Scientist - News - 03-06-2009:

Gut microbiota plays a role in liver disease
Beintema, Nienke

A recent Italian study showed that the composition of the gut microbiota in the small intestine is correlated with non-alcoholic fatty liver disease (NAFLD).

NAFLD is an nflammatory condition of the liver. In contrast to the very similar condition that results from alcohol abuse, NAFLD has been associated with the metabolic yndrome, which in turn is related to insulin resistance. It is a condition often seen in obese people, but it may in rare cases be caused by hypersensitivity to certain medicines, malnutrition, and sudden changes in hormone levels, for instance during pregnancy.
It has been suggested that gut bacteria and/or the permeability of the gut may play a role in this disease, but this was never studied in detail. Researchers from the Catholic University of Rome now confirmed this link in a study published in the June issue of the journal Hepatology.

Bacterial overgrowth
The researchers examined 35 patients with NAFLD and 24 healthy volunteers. They assessed the presence of small intestinal bacterial overgrowth (SIBO) and intestinal permeability. Patients with NAFLD had significantly increased gut permeability compared with healthy subjects, and a higher prevalence of SIBO. Both parameters correlated with the severity of the build-up of fat in the liver.
Although they did not conduct an experiment to establish a causal relationship, the authors hypothesize that the two gut-related parameters may be the cause of the fat build-up. This notion is supported by studies on mice, and by reports that probiotics can reduce fat build-up that is the result of a high fat diet.
The article in Hepatology is accompanied by an editorial that is enthusiastic about the results. "It raises the possibility that gut microbiota and intestine permeability are important mediators of diet-induced metabolic disturbances in NAFLD," it states. Although both the original study and the editorial suggest that lifestyle therapy would be the preferred strategy for NAFLD patients, they suggest that manipulating gut flora by antibiotics, prebiotics, or probiotics could help combat the conditions associated with metabolic diseases.

More information:
Article in June issue of journal Hepatology
Editorial on this issue in Hepatology