Desulfovibrio desulfuricansisolates from the gut of a single individual: Structural and biological lipid A characterization

Cilostazol Attenuates Hepatic Steatosis and Intestinal Disorders in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases in the world, which begins with liver lipid accumulation and is associated with metabolic syndrome. Also, the name chosen to replace NAFLD was metabolic dysfunction-associated steatotic liver disease (MASLD). We performed focused drug screening and found that Cilostazol effectively ameliorated hepatic steatosis and might offer potential for NAFLD treatment. Our aim was to investigate the therapeutic effects of Cilostazol on the glycolipid metabolism and intestinal flora in NAFLD mice and explore the specific mechanism. In this study, 7-week-old male C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks to induce NAFLD, and then treated with intragastric administration for 12 weeks. The results showed that Cilostazol inhibited liver lipid de novo synthesis by regulating the AMPK-ACC1/SCD1 pathway and inhibited liver gluconeogenesis by the AMPK-PGC1α-G6P/PEPCK pathway. Cilostazol improved the intestinal flora diversity and intestinal microbial composition in the NAFLD mice, and specifically regulated Desulfovibrio and Akkermansia. In addition, Cilostazol increased the level of short-chain fatty acids in the NAFLD mice to a level similar to that in the blank Control group. Cilostazol reduces liver lipid accumulation in NAFLD mice by improving glucose and lipid metabolism disorders and intestinal dysfunction, thereby achieving the purpose of treating NAFLD.

Wuliangye strong aroma baijiu promotes intestinal homeostasis by improving gut microbiota and regulating intestinal stem cell proliferation and differentiation

BACKGROUND

Wuliangye strong aroma baijiu (hereafter, Wuliangye baijiu) is a traditional Chinese grain liquor containing short-chain fatty acids, ethyl caproate, ethyl lactate, other trace components, and a large proportion of ethanol. The effects of Wuliangye baijiu on intestinal stem cells and intestinal epithelial development have not been elucidated. Here, the role of Wuliangye baijiu in intestinal epithelial regeneration and gut microbiota modulation was investigated by administering a Lieber-DeCarli chronic ethanol liquid diet in a mouse model to mimic long-term (8 weeks') light/moderate alcohol consumption (1.6 g kg-1 day-1) in healthy human adults.

RESULTS

Wuliangye baijiu promoted colonic crypt proliferation in mice. According to immunofluorescence and reverse transcription-quantitative polymerase chain reaction analyses, compared with the ethanol-only treatment, Wuliangye baijiu increased the number of intestinal stem cells and goblet cells and the expression of enteroendocrine cell differentiation markers in the mouse colon. Furthermore, gut microbiota analysis showed an increase in the relative abundance of microbiota related to intestinal homeostasis following Wuliangye baijiu administration. Notably, increased abundance of Bacteroidota, Faecalibaculum, Lachnospiraceae, and Blautia may play an essential role in promoting stem-cell-mediated intestinal epithelial development and maintaining intestinal homeostasis.

CONCLUSIONS

In summary, these findings suggest that Wuliangye baijiu can be used to regulate intestinal stem cell proliferation and differentiation in mice and to alter gut microbiota distributions, thereby promoting intestinal homeostasis. This research elucidates the mechanism by which Wuliangye baijiu promotes intestinal health. © 2024 Society of Chemical Industry.

Integrated physiological, intestinal microbiota, and metabolomic responses of adult zebrafish (Danio rerio) to subacute exposure to antimony at environmentally relevant concentrations

The available information regarding the impact of antimony (Sb), a novel environmental pollutant, on the intestinal microbiota and host health is limited. In this study, we conducted physiological characterizations to investigate the response of adult zebrafish to different environmental concentrations (0, 30, 300, and 3000 µg/L) of Sb over a period of 14 days. Biochemical and pathological changes demonstrated that Sb effectively compromised the integrity of the intestinal physical barrier and induced inflammatory responses as well as oxidative stress. Analysis of both intestinal microbial community and metabolome revealed that exposure to 0 and 30 µg/L of Sb resulted in similar microbiota structures; however, exposure to 300 µg/L altered microbial communities' composition (e.g., a decline in genus Cetobacterium and an increase in Vibrio). Furthermore, exposure to 300 µg/L significantly decreased levels of bile acids and glycerophospholipids while triggering intestinal inflammation but activating self-protective mechanisms such as antibiotic presence. Notably, even exposure to 30 µg/L of Sb can trigger dysbiosis of intestinal microbiota and metabolites, potentially impacting fish health through the "microbiota-intestine-brain axis" and contributing to disease initiation. This study provides valuable insights into toxicity-related information concerning environmental impacts of Sb on aquatic organisms with significant implications for developing management strategies.

Modulation of Gut Microbial Metabolism by Cyanidin-3-O-Glucoside in Mitigating Polystyrene-Induced Colonic Inflammation: Insights from 16S rRNA Sequencing and Metabolomics

Microplastics derived from plastic waste have emerged as a pervasive environmental pollutant with potential transfer and accumulation through the food chain, thus posing risks to both ecosystems and human health. The gut microbiota, tightly intertwined with metabolic processes, exert substantial influences on host physiology by utilizing dietary compounds and generating bacterial metabolites such as tryptophan and bile acid. Our previous studies have demonstrated that exposure to microplastic polystyrene (PS) disrupts the gut microbiota and induces colonic inflammation. Meanwhile, intervention with cyanidin-3-O-glucoside (C3G), a natural anthocyanin derived from red bayberry, could mitigate colonic inflammation by reshaping the gut bacterial composition. Despite these findings, the specific influence of gut bacteria and their metabolites on alleviating colonic inflammation through C3G intervention remains incompletely elucidated. Therefore, employing a C57BL/6 mouse model, this study aims to investigate the mechanisms underlying how C3G modulates gut bacteria and their metabolites to alleviate colonic inflammation. Notably, our findings demonstrated the efficacy of C3G in reversing the elevated levels of pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) and the upregulation of mRNA expression (Il-6, Il-1β, and Tnf-α) induced by PS exposure. Meanwhile, C3G effectively inhibited the reduction in levels (IL-22, IL-10, and IL-4) and the downregulation of mRNA expression (Il-22, Il-10, and Il-4) of anti-inflammatory cytokines induced by PS exposure. Moreover, PS-induced phosphorylation of the transcription factor NF-κB in the nucleus, as well as the increased level of protein expression of iNOS and COX-2 in the colon, were inhibited by C3G. Metabolisms of gut bacterial tryptophan and bile acids have been extensively implicated in the regulation of inflammatory processes. The 16S rRNA high-throughput sequencing disclosed that PS treatment significantly increased the abundance of pro-inflammatory bacteria (Desulfovibrio, norank_f_Oscillospiraceae, Helicobacter, and Lachnoclostridium) while decreasing the abundance of anti-inflammatory bacteria (Dubosiella, Akkermansia, and Alistipes). Intriguingly, C3G intervention reversed these pro-inflammatory changes in bacterial abundances and augmented the enrichment of bacterial genes involved in tryptophan and bile acid metabolism pathways. Furthermore, untargeted metabolomic analysis revealed the notable upregulation of metabolites associated with tryptophan metabolism (shikimate, l-tryptophan, indole-3-lactic acid, and N-acetylserotonin) and bile acid metabolism (3b-hydroxy-5-cholenoic acid, chenodeoxycholate, taurine, and lithocholic acid) following C3G administration. Collectively, these findings shed new light on the protective effects of dietary C3G against PS exposure and underscore the involvement of specific gut bacterial metabolites in the amelioration of colonic inflammation.

Polyphenols synergistic drugs to ameliorate non-alcoholic fatty liver disease via signal pathway and gut microbiota: A review

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease with an increasing incidence worldwide. Single drug therapy may have toxic side effects and disrupt gut microbiota balance. Polyphenols are widely used in disease intervention due to their distinctive nutritional properties and medicinal value, which a potential gut microbiota modulator. However, there is a lack of comprehensive review to explore the efficacy and mechanism of combined therapy with drugs and polyphenols for NAFLD.

AIM OF REVIEW

Based on this, this review firstly discusses the link between NAFLD and gut microbiota, and outlines the effects of polyphenols and drugs on gut microbiota. Secondly, it examined recent advances in the treatment and intervention of NAFLD with drugs and polyphenols and the therapeutic effect of the combination of the two. Finally, we highlight the underlying mechanisms of polyphenol combined drug therapy in NAFLD. This is mainly in terms of signaling pathways (NF-κB, AMPK, Nrf2, JAK/STAT, PPAR, SREBP-1c, PI3K/Akt and TLR) and gut microbiota. Furthermore, some emerging mechanisms such as microRNA potential biomarker therapies may provide therapeutic avenues for NAFLD.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Drawing inspiration from combination drug strategies, the use of active substances in combination with drugs for NAFLD intervention holds transformative and prospective potential, both improve NAFLD and restore gut microbiota balance while reducing the required drug dosage. This review systematically discusses the bidirectional interactions between gut microbiota and NAFLD, and summarizes the potential mechanisms of polyphenol synergistic drugs in the treatment of NAFLD by modulating signaling pathways and gut microbiota. Future researches should develop multi-omics technology to identify patients who benefit from polyphenols combination drugs and devising individualized treatment plans to enhance its therapeutic effect.

