The anti-inflammatory and analgesic potential of the probiotic Streptococcus thermophilus via inhibition of endocannabinoid-degrading enzymes: a preliminary in vitro study

Aim: The benefit of topical application of probiotics on pain and itching associated with skin disorders has become an increasingly intriguing topic in recent years. These effects are mainly associated with the anti-inflammatory activity of probiotics. Given the crucial role of the endocannabinoid system (ECS) in skin pathophysiology, here, the ability of Streptococcus thermophilus was evaluated, in comparison with Lactobacillus acidophilus, to inhibit two enzymes involved in endocannabinoid (eCB) degradation: fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Methods: Bacterial lysates were obtained from both probiotics. FAAH and MAGL activities were assayed using fluorometric and colorimetric methods. The effect of probiotic lysates on FAAH and MAGL activities was also evaluated on human keratinocytes stimulated with lipopolysaccharide (LPS). Results: S. thermophilus inhibited both FAAH and MAGL, although to varying extents. In comparison, L. acidophilus had a minimal effect on FAAH and did not influence MAGL activity. Conclusions: Although preliminary, our findings suggest that S. thermophilus may exert both potential analgesic and anti-inflammatory effects by modulating the ECS and reducing the degradation of EC, known to play a key role in immune regulation and inflammation. Results presented confirm the selective actions of probiotics and propose a novel mechanism that may contribute to the beneficial effects of S. thermophilus in alleviating signs and symptoms associated with inflammatory skin conditions. Our evidence shows significant inhibitory activity of S. thermophilus on FAAH and MAGL activity, suggesting its ability to influence skin conditions by modulating ECS and preventing the eCB degradation.