Fu Brick Tea Alleviates Chronic Kidney Disease of Rats with High Fat Diet Consumption through Attenuating Insulin Resistance in Skeletal Muscle

Evaluation of the Effect of Fuzhuan Brick Tea on Bread Quality and In Vitro Digestion

In this study, the chemical constituents, quality and functional characteristics of the mixture of Fuzhuan brick tea and wheat bread (2:100, 4:100, 6:100, 8:100, 10:100) were investigated to guide the production of slow-digested wheat bread. The dough fermentability, the content of free sulfhydryl groups and wet gluten, specific volume, sensory evaluation were determined to evaluate the influence of Fuzhuan brick tea on wheat bread quality. When the ratio of tea to water was 6:100, the dough fermented faster, and the resulting bread, with the flavor of Fuzhuan brick tea, was of higher quality and more acceptable to consumers. Further activity studies showed that the water extract of Fuzhuan brick tea (WFT) had a good inhibitory effect on α-amylase and amyloglucosidase, which could slow down the digestion of bread in the intestines. When the ratio of tea to water was 6:100, more slowly digestible starch in the bread was produced, allowing for a steady and prolonged release of energy. The results suggested that Fuzhuan brick tea is suitable for the development of functional wheat bread in terms of bread processing, quality and healthy diet structure.

Molecular Insight into Obesity-Associated Nephropathy: Clinical Implications and Possible Strategies for its Management

Obesity is a significant health concern due to its rapid increase worldwide. It has been linked to the pathogenic factors of renal diseases, cancer, cardiovascular diseases, hypertension, dyslipidemia, and type 2 diabetes. Notably, obesity raises the likelihood of developing chronic kidney disease (CKD), leading to higher adult mortality and morbidity rates. This study explores the molecular mechanisms that underlie obesity-associated nephropathy and its clinical implications. Obesity-Associated Nephropathy (OAN) develops and worsens due to insulin resistance and hyperinsulinemia, which promote renal sodium reabsorption, glomerular hyperfiltration, and hypertension, leading to progressive kidney damage. Renal damage is further aggravated by persistent inflammation and redox damage, mediated by adipokines and proinflammatory cytokines, such as TNF-α and IL-6. Furthermore, stimulation of the sympathetic nervous system and the renin-angiotensin- aldosterone system (RAAS) intensifies glomerular hypertension and fibrosis. These elements cause glomerular hyperfiltration, renal hypertrophy, and progressive kidney damage. Clinical manifestations of obesity-associated nephropathy include proteinuria, reduced glomerular filtration rate (GFR), and ultimately, CKD. Management strategies currently focus on lifestyle modifications, such as weight loss through diet and exercise, which have been effective in reducing proteinuria and improving GFR. Pharmacological treatments targeting metabolic pathways, including GLP-1 receptor agonists and SGLT2 inhibitors, have shown renoprotective properties. Additionally, traditional RAAS inhibitors offer therapeutic benefits. Early detection and comprehensive management of OAN are essential to prevent its progression and lessen the burden of CKD.

Effects of Eurotium Cristatum on soybean (Glycine max L.) polyphenols and the inhibitory ability of soybean polyphenols on acetylcholinesterase under different conditions

Most phenolic compounds in beans exist in complex, insoluble binding forms that bind to cell wall components via ether, ester, or glucoside bonds. In the process of solid-state fermentation, Eurotium Cristatum can produce many hydrolase enzymes, such as α-amylase, pectinase, cellulase and β-glucosidase, which can effectively hydrolyze ether, ester or glucoside bond, release bound polyphenols, and increase polyphenol content in soybeans. When the fermentation conditions of soybean were fermentation time 12 days, inoculation amount 15% and initial pH 2, the content of free polyphenols in fermented soybean was 2.79 mg GAE/g d.w, which was 4.98 times that of unfermented soybean. The contents of bound polyphenols and total phenols in fermented soybean were 0.62 mg GAE/g d.w and 3.41 mg GAE/g d.w, respectively, which were 2.38 times and 4.16 times of those in unfermented soybean. At the same time, the inhibitory effect of free polyphenols in fermented soybean on acetylcholinesterase reached 91.51%. Thus, our results demonstrated that solid state fermentation and Eurotium Cristatum can be used as an effective way to increase soybean polyphenol content and combat Alzheimer's disease.

Dynamic changes and correlation analysis of microorganisms and flavonoids/ amino acids during white tea storage

White tea stored for various times have different flavors. However, the mechanism of flavor conversion remains elusive. Flavonoids and amino acids are two typical flavor components in tea. Herein, the contents of 46 flavonoids and 40 amino acids were measured in white tea (Shoumei) stored for 1, 3, 5 and 7 years, respectively. L-tryptophan, L-ornithine and L-theanine contribute to the refreshing taste of Shoumei 1 and 3. Quercetin, rutin and hesperidin contribute to aging charm and grain aroma of Shoumei 5 and 7. 306 bacterial OTUs and 268 fungal OTUs core microbiota existed in all samples. Interestingly, white teas contained higher richness of fungi than bacteria. The correlation analysis showed that the cooperation with bacteria and fungi may result in the flavonoids and amino acids composition changes in white teas during storage. Overall, this study provides new insights into flavor conversion of white tea during storage.

Exploration of the hypoglycemic mechanism of Fuzhuan brick tea based on integrating global metabolomics and network pharmacology analysis

Introduction: Fuzhuan brick tea (FBT) is a worldwide popular beverage which has the appreciable potential in regulating glycometabolism. However, the reports on the hypoglycemic mechanism of FBT remain limited. Methods: In this study, the hypoglycemic effect of FBT was evaluated in a pharmacological experiment based on Kunming mice. Global metabolomics and network pharmacology were combined to discover the potential target metabolites and genes. In addition, the real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed for verification. Results: Seven potential target metabolites and six potential target genes were screened using the integrated approach. After RT-qPCR analysis, it was found that the mRNA expression of VEGFA, KDR, MAPK14, and PPARA showed significant differences between normal and diabetes mellitus mice, with a retracement after FBT treatment. Conclusion: These results indicated that the hypoglycemic effect of FBT was associated with its anti-inflammatory activities and regulation of lipid metabolism disorders. The exploration of the hypoglycemic mechanism of FBT would be meaningful for its further application and development.

