'Mediterranean diet improves gut microbe diversity, cuts hospitalisation'

A Mediterranean-style diet, rich in vegetables and fermented milk products such as yoghurt, is associated with a greater gut microbial diversity and a lower risk of hospitalisation in patients with liver cirrhosis, a study claims.

The study by researchers at Virginia Commonwealth University in the US enrolled almost 300 individuals in the US and Turkey.

It showed that the entire Turkish cohort, including healthy individuals as well as those with cirrhosis, had a significantly higher microbial diversity than their counterparts in the US.

Liver cirrhosis is a major, growing and largely preventable cause of death worldwide, accounting for more than one million deaths globally per year, researchers said.

 

The risk of death from liver cirrhosis differs markedly between countries, driven primarily by alcohol consumption, the type and quality of alcohol consumed, and the presence of viral hepatitis B and C infections.

Gut microbiota have been implicated in the pathogenesis and progression of cirrhosis, and a progressive decrease in microbial diversity is observed in healthy individuals, those with compensated cirrhosis, and those with decompensated disease.

Patients with compensated cirrhosis do not have symptoms related to the disease, whereas those with decompensated cirrhosis have symptomatic complications

"Diet is a major determinant of gut microbial composition, but there is very little information currently linking diet, microbial diversity and clinical outcomes in patients with cirrhosis', said Jasmohan Bajaj from Virginia Commonwealth University and McGuire VA Medical Center.

"Our hypothesis for this study was that diet and the severity of cirrhosis might interact to determine microbiota composition and, ultimately, clinical outcomes in patients with liver cirrhosis," said Bajaj.

The study recruited three groups of individuals in the US and Turkey: healthy controls, outpatients with compensated cirrhosis, and outpatients with decompensated cirrhosis.

All individuals underwent dietary and stool microbiota analysis and those with liver cirrhosis were followed for at least 90 days to capture data on non-elective hospitalisations.

The US population tended to follow a Western diet with a relatively low consumption of fermented foods (yoghurt, ayran, curds) and a high consumption of coffee and carbonated drinks, while the Turkish cohort consumed a Mediterranean-style diet that was rich in fermented foods and vegetables.

Stool sample analysis revealed that the entire Turkish cohort had a significantly greater diversity in their gut microbiota than the US cohort and that there was no difference in diversity between healthy controls and those with liver cirrhosis in Turkey.

In contrast, in the US cohort, diversity was highest in the control group and lowest amongst those with decompensated cirrhosis.

Coffee, tea, vegetables, chocolate, and fermented milk intake predicted a higher diversity, while the Model for End-stage Liver Disease (MELD) score, lactulose use and carbonated drink consumption predicted a lower microbial diversity.