Is the gut flora making our liver sick?

Liver cirrhosis, the terminal stage of many chronic liver diseases, is becoming increasingly widespread. The composition of the gut flora in people suffering from liver cirrhosis is severely disturbed. With the help of modern laboratory techniques, it has become possible to verify that there is a reduction of diversity and a predominance of pathogenic germs in the guts of liver cirrhosis patients.

An “oralisation” of the gut microbiome is especially suspicious. This means germs from the mouth can be found in increased numbers within the gut. At the same time the number of bacteria which have a positive effect on humans decreases. The implications of such changes in the gut flora are an increased permeability of the gut (a “leaky gut”) and the passing over of bacterial components into the blood stream. This leads to a chronic overburdening of the patient’s immune system which subsequently leads to the development of an immunodeficiency. This in turn presents itself in the form of frequent dangerous infections. Thus, the gut-liver axis plays a substantial role in the development of chronic liver diseases.

The current therapy strategies for liver cirrhosis are based on treatment or prevention of complications such as oesophageal bleeding or hepatic coma. Liver function can only by improved sustainably if either the cause for the liver cirrhosis (such as alcohol or hepatitis) can be resolved or by means of a liver transplantation. Therefore, it is definitely preferable to fight the negative effects of liver cirrhosis while the disease is still at an early stage.

According to the definition from the WHO (World Health Organisation), probiotics are “living microorganisms which when taken in a sufficient quantity have a health-promoting effect”. Via direct and indirect mechanisms, they can positively influence the gut-liver axis. For example, probiotic germs can drive out other pathogenic germs, strengthen the intestinal barrier, and have a balancing effect on the intestinal immune system. There are reports that probiotics can positively influence the development and severity of hepatic coma.

Therefore, we evaluated the effects of a probiotic on patients with liver cirrhosis at the Medical University of Graz. We carried out a double blinded, randomised, placebo controlled study. This means that half of the patients received the probiotic and the other half received a product which looked and tasted identical but contained no active bacteria. We evaluated the effects on the gut microbiome, the gut-liver axis, and liver function. We examined 101 patients to check if they were suitable for the study and could finally include 92 of them. The study participants received a specially developed probiotic, the dietary supplement OMNi-BiOTiC® HETOX or a placebo. Afterwards the patients were observed for another 6 months. Most of them concluded the study as planned; only a small portion dropped out early. Interestingly only one patient from the probiotic group decided to drop out, while 11 dropped out in the placebo group. This striking difference could mean that the patients in the probiotic group simply felt better in general and were therefore able to attend all the study visits despite their chronic disease. The participants were also extremely exact when it came to the correct dosage; virtually all sachets with the trial drug were taken. As expected, the patients suffering from liver cirrhosis had a radically changed gut flora. To some extent these alterations could be reversed by the application of the probiotic. Furthermore, an enrichment of the stool with lactobacilli could be shown in the patients which received the probiotic. This shows that the probiotic germs can colonise the gut at least for a little while.