Fu Loose Tea Administration Ameliorates Obesity in High-Fat Diet-Fed C57BL/6J Mice: A Comparison with Fu Brick Tea and Orlistat

Fu tea is receiving increasing attention for its specific aroma, flavor, and dramatic functional benefits. Herein, we explored the effects and underlying mechanisms of Fu loose tea (FLT), Fu brick tea (FBT), and diet pills (orlistat) on a high-fat diet (HFD)-induced obesity. The results indicated that FLT and FBT administration effectively inhibited weight gain, glucose metabolic dysregulation, fat accumulation in organs, hepatic and kidney injury, and oxidative stress induced by HFD. Additionally, FLT and FBT treatments improved the lipid profiles and reduced the production of proinflammatory cytokines by regulating the expression levels of lipid metabolism- and inflammation-related genes. Furthermore, FLT and FBT ameliorated the gut microbiota dysbiosis in HFD-mice in a dose-dependent relationship by increasing the abundance of family Verrucomicrobiaceae and genus Akkermansia and Turicibacter and simultaneously reducing the abundance of family Erysipelotrichaceae and genus Bifidobacterium; in contrast, orlistat did not exert a regulatory effect on gut microbiota similar to FLT and FBT to improve HFD-induced obesity. KEGG analysis of gut microbiota annotation revealed that "metabolism" was the most enriched category. This study further provides a theoretical basis for FLT and FBT to be potential supplements to alleviate diet-induced obesity.

Chemical components of Fu brick tea and its potential preventive effects on metabolic syndrome

As living standards advance, an escalating emphasis is placed on health, particularly in relation to prevalent chronic metabolic disorders. It is necessary to explore safe and effective functional foods or drugs. Fu brick tea (FBT) is a kind of dark tea fermented by fungi. The extracts are rich in compounds that can effectively relieve metabolic diseases such as hyperglycemia and hyperlipidemia, protect the liver, improve human immunity, enhance antioxidant activity, and regulate intestinal flora. This paper summarizes the biological activities and mechanisms of the extracts, polysaccharides, and small molecular compounds of FBT, which provides a certain theoretical basis for the rational, systematic, comprehensive development and utilization of the FBT resources. It is expected to develop and apply these active substances in health care products and natural medicines and provide more beneficial and diversified FBT products for human beings.

Metabolic improvements of novel microbial fermentation on black tea by Eurotium cristatum

Due to its traditional fermentation, there are obvious limits on the quality improvements in black tea. However, microbial fermentation can provide an abundance of metabolites and improve the flavor of tea. The "golden flower" fungi are widely used in the microbial fermentation of tea and has unique uses in healthcare. To further explore the improvements in black tea quality achieved via microbial fermentation, we used widely targeted metabolomics and metagenomics analyses to investigate the changes in and effects of metabolites and other microorganisms during the interaction between the "golden flower" fungi and black tea. Five key flavor metabolites were detected, the levels of catechin, epigallocatechin gallate, (-)-epicatechin gallate were decreased by different degrees after the inoculation of the "golden flower" fungus, whereas the levels of caffeine and (+)-gallocatechin increased. Botryosphaeriaceae, Botryosphaeriales, Dothideomycetes, Aspergillaceae, Trichocomaceae, and Lecanoromycetes play a positive role in the black tea fermentation process after inoculation with the "golden flower" fungi. D-Ribose can prevent hypoxia-induced apoptosis in cardiac cells, and it shows a strong correlation with Botryosphaeriaceae and Botryosphaeriales. The interaction between microorganisms and metabolites is manifested in tryptophan metabolism, starch and sucrose metabolism, and amino sugar and nucleotide sugar metabolism. In conclusion, the changes in metabolites observed during the fermentation of black tea by "golden flower" fungi are beneficial to human health. This conclusion extends the knowledge of the interaction between the "golden flower" fungi and black tea, and it provides important information for improving the quality of black tea.

Effects of Fu brick tea polysaccharides on gut microbiota and fecal metabolites of HFD/STZ-induced type 2 diabetes rats

The prevalence of type 2 diabetes mellitus (T2DM) has dramatically increased globally, and the antidiabetic effects and underlying mechanisms of the polysaccharides extracted from Fu brick tea (FBTP) were investigated in high-fat diet (HFD)/streptozotocin (STZ)-induced T2DM rats. Administration of FBTP at 200 and 400 mg per kg bw significantly relieved dyslipidemia (i.e. TC, TG, LDL-C and HDL-C), insulin resistance (IR) and pancreas oxidative stress (i.e. CAT and GSH-Px) in T2DM rats. Mechanistically, FBTP rescued the HFD/STZ-induced alterations in the abundance of Bacteroidota, Actinobacteriota, Proteobacteria and Firmicutes. At the genus level, FBTP notably increased the abundance of Ruminococcus, Lactobacillus and Lachnospiraece_NK4A136_group, but reduced the population of Prevotella and Faecalibaculum in T2DM rats. FBTP also significantly elevated colonic short-chain fatty acid (SCFAs) levels. Moreover, apparent changes in amino acid absorption and metabolism were observed upon FBTP intervention. These findings suggested that FBTP might alleviate T2DM by reshaping the gut microbiota and regulating intestinal metabolites.

Eurotium cristatum from Fu Brick Tea Promotes Adipose Thermogenesis by Boosting Colonic Akkermansia muciniphila in High-Fat-Fed Obese Mice

This study investigated the potential fat-thermogenic effects of Eurotium cristatum, and elucidated the underlying mechanisms. The 12-week administration of E. cristatum in HFD-fed obese mice reduced body weight and improved glucolipid metabolism disorders. The administration of E. cristatum also efficiently promoted thermogenesis by increasing the expression of UCP1 and PRDM16 in both interscapular brown adipose tissue (iBAT) and inguinal white adipose tissue (iWAT) of HFD-fed mice. Furthermore, E. cristatum shaped the gut microbiome by increasing the abundance of Parabacteroides and Akkermansia muciniphila, and also elevated the levels of cecal short-chain fatty acids, particularly propionate and acetate. Of note, A. muciniphila was highly negatively correlated with body weight gain (r = -0.801, p < 0.05) and the iWAT index (r = -0.977, p < 0.01), suggesting that A. muciniphila may play an important role in the thermogenic mobilization induced by E. cristatum. Continuous supplementation with A. muciniphila suppressed adipose accumulation, improved glucolipid metabolism, and enhanced the thermogenic activity of iWAT and iBAT. Collectively, our results propose that boosted A. muciniphila acts as a key microbe in tea-derived probiotic E. cristatum-mediated fat-thermogenic and anti-obesity effects.

