Glasgow-based scientists from the Universities of Strathclyde and Glasgow are part of a team to have discovered an ancient medicinal clay that could inspire new insights into gut health in the present day.

Researchers also believe the clay, known as Lemnian Earth (LE), was a forerunner to modern pills. As far back as the first millennium Before the Common Era (BCE) it was shaped into a small pellet, stamped with a seal and taken with liquids such as wine.

This new study, by researchers from the University of Glasgow, University of Strathclyde, and the Technical University of Crete, points to the possibility that the clay’s healing properties were the result of a deliberate combination of specific clays with certain fungi.

Bioactive compounds

For more than 2,500 years Lemnian Earth – found on the Greek island of Lemnos – has been revered as a medicine to protect against poisons ingested or injected and, in the post-medieval period, even against the plague.

After examining historical LE samples from Basel University, the team grew their own fungus and clays together in a controlled environment to allow the creation of bioactive compounds.

The research, published in PLOS One journal, suggests that combining some clays with beneficial fungi may produce compounds that positively impact gut bacteria, which could help maintain a balanced gut microbiome – a key factor in overall wellness.

The paper says: “Regarding the LE, the precise recipe for its preparation remains, and is likely to remain, unclear and further, it may have been modified over time. Investigating LE, and what has been known about it, has served as a springboard to investigate the modulation of the microbiome in a targeted fashion.

“Our data provide a potential mechanism by which fungus plus clay co-cultures may be a valuable tool for manipulating the microbiota to prevent the progression of inflammatory diseases, and perhaps also limit intestinal infections; it therefore suggests avenues for the further development of ancient LE’s potential in a 21st century context.”

Analytical technologies

Analysis using liquid chromatography mass spectrometry by Dr Nicholas Rattray, senior lecturer (associate professor) in clinical metabolism at Strathclyde Institute of Pharmacy and Biomedical Sciences, revealed a whole host of bioactive compounds.

Dr Rattray said: “Often, liquid chromatography mass spectrometry metabolomics is applied in the analysis of natural product-based medicines but seldom on samples that are so old.

The identification of penicillic acid, alongside a range of other bio-active molecules from ancient Lemnian Earth tablets, shows that even without modern analytical technologies used today, biologically relevant medicines were made and prescribed to the Greek population. 

Professor Simon Milling, Professor of Immunology, Centre for Immunobiology, School of Infection and Immunity, University of Glasgow added: “Our reconfigured 21st century Lemnian Earth shows that this ancient remedy has the potential to support good gut health for people living today.”

Testing by the researchers showed that the combination of clay and fungus had broad antibacterial properties and uniquely positive effects on the gut microbiome.

Technical University of Crete colleague, Professor George Ε Christidis, School of Mineral Resources Engineering, said: “Clays which include iron and titanium compounds have been known to interact with microorganisms (bacteria) but the role of the clay minerals themselves, which are the main constituents of clays, has not been previously considered important.”