A novel montmorillonite clay-cetylpyridinium chloride material for reducing PFAS leachability and bioavailability from soils

Soils contaminated by per- and polyfluoroalkyl substances (PFAS) present a significant threat to both ecological and human health. Extensive research efforts are currently underway to develop effective strategies for immobilizing these chemicals in soils. In this study, calcium montmorillonite was modified with cetylpyridinium chloride (CPC-CM) to enhance its electrostatic and hydrophobic interactions with PFAS. CPC-CM exhibited high adsorption for perfluorooctanoate acid (PFOA), perfluorooctane sulfonate (PFOS) and 8:2 fluorotelomer sulfonic acids (8:2 FTSA) across initial concentrations of 50-1000 μg/L, outperforming both the parent CM and L-carnitine modified CM. Soil leaching tests demonstrated the superior immobilization capabilities of the CPC-CM, maintaining an average PFAS leaching rate below 7% after 120-day incubation. In the context of human exposure scenarios, the in vitro bioaccessibility and in vivo bioavailability of PFAS in soils were measured by gastrointestinal extraction and mouse assay. CPC-CM treatment effectively reduced the bioaccessibility (by up to 84%) and bioavailability (by up to 76%) of PFAS in soils. Furthermore, the safety and efficacy of CPC-CM were evaluated using enteric microorganisms of mice. CPC-CM treatment mitigated PFAS-induced changes in the abundance of Bacteroidetes and Firmicutes, thereby reducing PFAS-induced health risks for humans. Overall, CPC-CM synthesized in this study demonstrated superior adsorption performance and application safety, offering a highly promising approach for remediating PFAS-contaminated soil.

High-fat diet-disturbed gut microbiota-colonocyte interactions contribute to dysregulating peripheral tryptophan-kynurenine metabolism

BACKGROUND

Aberrant tryptophan (Trp)-kynurenine (Kyn) metabolism has been implicated in the pathogenesis of human disease. In particular, populations with long-term western-style diets are characterized by an excess of Kyn in the plasma. Host-gut microbiota interactions are dominated by diet and are essential for maintaining host metabolic homeostasis. However, the role of western diet-disturbed gut microbiota-colonocyte interactions in Trp metabolism remains to be elucidated.

RESULTS

Here, 4-week-old mice were fed with a high-fat diet (HFD), representing a typical western diet, for 4 weeks, and multi-omics approaches were adopted to determine the mechanism by which HFD disrupted gut microbiota-colonocyte interplay causing serum Trp-Kyn metabolism dysfunction. Our results showed that colonocyte-microbiota interactions dominated the peripheral Kyn pathway in HFD mice. Mechanistically, persistent HFD-impaired mitochondrial bioenergetics increased colonic epithelial oxygenation and caused metabolic reprogramming in colonites to support the expansion of Proteobacteria in the colon lumen. Phylum Proteobacteria-derived lipopolysaccharide (LPS) stimulated colonic immune responses to upregulate the indoleamine 2,3-dioxygenase 1 (IDO1)-mediated Kyn pathway, leading to Trp depletion and Kyn accumulation in the circulation, which was further confirmed by transplantation of Escherichia coli (E.coli) indicator strains and colonic IDO1 depletion. Butyrate supplementation promoted mitochondrial functions in colonocytes to remodel the gut microbiota in HFD mice, consequently ameliorating serum Kyn accumulation.

CONCLUSIONS

Our results highlighted that HFD disrupted the peripheral Kyn pathway in a gut microbiota-dependent manner and that the continuous homeostasis of gut bacteria-colonocytes interplay played a central role in the regulation of host peripheral Trp metabolism. Meanwhile, this study provided new insights into therapies against western diet-related metabolic disorders. Video Abstract.

Desulfovibrio in the Gut: The Enemy within?

Desulfovibrio (DSV) are sulfate-reducing bacteria (SRB) that are ubiquitously present in the environment and as resident commensal bacteria within the human gastrointestinal tract. Though they are minor residents of the healthy gut, DSV are opportunistic pathobionts that may overgrow in the setting of various intestinal and extra-intestinal diseases. An increasing number of studies have demonstrated a positive correlation between DSV overgrowth (bloom) and various human diseases. While the relationship between DSV bloom and disease pathology has not been clearly established, mounting evidence suggests a causal role for these bacteria in disease development. As DSV are the most predominant genera of SRB in the gut, this review summarizes current knowledge regarding the relationship between DSV and a variety of diseases. In this study, we also discuss the mechanisms by which these bacteria may contribute to disease pathology.

Short-Term Alternate Feeding between Terrestrially Sourced Oil- and Fish Oil-Based Diets Modulates the Intestinal Microecology of Juvenile Turbot

A nine-week feeding trial was conducted to investigate changes in the intestinal microbiota of turbot in response to alternate feeding between terrestrially sourced oil (TSO)- and fish oil (FO)-based diets. The following three feeding strategies were designed: (1) continuous feeding with the FO-based diet (FO group); (2) weekly alternate feeding between soybean oil (SO)- and FO-based diets (SO/FO group); and (3) weekly alternate feeding between beef tallow (BT)- and FO-based diets (BT/FO group). An intestinal bacterial community analysis showed that alternate feeding reshaped the intestinal microbial composition. Higher species richness and diversity of the intestinal microbiota were observed in the alternate-feeding groups. A PCoA analysis showed that the samples clustered separately according to the feeding strategy, and among the three groups, the SO/FO group clustered relatively closer to the BT/FO group. The alternate feeding significantly decreased the abundance of Mycoplasma and selectively enriched specific microorganisms, including short-chain fatty acid (SCFA)-producing bacteria, digestive bacteria (Corynebacterium and Sphingomonas), and several potential pathogens (Desulfovibrio and Mycobacterium). Alternate feeding may maintain the intestinal microbiota balance by improving the connectivity of the ecological network and increasing the competitive interactions within the ecological network. The alternate feeding significantly upregulated the KEGG pathways of fatty acid and lipid metabolism, glycan biosynthesis, and amino acid metabolism in the intestinal microbiota. Meanwhile, the upregulation of the KEGG pathway of lipopolysaccharide biosynthesis indicates a potential risk for intestinal health. In conclusion, short-term alternate feeding between dietary lipid sources reshapes the intestinal microecology of the juvenile turbot, possibly resulting in both positive and negative effects.

Microbiome Structure and Mucosal Morphology of Jejunum Appendix and Colon of Rats in Health and Dysbiosis

Gut microbiota contributes to human health. Plenty of studies demonstrate that antibiotics can disrupt gut ecosystem leading to dysbiosis. Little is known about the microbial variation of appendix and its up/downstream intestine after antibiotic treatment. This study aimed to investigate the microbiome and mucosal morphology of jejunum, appendix, and colon of rats in health and dysbiosis. A rodent model of antibiotic-induced dysbiosis was employed. Microscopy was used to observe mucosal morphological changes. 16S rRNA sequencing was performed for identifying bacterial taxa and microbiome structure. The appendices of dysbiosis were found enlarged and inflated with loose contents. Microscopy revealed the impairment of intestinal epithelial cells. High-throughput sequencing showed the Operational Taxonomic Units changed from 361 ± 33, 634 ± 18, 639 ± 19 in the normal jejunum, appendix, colon to 748 ± 98, 230 ± 11, 253 ± 16 in the disordered segments, respectively. In dysbiosis, Bacteroidetes translocated inversely from the colon and appendix (0.26%, 0.23%) to the jejunum (13.87% ± 0.11%); the relative abundance of all intestinal Enterococcaceae increased, while Lactobacillaceae decreased. Several bacterial clusters were found correlated to the normal appendix, whereas nonspecific clusters correlated to the disordered appendix. In conclusion, species richness and evenness reduced in the disordered appendix and colon; similar microbiome patterns were shared between the appendix and colon regardless of dysbiosis; site-specific bacteria were missing in the disordered appendix. Appendix is likely a transit region involving in upper and lower intestinal microflora modulation. The limitation of this study is all the data were derived from rats. We must be cautious about translating the microbiome results from rats to humans.

Dietary Bacillus licheniformis shapes the foregut microbiota, improving nutrient digestibility and intestinal health in broiler chickens

Bacillus licheniformis is considered a potential alternative to antibiotic growth promoters of animal growth and health. However, the effects of Bacillus licheniformis on the foregut and hindgut microbiota, and their relationships with nutrient digestion and health, in broiler chickens remain unclear. In this study, we aimed to identify the effects of Bacillus licheniformis BCG on intestinal digestion and absorption, tight junctions, inflammation, and the fore- and hind-gut microbiota. We randomly assigned 240 1-day-old male AA broilers into three treatment groups: CT (basal diet), BCG1 (basal diet + 1.0 × 10⁸ CFU/kg B. licheniformis BCG), and BCG2 (basal diet + 1.0 × 10⁹ CFU/kg B. licheniformis BCG). On day 42, the jejunal and ileal chyme and mucosa were subjected to analysis of digestive enzyme activity, nutrient transporters, tight junctions, and signaling molecules associated with inflammation. The ileal and cecal chyme were subjected to microbiota analysis. Compared with the CT group, the B. licheniformis BCG group showed significantly greater jejunal and ileal α-amylase, maltase, and sucrase activity; moreover, the α-amylase activity in the BCG2 group was higher than that in the BCG1 group (P < 0.05). The transcript abundance of FABP-1 and FATP-1 in the BCG2 group was significantly greater than that in the CT and BCG1 groups, and the GLUT-2 and LAT-1 relative mRNA levels were greater in the BCG2 group than the CT group (P < 0.05). Dietary B. licheniformis BCG resulted in significantly higher ileal occludin, and lower IL-8 and TLR-4 mRNA levels than observed in the CT group (P < 0.05). B. licheniformis BCG supplementation significantly decreased bacterial community richness and diversity in the ileum (P < 0.05). Dietary B. licheniformis BCG shaped the ileac microbiota by increasing the prevalence of f_Sphingomonadaceae, Sphingomonas, and Limosilactobacillus, and contributed to nutrient digestion and absorption; moreover, it enhanced the intestinal barrier by increasing the prevalence of f_Lactobacillaceae, Lactobacillus, and Limosilactobacillus. Dietary B. licheniformis BCG decreased microbial community diversity by diminishing Desulfovibrio, Alistipes, Campylobacter, Vibrio, Streptococcus, and Escherichia coli-Shigella levels, and down-regulating inflammatory associated molecule expression. Therefore, dietary B. licheniformis BCG contributed to digestion and absorption of nutrients, enhanced the intestinal physical barrier, and decreased intestinal inflammation in broilers by decreasing microbial diversity and optimizing the microbiota structure.