Fu brick tea alleviates high fat induced non-alcoholic fatty liver disease by remodeling the gut microbiota and liver metabolism

Fu brick tea (FBT) and its extracts have good lipid-lowering effects and have been used in the treatment of obesity in previous studies. Unfortunately, the therapeutic effect of FBT on non-alcoholic fatty liver disease (NAFLD) has not been thoroughly studied. In this study, we explored the mechanism by which FBT alleviates NAFLD from the perspective of the gut microbiota and liver metabolites. The results showed that FBT could reduce the body weight, liver weight and abdominal fat of NAFLD mice, and improve liver pathological morphology, liver lipid deposition, blood lipids and liver function. Moreover, FBT improved the diversity of the gut microbiota and changed the profile of liver metabolism in NAFLD mice. Further studies showed that FBT could ameliorate the cecum barrier, and regulate the effects of factors related to lipid synthesis in the cecum and liver of NAFLD mice. In conclusion, the present study confirmed that FBT can alleviate high fat induced NAFLD by regulating the homeostasis of the gut microbiota and liver metabolites.

Heimao tea polysaccharides ameliorate obesity by enhancing gut microbiota-dependent adipocytes thermogenesis in mice fed with high fat diet

Heimao tea (HMT) is a kind of fermented dark tea that has various health benefits. However, the available information regarding the anti-obesity effect of HMT and its active ingredients is still limited. Herein, we extracted the polysaccharides from Heimao tea (HMTP) and evaluated the anti-obesity effect and the underlying mechanism of HMTP. 12-Week administration of HMTP ameliorated lipid accumulation in the adipose tissue and improved glucolipid metabolism in high-fat diet (HFD)-fed mice. HMTP also induced browning of inguinal white adipose tissue (iWAT) and enhanced the thermogenic activity of interscapular brown adipose tissue (iBAT) by upregulating the expression of a series of thermogenic genes, such as Ucp1, Prdm16, and Pgc1α. Interestingly, the anti-obesity effect of HMTP was closely associated with altered relative abundance of the gut microbes, especially Dubosiella and Romboutsia, with significant increases, in which the abundance of Dubosiella and Romboutsia was negatively correlated with the body weight (r = -0.567, p < 0.05; r = -0.407, p < 0.05) and positively correlated with the iBAT index (r = 0.520, p < 0.05; r = 0.315, p < 0.05). Our data suggest that the alteration of the gut microbiota may play a critical role in HMTP-induced iWAT browning and iBAT activation, and our findings may provide a promising way for preventing obesity.

New Perspectives on Sleep Regulation by Tea: Harmonizing Pathological Sleep and Energy Balance under Stress

Sleep, a conservative evolutionary behavior of organisms to adapt to changes in the external environment, is divided into natural sleep, in a healthy state, and sickness sleep, which occurs in stressful environments or during illness. Sickness sleep plays an important role in maintaining energy homeostasis under an injury and promoting physical recovery. Tea, a popular phytochemical-rich beverage, has multiple health benefits, including lowering stress and regulating energy metabolism and natural sleep. However, the role of tea in regulating sickness sleep has received little attention. The mechanism underlying tea regulation of sickness sleep and its association with the maintenance of energy homeostasis in injured organisms remains to be elucidated. This review examines the current research on the effect of tea on sleep regulation, focusing on the function of tea in modulating energy homeostasis through sickness sleep, energy metabolism, and damage repair in model organisms. The potential mechanisms underlying tea in regulating sickness sleep are further suggested. Based on the biohomology of sleep regulation, this review provides novel insights into the role of tea in sleep regulation and a new perspective on the potential role of tea in restoring homeostasis from diseases.

Cedrol from ginger alleviates rheumatoid arthritis through dynamic regulation of intestinal microenvironment

The imbalance of intestinal flora would induce immune inflammation. Cedrol (CE), found from ginger by our group earlier, has been proven to play an excellent role in ameliorating rheumatoid arthritis (RA) via acting on JAK3, MAPK, and NF-κB. However, there have been no studies on CE ameliorating RA through the regulation of the micro-environment. In this study, the adjuvant arthritis model (AIA) is established to evaluate the weight, arthritis score, paw swelling, bone destruction, immune organ index, inflammatory cell infiltration, cartilage erosion, and metabolic enzymes of kidneys in AIA rats after CE intervention. The results indicated CE could alleviate paw swelling, reduce arthritis score, decrease the secretion of TNF-α, IL-6, and IL-1β in serum in a dose-dependent manner, and inhibit the immune organ index of the spleen while having no significant effect on metabolic enzymes of the kidney. In addition, pathological sections of ankle and knee joints suggested CE might significantly prevent inflammatory cell infiltration, synovial hyperplasia, and joint degeneration and protect articular cartilage. Then, for the first time, 16S rRNA gene was applied to analyze the regulatory effect of CE on intestinal flora. CE could effectively improve the uniformity, diversity, and richness of intestinal flora, reduce the number of pathogenic bacteria, and increase the proportion of beneficial bacteria, and it significantly inhibited the abundance of Prevotella in RA rats, which was 12.43 times smaller than that in methotrexate. The distribution and excretion of CE in vivo were detected by GC-MS. It was found that CE would massively accumulate in the gastrointestinal tract after oral administration, which is then mainly excreted through feces. Interestingly, the research suggested that CE, which plays a role in the dynamic regulation of the intestinal micro-environment, could be used as a potential component to prevent RA.

