Scientists have discovered a possible link between the microbiome and liver disease in individuals with cystic fibrosis. Cystic fibrosis (CF) is a genetic disease that can be fatal and affects 30,000 people in the United States with another 1,000 diagnosed every year. While pulmonary disease is the most common cause of death in patients with CF, liver disease results in 2.5% of deaths and occurs in up to 72% of patients with the disease. Approximately 5-7% of these liver diseased CF patients have cirrhosis, a disease marked by the replacement of healthy liver tissue with scar tissue, preventing the liver from properly functioning.
A team of scientists from University of Colorado Medical Center recently published a study pertaining to CF patients with liver disease in PLoS One. They studied 11 adolescents with CF and cirrhosis as well as 19 age-matched adolescents with CF without liver disease. They found that the two groups of patients had different gut microbiomes, leading the researchers to believe that there is communication between the gut bacteria and the liver, specifically in CF patients.
Patients with CF and cirrhosis had more severe lesions in their intestines than those without liver disease. Also, specific bacteria were less abundant in cirrhosis patients (e.g. Bacteroidetes) and others more abundant (e.g. Firmicutes) compared to CF patients without liver disease. Similar ratios have been seen in other studies of liver disease and obesity. However, we must remember that in complex diseases like CF, the microbiome is only one component of a very dynamic ailment, and at least one other disease study has measured the opposite Bacteroidetes/Firmicutes abundances.
Despite differences in previous studies and the lack of a mechanism relating the microbiome to cirrhosis, this identification of bacterial differences between CF patients with and without liver diseases is promising. The authors of the study point out that the sample size was small and this was only meant to be a pilot study but further longitudinal studies may now be warranted to investigate the development of cirrhosis in cystic fibrosis patients.