A bacterium capable of reducing visceral pain

Lactococcus lactis is a bacterium that naturally produces a pain-relieving neuromediator. Scientists at the Toulouse Biotechnology Institute (TBI-INSA Toulouse/INRAE/CNRS) and Toxicologie alimentaire (Toxalim-INRAE/ENVT/INP-Purpan/UT3 Paul Sabatier) laboratories at the INRAE Occitanie-Toulouse center have proven its value in relieving visceral pain, such as that felt in irritable bowel syndrome.

Published May 31, 2023 - sur le site INRAE

Stress and anxiety exacerbate visceral pain, particularly for patients suffering from irritable bowel syndrome. Until now, symptomatic treatment of pain has been unsatisfactory. It is therefore important to provide new therapeutic solutions. By acting on the microbiota-gut-brain axis, certain probiotic lactic acid bacteria are able to reduce visceral pain. In fact, through decarboxylation mechanisms, they can synthesize neuromediators that reduce visceral pain hypersensitivity.

By studying a collection of over 150 lactococci, scientists from the Toulouse Biotechnology Institute and the Toxalim laboratory have demonstrated, in a preclinical model, that certain strains of Lactococcus lactis, when administered orally, have a highly interesting visceral pain-relieving effect. In fact, these particular bacteria can produce significant quantities of a central nervous system inhibitory neuromediator: y-aminobutyric acid or GABA. "This molecule has been shown to be effective in preventing and treating visceral pain", explains Muriel Cocaign-Bousquet, an INRAE researcher at TBI. Bacteria of the L. lactis species are considered non-pathogenic (generally recognized as safe) and are widely used in the agri-food industry for the manufacture of dairy products.

A confirmed pain-relieving effect

"In our studies, we administered the L. lactis strain orally on a daily basis for 10 days. And it was shown, for the first time, that this bacterium exerts significant effects against visceral hypersensitivity in a preclinical model of acute stress, thanks to its ability to produce high levels of GABA", shares Muriel Cocaign-Bousquet.

This discovery opens up promising prospects for the prevention or treatment of visceral pain. A patent has been filed to protect the use of L. lactis strains. The scientists are continuing their joint work to better understand the mechanisms behind the antinociceptive effect of these GABA-hyperproducing bacteria.