Fu Brick Tea Polysaccharides Prevent Obesity via Gut Microbiota-Controlled Promotion of Adipocyte Browning and Thermogenesis

The antiobesity efficacy and underlying mechanisms of polysaccharides extracted from Fu brick tea (FBTP) were investigated. An 8-week administration of FBTP dose-dependently inhibited increases in body weight and weights of the epididymal-, retroperitoneal- and inguinal-white adipose tissues and stimulated beige-fat development and brown adipose tissue-derived nonshivering thermogenesis in high-fat diet-induced obese mice. FBTP protected against obesity-associated abnormality in serum adiponectin and leptin, indicating its positive regulation of energy metabolism. FBTP reversed gut dysbiosis by enriching beneficial bacteria, for example, Lactobacillus, Parabacteroides, Akkermansia, Bifidobacterium, and Roseburia. Results from the fecal microbiota transplantation further confirmed that FBTP-induced microbial shifts contributed to adipose browning and thermogenesis, thereby alleviating host adiposity, glucose homeostasis, dyslipidemia, and its related hepatic steatosis. Our study demonstrates the great potential of FBTP with prebiotic-like activities in preventing diet-induced obesity and its related metabolic complications via gut microbiota-derived enhancement of fat burning and energy expenditures.

Fuzhuan brick tea polysaccharides serve as a promising candidate for remodeling the gut microbiota from colitis subjects in vitro: Fermentation characteristic and anti-inflammatory activity

The purified fraction 3 of polysaccharides from Fuzhuan brick tea (FBTPS-3) could attenuate the colitis and modulate the gut microbiota. However, the relationship between anti-inflammatory effect of FBTPS-3 and the gut microbiota is still unknown. Thus, the anaerobic fermentation in vitro was used to investigate the potential mechanism. FBTPS-3 could be utilized and degraded by gut microbiota from inflammatory bowel disease (IBD) subjects. Furthermore, FBTPS-3 could modulate the composition and structure of IBD gut microbiota toward to that of healthy group. FBTPS-3 showed a superior modulated effect on IBD gut microbiota by increasing Bacteroides and decreasing Escherichia/Shigella. Furthermore, the fermentation solution rather than FBTPS-3 itself showed anti-inflammatory effects on lipopolysaccharide-treated RAW264.7 macrophages, which might be due to the metabolites such as short-chain fatty acids (SCFAs). Thus, FBTPS-3 can be expected as novel prebiotics for treatment of IBD via modulating gut microbiota, and promoting the production of SCFAs.

Multiomic analysis of dark tea extract on glycolipid metabolic disorders in db/db mice

Glycolipid metabolic disorder is a serious threat to human health. Dark tea is a kind of traditional Chinese tea, which may regulate the glycolipid metabolic disorders. Dark tea extract (DTE) is the water extraction obtained from dark tea. Compared with traditional dark tea, DTE has the benefits of convenient consumption and greater potential for promoting health. However, the regulation of DTE on glycolipid metabolism and its molecular mechanism is rarely investigated. In our study, DTE was used as raw material to study the effect and molecular mechanism of its intervention on the glycolipid metabolic in db/db diabetic mice by using multiomics analysis and modern biological techniques. (1) DTE could significantly reduce fasting glucose in diabetic db/db mice, and the higher dose group has a better effect. Histopathological examination showed that DTE slightly improve the number of islets and decrease the number of islet β cells in the pancreatic tissue in db/db mice. (2) RNA-Seq was used to analyze the gene expression in liver tissue. In terms of biological processes, DTE mainly affected the inflammation and fatty acid metabolism. In terms of cell components, the lipoprotein and respiratory chain are mainly affected. In the aspect of molecular function, DTE mainly affected the redox related enzyme activity, iron ion binding and glutathione transferase. Arachidonic acid metabolism pathway, glutathione metabolism and PPAR signaling pathway were enriched by DTE with the results of KEGG pathway enrichment. In addition, real-time PCR results confirmed that DTE could significantly activate key genes of PPAR signaling pathway like Fabp1, Cyp4a1, Ehhadh, Cyp4a32, Aqp7 and Me1. (3) 16s rDNA showed that DTE could significantly decrease the ratio of Firmicutes/Bacteroidetes and the abundance of Proteobacteria, and increased the relative abundance of Verrucomicrobia at the phylum level. At the genus level, the relative abundance of Akkermansia, Prevotellaceae, Bacteroides and Alloprevotella was significantly increased after DTE treatment. This study provides multiomics molecular evidence for the intervention effect of DTE on abnormal glucose and lipid metabolism and the application of precise nutritional diet intervention of dark tea extract.

Fu brick tea alleviates alcoholic liver injury by modulating the gut microbiota-liver axis and inhibiting the hepatic TLR4/NF-κB signaling pathway

This study first evaluated the protective effects of Fu brick tea water extracts (FTE) on alcoholic liver injury and its underlying mechanism in C57BL/6J mice. Oral administration of FTE by oral gavage (400 mg per kg bw) for 12 weeks significantly alleviated lipid metabolism disorder, reduced the activities of serum ALT and AST, decreased the expression of the liver CYP2E1 gene, and enhanced the antioxidant capacities of the livers in alcohol-fed mice (p < 0.05). FTE also relieved alcohol-induced gut microbiota dysbiosis by promoting the proliferation of probiotics such as Muribaculaceae and Lactobacillus, and subsequently increased the cecal levels of short-chain fatty acids (SCFAs) and decreased the tryptophan content of alcohol-fed mice (p < 0.05). Importantly, FTE was found to improve the alcohol-impaired gut barrier function by up-regulating the expression of the epithelial tight junction protein. Accordingly, FTE decreased the circulating lipopolysaccharide (LPS) and thus inhibited the hepatic TLR4/NF-κB signaling pathway to ameliorate alcoholic liver injury. Cumulatively, these findings shed light on the important role of the gut microbiota-liver axis behind the protective efficacy of FTE on alcoholic liver injury.

Efficient production of a cyclic dipeptide (cyclo-TA) using heterologous expression system of filamentous fungus Aspergillus oryzae

Background

Cyclic dipeptides are an important class of natural products owing to their structural diversity and biological activities. In fungi, the cyclo-ring system is formed through the condensation of two α-amino acids via non-ribosomal peptide synthetase (NRPS). However, there are few investigations on the functional identification of this enzyme. Additionally, information on how to increase the production of cyclic dipeptide molecules is relatively scarce.

