Scientists find link between genetic make-up of bacteria in the gut and several diseases

Scientists have discovered a link between the presence of specific bacterial genes in the gut and multiple diseases.

Researchers from the Harvard Medical School and Joslin Diabetes Center analysed the genetic make-up of bacteria in the human gut and successfully linked groups of bacterial genes, known as "genetic signatures", to the presence of diseases and conditions such as coronary artery disease, cirrhosis of the liver, inflammatory bowel disease, colon cancer, and Type 2 diabetes.

The findings showed that coronary artery disease, inflammatory bowel disease, and liver cirrhosis share many of the same bacterial genes, meaning people who have guts harbouring these genes seem more likely to have one or more of these conditions.

In contrast, they found Type 2 diabetes has a microbiome signature unlike any other phenotype the team tested.

The researchers said their study represents a significant advance in the understanding of the link between microbes in the gut and specific diseases, and could eventually pave the way for scientists to develop tests that could gauge a person's risk of a range of conditions using a stool sample.

"This opens a window for the development of tests using cross-disease, gene-based indicators of patient health," said first author Braden Tierney. "We've identified genetic markers that we think could eventually lead to tests, or just one test, to identify associations with a number of medical conditions."

The experts, who collected microbiome data from 13 groups of patients resulting in more than 2,500 samples for their study, have warned that their investigations require further research because it currently remains unclear whether these bacterial genes have a role to play in the development of diseases or are simply bystanders.

Senior author Chirag Patel also explained their findings showed that it wasn't just the presence of specific bacterial families that indicated risk, but rather the strains and gene signatures of them that are the most important.

The findings were published in Nature Communications.