Desulfovibrio bacteria enhance alpha-synuclein aggregation in a Caenorhabditis elegans model of Parkinson's disease

Introduction

The aggregation of the neuronal protein alpha-synuclein (alpha-syn) is a key feature in the pathology of Parkinson's disease (PD). Alpha-syn aggregation has been suggested to be induced in the gut cells by pathogenic gut microbes such as Desulfovibrio bacteria, which has been shown to be associated with PD. This study aimed to investigate whether Desulfovibrio bacteria induce alpha-syn aggregation.

Methods

Fecal samples of ten PD patients and their healthy spouses were collected for molecular detection of Desulfovibrio species, followed by bacterial isolation. Isolated Desulfovibrio strains were used as diets to feed Caenorhabditis elegans nematodes which overexpress human alpha-syn fused with yellow fluorescence protein. Curli-producing Escherichia coli MC4100, which has been shown to facilitate alpha-syn aggregation in animal models, was used as a control bacterial strain, and E. coli LSR11, incapable of producing curli, was used as another control strain. The head sections of the worms were imaged using confocal microscopy. We also performed survival assay to determine the effect of Desulfovibrio bacteria on the survival of the nematodes.

Results and Discussion

Statistical analysis revealed that worms fed Desulfovibrio bacteria from PD patients harbored significantly more (P<0.001, Kruskal-Wallis and Mann-Whitney U test) and larger alpha-syn aggregates (P<0.001) than worms fed Desulfovibrio bacteria from healthy individuals or worms fed E. coli strains. In addition, during similar follow-up time, worms fed Desulfovibrio strains from PD patients died in significantly higher quantities than worms fed E. coli LSR11 bacteria (P<0.01). These results suggest that Desulfovibrio bacteria contribute to PD development by inducing alpha-syn aggregation.

Bile acid metabolism involved into the therapeutic action of Xiaojianzhong Tang via gut microbiota to treat chronic atrophic gastritis in rats

BACKGROUND

As a classical traditional Chinese medicine (TCM), Xiaojianzhong Tang (XJZ) is effective in treating chronic atrophic gastritis (CAG). However, the pharmacological mechanism of XJZ has not been fully explained.

PURPOSE

The purpose of this study was to investigate the mechanism of XJZ against CAG rats via gut microbiome using a multi-omics approach.

METHODS

The rat cecal contents were analyzed through the integration of an untargeted metabolomic approach based on ultra-high performance liquid chromatography coupled with the quadrupole-time of flight mass spectrometry (UHPLC-QTOF-MS) and 16S rRNA gene sequencing. Finally, the interaction of differential metabolites with bile acid (BA)-related targets was verified by molecular docking.

RESULTS

A new strategy was adopted to screen out the differential metabolites based on the comprehensive evaluation of VIP, |log2(FC)|, -ln(p-value) and ǀp(corr)ǀ. As results, XJZ showed favor regulations on the screened metabolites, cholic acid, deoxycholic acid, glycoursodeoxycholic acid, taurochenodesoxycholic acid, docosahexaenoic acid and L-isoleucine. The 16S rRNA gene sequencing analysis showed that XJZ could regulate gut microbiota disturbances in CAG rats, especially bile acid (BA) metabolism-related bacteria (Butyricimonas, Desulfovibrio, Bacteroides, Parabacteroides, Acetobacter and Alistipes). Molecular docking further showed that the differential metabolites regulated by XJZ had a good docking effect on BA-related targets.

CONCLUSION

The current work indicated that XJZ's therapeutic action was strongly linked to BA-related microorganisms and metabolic processes. These findings provided new insights into the effects of XJZ for the treatment of CAG.

Intestinal flora: A new target for traditional Chinese medicine to improve lipid metabolism disorders

Lipid metabolism disorders (LMD) can cause a series of metabolic diseases, including hyperlipidemia, obesity, non-alcoholic fatty liver disease (NAFLD) and atherosclerosis (AS). Its development is caused by more pathogenic factors, among which intestinal flora dysbiosis is considered to be an important pathogenic mechanism of LMD. In recent years, the research on intestinal flora has made great progress, opening up new perspectives on the occurrence and therapeutic effects of diseases. With its complex composition and wide range of targets, traditional Chinese medicine (TCM) is widely used to prevent and treat LMD. This review takes intestinal flora as a target, elaborates on the scientific connotation of TCM in the treatment of LMD, updates the therapeutic thinking of LMD, and provides a reference for clinical diagnosis and treatment.

Salvia miltiorrhiza extract may exert an anti-obesity effect in rats with high-fat diet-induced obesity by modulating gut microbiome and lipid metabolism

BACKGROUND

Studies have shown that a high-fat diet (HFD) can alter gut microbiota (GM) homeostasis and participate in lipid metabolism disorders associated with obesity. Therefore, regulating the construction of GM with the balance of lipid metabolism has become essential for treating obesity. Salvia miltiorrhiza extract (Sal), a common traditional Chinese medicine, has been proven effective against atherosclerosis, hyperlipidemia, obesity, and other dyslipidemia-related diseases.

AIM

To investigate the anti-obesity effects of Sal in rats with HFD-induced obesity, and explore the underlying mechanism by focusing on GM and lipid metabolism.

METHODS

Obesity was induced in rats with an HFD for 7 wk, and Sal (0.675 g/1.35 g/2.70 g/kg/d) was administered to treat obese rats for 8 wk. The therapeutic effect was evaluated by body weight, body fat index, waistline, and serum lipid level. Lipid factors (cAMP, PKA, and HSL) in liver and fat homogenates were analyzed by ELISA. The effect of Sal on GM and lipid metabolism was assessed by 16S rRNA-based microbiota analysis and untargeted lipidomic analysis (LC-MS/MS), respectively.

RESULTS

Sal treatment markedly reduced weight, body fat index, serum triglycerides (TG), total cholesterol (TC), low-density lipoprotein, glucose, free fatty acid, hepatic lipid accumulation, and adipocyte vacuolation, and increased serum high-density lipoprotein (HDL-C) in rats with HFD-induced obesity. These effects were associated with increased concentrations of lipid factors such as cAMP, PKA, and HSL in the liver and adipose tissues, enhanced gut integrity, and improved lipid metabolism. GM analysis revealed that Sal could reverse HFD-induced dysbacteriosis by promoting the abundance of Actinobacteriota and Proteobacteria, and decreasing the growth of Firmicutes and Desulfobacterita. Furthermore, LC-MS/MS analysis indicated that Sal decreased TGs (TG18:2/18:2/20:4, TG16:0/18:2/22:6), DGs (DG14:0/22:6, DG22:6/22:6), CL (18:2/ 18:1/18:1/20:0), and increased ceramides (Cers; Cer d16:0/21:0, Cer d16:1/24:1), (O-acyl)-ω-hydroxy fatty acids (OAHFAs; OAHFA18:0/14:0) in the feces of rats. Spearman’s correlation analysis further indicated that TGs, DGs, and CL were negatively related to the abundance of Facklamia and Dubosiella, and positively correlated with Blautia and Quinella, while OAHFAs and Cers were the opposite.

CONCLUSION

Sal has an anti-obesity effect by regulating the GM and lipid metabolism.

High fat diet-induced hyperlipidemia and tissue steatosis in rabbits through modulating ileal microbiota

High-fat diet (HFD) and overnutrition are important starting factors that may alter intestinal microbiota, lipid metabolism, and systemic inflammation. However, there were few studies on how intestinal microbiota contributes to tissue steatosis and hyperlipidemia. Here, we investigated the effect of lipid metabolism disorder-induced inflammation via toll-like receptor 2 (TLR-2), toll-like receptor 4 (TLR-4), and nuclear factor-κB (NF-κB) pathways at the intestinal level in response to HFD. Twenty 80-day-old male New Zealand White rabbits were randomly divided into the normal diet group (NDG) and the high-fat diet group (HDG) for 80 days. Growth performance, blood biochemical parameters, lipid metabolism, inflammation, degree of tissue steatosis, and intestinal microbial composition were measured. HFD increased the relative abundance of Christensenellaceae_R_7_group, Marvinbryantia, Akkermansia etc., with a reduced relative abundance of Enterorhabdus and Lactobacillus. Moreover, HFD caused steatosis in the liver and abdominal fat and abnormal expression of some genes related to lipid metabolism and tight junction proteins. The TLR-2, TLR-4, NF-κB, TNF-α, and IL-6 were confirmed by overexpression with downregulation of IL-10. Serum biochemical indices (TG, TCHO, LDL-C, and HDL-C) were also increased, indicating evidence for the development of the hyperlipidemia model. Correlation analysis showed that this microbial dysbiosis was correlated with lipid metabolism and inflammation, which were associated with the intestinal tract's barrier function and hyperlipidemia. These results provide an insight into the relationship between HFD, the intestinal microbiota, intestinal barrier, tissue inflammation, lipid metabolism, and hyperlipidemia. KEY POINTS: • High-fat diet leads to ileal microbiota disorders • Ileal microbiota mediates local and systemic lipid metabolism disorders and inflammation • There is a specific link between ileal microbiota, histopathology, and hyperlipidemia.

