Biotransformation of Ganoderma lucidum and Hericium erinaceus for ex vivo gut-brain axis modulation and mood-related outcomes in humans: CREB/BDNF signaling and microbiota-driven synergies.

BACKGROUND

The human gut microbiota plays a crucial role in various aspects of health, extending beyond digestion and nutrient absorption. Ganoderma lucidum (Reishi) and Hericium erinaceus (Lion's Mane), traditional medicinal mushrooms, have garnered interest due to their potential to exert positive health effects. The aim of our study was to investigate the molecular impact of Reishi and Lion's Mane on mood regulation through the gut-brain axis.

METHODS

We utilized a dynamic simulator of the human intestinal microbial ecosystem (SHIME), followed by HPLC-ESI-QTOF-MS/MS and a series of biochemical and molecular assays, including MTT for cell viability, fluorogenic probes for redox balance (ROS and GSH), and Western blot for protein analysis.

RESULTS

Chromatographic analysis confirmed the presence of bioactive compounds in both mushrooms, including triterpenoids (ganoderic acids) and polysaccharides in G. lucidum, as well as hericenones and erinacines in H. erinaceus. We observed concentration-dependent changes in metabolic activity and redox balance due to microbiome cell-free supernatant treatment (M-CFSs). M-CFSs also influenced the Nrf2 pathway and activated heat shock proteins, which may confer neuroprotective effects. Notably, M-CFSs upregulated neurotrophic factors such as BDNF, CDNF, and MANF, crucial for neuronal function. Our study revealed alterations in intracellular signaling cascades, most notably the CREB/BDNF pathway. Moreover, the Akt/mTOR and ERK1/2 showed no significant changes, while Akt/GSK3α/β displayed only partial modifications. The overlapping effects of synaptic activity and activation of the gut-brain axis appear to contribute to mood enhancement.

CONCLUSIONS

These pilot findings suggest a potential role for G. lucidum and H. erinaceus in mood disorder regulation through multifaceted mechanisms involving the gut microbiota. The study underscores the importance of understanding the synergistic interactions between medicinal fungi, gut microbiota, and neural processes to develop novel or preventive strategies for mental health disorders.