Research is confirming that liver disease is associated with leaky gut syndrome, as well as the health of our microbiome.
Yes, alcohol certainly hurts the liver, and many cases of liver disease are caused by drinking too much. But this is not the only type of liver disease.
In fact, chronic liver disease is often of a type called nonalcoholic liver disease – a chronic disorder that has mystified medical researchers and doctors over recent years, as the incidence of nonalcoholic liver disease – also called NAFLD for nonalcoholic fatty liver disease – has expanded among western countries.
There are some rather surprising relationships between liver disease and our gut health.
One of these is that our gut’s bacteria. Our gut bacteria – whether probiotic or pathogenic – together makes up what is referred to as our microbiome.
Gut bacteria and nonalcoholic liver disease
Several studies have linked nonalcoholic liver disease with an increase in pathogenic bacteria within the small intestines.
For example, researchers from the National University of Ireland studied 18 nonalcoholic liver disease patients together with 16 healthy people who were matched for age and sex.
The research found that the nonalcoholic patients had over double the frequency of small intestine bacterial overgrowth compared to the healthy patients.
In another study – this from Rome’s Catholic University – researchers examined 35 patients with nonalcoholic liver disease along with 24 matched healthy volunteers. This study tested patients using glucose breath tests – which reveal intestinal overgrowth because of the byproducts of bacteria overgrowth.
Again the research found that bacterial overgrowth – meaning pathogenic – was significantly higher in the nonalcoholic liver disease patients.
Several other studies have also put these pieces together.
What does bacterial overgrowth mean?
While the terminology relates to bacteria, it can also be contributed by fungal overgrowth. Basically, the overgrowth of bacteria and yeasts within our small intestines means that microorganisms that are not healthy for us have taken over and diminished the healthy gut bacteria – probiotics – existing within our small intestines.
The small intestines are differentiated between the colon in these studies, because, first, the colon is examined differently – typically by stool analysis. But stool analysis can also reveal both small and large intestine overgrowth – so it is more difficult to distinguish.
The reason this is critical for our understanding of the liver disease is that pathogenic bacteria produce something called endotoxins – their waste products. When these waste products enter our bloodstream through our intestinal walls, they must be filtered out by the liver – because the liver filters toxins from the blood.
This issue of these endotoxins leaking through the walls of the intestines becomes more of an issue when the walls of the intestines allow more of these waste metabolites into the bloodstream.
As I prove in my book – “The Science of Leaky Gut Syndrome” – leaky gut syndrome is not just an anecdotal condition professed by natural health proponents.
In addition to linking nonalcoholic liver disease to bacteria overgrowth, the Rome University study – among others – also found that increased intestinal permeability – the medical term for leaky gut – is significantly more prevalent in these liver disease cases.
To this we can add a new study from the School of Medicine at Brazil’s Universidade Federal de Minas Gerais. Here 15 patients who had nonalcoholic liver disease and were headed for liver transplantation were tested and compared with 15 healthy volunteers.
In this study, increased intestinal permeability was significantly more prevalent among the liver patients compared with the healthy control subjects.
What about alcoholic liver disease?
These relationships – between bacteria overgrowth and intestinal permeability and the liver’s health – are not only linked in nonalcoholic liver disease.
The reality is that alcohol deters the health of our probiotics, and thus also permits the overgrowth of pathogenic bacteria in the gut. And as I showed in my book, The Science of Leaky Gut Syndrome, alcohol also promotes increased intestinal permeability – allowing more of the endotoxins from bacteria entry into the bloodstream – which also harms the liver.
In addition to this, ethanol metabolites also directly harm the liver.
Wang L, Llorente C, Hartmann P, Yang AM, Chen P, Schnabl B. Methods to determine intestinal permeability and bacterial translocation during liver disease. J Immunol Methods. 2015 Jan 13. pii: S0022-1759(15)00005-8. doi: 10.1016/j.jim.2014.12.015.
Scarpellini E, Lupo M, Iegri C, Gasbarrini A, De Santis A, Tack J. Intestinal Permeability In Non-Alcoholic Fatty Liver Disease: The Gut-Liver Axis. Rev Recent Clin Trials. 2014 Dec 15.
Costa Liboredo J, Abreu Ferrari ML, Garcia Vilela E, Soares Lima A, Toulson Davisson Correia MI. The effect of Saccharomyces boulardii in patients eligible for liver transplantation. Nutr Hosp. 2014 Sep 12;31(n02):778-784.
Ferolla SM, Armiliato GN, Couto CA, Ferrari TC. The role of intestinal bacteria overgrowth in nonalcoholic fatty liver disease. Nutrients. 2014 Dec 3;6(12):5583-99. doi: 10.3390/nu6125583.
Shanab AA, Scully P, Crosbie O, Buckley M, O’Mahony L, Shanahan F, Gazareen S, Murphy E, Quigley EM. Small intestinal bacterial overgrowth in nonalcoholic steatohepatitis: association with toll-like receptor 4 expression and plasma levels of interleukin 8. Dig Dis Sci. 2011 May;56(5):1524-34. doi: 10.1007/s10620-010-1447-3.
Miele L, Valenza V, La Torre G, Montalto M, Cammarota G, Ricci R, Mascianà R, Forgione A, Gabrieli ML, Perotti G, Vecchio FM, Rapaccini G, Gasbarrini G, Day CP, Grieco A. Increased intestinal permeability and nonalcoholic fatty liver disease. Hepatology. 2009 Jun;49(6):1877-87. doi: 10.1002/hep.22848.
Case Adams is a California Naturopath and a Board Certified Alternative Medicine Practitioner with a PhD in Natural Health Sciences, and diplomas in Homeopathy, Aromatherapy, Bach Flower Remedies, Blood Chemistry, Clinical Nutritional Counseling and Colon Hydrotherapy. He has authored 26 books on natural healing strategies.