Ramulus Mori (Sangzhi) alkaloids ameliorate high-fat diet induced obesity in rats by modulating gut microbiota and bile acid metabolism.

The objective of this study is to investigate the ability of Ramulus Mori (Sangzhi) alkaloid tablets (SZ-A) to ameliorate obesity and lipid metabolism disorders in rats subjected to a high-fat diet (HFD) through metagenomics, untargeted lipidomics, targeted metabolism of bile acid (BA), and BA pathways, providing a novel perspective on the management of metabolic disorders. In this research, HFD-fed rats were concurrently administered SZ-A orally. We measured changes in body weight (BW), blood lipid profiles, and liver function to assess therapeutic effects. Liver lipid status was visualized through H&E and Oil Red O. Gut microbiota composition was elucidated using metagenomics. The LC-MS-targeted metabolomics approach was utilized to define the fecal BA profiles. Furthermore, the lipid metabolomics of adipose tissue samples was investigated using an LC-MS analysis platform. The expression levels of the BA receptor were determined by western blotting. Additionally, serum insulin (INS), glucagon-like peptide-1 (GLP-1), and inflammatory cytokines were quantified using an ELISA kit. The integrity of the colonic epithelial barrier was assessed using immunofluorescence. SZ-A notably decreased BW and blood lipid levels in obese rats while also alleviating liver injury. Additionally, SZ-A reduced the serum levels of leptin (LEP), INS, and GLP-1, indicating its potential to modulate key metabolic hormones. Most notably, SZ-A substantially improved gut microbiota composition. Specifically, it reshaped the gut microbiota structure in HFD-fed rats by increasing the relative abundance of beneficial bacteria, such as Bacteroides, while decreasing the populations of potentially harmful bacteria, such as Dorea and Blautia. At the BA level, SZ-A decreased the levels of harmful BAs, including hyodeoxycholic acid (HDCA), deoxycholic acid (DCA), 12-keto lithocholic acid (12-KLCA), lithocholic acid (LCA), and muricholic acid (MDCA). Between the model group and SZ-A, 258 differentially abundant metabolites were detected, with 72 upregulated and 186 downregulated. Furthermore, these BAs are implicated in the activation of the FXR-FGF15 and TGR5-GLP-1 pathways in the intestine. This activation helps to alleviate HFD-fed intestinal inflammation and restore intestinal barrier damage by modulating inflammatory cytokines and bolstering the intestinal barrier's capabilities. Our findings indicate that SZ-A effectively modulates BW, serum lipid profiles, and liver function in HFD-fed rats. Moreover, SZ-A exerts a positive influence on inflammatory cytokines, thereby mitigating inflammation and promoting the restoration of the intestinal barrier. Significantly, our research indicates that adjusting the gut microbiome and BA levels could serve as an effective approach for both preventing and treating obesity and related metabolic dyslipidemia.

Shang X ，Fu Y ，Wang Y ，Yan S ... -  《Frontiers in Endocrinology》

Growth performance, bile acid profile, fecal microbiome and serum metabolomics of growing-finishing pigs fed diets with bile acids supplementation.

The present experiment was conducted to determine the effect of bile acids (BAs) supplementation on growth performance, BAs profile, fecal microbiome, and serum metabolomics in growing-finishing pigs. A total of 60 pigs [Duroc × (Landrace × Yorkshire)] with an average body weight of 27.0 ± 1.5 kg were selected and allotted into one of 2 groups (castrated male to female ratio = 1:1), with 10 replicates per treatment and 3 pigs per replicate. The 2 treatments were the control group (control) and a porcine bile extract-supplemented group dosed at 0.5 g/kg feed (BA). After a 16-wk treatment, growth performance, BAs profiles in serum and feces, and fecal microbial composition were determined. An untargeted metabolomics approach using gas chromatography with a time-of-flight mass spectrometer was conducted to identify the metabolic pathways and associated metabolites in the serum of pigs. We found that BAs supplementation had no effect on the growth performance of the growing-finishing pig. However, it tended to increase the gain-to-feed ratio for the whole period (P = 0.07). BAs supplementation resulted in elevated serum concentrations of secondary bile acids, including hyodeoxycholic acid (HDCA), glycoursodeoxycholic acid, and tauro-hyodeoxycholic acid, as well as fecal concentration of HDCA (P < 0.05). Fecal microbiota analysis revealed no differences in alpha and beta diversity indices or the relative abundance of operational taxonomic units (OTUs) at both phylum and genus levels between groups. Metabolic pathway analysis revealed that the differential metabolites between control and BA groups are mainly involved in purine metabolism, ether lipid metabolism, glycerophospholipid metabolism, and amino sugar and nucleotide sugar metabolism, as well as primary bile acid biosynthesis. Our findings indicate that BAs supplementation tended to improve the feed efficiency, and significantly altered the BA profile in the serum and feces of growing-finished pigs, regardless of any changes in the gut microbial composition. The altered metabolic pathways could potentially play a vital role in improving the feed efficiency of growing-finished pigs with BAs supplementation.