Results

We isolated the Eurotium cristatum NWAFU-1 fungus from Jing-Wei Fu brick tea, whose fermentation metabolites contain echinulin-related cyclic dipeptide molecules. We cloned the cirC gene, encoding an NRPS, from E. Cristatum NWAFU-1 and transferred it into the heterologous host Aspergillus oryzae. This transformant produced a novel metabolite possessing an l-tryptophan-l-alanine cyclic dipeptide backbone (Cyclo-TA). Based on the results of heterologous expression and microsomal catalysis, CriC is the first NRPS characterized in fungi that catalyzes the formation of a cyclic dipeptide from l-tryptophan and l-alanine. After substrate feeding, the final yield reached 34 mg/L. In this study, we have characterized a novel NRPS and developed a new method for cyclic dipeptide production.

Conclusions

In this study we successfully expressed the E. Cristatum NWAFU-1 criC gene in A. oryzae to efficiently produce cyclic dipeptide compounds. Our findings indicate that the A. oryzae heterologous expression system constitutes an efficient method for the biosynthesis of fungal Cyclic dipeptides.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01872-8.

Fu Brick Tea Manages HFD/STZ-Induced Type 2 Diabetes by Regulating the Gut Microbiota and Activating the IRS1/PI3K/Akt Signaling Pathway

The antidiabetic effects of Fu brick tea aqueous extract (FTE) and its underlying molecular mechanism in type 2 diabetes mellitus (T2DM) mice were investigated. FTE treatment significantly relieved dyslipidemia, insulin resistance (IR), and hepatic oxidative stress caused by T2DM. FTE also ameliorated the T2DM-induced gut dysbiosis by decreasing the Firmicutes/Bacteroidota (F/B) ratio at the phylum level and promoting the proliferation of Bifidobacterium, Parabacteroides, and Roseburia at the genus level. Besides, FTE significantly improved colonic short-chain fatty acid levels of T2DM mice. Furthermore, the antidiabetic effects of FTE were proved to be mediated by the IRS1/PI3K/Akt and AMPK-mediated gluconeogenesis signaling pathways. Metabolomics analysis illustrated that FTE recovered the levels of 28 metabolites associated with T2DM to the levels of normal mice. Taken together, these findings suggest that FTE can alleviate T2DM by reshaping the gut microbiota, activating the IRS1/PI3K/Akt pathway, and regulating intestinal metabolites.

Fermented food: Should patients with cardiometabolic diseases go back to an early neolithic diet?

Fermentation has been used since the Early Neolithic period to preserve foods. It has inherent organoleptic and nutritive properties that bestow health benefits, including reducing inflammation and oxidative stress, supporting the growth of salutogenic microbiota, enhancing intestinal mucosal protection and promoting beneficial immunometabolic health effects. The fermentation of food with specific microbiota increases the production salutogenic bioactive compounds that can activate Nrf2 mediated cytoprotective responses and mitigate the effects of the 'diseasome of aging' and its associated inflammageing, which presents as a prominent feature of obesity, type-2 diabetes, cardiovascular and chronic kidney disease. This review discusses the importance of fermented food in improving health span, with special reference to cardiometabolic diseases.

Aged green tea reduces high-fat diet-induced fat accumulation and inflammation via activating the AMP-activated protein kinase signaling pathway

Background

Obesity is a global public health concern and increases the risk of metabolic syndrome and other diseases. The anti-obesity effects of various plant-derived bioactive compounds, such as tea extracts, are well-established. The mechanisms underlying the anti-obesity activity of Jinxuan green tea (JXGT) from different storage years are still unclear.

Objective

The aim of this study was to evaluate the effects of JXGTs from three different years on the high fat diet (HFD)-fed mouse model.

Design

The mice were divided into six groups, the control group received normal diet and the obese model group received HFD. We analyzed the effects of JXGTs from 2005, 2008, and 2016 on HFD-fed obese mice over a period of 7 weeks.

Results

The JXGTs reduced the body weight of the obese mice, and also alleviated fat accumulation and hepatic steatosis. Mechanistically, JXGTs increased the phosphorylation of AMP-activated protein kinase (p-AMPK)/AMP-activated protein kinase (AMPK) ratio, up-regulated carnitine acyl transferase 1A (CPT-1A), and down-regulated fatty acid synthase (FAS), Glycogen synthase kinase-3beta (GSK-3β), Peroxisome proliferator-activated receptor-gamma co-activator-1alpha (PGC-1α), Interleukin 6 (IL-6), and Tumour necrosis factor alpha (TNFα). Thus, JXGTs can alleviate HFD-induced obesity by inhibiting lipid biosynthesis and inflammation, thereby promoting fatty acid oxidation via the AMPK pathway.

Discussion

The anti-obesity effect of three aged JXGTs were similar. However, JXGT2016 exhibited a more potent activation of AMPK, and JXGT2005 and JXGT2008 exhibited a more potent inhibiting glycogen synthase and inflammation effect. Furthermore, the polyphenol (–)-epicatechin (EC) showed the strongest positive correlation with the anti-obesity effect of JXGT.

Conclusions

These findings demonstrate that JXGT treatment has a potential protection on HFD-induced obesity mice via activating the AMPK/CPT-1A and down-regulating FAS/GSK-3β/PGC-1α and IL-6/TNFα. Our study results also revealed that different storage time would not affect the anti-obesity and anti-inflammation effect of JXGT.

Graphical abstract

Kidney Damage Caused by Obesity and Its Feasible Treatment Drugs

The rapid growth of obesity worldwide has made it a major health problem, while the dramatic increase in the prevalence of obesity has had a significant impact on the magnitude of chronic kidney disease (CKD), especially in developing countries. A vast amount of researchers have reported a strong relationship between obesity and chronic kidney disease, and obesity can serve as an independent risk factor for kidney disease. The histological changes of kidneys in obesity-induced renal injury include glomerular or tubular hypertrophy, focal segmental glomerulosclerosis or bulbous sclerosis. Furthermore, inflammation, renal hemodynamic changes, insulin resistance and lipid metabolism disorders are all involved in the development and progression of obesity-induced nephropathy. However, there is no targeted treatment for obesity-related kidney disease. In this review, RAS inhibitors, SGLT2 inhibitors and melatonin would be presented to treat obesity-induced kidney injury. Furthermore, we concluded that melatonin can protect the kidney damage caused by obesity by inhibiting inflammation and oxidative stress, revealing its therapeutic potential.

