Leaky gut syndrome
Leaky gut syndrome describes a condition of altered or damaged bowel lining, caused by toxins, poor diet, parasites, infection or medications, which has led to increased permeability of the gut wall to substances which normally remain isolated in the lumen, away from the body's internal circulatory or interstitial areas.[1] NSAIDS such as aspirin are known to erode the gut lining and cause inflammation[2], other medications such as corticosteroids suppress immune function and disturb intestinal flora[3][4][5], and antibiotics indiscriminately kill bacteria causing bacterial flora disruptions in the small intestine[6].
It has been proposed that, when substances such as toxins, microbes, undigested food, waste or larger than normal macromolecules leak through an abnormally-permeable gut wall, they affect the body directly, while others postulate an immune reaction to these substances.[7]
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[edit] Hypotheses
Doctors or other health care practitioners who diagnose this syndrome explain that intestinal inflammation which may originate from intestinal dysbiosis or other sources of irritation, widens the junctions between the cells of the intestinal lining, allowing endotoxins and incompletely digested particles to be partially absorbed. These are targeted by antibodies, forming immune complexes which cause a semi-infectious state and can be carried by the bloodstream to distant sites where they may stimulate the release of cytokines. Low grade fever, transient gut pain, and a sense of inability to absorb nutrients are some reported symptoms in otherwise undiagnosed patients.[8][9].
[edit] Controversy
While many practitioners maintain that leaky gut syndrome is a bona fide medical condition, the area of "gut problems" lies between conventional and alternative medicine, and includes other diagnoses such as small bowel bacterial overgrowth syndrome or small intestine bacterial overgrowth (SIBO), and yeast syndrome or systemic candidiasis, and remains controversial and scientifically unsettled.[10]
Alternative practitioners believe that leaky gut syndrome is a possible starting point or connection with many disorders such as asthma, diabetes, autoimmune diseases like lupus, diseases like scleroderma, internal colitis, long term disorders like rheumatoid arthritis, severe illnesses like multiple sclerosis and chronic fatigue syndrome and Crohn's disease. [11]
[edit] Autism
Andrew Wakefield has proposed a condition called Autistic enterocolitis to describe a condition where bowel disorders can contribute to autism,[12]. However 10 of the 13 authors of the paper have since retracted its interpretations[13], and Wakefield is accused by the British General Medical Council (GMC) of suppressing and falsifying data[14].
Parents have reported gastrointestinal (GI) disturbances in autistic children, and several studies have investigated possible associations between autism and the gut.[15] The disputed Wakefield et al. paper also suggested that some bowel disorders may allow antigens to pass from food into the bloodstream and then to contribute to brain dysfunction.[12] Although Wakefield later proposed the term autistic enterocolitis, his studies' methodology has been criticized, their results have not been replicated by other groups,[16] and Wakefield has been accused of manipulating patient data and misreporting results.[17]
There is no research evidence that autistic children are more likely to have GI symptoms than typical children.[15] In particular, design flaws in studies of elimination diets mean that the currently available data are inadequate to guide treatment recommendations.[18] A 2008 study found that children with autism had no more peptides in their urine than typical children, casting doubt on the proposed mechanism underlying the leaky-gut theory.[19]
In another example, a 1998 study of three children with ASD treated with secretin infusion reported improved GI function and dramatic improvement in behavior, which suggested an association between GI and brain function in autistic children, although the low number of patients is statistically insignificant.[20] After this study, many parents sought secretin treatment and a black market for the hormone developed quickly.[15] However, later studies found secretin ineffective in treating autism.[21]
[edit] Treatment
Leaky gut syndrome theories inspired several dietary treatments, including gluten-free diets, casein-free diets, antifungal diets, low-sugar diets, as well as supplements that include nystatin, B12, and probiotics. These treatments are cumbersome and not proven to be efficacious in the treatment of autism. [22]
[edit] References
- ^ Liu Z, Li N, Neu J (April 2005). "Tight junctions, leaky intestines, and pediatric diseases". Acta Paediatr. 94 (4): 386–93. PMID 16092447.
- ^ NSAIDS#Gastrointestinal
- ^ Prednisone
- ^ Glucocorticoid
- ^ Immunosuppressive drug
- ^ Intestinal flora#Alterations_in_flora_balance
- ^ Kiefer D, Ali-Akbarian L (2004). "A brief evidence-based review of two gastrointestinal illnesses: irritable bowel and leaky gut syndromes". Altern Ther Health Med 10 (3): 22–30; quiz 31, 92. PMID 15154150.
- ^ Leaky Gut Syndromes: Breaking the Vicious Cycles. Galland L. Townsend Letter for Doctors, August/September 1995, p. 63.
- ^ http://www.mdheal.org/leakygut.htm Galland 1995 fulltext article
- ^ Pizzorno, JE, Murray, MT, (November 2005) Textbook of Natural Medicine, 3rd edition, Churchill Livingstone, pp 167, 584, 1527 ISBN 0-443-07300-7
- ^ Leaking Gut Syndrome
- ^ a b Wakefield A, Murch S, Anthony A et al. (1998). "Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children". Lancet 351 (9103): 637–41. doi:10.1016/S0140-6736(97)11096-0. PMID 9500320. http://briandeer.com/mmr/lancet-paper.htm. Retrieved 2007-09-05.
- ^ McKee, Maggie (2004-03-04). "Controversial MMR and autism study retracted". New Scientist. http://www.newscientist.com/article.ns?id=dn4743. Retrieved 2007-08-10.
- ^ Fitzpatrick M (2007-07-04). "'The MMR-autism theory? There's nothing in it'". spiked. http://spiked-online.com/index.php?/site/article/3562/. Retrieved 2008-01-22.
- ^ a b c Johnson TW (2006). "Dietary considerations in autism: identifying a reasonable approach". Top Clin Nutr 21 (3): 212–25.
- ^ MacDonald TT, Domizio P (2007). "Autistic enterocolitis; is it a histopathological entity?". Histopathology 50 (3): 371–9. doi:10.1111/j.1365-2559.2007.02606.x. PMID 17257133.
- ^ Deer B (2009-02-08). "MMR doctor Andrew Wakefield fixed data on autism". Sunday Times. http://www.timesonline.co.uk/tol/life_and_style/health/article5683671.ece. Retrieved 2009-02-09.
- ^ Christison GW, Ivany K (2006). "Elimination diets in autism spectrum disorders: any wheat amidst the chaff?". J Dev Behav Pediatr 27 (2 Suppl 2): S162–71. doi:10.1097/00004703-200604002-00015. PMID 16685183.
- ^ Cass H, Gringras P, March J et al. (2008). "Absence of urinary opioid peptides in children with autism". Arch Dis Child 93 (9): 745–50. doi:10.1136/adc.2006.114389. PMID 18337276. Lay summary – BBC News (2008-03-17).
- ^ Horvath K, Stefanatos G, Sokolski KN, Wachtel R, Nabors L, Tildon JT (1998). "Improved social and language skills after secretin administration in patients with autistic spectrum disorders". J Assoc Acad Minor Phys 9 (1): 9–15. PMID 9585670.
- ^ Sturmey P (2005). "Secretin is an ineffective treatment for pervasive developmental disabilities: a review of 15 double-blind randomized controlled trials". Res Dev Disabil 26 (1): 87–97. doi:10.1016/j.ridd.2004.09.002. PMID 15590241.
- ^ Johnson TW (2006). "Dietary considerations in autism: identifying a reasonable approach". Top Clin Nutr 21 (3): 212–25.
