A high-fat (HF) diet is a major predisposing factor of
neuroinflammation and cognitive deficits. Recently, changes in the gut microbiota have been associated with
neuroinflammation and
cognitive impairment, through the gut-brain axis.
Curdlan, a bacterial
polysaccharide widely used as
food additive, has the potential to alter the composition of the microbiota and improve the gut-brain axis. However, the effects of
curdlan against HF diet-induced
neuroinflammation and
cognitive decline have not been investigated. We aimed to evaluate the
neuroprotective effect and mechanism of dietary
curdlan supplementation against the
obesity-associated
cognitive decline observed in mice fed a HF diet. C57Bl/6J male mice were fed with either a control, HF, or HF with
curdlan supplementation diets for 7 days (acute) or 15 weeks (chronic). We found that acute
curdlan supplementation prevented the gut microbial composition shift induced by HF diet. Chronic
curdlan supplementation prevented
cognitive declines induced by HF diet. In addition,
curdlan protected against the HF diet-induced abnormities in colonic permeability, hyperendotoxemia, and colonic
inflammation. Furthermore, in the prefrontal cortex (PFC) and hippocampus,
curdlan mitigated microgliosis,
neuroinflammation, and synaptic impairments induced by a HF diet. Thus,
curdlan-as a
food additive and
prebiotic-can prevent cognitive deficits induced by HF diet via the colon-brain axis.