GOS Ameliorates Nonalcoholic Fatty Liver Disease Induced by High Fat and High Sugar Diet through Lipid Metabolism and Intestinal Microbes

The treatment of nonalcoholic fatty liver disease (NAFLD) remains very challenging. This study investigated the therapeutic effect of galactose oligosaccharide (GOS), an important prebiotic, on NAFLD through in vivo and in vitro experiments and preliminarily explored the mechanism by which GOS improves liver lipid metabolism and inflammation through liver and intestinal microbiological analysis. The results of mouse liver lipidomics showed that GOS could promote body thermogenesis in mice with high-fat and high-sugar diet (HFHSD)-induced NAFLD, regulate lipolysis in liver fat cells, and accelerate glycine and cholesterol metabolism. GOS dose-dependently reduced the contents of total cholesterol (TC) and triglyceride (TG) in cells and reduced the accumulation of lipid droplets in cells. GOS also reduced the Firmicutes/Bacteroidetes ratio and altered the composition of the intestinal microbiota in mice fed a HFHSD. GOS can improve liver lipid metabolism and intestinal structure of NAFLD. These results provide a theoretical and experimental basis supporting the use of GOS as a health food with anti-NAFLD functions.

Comparison of Coated and Uncoated Trace Minerals on Growth Performance, Tissue Mineral Deposition, and Intestinal Microbiota in Ducks

Abnormally low or high levels of trace elements in poultry diets may elicit health problems associated with deficiency and toxicity, and impact poultry growth. The optimal supplement pattern of trace mineral also impacts the digestion and absorption in the body. For ducks, the limited knowledge of trace element requirements puzzled duck production. Thus, the objective of this study was to investigate the influence of dietary inclusions of coated and uncoated trace minerals on duck growth performance, tissue mineral deposition, serum antioxidant status, and intestinal microbiota profile. A total of 1,080 14-day-old Cherry Valley male ducks were randomly divided into six dietary treatment groups in a 2 (uncoated or coated trace minerals) × 3 (300, 500, or 1,000 mg/kg supplementation levels) factorial design. Each treatment was replicated 12 times (15 birds per replicate). Coated trace minerals significantly improved average daily gain (p < 0.05), increased Zn, Se, and Fe content of serum, liver, and muscle, increased serum antioxidant enzyme (p < 0.05) and decreased the excreta Fe, Zn, and Cu concentrations. Inclusions of 500 mg/kg of coated trace minerals had a similar effect on serum trace minerals and tissue metal ion deposition as the 1,000 mg/kg inorganic trace minerals. Higher concentrations of Lactobacillus, Sphaerochatea, Butyricimonas, and Enterococcus were found in birds fed with coated trace minerals. In conclusion, diets supplemented with coated trace minerals could reduce the risk of environmental contamination from excreted minerals without affecting performance. Furthermore, coated trace minerals may improve the bioavailability of metal ions and the colonization of probiotic microbiota to protect microbial barriers and maintain gut health.

Exposure to microplastics reduces the bioaccumulation of sulfamethoxazole but enhances its effects on gut microbiota and the antibiotic resistome of mice

Microplastics (MPs) have aroused a global health concern and their coexistence with antibiotics is inevitable. However, how MPs would affect the bioaccumulation and risks of antibiotics in humans remains poorly understood. Here a mouse model was used, and through dietary exposure, we observed that while the relative distributions of sulfamethoxazole (SMX) in tissues were relatively stable, MPs significantly reduced the bioaccumulation of SMX in mice tissues (liver, lung, spleen, heart and kidney). Notably, while SMX and MPs showed a differential effect, MPs could exacerbate the effects of SMX on gut microbiota and antibiotic resistance gene (ARG) profile, with the relative abundances of sulfonamide resistance genes and multidrug genes being significantly increased. We further identified that shifts in gut microbiota contributed to the changes in ARG profiles in mice. Combined, our results demonstrate that MPs reduced the bioaccumulation of SMX, but they enhanced its effects on gut microbiota and the antibiotic resistome of mice, indicating they might have high risks to humans.

Food-derived cyanidin-3-O-glucoside reverses microplastic toxicity via promoting discharge and modulating the gut microbiota in mice

Microplastics (MPs) ingested and accumulated by organisms would ultimately pose a threat to humans via the food chain. A balanced gut microbiota contributes to many health benefits, which is readily influenced by environmental chemicals such as MPs. Cyanidin-3-O-glucoside (C3G), a bioactive compound of the anthocyanin family, possesses a variety of functional effects including anti-oxidant and anti-inflammatory, as well as gut microbiota modulation. C3G has been demonstrated to prevent polystyrene (PS) induced toxicities in Caco-2 cells and Caenorhabditis elegans (C. elegans) via activating autophagy and promoting discharge. In the present study, we aimed to explore the alleviation effect of C3G on PS induced toxicities in C57BL/6 mice. Our results showed that the supplementation of C3G effectively reduced the tissue accumulation and promoted the fecal PS discharge, leading to alleviation of the PS-caused oxidative stress and inflammatory response. Meanwhile, C3G modulated PS-associated gut microbiome perturbations and regulated functional bacteria in inflammation such as Desulfovibrio, Helicobacter, Oscillospiraceae and Lachnoclostridium. Also, C3G administration initiated alterations in functional pathways in response to xenobiotic PS, and reduced bacterial functional genes related to inflammation and human diseases. These findings may offer evidence for the protective role of C3G in the intervention of PS-induced toxicity and gut dysbiosis.

Effect of l-carnitine and mildronate on the mitochondrial metabolism of heart and bacterial composition of the gut microbiome in ageing mice

Ageing is the most significant risk factor for cardiovascular diseases. l-Carnitine has a potent cardioprotective effect and its synthesis decreases during ageing. At the same time, there are pharmaceuticals, such as mildronate which, on the contrary, are aimed at reducing the concentration of l-carnitine in the heart and lead to slows down the oxidation of fatty acids in mitochondria. Despite this, both l-carnitine and mildronate are positioned as cardio protectors. We showed that l-carnitine supplementation to the diet of 15-month-old mice increased expression of the PGC-1α gene, which is responsible for the regulation of fatty acid oxidation, and the Nrf2 gene, which is responsible for protecting mitochondria by regulating the expression of antioxidants and mitophagy, in the heart. Mildronate activated the expression of genes that regulate glucose metabolism. Probably, this metabolic shift may protect the mitochondria of the heart from the accumulation of acyl-carnitine, which occurs during the oxidation of fatty acids under oxygen deficiency. Both pharmaceuticals impacted the gut microbiome bacterial composition. l-Carnitine increased the level of Lachnoanaerobaculum and [Eubacterium] hallii group, mildronate increased the level of Bifidobacterium, Rikinella, Christensenellaceae. Considered, that these bacteria for protection the organism from various pathogens and chronic inflammation. Thus, we suggested that the positive effects of both drugs on the mitochondria metabolism and gut microbiome bacterial composition may contribute to the protection of the heart during ageing.

Methionine Restriction Improves Gut Barrier Function by Reshaping Diurnal Rhythms of Inflammation-Related Microbes in Aged Mice

Age-related gut barrier dysfunction and dysbiosis of the gut microbiome play crucial roles in human aging. Dietary methionine restriction (MR) has been reported to extend lifespan and reduce the inflammatory response; however, its protective effects on age-related gut barrier dysfunction remain unclear. Accordingly, we focus on the effects of MR on inflammation and gut function. We found a 3-month methionine-restriction reduced inflammatory factors in the serum of aged mice. Moreover, MR reduced gut permeability in aged mice and increased the levels of the tight junction proteins mRNAs, including those of occludin, claudin-1, and zona occludens-1. MR significantly reduced bacterial endotoxin lipopolysaccharide concentration in aged mice serum. By using 16s rRNA sequencing to analyze microbiome diurnal rhythmicity during 24 h, we found MR moderately recovered the cyclical fluctuations of the gut microbiome which was disrupted in aged mice, leading to time-specific enhancement of the abundance of short-chain fatty acid-producing and lifespan-promoting microbes. Moreover, MR dampened the oscillation of inflammation-related TM7-3 and Staphylococcaceae. In conclusion, the effects of MR on the gut barrier were likely related to alleviation of the oscillations of inflammation-related microbes. MR can enable nutritional intervention against age-related gut barrier dysfunction.

Suppression of high-fat-diet-induced obesity in mice by dietary folic acid supplementation is linked to changes in gut microbiota

PURPOSE

To investigate whether the effects of dietary folic acid supplementation on body weight gain are mediated by gut microbiota in obesity.