Zhou P ，Yan H ，Zhang Y ，Qi R ，Zhang H ，Liu J ... -  《-》

Effects of a veterinary gastrointestinal low-fat diet on fecal characteristics, metabolites, and microbiota concentrations of adult dogs treated with metronidazole.

Antibiotics are known to cause loose stools, disrupt the fecal microbiota, and alter fecal bile acid (BA) profiles of dogs. Recovery may be aided by diet, but little research has been conducted. The objective of this study was to determine how a veterinary low-fat diet affected the fecal characteristics, metabolites, BA, and microbiota of dogs receiving antibiotics. Twenty-four healthy adult dogs [7.38 ± 1.95 yr; 7.67 ± 0.76 kg body weight (BW)] were used in an 8-wk completely randomized design study. During a 2-wk baseline, all dogs were fed a leading grocery brand diet (GBD). Over the next 2 wk, dogs were fed GBD and received metronidazole orally (20 mg/kg BW twice daily). At week 4, dogs were randomly allotted to one of two treatments [GBD or Blue Buffalo Natural Veterinary Diet GI Gastrointestinal Support Low-Fat (BB)] and fed for 4 wk. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter content, and metabolite and BA concentrations. Fecal microbiota populations were analyzed using 16S rRNA gene amplicon sequencing and qPCR-based dysbiosis index (DI). All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of treatment, time, and treatment*time and significance set at P < 0.05. Metronidazole increased (P < 0.0001) fecal scores (looser stools), reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations, increased primary BA concentrations, and decreased secondary BA concentrations. Metronidazole also reduced fecal bacterial alpha diversity, altered the abundance of 58 bacterial genera, and increased DI. During antibiotic recovery, changes in fecal pH, dry matter percentage, and metabolite and immunoglobulin A concentrations were altered (P < 0.05) by diet. Fecal BA concentrations recovered quickly for all dogs. Change in lithocholic acid was affected (P < 0.0001) by diet, but other BA were not. Recovery of over 25 bacterial genera was impacted by diet (P < 0.05). While many bacterial taxa returned to baseline levels after 4 wk, others did not fully recover. DI and bacterial alpha diversity measures recovered quickly for all dogs but were not impacted by diet. In conclusion, metronidazole drastically altered the fecal microbiota and metabolites of dogs. While most variables returned to baseline by week 8, diet may be used to aid in recovery.

Belchik SE ，Oba PM ，Lin CY ，Swanson KS ... -  《-》

Integrative transcriptomics and lipidomics unravels the amelioration effects of Radix Bupleuri on non-alcoholic fatty liver disease.

