Impact of Oral Bacteria on Gut Health and Liver Disease Risk

A new study highlights the significant impact of oral bacteria on gut health and its potential role in predicting chronic liver disease. Researchers found that as liver disease progresses, the oral and gut microbiomes become increasingly similar, suggesting a translocation of bacteria from the mouth to the gut. This research opens up new therapeutic possibilities for managing chronic liver disease by focusing on the gut barrier and oral microbiome. The findings could lead to innovative strategies to slow disease progression and prevent complications.

By Narendra Chaudhary Jan 16, 2026, 16:19 IST

Significance of Oral Microbiome in Liver Health

New Delhi, Jan 16: A recent study reveals that bacteria in the mouth can greatly influence gut health and may indicate the likelihood of chronic liver disease.

Annually, over two million individuals succumb to advanced chronic liver disease (ACLD).

This research, published in the journal Nature Microbiology, involved an analysis of bacterial populations in saliva and stool samples from 86 patients.

Researchers from the Technical University of Munich in Germany discovered that both oral and gut microbiomes experience notable alterations as liver disease progresses, with changes in the oral microbiome detectable even in the earlier stages of the disease.

In healthy individuals, the bacterial communities vary significantly across different body sites.

However, in liver disease patients, the oral and gut microbiomes became increasingly alike as the condition advanced, with nearly identical bacterial strains found in both the mouth and gut.

According to Melanie Schirmer, Professor of Translational Microbiome Data Integration at TUM, "These strains are typically found in the mouth and are rarely present in a healthy gut. We noted a rise in the absolute quantities of these oral bacteria in patients suffering from advanced chronic liver disease."

Schirmer further stated, "This strongly indicates that these bacteria migrate from the mouth to colonize the gut."

The research team identified various oral bacterial species that had colonized the guts of patients.

They also observed that elevated levels of these bacteria in stool samples correlated with damage to the intestinal barrier.

Gene analysis revealed that these bacteria possess genes that encode collagen-degrading enzymes.

The team confirmed the activity of these enzymes by testing isolated bacteria from stool samples and synthesizing the enzyme.

Aurelie Cenier, a doctoral researcher and co-first author, explained, "Collagen breakdown can weaken the gut barrier, potentially allowing bacteria and their products to reach other organs, including the liver, which may exacerbate the disease."

Dr. Vishal Patel from King's College London added, "Our findings suggest new therapeutic avenues for individuals with advanced chronic liver disease. Protecting or restoring the gut barrier could help slow disease progression. Targeting the oral microbiome may provide a means to positively influence the disease's trajectory and prevent clinical complications."