METHODS

Male C57 BL/6J conventional (CV) and germ-free (GF) mice both aged three to four weeks were fed a high-fat diet (HD), folic acid-deficient HD (FD-HD), folic acid-supplement HD (FS-HD) and a normal-fat diet (ND) for 25 weeks. Faecal microbiota were analyzed by 16S rRNA high-throughput sequencing, and the mRNA expression of genes was determined by the real-time RT-PCR. Short-chain fatty acids (SCFAs) in faeces and plasma were measured using gas chromatography-mass spectrometry.

RESULTS

In CV mice, HD-induced body weight gain was inhibited by FS-HD, accompanied by declined energy intake, smaller white adipocyte size, and less whitening of brown adipose tissue. Meanwhile, the HD-induced disturbance in the expression of fat and energy metabolism-associated genes (Fas, Atgl, Hsl, Ppar-α, adiponectin, resistin, Ucp2, etc.) in epididymal fat was diminished, and the dysbiosis in faecal microbiota was lessened, by FS-HD. However, in GF mice with HD feeding, dietary folic acid supplementation had almost no effect on body weight gain and the expression of fat- and energy-associated genes. Faecal or plasma SCFA concentrations in CV and GF mice were not altered by either FD-HD or FS-HD feeding.

CONCLUSION

Dietary folic acid supplementation differently affected body weight gain and associated genes' expression under HD feeding between CV and GF mice, suggesting that gut bacteria might partially share the responsibility for beneficial effects of dietary folate on obesity.

Effect of Fluoride in Drinking Water on Fecal Microbial Community in Rats

Intestinal nutrition has a close association with the onset and development of fluorosis. Intestinal microbes play a major role in intestinal nutrition. However, the effect of fluoride on intestinal microbes is still not fully understood. This study aimed to evaluate the dose-response of fluoride on fecal microbes as well as the link between fluorosis and fecal microbes. The results showed that fluoride did not significantly alter the diversity of fecal microbiota, but richness estimators (ACE and Chao) increased first, and then decreased with the increase of water fluoride. At the genus level, 150 mg/L fluoride significantly reduced the abundances of Roseburia and Clostridium sensu stricto, and 100 mg/L and 150 mg/L fluoride obviously increased the abundances of Unclassified Ruminococcaceaes and Unclassified Bdellovibrionales, respectively. The correlation analysis showed fluoride exposure had a negative association with Roseburia and Turicibacter and was positively associated with Pelagibacterium, Unclassified Ruminococcaceae, and Unclassified Bdellovibrionales. Dental fluorosis was negatively associated with Clostridium sensu stricto, Roseburia, Turicibacter, and Paenalcaligenes and had a positive association with Pelagibacterium, Unclassified Ruminococcaceae, and Unclassified Bdellovibrionales. In conclusion, this study firstly reports fluoride in drinking water has a remarkable biphasic effect on fecal microbiota in rats, and some bacteria are significantly associated with fluoride exposure and dental fluorosis. These results indicate the gut microbiota may play an important role in fluorosis, and some bacteria are likely to be developed as biomarkers for fluorosis.

Glucose but Not Fructose Alters the Intestinal Paracellular Permeability in Association With Gut Inflammation and Dysbiosis in Mice

A causal correlation between the metabolic disorders associated with sugar intake and disruption of the gastrointestinal (GI) homeostasis has been suggested, but the underlying mechanisms remain unclear. To unravel these mechanisms, we investigated the effect of physiological amounts of fructose and glucose on barrier functions and inflammatory status in various regions of the GI tract and on the cecal microbiota composition. C57BL/6 mice were fed chow diet and given 15% glucose or 15% fructose in drinking water for 9 weeks. We monitored caloric intake, body weight, glucose intolerance, and adiposity. The intestinal paracellular permeability, cytokine, and tight junction protein expression were assessed in the jejunum, cecum, and colon. In the cecum, the microbiota composition was determined. Glucose-fed mice developed a marked increase in total adiposity, glucose intolerance, and paracellular permeability in the jejunum and cecum while fructose absorption did not affect any of these parameters. Fructose-fed mice displayed increased circulation levels of IL6. In the cecum, both glucose and fructose intake were associated with an increase in Il13, Ifnγ, and Tnfα mRNA and MLCK protein levels. To clarify the relationships between monosaccharides and barrier function, we measured the permeability of Caco-2 cell monolayers in response to IFNγ+TNFα in the presence of glucose or fructose. In vitro, IFNγ+TNFα-induced intestinal permeability increase was less pronounced in response to fructose than glucose. Mice treated with glucose showed an enrichment of Lachnospiracae and Desulfovibrionaceae while the fructose increased relative abundance of Lactobacillaceae. Correlations between pro-inflammatory cytokine gene expression and bacterial abundance highlighted the potential role of members of Desulfovibrio and Lachnospiraceae NK4A136 group genera in the inflammation observed in response to glucose intake. The increase in intestinal inflammation and circulating levels of IL6 in response to fructose was observed in the absence of intestinal permeability modification, suggesting that the intestinal permeability alteration does not precede the onset of metabolic outcome (low-grade inflammation, hyperglycemia) associated with chronic fructose consumption. The data also highlight the deleterious effects of glucose on gut barrier function along the GI tract and suggest that Desulfovibrionaceae and Lachnospiraceae play a key role in the onset of GI inflammation in response to glucose.

Lifelong dietary omega-3 fatty acid suppresses thrombotic potential through gut microbiota alteration in aged mice

Aging is a major risk factor for cardiovascular diseases, including thrombotic events. The gut microbiota has been implicated in the development of thrombotic risk. Plant-derived omega-3 fatty acid ɑ-linolenic acid (ALA) confers beneficial anti-platelet and anti-inflammatory effects. Hence, antithrombotic activity elicited by ALA may be partly dependent on its interaction with gut microbiota during aging. Here, we demonstrate that lifelong dietary ALA decreases platelet hyperresponsiveness and thrombus formation in aged mice. These phenotypic changes can be partly attributed to alteration of microbial composition and reduction of its metabolite trimethylamine N-oxide and inflammatory mediators including TNF-α, as well as the upregulated production of short-chain fatty acid acetate. ALA-rich diet also dampens secretion of increased procoagulant factors, tissue factor and plasminogen activator inhibitor-1, in aged mice. Our results suggest long-term ALA supplementation as an attractive, accessible, and well-tolerated nutritional strategy against age-associated platelet hyperreactivity and thrombotic potential.

Comprehensive Analysis of Fecal Microbiome and Metabolomics in Hepatic Fibrosis Rats Reveal Hepatoprotective Effects of Yinchen Wuling Powder From the Host-Microbial Metabolic Axis

Hepatic fibrosis (HF) is a typical consequence in the development of multiple chronic liver diseases, which is intimately related to the composition and metabolic status of gut microbiota. A myriad of evidence has indicated that traditional Chinese medicine can treat HF by regulating gut microbiota. Yinchen Wuling powder (YCWLP) is a famous traditional Chinese medicine prescription, which has been used to relieve liver diseases for thousands of years. YCWLP has demonstrated protective function on HF, but its effect on the alterations of gut microbiota is still unclear, and its explicit therapeutic mechanism also needs to be further elucidated. In this study, 16S rRNA gene sequencing and fecal metabolomics analysis were combined to investigate the influence of YCWLP on gut microbiota in HF rats and the interactions between gut microbiota and host metabolism. The results showed that YCWLP treatment significantly improved the disorder of multiple organ indices, HF-related cytokines and plasma LPS induced by HF. Masson's trichrome stainings also showed that YCWLP treatment could significantly alleviate the severity of HF in rats. Additionally, YCWLP could reverse the significant changes in the abundance of certain genera closely related to HF phenotype, including Barnesiella [Ruminococcus] and Christensenella. Meanwhile, YCWLP significantly increased the abundance of Bifidobacterium, Coprococcus and Anaerostipes, which are closely related to butyrate production. Metabolomics and Spearman's correlation analysis showed that YCWLP could regulate the disorder of arginine biosynthesis, sphingolipid metabolism and alanine, aspartate and glutamate metabolism in HF rats, and these regulations were intimately related to Barnesiella, [Ruminococcus], Christensenella, Coprococcus and Anaerostipes. By explaining the biological significance of the above results, we concluded that YCWLP might ameliorate HF by regulating the imbalance of gut microbiota, increasing the abundance of butyrate-producing bacteria to reduce ammonia production, promote ammonia degradation, and regulate pro-inflammatory cytokines and immune function.

Relationship between gut microbiota and markers of myocardial fibrosis in with chronic heart failure with preserved ejection fraction

Aim. To study the relationship of gut microbiota (GM) with serum myocardial fibrosis markers in patients with heart failure with preserved ejection fraction (HFpEF).

Material and methods. The composition of the gut microbiota among 42 patients with HFpEF aged 67,0 [64,0; 71,5] years (men, 57,1%) was assessed by 16S ribosomal ribonucleic acid sequencing. The quantitative determination of myocardial fibrosis markers was carried out by enzyme-linked immunosorbent assay. Correlation and multivariate regression analysis of relationships between the relative abundance of intestinal bacteria and the concentration of the procollagen type I carboxy-terminal propeptide (PICP) and N-terminal propeptide of procollagen type III (PIIINP) was carried out.

