Microbiota Metabolism Research Articles

Kombucha polysaccharide alleviates DSS-induced colitis in mice by modulating the gut microbiota and remodeling metabolism pathways

Ulcerative colitis (UC) is incurable, and rational dietary interventions are important in preventing UC. Kombucha is a fermented beverage that originated in China and has a variety of activities, including antioxidant, antibacterial and hypoglycemic activities. The aim of this study was to analyze the protective effect of Kombucha polysaccharide (KP) against UC and determine its mechanism of action. The results showed that KP intervention was effective in alleviating dextran sulfate sodium salt (DSS)-induced colitis symptoms and inhibiting DSS-induced inflammation and oxidative stress. Moreover, KP was able to reduce intestinal permeability, promote the expression of tight junction proteins, and help maintain thrush cell numbers and promote mucus secretion. The 16S rDNA results indicated that KP intervention increased the abundance of Rikenellaceae_RC9_gut_group and Clostridiales_unclassified. Untargeted metabolomics techniques revealed that KP can reverse DSS-induced disorders in intestinal metabolism. This study demonstrated that KP alleviated DSS-induced colitis by helping maintain intestinal barrier integrity, regulating the gut microbiota and remodeling metabolism pathways. The findings provide a theoretical basis for the application of KP as a dietary supplement for the prevention of UC.

Molecular mechanism and promising treatments of chronic prostatitis/chronic pelvic pain syndrome: An exploratory bibliometric analysis and literature review of preclinical studies

AbstractBackgroundAs one of the most common diseases in urology, a large number of preclinical studies have been accumulated to explore the etiological mechanism and potential intervention of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).MethodsIn this study, we systematically evaluated the current status of preclinical research on CP/CPPS through bibliometrics analysis using VOSviewer and Citespace. Characteristics of publication such as year, country/region, institution, author, journal, citation, and keywords were analyzed. Based on the bibliometrics analysis results of keywords, we summarized the possible mechanisms and promising treatments for CP/CPPS narratively.ResultsAccording to the results of this study, the most common mechanisms involved in CP/CPPS were as follows: disturbed immune and inflammation mediators, immune cell dysfunction, oxidative stress, dysregulated signaling pathways, apoptosis, gut microbiota, and testosterone metabolism. Chinese Traditional Medicine and extracorporeal shock wave therapy have important potential in the treatment of CP/CPPS.ConclusionFurther translational studies targeting the above mechanisms and validating the objective efficacy of potential treatments indicated by preclinical studies in clinical patients are needed in the future.

Gut microb-aging and its relevance to frailty aging

This review explores ‘microb-aging’ in the gut and its potential link to frailty aging. We explore this connection through alterations in microbiota's taxonomy and metabolism, as well as with concepts of ecological resilience, pathobionts emergence, and biogeography. We examine microb-aging in interconnected body organs, emphasizing the bidirectional relationship with ‘inflammaging’. Finally, we discuss how targeting microb-aging could improve screening, diagnostic, and therapeutic approaches in geriatrics.

New mechanistic insights of anti-obesity by sleeve gastrectomy-altered gut microbiota and lipid metabolism.

The obesity epidemic has been on the rise due to changes in living standards and lifestyles. To combat this issue, sleeve gastrectomy (SG) has emerged as a prominent bariatric surgery technique, offering substantial weight reduction. Nevertheless, the mechanisms that underlie SG-related bodyweight loss are not fully understood. In this study, we conducted a collection of preoperative and 3-month postoperative serum and fecal samples from patients who underwent laparoscopic SG at the First Affiliated Hospital of Shandong First Medical University (Jinan, China). Here, we took an unbiased approach of multi-omics to investigate the role of SG-altered gut microbiota in anti-obesity of these patients. Non-target metabolome sequencing was performed using the fecal and serum samples. Our data show that SG markedly increased microbiota diversity and Rikenellaceae, Alistipes, Parabacteroides, Bactreoidales, and Enterobacteraies robustly increased. These compositional changes were positively correlated with lipid metabolites, including sphingolipids, glycerophospholipids, and unsaturated fatty acids. Increases of Rikenellaceae, Alistipes, and Parabacteroide were reversely correlated with body mass index (BMI). In conclusion, our findings provide evidence that SG induces significant alterations in the abundances of Rikenellaceae, Alistipes, Parabacteroides, and Bacteroidales, as well as changes in lipid metabolism-related metabolites. Importantly, these changes were found to be closely linked to the alleviation of obesity. On the basis of these findings, we have identified a number of microbiotas that could be potential targets for treatment of obesity.