A critical review of Fuzhuan brick tea: processing, chemical constituents, health benefits and potential risk

Fuzhuan brick tea (FBT) is a traditional popular beverage in the border regions of China. Nowadays, FBT has been attracted great attention due to its uniquely flavor and various health-promoting functions. An increasing number of efforts have been devoted to the studies on health benefits and chemistry of FBT over the last decades. However, FBT was still received much less attention than green tea, oolong tea and black tea. Therefore, it is necessary to review the current encouraging findings about processing, microorganisms, chemical constituents, health benefits and potential risk of FBT. The fungus fermentation is the key stage for processing of FBT, which is involved in a complex and unique microbial fermentation process. The fungal community in FBT is mainly dominated by "golden flower" fungi, which is identified as Aspergillus cristatus. A great diversity of novel compounds is formed and identified after a series of biochemical reactions during the fermentation process of FBT. FBT shows various biological activities, such as antioxidant, anti-inflammatory, anti-obesity, anti-bacterial, and anti-tumor activities. Furthermore, the potential risk of FBT was also discussed. It is expected that this review could be useful for stimulating further research of FBT.

Inhibitory Effects of Six Types of Tea on Aging and High-Fat Diet-Related Amyloid Formation Activities

Aging and lipid metabolism disorders promote the formation and accumulation of amyloid with β-sheet structure, closely related to cardiovascular disease, senile dementia, type 2 diabetes, and other senile degenerative diseases. In this study, five representative teas were selected from each of the six types of tea, and a total of 30 teas were selected to evaluate the inhibitory activities on the formation of aging-related amyloid in vitro. The results showed that the 30 teas had a significant inhibitory effect on the formation activity on aging-related amyloid at the protein level in vitro. Although the content of catechins is relatively low, black tea and dark tea still have significant antioxidant activity and inhibit the formation of amyloid. A high-fat diet established the model of lipid metabolism disorder in premature aging SAMP8 mice, and these mice were gavaged different tea water extracts. The results showed that different tea types have a significant inhibitory effect on the formation of β-amyloid and Aβ42 mediated by age-related lipid metabolism disorders, and the in vivo activity of fully fermented teas was better than that of green tea. The action mechanism was related to antioxidation, anti-inflammatory, and improving lipid metabolism.

Grape seed proanthocyanidins reduced the overweight of C57BL/6J mice through modulating adipose thermogenesis and gut microbiota

Activating the thermogenic function of adipocytes is an attractive therapeutic strategy against obesity and its associated metabolic complications. Proanthocyanidins are a class of polyphenols which are widely found in plants and daily foods. This aim of this study is to investigate the modulatory effects of grape seed proanthocyanidin extract (GSPE) on brown adipose tissue (BAT) activity, browning of white adipose tissue (WAT) and microbiome regulation in high-fat diet (HFD)-fed mice and its associated molecular mechanism. An 8-week administration of GSPE at 200 mg per kg bw in mice significantly reduced their final body weight, antagonized their HFD-induced insulin resistance and elevated their levels of adiponectin and leptin, respectively (p < 0.05). GSPE significantly increased the expression levels of thermogenic marker UCP1 in BAT and elevated the expression of a key transcription factor of browning, PRDM16, and thermogenic markers UCP1 and PGC-1α in inguinal white adipose tissue (iWAT). The high doses of GSPE also increased the levels of acetic acid, propionic acid and butyric acid in the colon of HFD-fed mice (p < 0.05). Furthermore, GSPE normalized the colonic Firmicutes/Bacteroidetes ratios, reversed the relative abundance of Weissella, Faecalibaculum, Bacteroides, Akkermansia and Ruminococcus 1 induced by HFD, and improved the structural diversity of the gut microbiota in C57BL/6J mice.

Lycium barbarum polysaccharide combined with aerobic exercise ameliorated nonalcoholic fatty liver disease through restoring gut microbiota, intestinal barrier and inhibiting hepatic inflammation

Gut microbiota and intestinal permeability have been demonstrated to be the key players in the gut-liver cross talk in nonalcoholic fatty liver disease (NAFLD). Lycium barbarum polysaccharides (LBPs), which seem to be a potential prebiotic, and aerobic exercise (AE) have shown protective effects on NAFLD. However, their combined effects on intestinal microecology remain unclear. This study evaluated the effects of LBP, AE, and its combination (LBP + AE) on gut microbiota composition, intestinal barrier, and hepatic inflammation in NAFLD. LBP + AE showed high abundance and diversity of gut microbiota, restored the gut microbiota composition, increased some Bacteroidetes, short chain fatty acids, but decreased Proteobacteria and the ratio of Firmicutes/Bacteroidetes. Simultaneously, LBP, AE, and LBP + AE could restore the colonic and ileum tight junctions by increasing the expression of zonula occludens-1 and occludin. They also downregulated gut-derived lipopolysaccharides (LPSs), hepatic LPS-binding proteins, inflammatory factors, and related indicators of the LPS/TLR4/NF-κB signaling pathway for the liver. Our results implied that LBP could be considered a prebiotic agent, and LBP + AE might be a promising treatment for NAFLD because it could maintain gut microbiota balance, thereby restoring intestinal barrier and exerting hepatic benefits.

Therapeutic implications of functional tea ingredients for ameliorating inflammatory bowel disease: a focused review

Inflammatory bowel disease (IBD) is a chronic gastro-intestinal disorders of unknown etiology. There are several drugs approved for treating IBD patients with active disease, including first-line use of aminosalicylates, and secondary choices of immunomodulators and other therapies. These medications might manage disease symptoms, but have also shown significant side-effects in IBD patients. Tea is the second largest beverage in the world and its main active ingredients including tea polyphenols, polysaccharides and tea pigments have been shown promising anti-inflammatory and antioxidant properties. In this review, we summarize the influence of different tea varieties including green tea, black tea and dark tea as potential nutritional therapy for preventing and treating IBD, and discuss the mechanisms of tea ingredients involved in the regulation of oxidative stress, inflammation, signaling pathways, and gut microbiota that could benefit for IBD disease management. Our observation directs further basic and clinical investigations on tea polyphenols and their derivatives as novel IBD therapeutic agents.

