Mucosal Barrier Defects in IBS. Who left the door open?

Summary

IBS patients
activated T lymphocytes and mast cells
increased mediators (epitehalial, neuronal, and muscle cells
predominant diarrhea-->increased permeability of mucosal barrier
mucosal barrier defects--> antigens from diet and bacteria pass through



Background

neuromuscular layers of the gut: sensory and motor dysfxn
psyhological component
new research: mucosa
“ ‘normal’ endoscopy or conventional histology”
increased
amounts of immunocytes ( T lymphocytes and mast cless)
histamine, proteases, and prostaglandins
mediators-->signal cells (epithelial, neuronal, muscles)
mucosal barrier defects--> antigens from diet and bacteria pass through
varied pathophysiology for different types of IBS
mucuosal layer
passage & selective permeation
mucus layer
enterocytes
intercellular tight junctions
Dunlop et al study
integrity by urinary excretion of radio-labeled prob Cr-EDTA
Theory: Since pathogens-->increase mucousal permeability-->post infectious IBS patients-->lack recovery of intercellular tight jxn recovery (intercell jxn problem post- acute infection)-->prostaglandin passage-->diarrhea
Mice study proves this (13)
Theory: mucosal inflammation (due to IBS)-->Diarrhea
Direct stimulation: epithelial ion



More studies to look into
10- enteric bacteria increase permeability
Dunlop et al “Abnormal intestinal permeability in subgroups of diarrhea predominant IBS”