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Objective: To investigate the protective effects of mannan oligosaccharide (MOS) and partially hydrolyzed guar gum (PHGG) on liver injury induced by long-term alcohol intake in mice. Methods: Mice were randomly divided into control (Ctrl), model (EtOH), positive control (PC, silymarin at 86 mg/(kg·d)), MOS intervention (2 000 mg/(kg·d)) and PHGG intervention (2 000 mg/(kg·d)) groups. A Lieber-DeCarli model of chronic alcoholic liver injury (ALD) was established in this study. After five weeks of feeding, the levels of liver function, oxidative stress and inflammatory factors were measured. Hematoxylin-eosin (HE) staining and oil red O (ORO) staining were used to observe hepatic histopathological alterations. The mRNA and protein expression levels of ileal tight junction proteins (zonula occludens-1 and occludin) were detected by real-time fluorescence quantitative polymerase chain reaction (qPCR) and immunofluorescence staining, respectively. The hepatic lipopolysaccharide (LPS) level was quantitatively determined by enzyme-linked immunosorbent assay (ELISA). Besides, the contents of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid and caproic acid in fecal samples were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). Results: Supplementation of MOS and PHGG could significantly attenuate hepatic steatosis, lipid accumulation, oxidative stress and inflammation induced by long-term ethanol exposure. Additionally, compared with the EtOH group, MOS and PHGG intake markedly improved liver function and intestinal barrier function, inhibited intestinal LPS leakage, and increased intestinal short-chain fatty acids (SCFAs) levels. Conclusion: Guar gum-derived MOS and PHGG could effectively alleviate chronic ALD in mice by enhancing intestinal integrity and regulating intestinal SCFA levels.

Huangjiu is rich in low-molecular-weight peptides and has an umami taste. In order for its umami peptides to be discovered, huangjiu was subjected to ultrafiltration, ethanol precipitation, and macroporous resin purification processes. The target fractions were gathered according to sensory evaluation. Subsequently, we used peptidomics to identify the sum of 4158 peptides in most umami fractions. Finally, six novel umami peptides (DTYNPR, TYNPR, SYNPR, RFRQGD, NFHHGD, and FHHGD) and five umami-enhancing peptides (TYNPR, SYNPR, NFHHGD, FHHGD, and TVDGPSH) were filtered via virtual screening, molecular docking, and sensory verification. Moreover, the structure–activity relationship was discussed using computational approaches. Docking analysis showed that all umami peptides tend to bind with T1R1 through hydrogen bonds and hydrophobic forces, which involve key residues HIS71, ASP147, ARG151, TYR220, SER276, and ALA302. The active site calculation revealed that the positions of the key umami residues D and R in the terminal may cause taste differences in identified peptides. [ABSTRACT FROM AUTHOR]

Aging is a time-consuming step in the manufacturing of fermented alcoholic beverages. Natural-aging huangjiu sealed in pottery jars was taken as an example to investigate the changes of physiochemical indexes during aging and to quantify intercorrelations between aging-related factors and metabolites through machine learning methods. Machine learning models provided significant predictions for 86% of metabolites. Physiochemical indexes well reflected the metabolic profile, and total acid was the most important index that needed to be controlled. For aging-related factors, several aging biomarkers of huangjiu were also well predicted. Feature attribution analysis showed aging year was the most powerful predictive factor, and several microbial species were significantly associated with aging biomarkers. Some of the correlations, mostly connected to environmental microorganisms, were newly found, showing considerable microbial influence on aging. Overall, our results reveal the potential determinants that affect the metabolic profile of aged huangjiu, paving the way for a systematical understanding of changes in metabolites of fermented alcoholic beverages. [ABSTRACT FROM AUTHOR]