The role of gut microbiota on obesity management: a review of the evidence

In the last 40 years, there has been a significant increase in the number of people who are overweight, obese and experience combined metabolic disorders. Gut microbiota has been shown to influence energy metabolism and is therefore a significant factor in the development of obesity. A person's diet, in particular, the nutritional value of that diet, is a crucial connection between gut microbiota composition and metabolism. This review explores the role of normal colonic microbiota and the gut environment. These mechanisms connect microbiota with obesity, the presence of gut microbiota in obese individuals and the impact of bioactive compounds in dairy products on gut microbiota. Research shows that gut microbiota play a crucial role in regulating energy metabolism and influencing the development of obesity. Changes in diet can alter the composition and levels of gut microbiota, and consuming bioactive components can help reshape the metabolic profile of obese individuals.

Recent advances in applying omic technologies for studying acetic acid bacteria in industrial vinegar production: A comprehensive review.

Vinegar and related bioproducts containing acetic acid as the main component are among the most appreciated fermented foodstuffs in numerous European and Asian countries because of their exceptional organoleptic and bio-healthy properties. Regarding the acetification process and obtaining of final products, there is still a lack of knowledge on fundamental aspects, especially those related to the study of biodiversity and metabolism of the present microbiota. In this context, omic technologies currently allow for the massive analysis of macromolecules and metabolites for the identification and characterization of these microorganisms working in their natural media without the need for isolation. This review approaches comprehensive research on the application of omic tools for the identification of vinegar microbiota, mainly acetic acid bacteria, with subsequent emphasis on the study of the microbial diversity, behavior, and key molecular strategies used by the predominant groups throughout acetification. The current omics tools are enabling both the finding of new vinegar microbiota members and exploring underlying strategies during the elaboration process. The species Komagataeibacter europaeus may be a model organism for present and future research in this industry; moreover, the development of integrated meta-omic analysis may facilitate the achievement of numerous of the proposed milestones. This work might provide useful guidance for the vinegar industry establishing the first steps towards the improvement of the acetification conditions and the development of new products with sensory and bio-healthy profiles adapted to the agri-food market.

Inside Front Cover: Oral Troxerutin Alleviates Depression Symptoms in Mice by Modulating Gut Microbiota and Microbial Metabolism

Inside Front Cover: Oral Troxerutin Alleviates Depression Symptoms in Mice by Modulating Gut Microbiota and Microbial Metabolism

Effect of Lactiplantibacillus plantarum CCFM8661 on serum metabolites and gut microbiota in a lead-exposed population

In this study, we investigated the impact of Lactiplantibacillus plantarum (L. plantarum) CCFM8661 on the gut microbiota, and the serum and fecal metabolomes in lead (Pb)-exposed individuals. The volunteers recruited for this study were divided into two treatment groups, (i) the placebo (control) and (ii) the L. plantarum CCFM8661 treatment groups. The analysis revealed that probiotic intervention reversed some of the changes in Pb exposure-induced intestinal bacterial abundance, including the abundance of Parabacteroides, Bacteroides, Clostridiaceae, and Erysipelotrichaceae. An analysis of the fecal metabolome identified 26 differential metabolites involved in purine metabolism, unsaturated fatty acid metabolism, and other pathways. Serum metabolite analysis showed that L. plantarum CCFM8661 treatment altered the serum metabolite levels of various metabolic pathways, such as the glycerophospholipid, amino acid, and glutathione metabolism pathways. These results suggest that L. plantarum CCFM8661 may have beneficial effects on Pb-exposed populations by modulating the gut microbiota, host serum metabolism, and the metabolism of the gut microbiota.

Bifidobacterium animalis subsp. lactis F1-7 Alleviates Lipid Accumulation in Atherosclerotic Mice via Modulating Bile Acid Metabolites to Downregulate Intestinal FXR.

