An ancient clay, used over 2,500 years ago for its medicinal properties, could teach us more about our gut health.
Researchers have rediscovered the astonishing properties of "Lemnos earth," a Greek volcanic clay, by combining it with a specific fungus. This unprecedented combination shows promising antibacterial effects and an ability to modulate the gut microbiome, paving the way for new therapies.
PLoS One recently published a study revealing the secrets of this medicinal clay. Lemnos earth was once used to treat digestive disorders, without anyone really knowing how it worked.
A team recently discovered that it is an association between this earth and a fungus that could give it these "miracle" effects. The team tested it in the lab with a fungus called
Penicillium purpurogenum, and the results show that this association produces bioactive compounds with significant antibacterial properties.
The researchers found that smectite, a type of clay, combined with the fungus, inhibits the growth of pathogenic bacteria such as Escherichia coli and Staphylococcus aureus. In contrast, kaolin, another clay tested alone, did not show the same effects. This discovery suggests that the healing properties lie in the interaction between the clay and the fungus.
Tests on mice confirmed these results. Rodents that received the clay-fungus mixture showed increased microbial diversity in their gut, a key indicator of gut health. This diversity is essential for preventing inflammatory diseases such as Crohn's disease.
Illustration of the workflow of experiments and analyses:
- Penicillium purpurogenum co-cultured with smectite or kaolin clays (step 2).
- Filtration of co-cultures (step 3).
- Testing of leachates for antibacterial activity in vitro (step 4). Reduction in the number of Gram-positive and Gram-negative bacteria (step 4a).
- Targeted analysis of fungal metabolites in each sample (step 5).
- Administration of leachates to mice as a supplement to their normal diet (step 6). Sequencing of bacterial DNA to analyze the effect on the microbiota (step 6a). Metabolomic analysis of feces collected on days 0 and 14 (step 6b).
The scientists used liquid chromatography-mass spectrometry to identify the compounds responsible for these effects. They found that certain metals, such as iron and titanium, play a key role in the interaction with microorganisms. Additionally, the mixture stimulates the production of short-chain fatty acids, which are beneficial for digestive health.
This research opens up interesting prospects for the treatment of microbiome imbalances. Unlike probiotics, which can be sensitive to gastrointestinal conditions, this approach uses stable and effective small molecules. It could be used to treat infections, inflammatory diseases, and even metabolic disorders.
The study also highlights the importance of revisiting ancient remedies with modern tools. Lemnos earth, long forgotten, could thus inspire innovative treatments. Although human trials remain to be conducted, these preliminary results are encouraging.
Article author: Cédric DEPOND