Results. The PICP and PIIINP concentrations were 918,0 [700,0; 1032,8] pg/ml and 6,2±2,7 pg/ml, respectively. Correlation analysis revealed a direct relationship between the relative abundance of Allisonella and PICP (r=0,32), as well as Blautia, Enterobаcteriaceae (unclassified) and PIIINP (r=0,37 and r=0,32), p<0,05. The inverse relationship was determined for the relative abundance of the genera Ruminococcus (r=-0,37), Ruminococcaceae (unclassified) (r=-0,31), Gemmiger (r=(-0,35) and PICP, as well as Bilophila and PIIICP (r=(-0,34). Multivariate regression found (normalized coefficient in parentheses) that the abundance of Butyricimonas (0,27) и Blautia (0,35) was directly related to the PICP levels, while the abundance of the genus Intestinimonas ((-0,23) showed an inverse association with the marker level. The abundance of most genera had an inverse relationship with PIIINP: Atopobium (-0,25), Cellulosilyticum (-0,31), Solobacterium (-0,32), Turicibacter (-0,47), Bilophila (-0,30). The directness of the association with  PIIINP concentration was demonstrated for the relative abundance of Paraprevotella (0,32) и Desulfovibrio (0,28). The p-value for all associations is <0,05.

Conclusion. The relative abundance of GM genera in patients with HFpEF is associated with fibrosis markers (PICP and PIIINP). The results obtained make it possible to deepen the understanding of the relationship between GM and pathogenesis of HFpEF, which may become a step towards understanding the GM role in the progression of left ventricular diastolic dysfunction and rationale for future studies.

Obesity-Induced Dysbiosis Exacerbates IFN-γ Production and Pulmonary Inflammation in the Mycobacterium tuberculosis Infection

The microbiota of the gut-lung axis affects local and far-reaching immune responses and might also trigger chronic and inflammatory diseases. We hypothesized that gut dysbiosis induced by obesity, which coexists in countries with a high tuberculosis burden, aggravates the host susceptibility and the pulmonary damage tolerance. To assess our hypothesis, we used a model of high-fat diet (HFD)-induced obesity, followed by infection of C57BL/6 mice with Mycobacterium tuberculosis. We showed that obesity increased the susceptibility, the pulmonary inflammation and IFN-γ levels in M. tuberculosis-infected mice. During the comorbidity obesity and tuberculosis, there is an increase of Bacteroidetes and Firmicutes in the lungs, and an increase of Firmicutes and butyrate in the feces. Depletion of gut microbiota by antibiotic treatment in the obese infected mice reduced the frequencies of CD4+IFN-γ+IL-17- cells and IFN-γ levels in the lungs, associated with an increase of Lactobacillus. Our findings reinforce the role of the gut-lung axis in chronic infections and suggest that the gut microbiota modulation may be a potential host-directed therapy as an adjuvant to treat TB in the context of IFN-γ-mediated immunopathology.

Dysbiosis of Gut Microbiota in Patients With Acute Myocardial Infarction

Acute myocardial infarction (AMI) continues as the main cause of morbidity and mortality worldwide. Interestingly, emerging evidence highlights the role of gut microbiota in regulating the pathogenesis of coronary heart disease, but few studies have systematically assessed the alterations and influence of gut microbiota in AMI patients. As one approach to address this deficiency, in this study the composition of fecal microflora was determined from Chinese AMI patients and links between gut microflora and clinical features and functional pathways of AMI were assessed. Fecal samples from 30 AMI patients and 30 healthy controls were collected to identify the gut microbiota composition and the alterations using bacterial 16S rRNA gene sequencing. We found that gut microflora in AMI patients contained a lower abundance of the phylum Firmicutes and a slightly higher abundance of the phylum Bacteroidetes compared to the healthy controls. Chao1 (P = 0.0472) and PD-whole-tree (P = 0.0426) indices were significantly lower in the AMI versus control group. The AMI group was characterized by higher levels of the genera Megasphaera, Butyricimonas, Acidaminococcus, and Desulfovibrio, and lower levels of Tyzzerella 3, Dialister, [Eubacterium] ventriosum group, Pseudobutyrivibrio, and Lachnospiraceae ND3007 group as compared to that in the healthy controls (P < 0.05). The common metabolites of these genera are mostly short-chain fatty acids, which reveals that the gut flora is most likely to affect the occurrence and development of AMI through the short-chain fatty acid pathway. In addition, our results provide the first evidence revealing remarkable differences in fecal microflora among subgroups of AMI patients, including the STEMI vs. NSTEMI, IRA-LAD vs. IRA-Non-LAD and Multiple (≥2 coronary stenosis) vs. Single coronary stenosis groups. Several gut microflora were also correlated with clinically significant characteristics of AMI patients, including LVEDD, LVEF, serum TnI and NT-proBNP, Syntax score, counts of leukocytes, neutrophils and monocytes, and fasting serum glucose levels. Taken together, the data generated enables the prediction of several functional pathways as based on the fecal microfloral composition of AMI patients. Such information may enhance our comprehension of AMI pathogenesis.

Glucosamine Ameliorates Symptoms of High-Fat Diet-Fed Mice by Reversing Imbalanced Gut Microbiota

Glucosamine (GlcN) is used as a supplement for arthritis and joint pain and has been proved to have effects on inflammation, cancer, and cardiovascular diseases. However, there are limited studies on the regulatory mechanism of GlcN against glucose and lipid metabolism disorder. In this study, we treated high-fat diet (HFD)-induced diabetic mice with GlcN (1 mg/ml, in drinking water) for five months. The results show that GlcN significantly reduced the fasting blood glucose of HFD-fed mice and improved glucose tolerance. The feces of intestinal contents in mice were analyzed using 16s rDNA sequencing. It was indicated that GlcN reversed the imbalanced gut microbiota in HFD-fed mice. Based on the PICRUSt assay, the signaling pathways of glucolipid metabolism and biosynthesis were changed in mice with HFD feeding. By quantitative real-time PCR (qPCR) and hematoxylin and eosin (H&E) staining, it was demonstrated that GlcN not only inhibited the inflammatory responses of colon and white adipose tissues, but also improved the intestinal barrier damage of HFD-fed mice. Finally, the correlation analysis suggests the most significantly changed intestinal bacteria were positively or negatively related to the occurrence of inflammation in the colon and fat tissues of HFD-fed mice. In summary, our studies provide a theoretical basis for the potential application of GlcN to glucolipid metabolism disorder through the regulation of gut microbiota.

Short-term exposure to synthetic flaxseed lignan LGM2605 alters gut microbiota in mice

LGM2605 is a synthetic version of the naturally occurring flaxseed lignan secoisolariciresinol diglucoside (SDG), with known anti‐inflammatory and antioxidant properties; however, its effects on gut microbial composition have not previously been evaluated. In the present study, we sought to determine how the 10‐day oral administration of LGM2605 alters the gut microbiota of mice. Eight‐week‐old female C57BL/6 mice were treated with either LGM2605 or saline, administered daily via oral gavage over a 10‐day treatment period. Upon termination of treatment, mouse cecums (n = 31) were collected, and cecal DNA was isolated. 16S rRNA genes were sequenced and analyzed in Mothur to identify changes in gut microbial composition induced by LGM2605 treatment (v. saline control). We then assessed community composition, performed indicator taxa analysis, and measured alpha and beta diversity. Overall, LGM2605 significantly altered the gut microbiota of mice; we reported alterations in 3 bacterial phyla and 22 genera as a result of treatment. The study here identifies for the first time significant alterations in the gut microbiota of mice following oral administration of LGM2605, in general shifting toward a more anti‐inflammatory composition. These findings lay the foundation for future investigations utilizing LGM2605 to control gut dysbiosis and, by extension, systemic inflammation.

Mixed conjugated linoleic acid sex-dependently reverses high-fat diet-induced insulin resistance via the gut-adipose axis

Conjugated linoleic acid (CLA) may prevent the development of obesity and metabolic disorders. However, the effects of CLA on inflammation and glucose metabolism are controversial. The underlying mechanisms governing the gut microbiota and sexual dimorphisms have also not been elucidated. The present study assessed the effect of CLA on glucose and lipid metabolism in established obesity and examined the mechanism of action based on gut microbiota. Four-week-old C57BL/6J mice were fed a high-fat diet (HFD) for 10 weeks to induce obesity. The diet-induced obese (DIO) mice were fed an HFD supplemented with mixed CLA (50% cis-9, trans-11 isomer and 50% trans-10, cis-12 isomers, 0.2% wt/wt) for 15 weeks. CLA supplementation remarkably reversed body weight in both sexes. CLA favored anti-inflammatory microbiota in male mice, mediating increased short-chain fatty acids and decreased lipopolysaccharide (LPS) production, which alleviated global inflammation and improved insulin sensitivity via inhibition of the TLR4-NF-κB pathway in adipose tissue. CLA promoted the growth of hydrogen sulfide-producing Desulfovibrio and the release of LPS in female mice, which aggravated adipose inflammation and insulin resistance. Although CLA impaired glucose metabolism in females, brown adipose tissue was significantly activated with browning of white adipose tissue in both sexes, which led to enhanced energy expenditure. Fecal transplantation from CLA-treated mice to DIO mice mimicked the sex-dependent phenotype. In conclusion, CLA decreased body weight and increased energy expenditure but sex-dependently modulated insulin resistance via the gut-adipose axis.