Different alcoholic beverages and drinking patterns might exert divergent impacts on alcoholic liver disease (ALD) progression. Whether the abundant non-alcoholic components (NAC) in fermented wine could alleviate ethanol (EtOH)-induced adverse influences on the liver remains unknown. Hence, the chronic ALD mouse model was established to compare the effects of Huangjiu (a typical fermented wine) and EtOH feeding on the liver, intestinal barrier, gut microbiota, and intestinal short-chain fatty acids (SCFAs) content. Although Huangjiu intake led to slight hepatic steatosis, it mitigated oxidative stress, inflammation, and intestinal damage relative to EtOH intake. In comparison with EtOH feeding, Huangjiu significantly improved the intestinal barrier integrity and reduced hepatic lipopolysaccharide levels by up-regulating the expression of intestinal tight junction proteins (ZO-1 and occludin) and antimicrobial activity peptides (Reg3β and Reg3γ). The administration of Huangjiu NAC partially restored alcohol-induced gut microbiota dysbiosis via recovering the abundance of Lactobacillus, Faecalibaculum, and Akkermansia. Moreover, mice receiving Huangjiu showed higher SCFAs levels (such as acetic acid and butyric acid) than those receiving EtOH. Huangjiu consumption resulted in lower hepatotoxicity than pure EtOH, at the same alcohol dose. The NAC in Huangjiu might attenuate the progression of ALD by regulating intestinal barrier function and microbiota-meditated gut ecology. [ABSTRACT FROM AUTHOR]

Aromatic alcohols (including β-phenylethanol, tyrosol and tryptophol) could contribute positively to the aroma flavor of huangjiu at an appropriate amount. In this study, it was found that the aromatic alcohols in huangjiu were predominantly synthesized by Saccharomyces cerevisiae HJ01. The Ehrlich pathway and shikimate pathway, including 31 genes, are responsible for aromatic alcohol biosynthesis in S. cerevisiae. During the first 120 h of huangjiu fermentation, the genes GAP1 HJ01 (permease), BAT2 HJ01 (transaminase), PDC1 HJ01 and PDC5 HJ01 (pyruvate decarboxylase), and ADH1 HJ01 (alcohol dehydrogenase) formed integrated Ehrlich pathway are responsible for aromatic alcohol biosynthesis. In S. cerevisiae HJ01, the mutations in the promoter region of genes GAP1 HJ01, BAT2 HJ01, PDC1 HJ01, and PDC5 HJ01 involved in the Ehrlich pathway increased the promoter strength and transcriptional levels of related genes. The addition of 20 U/g acid protease could substantially increase the expression levels of genes involved in the Ehrlich pathway, and therefore there were 34.7% increasing for the concentration of total aromatic alcohols. • Aromatic alcohols in huangjiu are synthesized by Saccharomyces cerevisiae. • Aromatic alcohols in huangjiu are mainly synthesized through the Ehrlich pathway. • Key genes and promoter mutations in Ehrlich pathway were identified. • Acid protease enhanced expression level of key genes. [ABSTRACT FROM AUTHOR]

Saccharopolyspora is an important microorganism in the fermentation process of wheat qu and huangjiu , yet the mechanisms by which it performs specific functions in huangjiu remain unclear. A strain with high amylase and glucoamylase activities was isolated from wheat qu and identified as Saccharopolyspora rosea ( S. rosea ) A22. We initially reported the whole genome sequence of S. rosea A22, which comprised a circular chromosome 6,562,638 bp in size with a GC content of 71.71%, and 6,118 protein-coding genes. A functional genomic analysis highlighted regulatory genes involved in adaptive mechanisms to harsh conditions, and in vitro experiments revealed that the growth of S. rosea A22 could be regulated in response to the stress condition. Based on whole-genome sequencing, the first genome-scale metabolic model of S. rosea A22 named i SR1310 was constructed to predict the growth ability on different media with 91% accuracy. Finally, S. rosea A22 was applied to huangjiu fermentation by inoculating raw wheat qu , and the results showed that the total higher alcohol content was reduced by 12.64% compared with the control group. This study has elucidated the tolerance mechanisms and enzyme-producing properties of S. rosea A22 at the genetic level, providing new insights into its application to huangjiu ., Competing Interests: SL, XH, YX, BQ, LW, and JM were employed by Zhejiang Guyuelongshan Shaoxing Wine Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ma, Liu, Han, Nan, Xu, Qian, Wang and Mao.)