Water extract of shepherd's purse prevents high-fructose induced-liver injury by regulating glucolipid metabolism and gut microbiota

Shepherd's purse as a wild vegetable is getting more and more attention on health benefits. Water extract of shepherd's purse (WESP) was prepared and analyzed for the chemical constituents. The mice were fed high-fructose (HF) diet and treated with WESP at 50, 100 and 200 mg/kg·bw for 8 weeks. The HF-fed mice receiving WESP exhibited the inhibitions against abnormal weight gain, hepatic fat accumulation and lipid metabolic by down-regulating FAS and ACC expressions. WESP also significantly alleviated hyperglycemia, oxidative stress, and inflammatory response by regulating of NF-κB pathway. Moreover, WESP dose-dependently increased the acetic, propionic, and butyric acids levels in HF-fed mice. Furthermore, WESP significantly alleviated the HF-induced gut dysbiosis by reducing the ratio of Firmicutes to Bacteroidetes and increasing the abundance of potential beneficial bacteria. Our findings indicate that WESP may be an effective dietary supplement for preventing the liver damage.

Compound Fu brick tea modifies the intestinal microbiome composition in high-fat diet-induced obesity mice

Compound Fu Brick Tea (CFBT), which is from Duyun city in China, is a traditional Chinese dark tea, Fu Brick Tea, mixed with six herbal medicine. It is consumed by local people for reducing weight, but the mechanism is not clear. The disorder of intestinal microbiome caused by long-term high-fat diet (HFD) is one of the inducements of obesity and related metabolic syndrome. In this study, mice were fed with HFD to establish a high-fat model. Fifty mice were randomly divided into six groups: normal control (CK), HFD model control (NK), positive control with medicine (YK), CFBT groups with low, middle, and high dose (FL, FM, FH). The V3-V4 DNA region of fecal microbiome from mouse intestine was sequenced. The results showed that the diversity of intestinal microflora was highest in CK and lowest in NK. Compared with CK, the dominant bacterium Firmicutes was increased and Bacteroidetes decreased at phylum level in NK. Compared with NK, the abundance of microbiome in CFBT groups was significantly higher and the composition was changed: Muribaculaceae, Bacteroidaceae, and Prevotellaceae increased and Lachnospiraceae decreased in CFBT groups at family level, while at the genus level, Bacteroides increased and Lactobacillus decreased. These results conclude that CFBT can increase the abundance of intestinal microbiome in mice, promote the growth of beneficial bacteria and reduce the number of pathogenic bacteria, and restore the imbalance of intestinal microbiome caused by poor diet.

Fubrick tea attenuates high-fat diet induced fat deposition and metabolic disorder by regulating gut microbiota and caffeine metabolism

Fubrick tea aqueous extract (FTEs) has been reported to improve lipid metabolism and gut microbiota communities in mice and humans. However, it is still unclear how FTEs prevents obesity through gut microbiota, and whether some other regulatory mechanisms are involved in the process. Here, we found that FTEs supplementation effectively alleviated the body weight gain, visceral fat accumulation, dyslipidemia, and impaired glucose tolerance induced by a high-fat diet (HFD), and fecal microbiota transplantation (FMT) from FTEs-treated mice showed similar protective effects as FTEs supplementation in mice fed with a HFD. The results confirmed that gut microbiota played key roles in attenuating HFD-induced fat deposition and metabolic disorder. In particular, FTEs reversed HFD-induced gut microbiota dysbiosis via increasing the relative abundances of Bacteroides, Adlercreutzia, Alistipes, Parabacteroides, and norank_f_Lachnospiraceae, and reducing that of Staphylococcus. Interestingly, FTEs could still alleviate HFD-induced lipid accumulation in mice treated with antibiotics, which had increased relative abundances of Bacteroidetes, Bacteroides, and Bacteroides_uniformis sp. In addition, supplementation with FTEs also modified the serum metabolome, especially the "caffeine metabolism" pathway. Furthermore, FTEs supplementation increased the concentrations of caffeine, theophylline, and theobromine in serum, which were positively correlated with an abundance of norank_f_Lachnospiraceae. Overall, FTEs exerts beneficial effects against obesity induced by HFD, and the underlying mechanism is partially related to the reprogramming of intestinal microbiota, while the metabolism of caffeine in FTEs also played an important role in the process. This study provides a theoretical basis for the further study of the anti-obesity effects of FTEs and the consideration of gut microbiota as a potential target for the treatment of obesity induced by a HFD.

Inhibitory Effects of Eurotium cristatum on Growth and Aflatoxin B1 Biosynthesis in Aspergillus flavus

Probiotic strain Eurotium cristatum was isolated from Chinese Fuzhuan brick-tea and tested for its in vitro activity against aflatoxigenic Aspergillus flavus. Results indicated that E. cristatum can inhibit the radial growth of A. flavus. Furthermore, this inhibition might be caused by E. cristatum secondary metabolites. The ability of culture filtrate of strain E. cristatum against growth and aflatoxin B₁ production by toxigenic A. flavus was evaluated in vitro. Meanwhile, the influence of filtrate on spore morphology of A. flavus was analyzed by scanning electron microscopy (SEM). Results demonstrated that both radial growth of A. flavus and aflatoxin B₁ production were significantly weakened following increases in the E. cristatum culture filtrate concentration. In addition, SEM showed that the culture filtrate seriously damaged hyphae morphology. Gas chromatography mass spectrometry (GC/MS) analysis of the E. cristatum culture supernatant revealed the presence of multiple antifungal compounds. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis showed that the expression of aflatoxin biosynthesis-related genes (aflD, aflQ, and aflS) were down-regulated. Importantly, this latter occurrence resulted in a reduction of the AflS/AflR ratio. Interestingly, cell-free supernatants of E. cristatum facilitated the effective degradation of aflatoxin B₁. In addition, two degradation products of aflatoxin B₁ lacking the toxic and carcinogenic lactone ring were identified. A toxicity study on the HepG2 cells showed that the degradation compounds were less toxic when compared with AFB₁.

