The brain-gut connection makes sense: The body is an interrelated organism where what we think and feel affects our physical functions, particularly our digestive systems—and a glitch in our gut can affect our psyche. And depression is known to be an inherited trait. Past studies have found that genetics also play a role in digestive conditions that include peptic ulcer, gastroesophageal reflux disease (GERD), irritable bowel syndrome and inflammatory bowel disease.

Genes and Helicobacter pylori

Researchers from The University of Queensland’s Institute for Molecular Bioscience in Australia used health and genetic data collected from nearly half a million people in the United Kingdom to learn more about how genes influence the susceptibility to peptic ulcer disease…eventually hitting on how depressive symptoms play into the mix. This type of study is called a genome-wide association study. This was the largest such study ever done for peptic ulcer disease.

The researchers identified eight genetic variations called single nucleotide polymorphisms (SNPs) associated with susceptibility to Helicobacter pylori, the bacteria that causes ulcer disease. Although about 50 percent of people have H. pylori in their gut, only 5 to 10 percent develop ulcer disease. Genetics may explain why some people are more susceptible. SNPs identified in the study may influence susceptibility, reaction to infection, and also gastric acid secretion and gastric motility.

In identifying SNP genes associated with peptic ulcer disease, the researchers found 11 SNPs that increase the risk of other common digestive disorders: GERD and irritable bowel syndrome. These SNPs have never been previously reported. The study is published in the journal Nature Communications.

If Your Mom or Dad Had an Ulcer…

Finally, because of the increasing amount of research showing a genetic link between the gut and the brain, called bi-directional signaling, the researchers looked for and were able to establish an increased genetic risk for major depression associated with GERD and peptic ulcer disease. Peptic ulcer and the other digestive disorders affect up to 10 percent of people at some time in their lives.

According to the National Institute of Mental Health, major depression affects nearly eight percent of U.S. adults. The researchers hope these findings may lead to genetic testing to identify people at risk for both digestive disorders and depression. That could allow early intervention and prevention strategies to keep both the brain and the gut in good working order.

Source: Study titled “GWAS of Peptic Ulcer Disease Implicates Helicobacter Pylori Infection, Other Gastrointestinal Disorders and Depression,” by researchers at Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia, published in Nature Communications.

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