The dysfunction of intestinal microbiota and bile acid metabolism is related to the pathogenesis of atherosclerosis. This study we explored the mechanism of Bifidobacterium animalis subsp. lactis F1-7 (Bif. animalis F1-7), improving atherosclerosis by regulating the bile acid metabolism and intestinal microbiota in the ApoE-/- mice. The Bif. animalis F1-7 effectively reduced aortic plaque accumulation and improved the serum and liver lipid levels in atherosclerotic mice. The untargeted metabolomics revealed that Bif. animalis F1-7 reduced the glycine-conjugated bile acids and the levels of differential metabolite lithocholic acid (LCA) significantly. Downregulation of LCA decreased the intestinal levels of the farnesoid X-activated receptor (FXR) and regulated the bile acid metabolism through the FXR/FGF15/CYP7A1 pathway. Furthermore, the 16srRNA gene sequencing analysis revealed that structural changes in intestinal microbiota with an increase in the abundance of Bifidobacterium, Lactobacillus, Faecalibaculum, Desulfovibrio, and a decrease in Dubosiella, Clostridium_sensu_stricto_1, and Turicibacter following the Bif. animalis F1-7 intervention. Correlation analysis showed that the changes in intestinal microbiota mentioned above were significantly correlated with bile acid metabolism in atherosclerotic mice. In conclusion, this study sheds light on the mechanisms by which Bif. animalis F1-7 regulates atherosclerosis.

Empagliflozin attenuates liver fibrosis in high-fat diet/streptozotocin-induced mice by modulating gut microbiota.

The effects of SGLT2 inhibitors on hepatic fibrosis in diabetes remain unclear. This study aimed to investigate the effects of empagliflozin on liver fibrosis in high-fat diet/streptozotocin-induced mice and the correlation with gut microbiota. After the application of empagliflozin for 6 weeks, we performed oral glucose tolerance and intraperitoneal insulin tolerance tests to assess glucose tolerance and insulin resistance, and stained liver sections to evaluate histochemical and hepatic pathological markers of liver fibrosis. Moreover, 16S rRNA amplicon sequencing was performed on stool samples to explore changes in the composition of intestinal bacteria. We finally analysed the correlation between gut microbiome and liver fibrosis scores or indicators of glucose metabolism. The results showed that empagliflozin intervention improved glucose metabolism and liver function with reduced liver fibrosis, which might be related to changes in intestinal microbiota. In addition, the abundance of intestinal probiotic Lactobacillus increased, while Ruminococcus and Adlercreutzia decreased after empagliflozin treatment, and correlation analysis showed that the changes in microbiota were positively correlated with liver fibrosis and glucose metabolism. Overall, considering the contribution of the gut microbiota in metabolism, empagliflozin might have improved the beneficial balance of intestinal bacteria composition. The present study provides evidence and indicates the involvement of the gut-liver axis by SGLT2 inhibitors in T2DM with liver fibrosis.

Traditional Chinese Medicine formula Dai-Zong-Fang alleviating hepatic steatosis in db/db mice via gut microbiota modulation.

Introduction: Hepatic steatosis is a hepatic pathological change closely associated with metabolic disorders, commonly observed in various metabolic diseases such as metabolic syndrome (MetS), with a high global prevalence. Dai-Zong-Fang (DZF), a traditional Chinese herbal formula, is widely used in clinical treatment for MetS, exhibiting multifaceted effects in reducing obesity and regulating blood glucose and lipids. This study aims to explore the mechanism by which DZF modulates the gut microbiota and reduces hepatic steatosis based on the gut-liver axis. Methods: This study utilized db/db mice as a disease model for drug intervention. Body weight and fasting blood glucose were monitored. Serum lipid and transaminase levels were measured. Insulin tolerance test was conducted to assess insulin sensitivity. Hematoxylin and eosin (HE) staining was employed to observe morphological changes in the liver and intestine. The degree of hepatic steatosis was evaluated through Oil Red O staining and hepatic lipid determination. Changes in gut microbiota were assessed using 16S rRNA gene sequencing. Serum lipopolysaccharide (LPS) levels were measured by ELISA. The expression levels of intestinal tight junction proteins, intestinal lipid absorption-related proteins, and key proteins in hepatic lipid metabolism were examined through Western blot and RT-qPCR. Results: After DZF intervention, there was a decrease in body weight, alleviation of glucose and lipid metabolism disorders, reduction in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, and mitigation of insulin resistance in mice. DZF significantly modulated the diversity of the gut microbiota, with a notable increase in the abundance of the Bacteroidetes phylum. PICRUSt indicated that DZF influenced various functions in gut microbiota, including carbohydrate and amino acid metabolism. Following DZF intervention, serum LPS levels decreased, intestinal pathological damage was reduced, and the expression of intestinal tight junction protein occludin was increased, while the expression of intestinal lipid absorption-related proteins cluster of differentiation 36 (CD36) and apolipoprotein B48 (ApoB48) were decreased. In the liver, DZF intervention resulted in a reduction in hepatic steatosis and lipid droplets, accompanied by a decrease fatty acid synthase (FASN) and stearoyl-CoA desaturase 1 (SCD1) and fatty acid transport protein 2 (FATP2). Conversely, there was an increase in the expression of the fatty acid oxidation-related enzyme carnitine palmitoyltransferase-1𝛂 (CPT-1𝛂). Conclusion: DZF can regulate the structure and function of the intestinal microbiota in db/db mice. This ameliorates intestinal barrier damage and the detrimental effects of endotoxemia on hepatic metabolism. DZF not only inhibits intestinal lipid absorption but also improves hepatic lipid metabolism from various aspects, including de novo lipogenesis, fatty acid uptake, and fatty acid oxidation. This suggests that DZF may act on the liver and intestine as target organs, exerting its effects by improving the intestinal microbiota and related barrier and lipid absorption functions, ultimately ameliorating hepatic steatosis and enhancing overall glucose and lipid metabolism.

