Intestinal permeability

The "leaky gut" syndrome or increased intestinal permeability or chronic increase of intestinal permeability hypothesis states that certain stressors increase intestinal mucosal paracellular permeability, which allows harmful bacteria and bacterial toxins to cross through the lining of intestines (gut) into circulation in the body, which is then proposed causes widespread inflammation and triggers a variety of diseases. In a healthy digestive tract, the intestinal walls provide a tight, selective barrier to allow the absorption of nutrients but prevent the entry of bacteria or pathogens.

The leaky gut hypothesis has been linked to irritable bowel syndrome (IBS), Alzheimer's disease, asthma, type 2 diabetes, numerous gastrointestinal diseases, and many others illnesses, although evidence supporting this is largely limited or lacking.

Possible causes
The physiologic stressors proposed to cause intestinal permeability are anxiety, intense exercise, or components in food (such as emulsifiers), short chain fatty acids and lipopolysaccharides (LPS), and others.

Potential treatments

 * Dietary changes
 * Probiotics
 * Glutamine
 * Fecal matter transplant (FMT)
 * Leaky gut diet
 * Low sulfur diet

Notable studies

 * 2007, Normalization of the increased translocation of endotoxin from gram negative entero- bacteria (leaky gut) is accompanied by a remission of chronic fatigue syndrome (Full text)
 * 2007, Increased serum IgA and IgM against LPS of enterobacteria in chronic fatigue syn- drome (CFS): indication for the involvement of gram-negative enterobacteria in the etiology of CFS and for the presence of an increased gut-intestinal permeability (Full text)
 * 2013, High-throughput 16S rRNA gene sequencing reveals alterations of intestinal microbiota in myalgic encephalomyelitis/chronic fatigue syndrome patients (Full text)
 * 2015, Increased expression of activation antigens on CD8+ T lymphocytes in Myalgic Encephalomyelitis/chronic fatigue syndrome: inverse associations with lowered CD19+ expression and CD4+/CD8+ ratio, but no associations with (auto) immune, leaky gut, oxidative and nitrosative stress biomarkers (Abstract)
 * 2015, Changes in gut and plasma microbiome following exercise challenge in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (Full text)
 * 2016, The role of microbiota and intestinal permeability in the pathophysiology of autoimmune and neuroimmune processes with an emphasis on inflammatory bowel disease type 1 diabetes and chronic fatigue syndrome (Full text)
 * 2016, A role for the intestinal microbiota and virome in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (Full text)
 * 2018, The Emerging Role of Gut Microbiota in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Current Evidence and Potential Therapeutic Applications (Full text)
 * 2018, A role for a leaky gut and the intestinal microbiota in the pathophysiology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (Thesis - Full text)
 * 2020, The “Leaky Gut”: Tight Junctions but Loose Associations? (Full text)
 * 2020, Mitochondria and immunity in chronic fatigue syndrome (Full text)
 * 2021, The Emerging Role of Gut Microbiota in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Current Evidence and Potential Therapeutic Applications (Full text)
 * 2021, Tryptophan Metabolites, Cytokines, and Fatty Acid Binding Protein 2 in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (Full text)