Novel high-docosahexaenoic-acid tuna oil supplementation modulates gut microbiota and alleviates obesity in high-fat diet mice

Studies have documented the benefits of fish oil in different diseases because of its high n-3 polyunsaturated fatty acid content. However, these studies mostly used commercially available fish oil supplements with a ratio of 18/12 for eicosapentaenoic acid and docosahexaenoic acid (DHA). However, increasing DHA content for this commonly used ratio might bring out a varied metabolic effect, which have remained unclear. Thus, in this study, a novel tuna oil (TO) was applied to investigate the effect of high-DHA content on the alteration of the gut microbiota and obesity in high-fat diet mice. The results suggest that high-DHA TO (HDTO) supplementation notably ameliorates obesity and related lipid parameters and restores the expression of lipid metabolism-related genes. The benefits of TOs were derived from their modification of the gut microbiota composition and structure in mice. A high-fat diet triggered an increased Firmicutes/Bacteroidetes ratio that was remarkably restored by TOs. The number of obesity-promoting bacteria-Desulfovibrio, Paraeggerthella, Terrisporobacter, Millionella, Lachnoclostridium, Anaerobacterium, and Ruminiclostridium-was dramatically reduced. Desulfovibrio desulfuricans, Alistipes putredinis, and Millionella massiliensis, three dysbiosis-related species, were especially regulated by HDTO. Regarding the prevention of obesity, HDTO outperforms the normal TO. Intriguingly, HDTO feeding to HFD-fed mice might alter the arginine and proline metabolism of intestinal microbiota.

Suppression of High-Fat Diet-Induced Obesity by Platycodon Grandiflorus in Mice Is Linked to Changes in the Gut Microbiota

BACKGROUND

The root of Platycodon grandiflorus (PG) has a long-standing tradition in the Asian diet and herbal medicine, because of its anti-inflammatory and antiobesity effects. Changes in the gut microbiota can have dietary effects on host health, which suggests a relation between the 2.

OBJECTIVES

The aim of our study was to investigate the relation between PG-mediated suppression of obesity and the composition and functioning of the gut microbiota.

METHODS

Six-week-old male C57BL/6J mice were fed either a control diet (CON, 10% kcal from fat), a high-fat diet (HFD, 60% kcal from fat), or a PG-supplemented HFD for 18 wk. PG was administered by oral gavage at 2 g · kg body weight-1 · d-1. Body weight and food intake were monitored. Lipid metabolism, inflammation, and intestinal barrier function were determined. Amplicon sequencing of the bacterial 16S ribosomal RNA gene was used to explore gut microbiota structure, and nontargeted metabolomics analysis was performed to investigate metabolite concentrations in fecal samples.

RESULTS

We found that PG significantly ameliorated HFD-induced inflammation, recovered intestinal barrier integrity (reduced permeability by 39% , P = 0.008), reduced fat accumulation by 26% (P = 0.009), and changed the expression of key genes involved in the development of white adipose tissue (P < 0.05) in HFD-fed mice to similar levels in CON mice. Moreover, PG attenuated HFD-induced changes in the gut microbiota; it especially increased Allobaculum (7.3-fold, P = 0.002) relative to HFD, whereas CON was 15.2-fold of HFD (P = 0.002). These changes by PG were associated with an increase in the production of SCFAs (butyrate and propionate, P < 0.001) and other carbohydrate-related metabolites known to have a major role in disease suppression.

CONCLUSIONS

Our study demonstrated that PG beneficially changed the gut microbiota and the gut metabolome in HFD-fed mice, and suggests that the antiobesity effects of PG may be mediated via changes in gut microbiota composition and metabolic activity.

Can Dietary Fatty Acids Affect the COVID-19 Infection Outcome in Vulnerable Populations?

There is high mortality in coronavirus disease 2019 (COVID-19)-infected individuals with chronic inflammatory diseases, like obesity, diabetes, and hypertension. A cytokine storm in some patients after infection contributes to this mortality. In addition to lungs, the intestine is targeted during COVID-19 infection. The intestinal membrane serves as a barrier to prevent leakage of microorganisms and their products into the bloodstream; however, dietary fats can affect the gut microbiome and may increase intestinal permeability.

There is high mortality in coronavirus disease 2019 (COVID-19)-infected individuals with chronic inflammatory diseases, like obesity, diabetes, and hypertension. A cytokine storm in some patients after infection contributes to this mortality. In addition to lungs, the intestine is targeted during COVID-19 infection. The intestinal membrane serves as a barrier to prevent leakage of microorganisms and their products into the bloodstream; however, dietary fats can affect the gut microbiome and may increase intestinal permeability. In obese or diabetic individuals, there is an increase in the abundance of either Gram-negative bacteria in the gut or their product, endotoxin, in systemic circulation. We speculate that when the COVID-19 infection localizes in the intestine and when the permeability properties of the intestinal membrane are compromised, an inflammatory response is generated when proinflammatory endotoxin, produced by resident Gram-negative bacteria, leaks into the systemic circulation. This review discusses conditions contributing to inflammation that are triggered by microbially derived factors from the gut.

Animal-Origin Prebiotics Based on Chitin: An Alternative for the Future? A Critical Review

The human gut microbiota has been revealed in recent years as a factor that plays a decisive role in the maintenance of human health, as well as in the development of many non-communicable diseases. This microbiota can be modulated by various dietary factors, among which complex carbohydrates have a great influence. Although most complex carbohydrates included in the human diet come from vegetables, there are also options to include complex carbohydrates from non-vegetable sources, such as chitin and its derivatives. Chitin, and its derivatives such as chitosan can be obtained from non-vegetable sources, the best being insects, crustacean exoskeletons and fungi. The present review offers a broad perspective of the current knowledge surrounding the impacts of chitin and its derived polysaccharides on the human gut microbiota and the profound need for more in-depth investigations into this topic. Overall, the effects of whole insects or meal on the gut microbiota have contradictory results, possibly due to their high protein content. Better results are obtained for the case of chitin derivatives, regarding both metabolic effects and effects on the gut microbiota composition.

Egg oil from Portunus trituberculatus alleviated obesity and regulated gut microbiota in mice

Egg oil from Portunus trituberculatus (Pt-egg oil) can overcome insulin resistance resulting from abundant bioactive lipids. However, its effects on obesity and gut microbiota were unclear. Here, we evaluated whether Pt-egg oil could improve obesity and gut microbiota or not in high-fat diet feeding mice. Results exhibited that Pt-egg oil markedly reduced body weight and adipose weight gain, improved lipid accumulation and circulatory cytokines, inhibited epididymal adipose cell size. Moreover, Pt-egg oil modified gut microbiota, involving decreases in the ratio of Firmicutes to Bacteroidetes, Proteobacteria, Actinobacteria, and increase in Verrucomicrobia phylum. Pt-egg oil reduced serum and fecal lipopolysaccharide (LPS) levels and down-regulated Toll-like receptor 4 pathway in both epididymal adipose and liver tissues. Meanwhile, Pt-egg oil increased short chain fatty acids and up-regulated of G-protein-coupled receptors in both epididymal adipose and liver tissues. These suggest that Pt-egg oil could be alternative food supplement for the prophylactic effects on anti-obesity and improvement in human gut health.

Oral Supplements of Combined Bacillus licheniformis Zhengchangsheng® and Xylooligosaccharides Improve High-Fat Diet-Induced Obesity and Modulate the Gut Microbiota in Rats

Gut dysbiosis induced by high-fat diet (HFD) may result in low-grade inflammation leading to diverse inflammatory diseases. The beneficial effects of probiotics and prebiotics on obesity have been reported previously. However, their benefits in promoting human health and the underlying mechanisms still need to be further characterized. This study is aimed at understanding how probiotic Bacillus licheniformis Zhengchangsheng® (BL) and prebiotic xylooligosaccharides (XOS) influence the health of a rat model with HF (60 kcal %) diet-induced obesity. Five groups of male Sprague Dawley (SD) rats were fed a normal fat diet (CON) or an HFD with or without BL and XOS supplementation for 3 weeks. Lipid profiles, inflammatory biomarkers, and microbiota composition were analyzed at the end of the experiment. Rats fed an HFD exhibited increased body weight and disordered lipid metabolism. In contrast, combined BL and XOS supplementation inhibited body weight gain and returned lipid metabolism to normal. Furthermore, BL and XOS administration changed the gut microbiota composition and modulated specific bacteria such as Prevotellaceae, Desulfovibrionaceae, and Ruminococcaceae. In addition, supplements of combined BL and XOS obviously reduced the serum LPS level, which was significantly related to microbial variations. Our findings suggest that modulation of the gut microbiota as a result of probiotic BL and prebiotic XOS supplementation has a positive effect on HFD-induced obesity in rats.

Polyethylene microplastics affect the distribution of gut microbiota and inflammation development in mice

Environmental pollution caused by plastics has become a public health problem. However, the effect of microplastics on gut microbiota, inflammation development and their underlying mechanisms are not well characterized. In the present study, we assessed the effect of exposure to different amounts of polyethylene microplastics (6, 60, and 600 μg/day for 5 consecutive weeks) in a C57BL/6 mice model. Treatment with a high concentration of microplastics increased the numbers of gut microbial species, bacterial abundance, and flora diversity. Feeding groups showed a significant increase in Staphylococcus abundance alongside a significant decrease in Parabacteroides abundance, as compared to the blank (untreated) group. In addition, serum levels of interleukin-1α in all feeding groups were significantly greater than that in the blank group. Of note, treatment with microplastics decreased the percentage of Th17 and Treg cells among CD4⁺ cells, while no significant difference was observed between the blank and treatment groups with respect to the Th17/Treg cell ratio. The intestine (colon and duodenum) of mice fed high-concentration microplastics showed obvious inflammation and higher TLR4, AP-1, and IRF5 expression. Thus, polyethylene microplastics can induce intestinal dysbacteriosis and inflammation, which provides a theoretical basis for the prevention and treatment of microplastics-related diseases.