Enhancing milk quality and modulating rectal microbiota of dairy goats in starch-rich diet: the role of bile acid supplementation.

Diets rich in starch have been shown to increase a risk of reducing milk fat content in dairy goats. While bile acids (BAs) have been used as a lipid emulsifier in monogastric and aquatic animals, their effect on ruminants is not well understood. This study aimed to investigate the impact of BAs supplementation on various aspects of dairy goat physiology, including milk composition, rumen fermentation, gut microbiota, and BA metabolism. We randomly divided eighteen healthy primiparity lactating dairy goats (days in milk = 100 ± 6 d) into two groups and supplemented them with 0 or 4g/d of BAs undergoing 5weeks of feeding on a starch-rich diet. The results showed that BAs supplementation positively influenced milk yield and improved the quality of fatty acids in goat milk. BAs supplementation led to a reduction in saturated fatty acids (C16:0) and an increase in monounsaturated fatty acids (cis-9 C18:1), resulting in a healthier milk fatty acid profile. We observed a significant increase in plasma total bile acid concentration while the proportion of rumen short-chain fatty acids was not affected. Furthermore, BAs supplementation induced significant changes in the composition of the gut microbiota, favoring the enrichment of specific bacterial groups and altering the balance of microbial populations. Correlation analysis revealed associations between specific bacterial groups (Bacillus and ChristensenellaceaeR-7group) and BA types, suggesting a role for the gut microbiota in BA metabolism. Functional prediction analysis revealed notable changes in pathways associated with lipid metabolism, suggesting that BAs supplementation has the potential to modulate lipid-related processes. These findings highlight the potential benefits of BAs supplementation in enhancing milk production, improving milk quality, and influencing metabolic pathways in dairy goats. Further research is warranted to elucidate the underlying mechanisms and explore the broader implications of these findings.

Bile acid and short chain fatty acid metabolism of gut microbiota mediate high-fat diet induced intestinal barrier damage in Macrobrachium rosenbergii

The limited tolerance of crustacean tissue physiology to a high-fat diet has captured the attention of researchers. Yet, investigations into the physiological response mechanisms of the crustacean intestinal barrier system to a high-fat diet are progressing slowly. Elucidating potential physiological mechanisms and determining the precise regulatory targets would be of great physiological and nutritional significance. This study established a high-fat diet-induced intestinal barrier damage model in Macrobrachium rosenbergii, and systematically investigated the functions of gut microbiota and its functional metabolites. The study achieved this by monitoring phenotypic indicators, conducting 16S rDNA sequencing, targeted metabolomics, and in vitro anaerobic fermentation of intestinal contents. Feeding prawns with control and high-fat diets for 8 weeks, the lipid level of 7 % in the CON diet and 12 % in the HF diet. Results showed that high-fat intake impaired the intestinal epithelial cells, intestinal barrier structure, and permeability of M. rosenbergii, activated the tight junction signaling pathway inhibiting factor NF-κB transcription factor Relish/myosin light chain kinase (MLCK), and suppressed the expression of downstream tight junction proteins zona occludens protein 1 (ZO-1) and Claudin. High-fat intake resulted in a significant increase in abundance of Aeromonas, Enterobacter, and Clostridium sensu stricto 3 genera, while Lactobacillus, Lactococcus, Bacteroides, and Ruminococcaceae UCG-010 genera were significantly decreased. Targeted metabolomics results of bile acids and short-chain fatty acids in intestinal contents and in vitro anaerobic fermentation products showed a marked rise in the abundance of DCA, 12-KetoLCA, 7,12-diketoLCA, and Isovaleric acid, and a significant reduction in the abundance of HDCA, CDCA, and Acetate in the HF group. Pearson correlation analysis revealed a substantial correlation between various genera (Clostridium sensu stricto 3, Lactobacillus, Bacteroides) and secondary metabolites (DCA, HDCA, 12-KetoLCA, Acetate), and the latter was significantly correlated with intestinal barrier function related genes (Relish, ZO-1, MLCK, vitamin D receptor, and ecdysone receptor). These findings indicate that gut microorganisms and their specific bile acids and short-chain fatty acid secondary metabolites play a crucial role in the process of high-fat-induced intestinal barrier damage of M. rosenbergii. Moreover, identifying and targeting these factors could facilitate precise regulation of high-fat nutrition for crustaceans.

