Extract of the Microalga Nitzschia laevis Prevents High‐Fat‐Diet‐Induced Obesity in Mice by Modulating the Composition of Gut Microbiota

Abstract

Scope The aim of the present study is to investigate the efficacy of Nitzschia laevis extract (NLE) in preventing obesity in mice fed with a high‐fat diet (HFD), and the potential underlying mechanisms focusing on modulation of the gut microbiota profile. Methods and results Physiological, histological, and biochemical parameters and gut microbiota compositions are compared among four experimental groups fed respectively with the following diets for 8 weeks: Normal chow diet, HFD, HFD + low concentration of NLE, and HFD + high concentration of NLE. The results demonstrate that NLE supplementation significantly reduces body weight gain and effectively prevents lipid accumulation in the white adipose tissue and liver of the mice. Mechanistic analysis reveals that NLE promotes the expression of uncoupling protein 1 and peroxisome proliferators‐activated receptor‐γ coactivator‐1 mRNA in brown adipose tissue. Furthermore, NLE protects the gut epithelium and positively reshapes the gut microbiota composition against the damaging effect of HFD. Conclusions NLE supplementation demonstrates a protective effect against HFD‐induced obesity in mice, which is associated with reshaping the profile of gut microbiota. To the best of our knowledge, this has been the first report on the potential of microalgal extract to prevent obesity by modulating gut microbiota.

Polysaccharide extracted from WuGuChong reduces high-fat diet-induced obesity in mice by regulating the composition of intestinal microbiota

“…5), resulting in maintaining intestinal epithelium integrity. This is consistent with the previous study, which reported that increased expression of occludin and ZO-1, along with modulation of the gut microbiota composition, contributed to strengthen the gut integrity and barrier function [48]. The results suggest that PEW may improve obesity-related metabolic disorders by modulating gut microbiota and maintaining intestinal epithelium integrity.…”

Polysaccharides isolated from Cordyceps Sinensis contribute to the progression of NASH by modifying the gut microbiota in mice fed a high-fat diet

“…Furthermore, we checked the expression of genes related to the de novo synthesis of endogenous fatty acids, including Srebp-1c and FAS [38][39][40]. Although it had been reported that the expression of Srebp1-c and FAS were increased in HFD-fed mice [2,41], some studies showed the opposite result [42,43]. Our results were consistent with the later findings.…”

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“…At the phylum level, NAR supplementation decreased the Firmicutes/Bacteroidetes ratio in HFD-fed mice (Figures 6A-C). Consistently, several reports revealed that polyphenols and Chinese herbal extracts, such as Nitzschia laevis extract (Guo et al, 2019), Citrus aurantium L. var. amara Engl.…”