Scientists from the National Yang Ming Chiao Tung University in Taiwan have previously reported that Limosilactobacillus fermentum PS150 may ameliorate caffeine-induced sleep disturbances.*
New data shows that the efficacy of the strain was the same regardless of whether it was alive (or viable, and therefore probiotic) or dead (heat-killed, and therefore postbiotic). This led the researchers to look for a “heat-stable effector, such as exopolysaccharide (EPS)” as the key bioactive.
To further elucidate the effects, the researchers went back to the same fermented sausage source to look for a suitable comparison strain, and identified L. fermentum GR1009, which they described as “phenotypically distinct but genetically similar”.
The two strains were found to biosynthesize EPS differently, with scanning electron microscopy imaging showing that the EPS structure in PS150 was :sheet-like”, but no such structure was observed for EPS in GR1009.
Additional testing showed that the sugar content of EPS from PS150 was approximately five times higher than EPS from GR1009, “indicating that GR1009 has a lower EPS production activity than PS150”.
Data from mouse studies supported the efficacy of EPS from PS150 to significantly reduce sleep latency and recovery time.
“EPS produced by lactic acid bacteria has long been recognized for its various bioactivities, including anti-oxidation, anti-lipogenic, anti-tumor, anti-hepatic steatosis, and anti-pathogen adhesion,” wrote the researchers. “Given our findings, we included the hypnotic effect as another potential application.”
The researchers noted that, while they have linked the EPS of PS150 to the strain’s potential sleep effects, the mechanism(s) of action is still to be elucidated.
“The present study provides morphological and genetic evidence linking the EPS of PS150 with its hypnotic effect,” they wrote. “Subsequently, using an animal study accompanied by chemical characterization, we suggested that C-EPS, a heteropolysaccharide-containing extract, might exhibit hypnotic effects.”
The study was funded by Bened Biomedical Co., Ltd.
Probiotics are defined as: “Live microorganisms that when administered in adequate amounts confer a health benefit on the host” (FAO/WHO, 2002)
Postbiotics are defined as: “Preparations of inanimate microorganisms and/or their components that confer a health benefit on the host” (Salminen et al., 2021).
Source: Frontiers in Microbiology
2023, 14:1209067. doi: 10.3389/fmicb.2023.1209067
“Exopolysaccharide is the potential effector of Lactobacillus fermentum PS150, a hypnotic psychobiotic strain”
Authors: Chin-Lin Huang et al.
* Lin et al., 2019, Nutrients, doi: 10.3390/nu11102409