Exploring the Relationship between Gut Microbiome Composition and Blood Indole-3-acetic Acid in Hemodialysis Patients.

Indole-3-acetic acid (IAA), a protein-bound uremic toxin resulting from gut microbiota-driven tryptophan metabolism, increases in hemodialysis (HD) patients. IAA may induce endothelial dysfunction, inflammation, and oxidative stress, elevating cardiovascular and cognitive risk in HD patients. However, research on the microbiome-IAA association is limited. This study aimed to explore the gut microbiome's relationship with plasma IAA levels in 72 chronic HD patients aged over 18 (August 2016-January 2017). IAA levels were measured using tandem mass spectrometry, and gut microbiome analysis utilized 16s rRNA next-generation sequencing. Linear discriminative analysis effect size and random forest analysis distinguished microbial species linked to IAA levels. Patients with higher IAA levels had reduced microbial diversity. Six microbial species significantly associated with IAA levels were identified; Bacteroides clarus, Bacteroides coprocola, Bacteroides massiliensi, and Alisteps shahii were enriched in low-IAA individuals, while Bacteroides thetaiotaomicron and Fusobacterium varium were enriched in high-IAA individuals. This study sheds light on specific gut microbiota species influencing IAA levels, enhancing our understanding of the intricate interactions between the gut microbiota and IAA metabolism.

Early-life antibiotic exposure promotes house dust mite-induced allergic airway inflammation by impacting gut microbiota and lung lipid metabolism

Asthma is a chronic inflammatory respiratory disease. Early-life antibiotic exposure is a unique risk factor for the incidence and severity of asthma later in life. Perturbations in microbial–metabolite–immune interaction caused by antibiotics are closely associated with the pathogenesis of allergy and asthma. We investigated the effect of early intervention with common oral antibiotics on later asthma exacerbations and found that different antibiotic exposures can amplify different types of immune responses induced by HDM. Cefixime (CFX) promoted a biased type 2 inflammation, azithromycin (AZM) enhanced Th17 immune response, and cefuroxime axetil (CFA) induced eosinophils recruitment. Moreover, early-life antibiotic exposure can have short- and long-term effects on the abundance, composition, and diversity of the gut microbiota. In the model of CFX-promoted type 2 airway inflammation, fecal metabolomics indicated abnormal lipid metabolism and T cell response. Lipidomic also suggested allergic airway inflammation amplified by CFX is closely associated with abnormal lipid metabolism in lung tissues. Moreover, abnormalities in lipid metabolism–related genes (LMRGs) were found to have cellular heterogeneity be associated with asthma severity by bioinformatics analysis.

Rapid adaptation of the rainbow trout intestinal microbiota to the use of a high-starch 100% plant-based diet.

Short-term adaptation of the microbiota could promote nutrient degradation and the host health. While numerous studies are currently undertaking feeding trials using sustainable diets for the aquaculture industry, the extent to which the microbiota adapts to these novel diets is poorly described. The incorporation of carbohydrates (CHO) within a 100% plant-based diet could offer a novel, cost-effective energy source that is readily available, potentially replacing the protein component in the diets. In this study, we investigated the short-term (3 weeks) effects of a high CHO, 100% plant-based diet on the mucosal and digesta associated microbiota diversity and composition, as well as several metabolic parameters in rainbow trout. We highlighted that the mucosa is dominated by Mycoplasma (44.86%). While the diets did not have significant effects on the main phyla (Proteobacteria, Firmicutes, and Actinobacteria), after 3 weeks, a lower abundance of Bacillus genus, and higher abundances of four lactic-acid bacteria were demonstrated in digesta. In addition, no post-prandial hyperglycemia was observed with high carbohydrate intake. These results provide evidence for the rapid adaptation of the gut microbiota and host metabolism to high CHO in combination with 100% plant ingredients in rainbow trout.

