McGill University researchers, in collaboration with colleagues in Israel and Ireland, have developed AI technology that can detect patterns in gut bacteria to identify complex regional pain syndrome (CRPS) with remarkable accuracy, potentially transforming how CRPS is diagnosed and treated.

CRPS, estimated to affect between 400,000 and 2.1 million people worldwide, typically develops in a limb after injury or surgery and can lead to long-term disability.

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It causes severe, persistent pain -- often far worse than the initial injury -- along with swelling and changes in skin colour and temperature.

"CRPS remains challenging to treat, with patients often experiencing prolonged suffering before receiving appropriate care," said senior author Dr. Amir Minerbi, Director of the Institute for Pain Medicine at Rambam Health Campus in Haifa, Israel, and senior lecturer at the Technion -- Israel Institute of Technology.

A 'microbiome signature' of CRPS

The study, published in the journal Anesthesiology, used advanced machine learning to analyze gut microbiome samples from two cohorts, one from Israel and one from Canada.

"What's remarkable about this study is that we trained our machine learning algorithms on high quality microbiome data from patients in Israel and successfully predicted CRPS in Canadian patients with over 90-per-cent accuracy," said Emmanuel Gonzalez, lead author and member of the McGill Centre for Microbiome Research and Canadian Centre for Computational Genomics.

"This is extraordinary because factors like geography, climate, diet and natural variation between people typically create large microbiome differences. Yet, our AI approach seems to have identified a common 'microbiome signature' of CRPS, suggesting microbiome-based diagnostics could work across populations in different countries."

The research identified significant differences between the gut bacteria of CRPS patients and pain-free individuals.

Findings suggest some people might be prone to CRPS

Surprisingly, the researchers also found that even patients whose symptoms completely disappeared after limb amputation still had the same gut bacteria pattern, or microbiome signature, linked to CRPS.

"This persistent signature suggests the gut microbiome might make some people more prone to developing CRPS, with an injury or other event triggering the condition," said Dr. Yoram Shir, Professor in the Department of Anesthesia at McGill's Faculty of Medicine and Health Sciences, who led the clinical work in Montreal.

The findings were based on analyses of 120 microbiome and over 100 plasma samples, making this one of the largest-ever investigations of the gut microbiome in connection with chronic pain conditions.

-Note: This news release was originally published by McGill University. As it has been republished, it may deviate from our style guide.