Wenli Huang

BACKGROUND: Previous observational studies have demonstrated inconsistent and inconclusive results of changes in the intestinal microbiota in patients with obesity and metabolic disorders. We performed a systematic review to explore evidence for this association across different geography and populations. METHODS: We performed a systematic search of MEDLINE (OvidSP) and Embase (OvidSP) of articles published from Sept 1, 2010, to July 10, 2021, for case-control studies comparing intestinal microbiome of individuals with obesity and metabolic disorders with the microbiome of non-obese, metabolically healthy individuals (controls). The primary outcome was bacterial taxonomic changes in patients with obesity and metabolic disorders as compared to controls. Taxa were defined as "lean-associated" if they were depleted in patients with obesity and metabolic disorders or negatively associated with abnormal metabolic parameters. Taxa were defined as "obesity-associated" if they were enriched in patients with obesity and metabolic disorders or positively associated with abnormal metabolic parameters. RESULTS: Among 2390 reports screened, we identified 110 full-text articles and 60 studies were included. Proteobacteria was the most consistently reported obesity-associated phylum. Thirteen, nine, and ten studies, respectively, reported Faecalibacterium, Akkermansia, and Alistipes as lean-associated genera. Prevotella and Ruminococcus were obesity-associated genera in studies from the West but lean-associated in the East. Roseburia and Bifidobacterium were lean-associated genera only in the East, whereas Lactobacillus was an obesity-associated genus in the West. CONCLUSIONS: We identified specific bacteria associated with obesity and metabolic disorders in western and eastern populations. Mechanistic studies are required to determine whether these microbes are a cause or product of obesity and metabolic disorders.

Hypercholesterolemia is closely associated with cardiovascular disease. Supplementation with probiotics has been shown to contribute to improving lipid metabolism. The probiotic mechanisms of cholesterol reduction are complicated and remain unclear. One of the potential probiotic mechanisms for cholesterol reduction is the deconjugation of bile salts. We previously found a high bile salt hydrolase (BSH) activity of Lactobacillus casei pWQH01 (overexpression of bsh1) and Lactobacillus plantarum AR113, but found no BSH activity for Lactobacillus casei LC2W in vitro. Therefore, we decided to investigate whether the high BSH activity of L. plantarum AR113 and L. casei pWQH01 could exert a cholesterol-reducing effect in vivo. Compared to the high-cholesterol diet (HCD) group, AR113 and pWQH01 groups had a significantly lower body weight (BW), serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) levels and atherogenic index (AI), whereas the LC2W group had a poor capability to mitigate the blood lipid levels in the hypercholesterolemic mice. In addition, the AR113 and pWQH01 groups decreased the hepatic levels of TC and LDL-C and improved hepatic steatosis compared with the HCD group. To explore their cholesterol-lowering mechanisms of action, we determined the expression levels of these genes on the cholesterol metabolic pathways. AR113 and pWQH01 groups downregulated the expression of farnesoid X receptor (FXR) and small heterodimer partner (SHP) genes, but upregulated the expression of the cholesterol 7α-hydroxylase (CYP7A1) gene in the liver. Simultaneously, the expression of cholesterol liver X receptor (LXR) and low density lipoprotein receptor (LDLR) genes was upregulated in the liver. These results indicated that L. plantarum AR113 and L. casei pWQH01 could inhibit the cholesterol absorption and accelerate the cholesterol transportation. Taken together, these findings suggest that Lactobacillus strain overexpression of bile salt hydrolase has beneficial effects against hypercholesterolemia by reducing cholesterol absorption and increasing cholesterol catabolism.

Macrofungus is defined as the fungus that grows an observable sporocarp. The sporocarps of many species are commonly called mushrooms and consumed by people all around the world as food and/or medicine. Most macrofungi belong to the divisions Basidiomycetes and Ascomycetes, which are estimated to contain more than 80,000 species in total. We report the draft genome assemblies of macrofungi (83 Basidiomycetes species and 7 Ascomycetes species) based on Illumina sequencing. The genome sizes of these species ranged from 27.4 Mb (Hygrophorus russula) to 202.2 MB (Chroogomphus rutilus). The numbers of protein-coding genes were predicted in the range of 9,511 (Hygrophorus russula) to 52,289 (Craterellus lutescens). This study provides the largest genomic dataset for macrofungi species. This resource will facilitate the artificial cultivation of edible mushrooms and the discovery of novel drug candidates.