Inoculation of Newborn Lambs with Ruminal Solids Derived from Adult Goats Reprograms the Development of Gut Microbiota and Serum Metabolome and Favors Growth Performance.

Microbial transplantation in early life was a strategy to optimize the health and performance of livestock animals. This study aimed to investigate the effect of active ruminal solids microorganism supplementation on newborn lamb gut microbiota and serum metabolism. Twenty-four Youzhou dark newborn lambs were randomly divided into three groups: (1) newborn lambs fed with sterilized goat milk inoculated with sterilized normal saline (CON), supernatant from ruminal solids (SRS), or autoclaved supernatant from ruminal solids (ASRS). Results showed that SRS increased gut bacterial richness and community, downregulating the Firmicutes/Bacteroidetes ratio, and increased the abundance of some probiotics (Bacteroidetes, Spirochaetota, and Fibrobacterota), while reducing the abundance of Fusobacteriota, compared to the CON group. SRS also improved the plasma metabolic function, such as arachidonic acid metabolism, primary bile acid biosynthesis, and tryptophan metabolism and then actively promoted the levels of ALP and HLD. Our study indicated that inoculation with active ruminal solids significantly affected the intestinal microbial communities and metabolic characteristics, and these changes can improve the growing health of the newborn lamb. These findings provided an experimental and theoretical basis for the application of ruminal solid-attached microorganisms in the nutritional management of lambs reared for human consumption.

Effect of vinegar steaming on the composition and structure of Schisandra chinensis polysaccharide and its anti-colitis activity.

In this study, infrared spectroscopy, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) technology were applied to systematically explain the Schisandra chinensis's polysaccharide transformation in configuration, molecular weight, monosaccharide composition, and anti-ulcerative colitis (UC) activity after vinegar processing. Scanning electron microscopic results showed that the appearance of S. chinensis polysaccharide changed significantly after steaming with vinegar. The MALDI-TOF-MS results showed that the mass spectra of raw S. chinensis polysaccharides (RSCP) were slightly lower than those of vinegar-processed S. chinensis polysaccharides (VSCP). The RSCP showed higher peaks at m/z 1350.790, 2016.796, and 2665.985, all with left-skewed distribution, and the molecular weights were concentrated in the range of 1300-3100, with no higher peak above m/z 5000. The VSCPs showed a whole band below m/z 3000, with m/z 1021.096 being the highest peak, and the intensity decreased with the increase of m/z. In addition, compared to RSCPs, VSCPs can significantly increase the content of intestinal short-chain fatty acids (SCFAs). This study showed that the apparent morphology and molecular weight of S. chinensis's polysaccharides significantly changed after steaming with vinegar. These changes directly affect its anti-UC effect significantly, and its mechanism is closely related to improving the structure and diversity of gut microbiota and SCFA metabolism.

Gut Microbiota Related Metabolites Changes - New Break through Point for Treating Diabetes

Diabetes is a common disease characterized by high blood glucose level, combined with metabolic disorder of carbohydrates, lipids, proteins and other substances. The relationship between the human gut microbes and diabetes is still not clear. Human intestinal tracts harbor trillions of microbes that maintaining a symbiotic relationship with the host. Gut microbiota not only helps the host to digest certain food, but also produces a large number of biologically active signaling molecules involved in immune regulation, anti-tumor, anti-aging regulation, which are also related to the pathogenesis of diabetes. These molecules can be used as targets for prediction, diagnosis and treatment of diabetes. Metabolomics, as a rising technology to study the changes of metabolites in human body quantitatively, can be a helpful tool for researchers in this area. This article reviews recent progresses about mechanism and emerging interventions of diabetes mellitus from the perspective of metabolism of gut microbiota.

The role of the gut microbiota in neurodegenerative diseases targeting metabolism.

In recent years, the incidence of neurodegenerative diseases (NDs) has gradually increased over the past decades due to the rapid aging of the global population. Traditional research has had difficulty explaining the relationship between its etiology and unhealthy lifestyle and diets. Emerging evidence had proved that the pathogenesis of neurodegenerative diseases may be related to changes of the gut microbiota's composition. Metabolism of gut microbiota has insidious and far-reaching effects on neurodegenerative diseases and provides new directions for disease intervention. Here, we delineated the basic relationship between gut microbiota and neurodegenerative diseases, highlighting the metabolism of gut microbiota in neurodegenerative diseases and also focusing on treatments for NDs based on gut microbiota. Our review may provide novel insights for neurodegeneration and approach a broadly applicable basis for the clinical therapies for neurodegenerative diseases.