Curdlan Prevents the Cognitive Deficits Induced by a High-Fat Diet in Mice via the Gut-Brain Axis

Abstract

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.

β-Glucan from Lentinula edodes prevents cognitive impairments in high-fat diet-induced obese mice: involvement of colon-brain axis

“…The gut microbiome has emerged as a major contributor to cognitive health, and it can be remodeled by dietary factors. Recently, our laboratory demonstrated that gut microbiota dysfunction negatively impacts the cognitive impairments induced by HF diet [ 15 , 16 , 35 ]. Nevertheless, only a few studies focused on the alternation of gut microbiota occur before the onset of body weight gain in this model [ 35 ].…”

“…Recently, our laboratory demonstrated that gut microbiota dysfunction negatively impacts the cognitive impairments induced by HF diet [ 15 , 16 , 35 ]. Nevertheless, only a few studies focused on the alternation of gut microbiota occur before the onset of body weight gain in this model [ 35 ]. In previous long-term studies for HF diet for 8–22 weeks, it is reported that the proportion of gut bacteria belong to phylum Bacteroidetes is decreased, while phylum Firmicutes is increased in rodents with an increased ratio of Firmicutes to Bacteroidetes [ 36 ].…”

Human milk oligosaccharide 2′-fucosyllactose supplementation improves gut barrier function and signaling in the vagal afferent pathway in mice

“…As metabolic substrates for beneficial bacteria, prebiotics have been shown to exert metabolic and cognitive benefits in association with compositional changes in the gut microbiota and their metabolites in the host. 5,[7][8][9][10][11][12][13][14] Human milk oligosaccharides (HMO) have been shown to have multi-functional, health-promoting activities and are consequently gaining considerable interest in the infant formula industry as well as for prebiotic applications in adults. 15 A handful of HMO are being produced industrially using recombinant methodology and supplementation of oligosaccharides such as 2′-fucosyllactose (2′-FL) and lacto-N-neotetraose (LNnT) to infant formula is now possible.…”

β-glucan from Lentinula Edodes Prevents Cognitive Impairments in High-Fat Diet-Induced Obese Mice: Involvement of Colon-Brain Xxis

“…Recently, our laboratory demonstrated that gut microbiota dysfunction negatively impacts the cognitive impairments induced by HF diet [15,16,34]. Nevertheless, only a few studies focused on the alternation of gut microbiota occur before the onset of body weight gain in this model [34]. This study showed that the altered gut microbiota composition with a signi cant shift observed in the Firmicutes/Bacteroides ratio after acute HF diet feeding for 7 days.…”

“…There is accumulating evidence revealing that an HF diet for 8-22 weeks can alter the richness, diversity and composition of gut microbiota in obese mice [32,33], which is characterized by decreased Chao index and Shannon index, and increased representation of bacteria belonging to the Firmicutes phylum and decreased Bacteroidetes. Recently, our laboratory demonstrated that gut microbiota dysfunction negatively impacts the cognitive impairments induced by HF diet [15,16,34]. Nevertheless, only a few studies focused on the alternation of gut microbiota occur before the onset of body weight gain in this model [34].…”