (FD) and unclassified (NC). During eCLE, spontaneous transfer of intravenously applied fluorescein into duodenal lumen (LGS) and following duodenal food challenge (DFC) were analyzed. Blood analysis comprised parameters of mast cell function, histology of duodenal mucosal biopsies analysis of mucosal inflammation, intraepithelial lymphocytes (IELs) as well as number, distribution and morphology of mast cells.

Results 24 patients (9 IBS, 9 FAP, 3 FAB, 1 FD, 2 NC), showed LGS, 50 patients (14 IBS-D, 4 IBS-C, 3 IBS-M, 23 FAP, 3 FAB, 3 NC) had no LGS but responded to DFC and 11 patients (6 NC, 3 FAP, 1 FAB, 1 FD) had no LGS and no response to DFC. The proportion of subgroups with/or without spontaneous leakage of fluorescein (+LGS/-LGS) were IBS-LGS/IBS+LGS 67%/33%, FAP-LGS/FAP+LGS 72%/28%,FAB-LGS/FAB+LGS 50%/50%, NC-LGS/NC+LGS 60%/40%. Subgroup analysis revealed no significant differences for all parameters tested.

Conclusion As a proof of concept, the results of our study indicate that eCLE is a clinical useful tool to evaluate patients with disorders of the gut brain axis and those suspicious of LGS. However, the clinical significance of LGS remains unclear. The study should be an incentive to perform a randomized study including healthy controls.

Zusammenfassung

Hintergrund Eine Dysfunktion der intestinalen Barriere („Leaky-gut-Syndrom“, LGS) spielt wahrscheinlich eine bedeutende Rolle in der Pathogenese von Störungen der Darm-Hirn-Achse. Die endoskopische konfokale Laserendomikroskopie (eCLE) ist eine Technik zur objektiven Messung der duodenalen Permeabilität. Wir haben diese Technik zur Untersuchung von Patienten mit funktionellen gastrointestinalen Beschwerden und Nahrungsunverträglichkeiten zur Charakterisierung eines LGS eingesetzt.

Methode In einer prospektiven Beobachtungsstudie wurden 85 Patienten mit funktionellen gastrointestinalen Beschwerden und Nahrungsunverträglichkeiten mit der eCLE untersucht. Die gastrointestinalen Beschwerden wurden anhand des Rom-IV-Konsensus in funktionelle Bauchschmerzen (FAP), Reizdarmsyndrom (IBS), Reizdarmsyndrom Diarrhoe-dominant (IBS-D), Reizdarmsyndrom Obstipations-dominant (IBS-C), Reizdarmsyndrom mit unterschiedlichem Stuhlverhalten (IBS-M), funktionelle Blähungen (FAB), funktionelle Diarrhose (FD) und unklassifizierbare Beschwerden (NC) differenziert. Während der eCLE wurden der spontane Übergang von intravenös appliziertem Fluoescein in das Duodenallumen (LGS) bzw. nach duodenaler Nahrungsallergenprovokation (DFC) untersucht. Die Blutuntersuchungen beinhalteten u. a. Parameter der Mastzellfunktionen, die Histologie der Duodenalbiopsien, die Analyse von Entzündungen, intraepithelialen Lymphozyten (IELs) und die Anzahl, Verteilung und Morphologie der Mastzellen.

Ergebnisse 24 Patienten zeigten LGS (9 IBS, 9 FAP, 3 FAB, 1 FD, 2 NC), 50 Patienten (14 IBS-D, 4 IBS-C, 3 IBS-M, 23 FAP, 3 FAB, 3 NC) hatten kein LGS, reagierten aber auf die DFC und 11 Patienten (6 NC, 3 FAP, 1 FAB, 1 FD) hatten kein LGS und zeigten keine Reaktion auf DFC. Die Proportion der Subgruppen mit/oder ohne spontanen Übertritt von Fluorescein in das Duodenallumen (+LGS/-LGS) waren IBS-LGS/IBS+LGS 67%/33, FAP-LGS/FAP+LGS 72%/28%, FAB-LGS/FAB+LGS 50%/50%, NC-LGS/NC+LGS 60%/40%. Die Subgruppenanalyse ergab für alle getesteten Parameter keinen signifikanten Unterschied.

Schlussfolgerung Die Ergebnisse unserer “proof of concept”-Studie zeigen, dass die eCLE eine klinisch nützliche Untersuchungstechnik bei Patienten mit Störungen der Darm-Hirn-Achse und V. a. LGS ist. Die klinische Relevanz von LGS ist allerdings noch unklar. Die Ergebnisse sollten eine randomisierte Studie mit gesunden Kontrollen initiieren.

Keywords

Endoscopic laser endomicroscopy (eCLE) - “leaky gut syndrome” - functional gastrointestinal symptoms - irritable bowel syndrome (IBS) - disorders of the gut-brain-axis - food intolerance

Schlüsselwörter

Endoskopische Laserendomikroskopie (eCLE) - „leaky gut Syndrom“ - funktionelle gastrointestinale Beschwerden - Reizdarmsyndrom (IBS) - Störungen der Darm-Hirn-Achse - Nahrungsunverträglichkeiten

Publication History

Received: 26 June 2022

Accepted after revision: 06 October 2022

Article published online:
23 November 2022

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