Dendrobium officinale polysaccharides alleviate depression-like symptoms via regulating gut microbiota-neuroinflammation in perimenopausal mice

•DOP attenuate depression-like symptoms in perimenopausal mice.•DOP modulate gut microbiota to inhibit peripheral inflammation.•DOP reverse the dysfunction of hormone release in the serum.•DOP inhibit prefrontal cortex microglial activation via gut-brain axis.