β-glucan attenuates cognitive impairment via the gut-brain axis in diet-induced obese mice

Abstract

Background: “Western” style dietary patterns are characterised by a high proportion of highly processed foods rich in fat and low in fibre. This diet-pattern is associated with myriad metabolic dysfunctions including neuroinflammation and cognitive impairment. β-glucan, the major soluble fibre in oat and barley grains, are fermented in the lower gastrointestinal tract, potentially impacting the microbial ecosystem and thus may improve elements of the gut-brain axis. The present study aimed to evaluate the effect of β-glucan on the microbiota-gut-brain axis and cognitive function in an obese mouse model induced by a high-fat and fibre deficient diet (HFFD). Results: After chronic supplementation for 15 weeks, β-glucan prevented HFFD diet-induced cognitive impairment assessed behaviourally by object location and nesting building tests. In the hippocampus, β-glucan countered the HFFD-induced microglia activation and its engulfment of synaptic puncta, and up-regulation of proinflammatory cytokine (TNF-α, IL-1β and IL-6) mRNA expression. Also in the hippocampus, β-glucan significantly promoted PTP1B-IRS-pAKT-pGSK3β-pTau signalling for synaptogenesis; improved the synaptic ultrastructure examined by transmission electron microscopy and increased both pre- and post-synaptic protein levels compared to the HFFD-treated group. In the colon, β-glucan reversed HFFD-induced gut barrier dysfunction: increased the thickness of colonic mucus (Alcian blue and mucin-2 glycoprotein immunofluorescence staining); increased the levels of tight junction proteins occludin and zonula occludens-1; and attenuated bacterial endotoxin translocation. The HFFD diet resulted in widespread microbiota dysbiosis, effects abrogated by chronic β-glucan supplementation, with the β-glucan effects on bacteroidetes and its lower taxa particularly striking. Importantly, acute study of β-glucan supplementation for 7 days demonstrated pronounced, rapid differentiating microbiota changes before the cognitive improvement, suggesting the possible causality of gut microbiota profile on cognition. In support, broad-spectrum antibiotic intervention to severely deplete gut microbiota colonisation, eliminated β-glucan’s effects on improving cognition, highlighting the role of gut microbiota to mediate cognitive behavior. Conclusion: This study provides the first evidence that β-glucan improves indices of cognition and brain function with major beneficial effects all along the gut microbiota-brain axis. Our data suggest that elevating consumption of β-glucan-rich foods is an easily implementable nutritional strategy to alleviate detrimental features of gut-brain dysregulation and prevent neurodegenerative diseases associated with Westernized dietary patterns.

Mechanical stimulation activates Piezo1 to promote mucin2 expression in goblet cells

“…After the tissue is embedded and sliced, the staining operation is carried out according to the instructions (Baso, China) and bright field images were captured. Next, a researcher who was not clear about the grouping measured the thickness as previously published 25 (10 measurements per section/two sections per animal/five animals per group) with IMAGEJ. Immunohistochemistry. Immunofluorescence were carried as previous research, 26 Piezo1 antibody (Proteintech, 15939-1-AP) were diluted at the ratio of 1 to 400 for specific staining.…”

Soluble Dietary Fiber Significance against Obesity in a Western China Population

“…Recently, obesity is supposed to be the mechanism of high-fat diet enrichment of gut microbial communities that exhibit an increased capacity for energy harvest and storage. Most interventions of SDFs treated on obesity are performed with rodents or few individuals [9]. Most studies have been focused on body weight gain, visceral adipose tissue weight, or increased adiposity [7,10].…”

Improvement of sleep patterns and serum melatonin levels in children with autism spectrum disorders after consumption of beta-1,3/1,6-glucan in a pilot clinical study

“…This is advantageous for individuals with ASD because chronic in ammation has been shown to be associated with the severity of their symptoms [18]. Thus, with the current study showing that beta-glucans can enhance melatonin and sleep quality in children with ASD, it is necessary to further investigate the ability of beta-glucans to modulate gut microbiota and reverse gut dysbiosis, which are the possible mechanisms behind increased melatonin levels [6,19,20], and thereby improving sleep.…”