New research unveils critical link between liver disease and muscle wasting

Graz, Austria – A groundbreaking study from the Medical University of Graz has shed light on a crucial connection between liver cirrhosis and muscle wasting, known as sarcopenia. Affecting nearly half of all cirrhosis patients, this condition can become so severe that it hinders life-saving surgeries. Researchers have identified the intestinal microbiome as a pivotal factor in this process, suggesting new therapeutic avenues that could significantly impact patient care.

The body's ecosystem: the role of gut bacteria

The human body, much like an ecosystem, is home to trillions of microorganisms that aid in digestion, immune defence, and more. However, an imbalanced gut microbiome has now been linked to sarcopenia in patients with chronic liver disease. Austria, with over 1,100 cases per 100,000 people, ranks second in Europe for chronic liver disease prevalence, trailing only Romania.

Unveiling the liver-muscle connection

The research project, funded by the Austrian Science Fund (FWF) and titled 'The gut-liver-muscle axis in liver cirrhosis', pinpointed specific bacterial strains that proliferate when liver cirrhosis coincides with muscle wasting. Gut bacteria convert primary bile acids into secondary bile acids, and the study revealed that an altered microbiome led to an excess of these secondary bile acids in participants.

'The results suggest that these bile acid products enter the muscle via the bloodstream, causing damage,' explained Vanessa Stadlbauer-Köllner, the principal investigator and Professor of Translational Microbiome Research and Hepatology. Her goal is to develop new therapies that specifically target the intestinal microbiome.

New insights into bile acids

The study involved 217 participants with and without liver cirrhosis, categorised by the presence or absence of sarcopenia. Researchers discovered that bacterial strains like Bacteroides fragilis, Blautia marseille, Sutterella spp., and Veillonella parvula were more common in those with muscle wasting. Conversely, Bacteroides ovatus appeared beneficial, being present in those without sarcopenia despite having cirrhosis. The detrimental strains produced higher levels of secondary bile acids.

Initially, bile acids were thought to merely aid fat digestion. 'Now we understand that these substances can act as hormones affecting other cells,' Stadlbauer-Köllner noted. Laboratory tests indicated that secondary bile acids damage muscle cells. Stadlbauer-Köllner plans to explore if this damage occurs in humans, hypothesising that these substances enter the bloodstream through a compromised intestinal barrier in chronically ill individuals.

The serious issue of muscle wasting

Sarcopenia poses significant challenges, particularly in chronic diseases and ageing. Stadlbauer-Köllner, who leads the internal medicine liver transplant outpatient clinic in Graz, emphasised, 'Muscle atrophy can be so severe that patients are too weak for liver transplants.' Most individuals are unaware of their condition until severe complications necessitate hospitalisation. Liver cirrhosis, often the culmination of hepatitis infections, alcohol use, autoimmune diseases, or metabolic disorders like obesity and diabetes, typically develops over extended periods.

Towards targeted therapies

The identification of harmful bacterial strains is a crucial step toward developing targeted therapies to promote beneficial gut bacteria. Stadlbauer-Köllner is also investigating a drug containing special amino acids that may positively affect the microbiome and muscle health. The FWF-funded project lays the groundwork for these innovative treatments. 'This funding programme is invaluable for medical research,' Stadlbauer-Köllner remarked, highlighting its role in advancing independent therapeutic research.

Public interest in the gut microbiome has surged, partly due to the approval of the first microbiome-targeting drug in the USA last year. However, Stadlbauer-Köllner cautions, 'While there is immense potential in microbiome research, much foundational work remains to be done.'

This pioneering research underscores the vital interplay between the gut microbiome, liver health, and muscle integrity, offering hope for improved treatments and patient outcomes.


Also read: Maintaining muscle strength is essential as we age

An organic compound that is the basic building block of all proteins. Full medical glossary
Withering or weakening of a body tissue due to disease or disuse. Full medical glossary
Any condition caused by the body’s immune response against its own tissues. Full medical glossary
A group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. Full medical glossary
A fluid produced by the liver, which helps the fat ingested in food to combine with the digestive juices in the gut. Full medical glossary
Any of a group of acids produced by the liver and present in the bile. Full medical glossary
A fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. Full medical glossary
The basic unit of all living organisms. Full medical glossary
A disease of long duration generally involving slow changes. Full medical glossary
scarring of the liver. Full medical glossary
A condition that is linked to, or is a consequence of, another disease or procedure. Full medical glossary
A disorder caused by insufficient or absent production of the hormone insulin by the pancreas, or because the tissues are resistant to the effects. Full medical glossary
One of the three main food constituents (with carbohydrate and protein), and the main form in which energy is stored in the body. Full medical glossary
Inflammation to the liver with accompanying damage to liver cells. Full medical glossary
A substance produced by a gland in one part of the body and carried by the blood to the organs or tissues where it has an effect. Full medical glossary
Prefix suggesting a deficiency, lack of, or small size. Full medical glossary
Invasion by organisms that may be harmful, for example bacteria or parasites. Full medical glossary
relating to the intestines, the digestive tract between the stomach and the anus Full medical glossary
A large abdominal organ that has many important roles including the production of bile and clotting factors, detoxification, and the metabolism of proteins, carbohydrates and fats. Full medical glossary
A mood disorder featuring excessive behaviour, sometimes euphoric and sometimes violent. Full medical glossary
Relating to metabolism. Full medical glossary
Organisms that are too small to be seen with the naked eye, such as bacteria and viruses. Full medical glossary
Tissue made up of cells that can contract to bring about movement. Full medical glossary
Excess accumulation of fat in the body. Full medical glossary
A craving to eat non-food substances such as earth or coal. Full medical glossary
septic arthritis Full medical glossary