Targeting the gut microbiota with resveratrol: a demonstration of novel evidence for the management of hepatic steatosis

Resveratrol is a natural polyphenol that has been reported to reduce the risk of obesity and nonalcoholic fatty liver disease (NAFLD). Recent evidence has demonstrated that the gut microbiota plays an important role in the protection against NAFLD and other metabolic diseases. The present study aimed to investigate the relationship between the gut microbiota and the beneficial effects of resveratrol on the amelioration of NAFLD in mice. We observed marked decreases in body weight and liver steatosis and improved insulin resistance in high-fat diet (HFD)-fed mice treated with resveratrol. Furthermore, we found that resveratrol treatment alleviated NAFLD in HFD-fed mice by improving the intestinal microenvironment, including gut barrier function and gut microbiota composition. On the one hand, resveratrol improved gut intestinal barrier integrity through the repair of intestinal mucosal morphology and increased the expression of physical barrier- and physiochemical barrier-related factors in HFD-fed mice. On the other hand, in HFD-fed mice, resveratrol supplementation modulated the gut bacterial composition. The resveratrol-induced gut microbiota was characterized by a decreased abundance of harmful bacteria, including Desulfovibrio, Lachnospiraceae_NK4A316_group and Alistipes, as well as an increased abundance of short-chain fatty acid (SCFA)-producing bacteria, such as Allobaculum, Bacteroides and Blautia. Moreover, transplantation of the HFDR-microbiota into HFD-fed mice sufficiently decreased body weight, liver steatosis and low-grade inflammation and improved hepatic lipid metabolism. Collectively, resveratrol would provide a potentially dietary intervention strategy against NAFLD through modulating the intestinal microenvironment.

Daisaikoto Prevents Post-dieting Weight Regain by Reversing Dysbiosis and Reducing Serum Corticosterone in Mice

Weight loss is often temporary and is generally followed by recurrent weight gain and a relapse of metabolic complications, whose severity may be even greater upon recurrence. Preventing recurrent obesity, understanding the control of the energy balance subsequent to weight loss, and reversing the predisposition to obesity are critical factors that warrant an in-depth study. Several Kampo medicines, including daisaikoto, have traditionally been used to manage obesity, but their mechanisms of action are not well studied and their effects on weight regain are unknown. Here, we investigated the therapeutic potential and mechanism of action of daisaikoto in a mouse model of recurrent obesity. The mouse model was established by feeding mice a high-fat diet, followed by a normal chow, and a second course of the high-fat diet. Daisaikoto inhibited not only obesity and regaining of weight post-dieting, but also dysbiosis, thereby overcoming the predisposition to obesity. Furthermore, we found that recurrent obesity or long-term consumption of the high-fat diet elevated serum glucose, insulin, and corticosterone levels, and that daisaikoto lowered serum cholesterol and free fatty acid levels. These results are consistent with the hypothesis that this medication may inhibit lipid absorption by inhibiting pancreatic lipase. However, daisaikoto had no effect on the body weight of lean mice fed a normal chow, suggesting that although this medicine prevents lipid absorption, it does not cause excessive weight loss. In conclusion, our results elucidate the mechanisms underlying daisaikoto activity, and suggest that it may serve as a safe and effective anti-obesity drug.

Fish Oil Is More Potent than Flaxseed Oil in Modulating Gut Microbiota and Reducing Trimethylamine-N-oxide-Exacerbated Atherogenesis

Trimethylamine-N-oxide (TMAO) is a risk factor for atherosclerosis. We compared the potency of fish oil with flaxseed oil in reducing TMAO-exacerbated atherogenesis. Five groups of ApoE^-/- mice were given one of five diets, namely, a low-fat diet, a Western high fat diet (WD), a WD plus 0.2% TMAO, and two WDs containing 0.2% TMAO with 50% lard being replaced by flaxseed oil or fish oil. TMAO accelerated atherosclerosis and disturbed cholesterol homeostasis. Compared with flaxseed oil, fish oil was more effective in inhibiting TMAO-induced atherogenesis by lowering plasma cholesterol and inflammatory cytokines. Both oils could reverse TMAO-induced decrease in fecal acidic sterols. Fish oil promoted fecal output of neutral sterols and downregulated hepatic cholesterol biosynthesis. Fish oil was more effective than flaxseed oil in promoting the growth of short-chain fatty acid-producing bacteria and lowering microbial generation of lipopolysaccharide. In conclusion, fish oil is more potent than flaxseed oil to ameliorate TMAO-exacerbated atherogenesis.

The Gut Microbiome on a Periodized Low-Protein Diet Is Associated With Improved Metabolic Health

A periodized (14 days on/14 days off) 5% low protein-high carbohydrate (pLPHC) diet protects against weight gain, improves glucose tolerance in mice and interacts with concurrent voluntary activity wheel training on several parameters including weight maintenance and liver FGF21 secretion. The gut microbiome (GM) responds to both diet and exercise and may influence host metabolism. This study compared the cecal GM after a 13.5-week intervention study in mice on a variety of dietary interventions ± concurrent voluntary exercise training in activity wheels. The diets included chronic chow diet, LPHC diet, 40 E% high protein-low carbohydrate (HPLC) diet, an obesigenic chronic high-fat diet (HFD) and the pLPHC diet. Our hypothesis was that the GM changes with pLPHC diet would generally reflect the improved metabolic health of the host and interact with concurrent exercise training. The GM analyses revealed greater abundance phylum Bacteroidetes and the genus Akkermansia on chronic and periodized LPHC and higher abundance of Oscillospira and Oscillibacter on HFD. The differences in diet-induced GM correlated strongly with the differences in a range of host metabolic health-measures. In contrast, no significant effect of concurrent exercise training was observed. In conclusion, pLPHC diet elicits substantial changes in the GM. In contrast, only subtle and non-significant effects of concurrent activity wheel exercise were observed. The pLPHC-associated microbiome may contribute to the healthier host phenotype observed in these mice.

Structure function relationships in three lipids A from the Ralstonia genus rising in obese patients

The identification of a functional molecular moiety relating the lipopolysaccharides (LPSs) to their capacity to induce inflammation-mediated metabolic diseases needed to be performed. We previously described a proportional increase in the relative abundance of the 16 SrDNA bacterial gene from the genus Ralstonia, within the microbiota from the adipose tissue stroma vascular fraction of obese patients, suggesting a causal role of the bacteria. Therefore, we first characterized the structures of the lipids A, the inflammatory inducing moieties of LPSs, of three Ralstonia species: Ralstonia eutropha, R. mannitolilytica and R. pickettii, and then compared each, in terms of in vitro inflammatory capacities. R. pickettii lipid A displaying only 5 Fatty Acids (FA) was a weaker inducer of inflammation, compared to the two other species harboring hexa-acylated lipids A, despite the presence of 2 AraN substituents on the phosphate groups. With regard to in vitro pro-inflammatory activities, TNF-α and IL-6 inducing capacities were compared on THP-1 cells treated with LPSs isolated from the three Ralstonia. R. pickettii, with low inflammatory capacities, and recently involved in nosocomial outcomes, could explain the low inflammatory level reported in previous studies on diabetic patients and animals. In addition, transmission electron microscopy was performed on the three Ralstonia species. It showed that the R. pickettii under-acylated LPSs, with a higher level of phosphate substitution had the capacity of producing more outer membrane vesicles (OMVs). The latter could facilitate transfer of LPSs to the blood and explain the increased low-grade inflammation observed in obese/diabetic patients.

N-Acetylcysteine alleviates gut dysbiosis and glucose metabolic disorder in high-fat diet-fed mice

BACKGROUND

N-Acetylcysteine (NAC), an antioxidative reagent for clinical diseases, shows potential in the treatment of diabetes and other metabolic diseases. However, it is unknown how NAC modulates the gut microbiota of mice with metabolic syndrome. The aim of the present study was to demonstrate the preventive effect of NAC on intestinal dysbiosis and glucose metabolic disorder.

METHODS

Mice (C57BL/6J strain) were fed either a normal chow diet (NCD), NCD plus NAC, a high-fat diet (HFD), or HFD plus NAC for 5 months, after which glucose levels, circulating endotoxins and key metabolism-related proteins were determined. Fecal samples were analyzed by 16S rRNA sequencing. A novel analysis was performed to predict functional changes in gut microbiota. In addition, Spearman's correlation analysis was performed between metabolic biomarkers and bacterial abundance.

RESULTS

Treatment with NAC significantly reversed the glucose intolerance, fasting glucose concentrations, and gains in body weight and plasma endotoxin in HFD-fed mice. Further, NAC upregulated occludin and mucin glycoprotein levels in the proximal colon of HFD-treated mice. Noticeably, NAC promoted the growth of beneficial bacteria (i.e. Akkermansia, Bifidobacterium, Lactobacillus and Allobaculum) and decreased populations of diabetes-related genera, including Desulfovibrio and Blautia. In addition, NAC may affect the metabolic pathways of intestinal bacteria, including lipopolysaccharide biosynthesis, oxidative stress, and bacterial motility. Finally, the modified gut microbiota was closely associated with the metabolic changes in NAC-treated HFD-fed mice.

CONCLUSIONS

N-Acetylcysteine may be a potential drug to prevent glucose metabolic disturbances by reshaping the structure of the gut microbiota.