Radix Bupleuri (Bupleurum chinense DC.) is the most commonly used traditional Chinese medicine (TCM) for the treatment of liver diseases. While the effects of Radix Bupleuri (BR) on lipid-lowering and liver protection have been established, its role in the development of non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet remains unclear. The objective of this study was to evaluate the alleviation effects of the active fraction of BR on NAFLD in vivo and to explore the underlying mechanisms through an analysis of liver transcriptome and lipidomics. The NAFLD model was established in SD rats by administering a high-fat diet (HFD) for 8 weeks. Subsequently, the NAFLD model rats were continuously gavaged with different polarity fractions of BR (25 g/kg/d) and melatonin (MT) (30 mg/kg/d) for an additional 6 weeks to assess therapeutic effects. The potential mechanism of the low polarity fraction of BR (LBR) in treating NAFLD was investigated through hepatic transcriptome analysis, non-targeted lipidomics, RT-qPCR, protein-protein interaction (PPI) network construction, molecular docking, and Western blotting, aiming to elucidate the underlying mechanisms by which LBR may ameliorate NAFLD. These results demonstrated that LBR significantly alleviated the effects of HFD-induced NAFLD, as evidenced by reductions in body weight (BW), liver weight (LW), and epididymal fat weight (EFW) compared to model rats and other polarity fractions of BR. Furthermore, LBR notably down-regulated serum and liver levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C), while up-regulating high-density lipoprotein cholesterol (HDL-C) in serum. Mechanistically, liver transcriptome analysis indicated that fatty acid metabolism may be a crucial pathway for the improvement of NAFLD following LBR treatment. Lipidomics data suggested that LBR can modulate the metabolic profile in NAFLD rats. Enrichment analysis revealed that glycerophospholipid and glycerolipid metabolism might be key pathways involved in the development of NAFLD. RT-qPCR analysis demonstrated that LBR could regulate the expression of lipid-related genes in these critical pathways. Additionally, Spearman correlation analysis showed a strong relationship between lipid metabolic biomarkers, pathological indices, and lipid-related genes. Moreover, protein-protein interaction (PPI) network and molecular docking analyses identified seven key targets with six ingredients of LBR exhibiting good binding capacity (<-5.0 kcal/mol). Finally, Western blotting analysis indicated that LBR up-regulates the expression levels of PPARα, CPT1, and FABP1 while down-regulating the expression levels of SREBF1 and SCD1, thereby improving metabolism and exerting a lipid-lowering effect. In conclusion, the present research elucidated the lipid-lowering mechanisms of the active fractions of BR. Both BR and LBR presented themselves as promising candidates for the development of novel pharmacological agents targeting NAFLD. LBR effectively ameliorated lipid disturbances associated with HFD-induced NAFLD by modulating the metabolism of fatty acids, cholesterol, glycerolipid, and glycerophospholipids. Consequently, LBR held significant potential for development as an effective lipid-lowering therapeutic.

Wang W ，Qin J ，Bai S ，Tian J ，Zhou Y ，Qin X ，Gao X ... -  《-》

Effects of a veterinary gastrointestinal diet on fecal characteristics, metabolites, and microbiota concentrations of adult cats treated with metronidazole.

Antibiotics are used to treat gastrointestinal diseases or infections but are known to negatively affect stool quality and gut microbiota in cats and dogs. Therefore, identifying dietary strategies that may aid in antibiotic recovery is of interest. The objective of this study was to determine how a veterinary gastrointestinal diet affected the fecal characteristics, microbiota, and metabolite and bile acid (BA) concentrations of cats recovering from metronidazole administration. Twenty-four healthy adult cats were used in an 8-wk completely randomized design study. During a 2-wk baseline, all cats consumed a leading grocery brand diet (GBD). Over the next 2 wk, cats consumed GBD and received metronidazole (20 mg/kg body weight twice daily). At week 4, cats were randomly allotted to one of 2 treatments [GBD; BLUE Natural Veterinary Diet GI Gastrointestinal Support (BB)] and fed for 4 wk. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter (DM) %, metabolites, and microbiota. Microbiota was analyzed by 16S rRNA gene sequencing and qPCR, which was used to calculate dysbiosis index. Data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of diet, time and diet*time. Metronidazole had dramatic effects on all outcomes, including increased fecal scores (looser stools), reduced fecal pH and DM%, reduced fecal short-chain fatty acid, branched-chain fatty acid, ammonia, phenol, and indole concentrations, and altered fecal BA concentrations (increased primary BA; reduced secondary BA). Metronidazole reduced fecal bacterial alpha diversity, increased dysbiosis index, and altered the relative abundance of 78 bacterial genera. Fecal outcomes partially recovered over the next 4 wk, with some being impacted by diet. Fecal acetate concentrations were higher after metronidazole in cats fed BB. Dysbiosis index and alpha diversity measures slowly recovered over 4 wk, without diet differences. Recovery of 16 bacterial genera was impacted by diet. Fecal BA profiles demonstrated a prolonged impairment of primary to secondary BA conversion, with cholic acid being lower after metronidazole in cats fed BB. In conclusion, our data demonstrate that metronidazole is a powerful antibiotic that has long-lasting effects on the fecal microbiota and metabolites of cats. Outcome variables slowly recovered over time, but a gastrointestinal diet may aid in recovery.

Belchik SE ，Oba PM ，Lin CY ，Swanson KS ... -  《-》