Distinct Changes of Metabolic Profile and Sensory Quality during Qingzhuan Tea Processing Revealed by LC-MS-Based Metabolomics

Qingzhuan tea (QZT) is a unique type of dark tea exclusively produced in Hubei Province of China. In the current study, liquid chromatography-mass spectrometry (LC-MS) coupled with multivariate analysis was applied to characterize the chemical composition of QZT and investigate the effect of QZT processing on its metabolic profile and sensory quality. The contents of polyphenols and flavonoids decreased significantly while the polysaccharides content remained stable, while the theabrownin content inversely increased during QZT processing. LC-MS-based metabolomics analyses revealed that the tea sample after microbial fermentation (MFT) was dramatically different from the sample before microbial fermentation (UFT), while MFT was very similar to QZT. A total of 102 compounds were identified as critical metabolites responsible for metabolic changes caused by QZT processing, with the contents of catechins and flavonoids significantly decreased, and some novel phenolic acids and catechin derivatives were formed. The sensory quality of QZT was mainly formed during microbial fermentation, which greatly reduced the astringency and bitterness of raw tea leaves and produced its characteristic woody and stale aroma as well as mellow taste. These results suggested that microbial fermentation is the critical process in changing the metabolic profile of raw tea leaves and forming the sensory quality of QZT.

Modulation of Glucose Metabolism by Leaf Tea Constituents: A Systematic Review of Recent Clinical and Pre-clinical Findings

Leaf teas are widely used as a purported treatment for dysregulated glucose homeostasis. The objective of this study was to systematically evaluate the clinical and cellular-metabolic evidence, published between January 2013 and May 2019, and indexed on PubMed, ScienceDirect, and Web of Science, supporting the use of leaf teas for this purpose. Fourteen randomized controlled trials (RCTs) (13 on Camellia sinensis teas) were included, with mixed results, and providing scant mechanistic information. In contrast, 74 animal and cell culture studies focusing on the pancreas, liver, muscle, and adipose tissue yielded mostly positive results and highlighted enhanced insulin signaling as a recurring target associated with the effects of teas on glucose metabolism. We conclude that more studies, including RCTs and pre-clinical studies examining teas from a wider variety of species beyond C. sinensis, are required to establish a stronger evidence base on the use of leaf teas to normalize glucose metabolism.

Supplementation of Inulin with Various Degree of Polymerization Ameliorates Liver Injury and Gut Microbiota Dysbiosis in High Fat-Fed Obese Mice

The chain length of fructan determines its different physiological effects. This study is to explore the effects of low-performance inulin [LPI, degree of polymerization (DP) ≤ 9] and high-performance inulin (HPI, DP ≥ 23) on obesity-associated liver injury of high-fat diet (HFD) feeding mice and its underlying mechanism. Eight weeks of supplementation of C57BL/6J mice with HPI, relative to LPI (p < 0.05), caused the more efficient improvement against the HFD-induced liver insulin resistance through activating IRS1/PI3K/Akt pathway and reduced protein expressions of inflammatory factors nuclear factor-kappaB (NF-κB) and interleukin-6 (IL-6) in the liver. HPI exhibited the more positive effects on liver steatosis by inhibiting acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and sterol regulatory element binding protein 1 (SREBP1) in comparison with LPI (p < 0.05). HPI also increased acetic acid, propionic acid, and butyric acid levels in the colon of HFD-fed mice (p < 0.05). Compared to LPI, HPI feeding of HFD-fed mice led to the more effective decrease in the Firmicutes abundance from 72.1% to 34.5%, but a more significant increase in the Bacteroidetes population from 19.8 to 57.1% at the phyla level, and increased the abundance of Barnesiella, Bacteroides, and Parabacteroides at the genus level (p < 0.05). Depending on DP, HPI exerts the more positive regulation on liver injury and gut microbiota dysfunction than LPI.

Effects and Mechanisms of Tea for the Prevention and Management of Diabetes Mellitus and Diabetic Complications: An Updated Review

Diabetes mellitus has become a serious and growing public health concern. It has high morbidity and mortality because of its complications, such as diabetic nephropathy, diabetic cardiovascular complication, diabetic neuropathy, diabetic retinopathy, and diabetic hepatopathy. Epidemiological studies revealed that the consumption of tea was inversely associated with the risk of diabetes mellitus and its complications. Experimental studies demonstrated that tea had protective effects against diabetes mellitus and its complications via several possible mechanisms, including enhancing insulin action, ameliorating insulin resistance, activating insulin signaling pathway, protecting islet β-cells, scavenging free radicals, and decreasing inflammation. Moreover, clinical trials also confirmed that tea intervention is effective in patients with diabetes mellitus and its complications. Therefore, in order to highlight the importance of tea in the prevention and management of diabetes mellitus and its complications, this article summarizes and discusses the effects of tea against diabetes mellitus and its complications based on the findings from epidemiological, experimental, and clinical studies, with the special attention paid to the mechanisms of action.

Consumption of post-fermented Jing-Wei Fuzhuan brick tea alleviates liver dysfunction and intestinal microbiota dysbiosis in high fructose diet-fed mice

Emerging evidence supports the health-promoting ability of a special microbial-fermented Fuzhuan brick tea. Epigallocatechin gallate was identified as a dominant flavonoid of Fuzhuan tea aqueous extract (FTE). Mice were treated with 30% high fructose (HF) water feeding alone or in combination with administration of FTE at 400 mg per kg bw for 13 weeks. FTE caused strong inhibition against the elevation of liver weight, serum enzymatic (aspartate aminotransferase, aspartate aminotransferase and alkaline phosphatase) activities and hepatic inflammatory cytokines (interleukin-1, interleukin-6, tumor necrosis factor-α and tumor necrosis factor-β) formation, as well as dyslipidemia (total cholesterol, total triglyceride, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol) in HF-fed mice (p < 0.05). Hepatic malonaldehyde formation was lowered, while superoxide dismutase and glutathione peroxidase activities were enhanced by FTE treatment, relative to HF-fed mice (p < 0.05), and histopathological evaluation confirmed the protection. As revealed by 16S rDNA gene sequencing, FTE notably increased abundance of Bacteroidetes and Lactobacillus, but reduced population of Firmicutes, Proteobacteria and Tenericutes in HF feeding mice. These findings suggest that FTE exerts a hepatoprotective effect by modifying hepatic oxidative stress, inflammatory response and gut microbiota dysfunction.

Fuzhuan brick tea can improve non-alcoholic fatty liver disease (NAFLD) and intestinal microbiota imbalance induced by a high fructose diet (HFD) intake in mice.