ETD

• 16S rRNA sequencing
• dysbiosis
• Faecal Microbiota Transplant
• gut-brain axis
• high-fat diet
• microglia

The gut-brain axis represents a pivotal bidirectional communication system, wherein the gut microbiota significantly influences central nervous system homeostasis and neuroimmune responses. Chronic dysbiosis induced by a High-Fat Diet (HFD) has been linked to systemic inflammation and cognitive decline; however, whether diet-driven alterations in the microbiota are sufficient to directly modulate microglial states independently of dietary confounding factors remains to be fully elucidated.
The aim of this study is to investigate the specific impact of an HFD-altered microbiota on microglial activation and functional phenotypes. To decouple the effects of the diet from those of the microbiota, a Faecal Microbiota Transplant (FMT) approach was implemented, transferring microbiota from HFD or Control Diet (CC) donors into antibiotic-depleted recipient mice.
To characterize the underlying mechanisms, changes in the gut microbial ecosystem and its predicted functional pathways were investigated via 16S rRNA sequencing. Concurrently, microglia of recipient mice were isolated using a specialized cocktail of transcription and translation inhibitors to strictly preserve their in vivo functional states, followed by ultra-low input RNA sequencing to comprehensively evaluate the microglial transcriptional profile.