Research
The regulated movement of molecules across the intestinal barrier.
Research library
Mechanistic · Editorial synthesis
Selective permeability is necessary physiology; scientific interpretation depends on route, magnitude, duration, context and evidence that regulation has become inappropriate.
Human observational · Editorial synthesis
Every permeability result is method-, route-, specimen-, time- and population-specific; no single measurement is equivalent to the intestinal barrier.
Mechanistic · Human observational · Systematic review · Meta-analysis · Editorial synthesis
Mechanism, biomarker, analytical assay and clinical use are separate evidentiary layers that must not be collapsed into one zonulin claim.
Human observational · Systematic review · Meta-analysis
A worked interpretation of observational evidence, heterogeneity and causal limits using Birna’s paediatric systematic review and meta-analysis.
Perspective · Regulation · Aug 25, 2026
Health lies less in maintaining a fixed state than in a system’s capacity to regulate, adapt and recover. Intestinal permeability provides a biological starting point for asking when a response is appropriate—and when regulation becomes dysregulation.
Evidence interpretation · Zonulin · Aug 25, 2026
Zonulin provides a concrete example of a wider scientific problem: turning a dynamic regulatory mechanism into a simple linear disease model. Each step from pathway to measurement, permeability and pathology requires its own evidence.