Published in the Journal of Functional Foods, the review looked at current data on the role of gut microbiota and its relationship with the immune system and the progression of liver diseases, as well as the use of different strains of bacteria for management of such conditions.
The researchers said probiotics showed promise for liver cirrhosis – scaring due to long-term liver damage – through local and systemic pathways moderating immune, inflammatory and fibrotic mechanisms.
However this could only be said for compensated cirrhosis - whereby the liver is severely scarred but has enough healthy cells to perform all its functions adequately - not decompensated cirrhosis when the liver is not capable of performing all its functions resulting in complications like fluid retention and mental confusion. For this latter condition they said probiotics had "little or no benefit".
“Probiotics seem a good adjuvant therapy under some specific characteristics,” wrote the researchers from the Obesity and Digestive Diseases Unit at the Mexican Medica Sur Clinic & Foundation and the Gastroenterology Department at the Pontificia University in Chile.
In mostly chronic liver diseases like alcoholic liver disease (ALD), non-alcoholic fatty liver diseases (NAFLD), viral hepatitis and compensated cirrhosis, the main effect of probiotics lay in the resolution of endotoxemia and pro-inflammatory mechanisms.
This meant probiotics could have an impact on variceal bleeding - increased pressure in the portal vein often caused by cirrhosis.
Greater research was needed on minimal hepatic encephalopathy – the mildest form of the confusion that can be the result of liver failure. The most most severe cases of hepatic encephalopathy can mean the patient falling into a coma.
Evidence for hepatocellular carcinoma (HCC), the most common type of liver cancer, was also still weak.
Last month the consultancy firm Naturalpha launched a clinical trial platform which aimed to tap into the relatively unexplored area of NAFLD.
At the time the company said: “Our feeling is that this topic, which is poorly addressed to date by the nutrition and nutraceutical industry, will become a major topic in the coming years. However the lack of understanding of the epidemiological burden of these conditions as well as sometimes short-term vision of the nutra industry has not yet led to concrete development.”
It identified probiotics as a key area of opportunity.
NAFLD is a growing medical issue with an estimated worldwide prevalence of 20% in the general population and 40-90% in obese people.
Source: Journal of Functional Foods
Vol 17, Aug 15, pp. 137-151, doi:10.1016/j.jff.2015.05.009
“Current evidence on the use of probiotics in liver diseases”
Authors: N. C. Chávez-Tapia, L. González-Rodríguez, M. Jeong, Y. López-Ramírez, V. Barbero-Becerra, E. Juárez-Hernández, J. L. Romero-Flores, M. Arrese, N. Méndez-Sánchez and M. Uribe