Enterobacter cloacae administration induces hepatic damage and subcutaneous fat accumulation in high-fat diet fed mice

Unraveling the gut microbiota's role in obesity: key metabolites, microbial species, and therapeutic insights

Obesity, characterized by excessive fat accumulation, stems from an imbalance between energy intake and expenditure, with the gut microbiota playing a crucial role. This review highlights how gut microbiota influences metabolic pathways, inflammation, and adipose tissue regulation in obesity. Specific bacteria and metabolites, such as lipopolysaccharides (LPS) and short-chain fatty acids (SCFAs), modulate gut permeability, inflammation, and energy harvest, impacting obesity development. Certain gut bacteria, including Clostridium XIVb, Dorea spp., Enterobacter cloacae, and Collinsella aerofaciens, promote obesity by increasing energy harvest, gut permeability, and inflammatory response through LPS translocation into the bloodstream. Conversely, beneficial bacteria like Akkermansia muciniphila, Lactobacillus spp., and Bifidobacterium spp. enhance gut barrier integrity, regulate SCFA production, and modulate fasting-induced adipose factor, which collectively support metabolic health by reducing fat storage and inflammation. Metabolites such as SCFAs (acetate, propionate, and butyrate) interact with G-protein coupled receptors to regulate lipid metabolism and promote the browning of white adipose tissue (WAT), thus enhancing thermogenesis and energy expenditure. However, LPS contributes to insulin resistance and fat accumulation, highlighting the dual roles of these microbial metabolites in both supporting and disrupting metabolic function. Therapeutic interventions targeting gut microbiota, such as promoting WAT browning and activating brown adipose tissue (BAT), hold promise for obesity management. However, personalized approaches are necessary due to individual microbiome variability. Further research is essential to translate these insights into microbiota-based clinical therapies.

Milk phospholipid-coated lipid droplets modulate the infant gut microbiota and metabolome influencing weight gain

BACKGROUND

The supramolecular structure and composition of milk fat globules in breast milk is complex. Lipid droplets in formula milk are typically smaller compared to human milk and differ in their lipid and protein composition. These droplets play an important role in gut and immune maturation, and their components possess antimicrobial and antiviral properties. Here, the influence of a concept infant formula (IF) containing large milk phospholipid-coated lipid droplets on the maturation of the infant microbiota, metabolome, and weight gain in the first year of life was investigated.

RESULTS

Formula-fed infants were randomized to receive either a standard IF (Control) or a Test formula containing large milk phospholipid-coated lipid droplets (Test) until 17 weeks of age. A breast-fed Reference group was also investigated. At 3 months of age, several taxa identified as opportunistic pathogens (e.g., Enterobacter, Klebsiella, Enterococcus, Streptococcus) were less abundant in the Test stools compared to Control, while an enrichment of the butyrate-producing Ruminococcaceae and Lachnospiraceae was observed. These findings indicate that the Test formula resulted in gut microbiota maturation trajectories more comparable to healthy breast-fed infants. This was accompanied by variation in several fecal and plasma metabolites at 3 months of age related to gut microbial metabolism including bile acids, hippurate, phenylacetylglycine, trimethylamine, and various lipids and fatty acids. At 12 months, measures of subcutaneous fat and body mass index (BMI) were significantly higher in infants receiving standard IF compared to those receiving breast milk. However, this weight gain and adiposity was attenuated in the Test group infants.

CONCLUSIONS

The presence of large phospholipid-coated lipid droplets in formula milk positively influenced the development of the infants' gut microbiota, their metabolomic profiles, and their body composition to more closely resemble breast-fed infants compared to standard IF. These droplets may further enhance the restriction of pathogenic bacteria seen with standard infant formula and suggest a potential impact on infant metabolic programming that may contribute to physiological development. Video Abstract.

A Two-Phage Cocktail Modulates Gut Microbiota Composition and Metabolic Profiles in an Ex Vivo Colon Model

Bacteriophage therapy is a promising approach for targeting antibiotic-resistant bacteria and modulating gut microbiota in metabolic diseases such as obesity. This study evaluated the impact of a two-phage cocktail on an ex vivo colonic simulation model of gut microbiota derived from obese individuals, both in its normalized state and after enrichment with Enterobacter cloacae, an obesity-related bacteria. Microbiological analyses confirmed that the phage cocktail remained active throughout the colonic regions over three digestion cycles and effectively reduced enterobacterial populations in the enriched microbiota. Metabarcoding of the 16S rRNA gene revealed that phage therapy did not significantly alter the abundance of dominant genera, but selectively reduced E. cloacae across all colonic regions. Alpha diversity was significantly affected only in the enriched microbiota, while beta diversity analysis indicated significant compositional shifts during therapy, with reduced dispersion in the final treatment stage. Short-chain fatty acid profiling demonstrated region- and group-specific metabolic responses, with increased lactic and butyric acid concentrations in the ascending colon of the enriched microbiota following phage treatment. This study provides the first ex vivo evidence that a two-phage cocktail can selectively eliminate E. cloacae while preserving overall microbiota structure and functionality. These findings establish a foundation for future in vivo studies exploring the role of phage therapy in reshaping gut microbial communities and metabolic profiles, highlighting its potential as a precision tool for managing gut dysbiosis in metabolic disorders.

The role of gut microbiota in predicting the weight loss following laparoscopic sleeve gastrectomy

Background

Laparoscopic sleeve gastrectomy (LSG) has emerged as a highly effective intervention in the management of obesity. While there has been a recent surge in research exploring the relationship between obesity and gut microbiota, the association between gut microbiota and LSG remains relatively underexplored. This study aimed to investigate the relationship between gut microbiota and both early and later effects of LSG.

Methods

In this retrospective study, clinical characteristics and preoperative fecal samples were collected from 52 individuals who underwent LSG. Using 16S rRNA gene sequencing, we compared the community composition, alpha diversity, and beta diversity of gut microbiota between patients who experienced efficient weight loss and those who did not. Additionally, comprehensive and correlation analyses were performed to identify potential associations between specific microbial taxa and LSG outcomes.

Results

The abundances of gut microbiota in patients who experienced efficient weight loss and those who experienced general weight loss were comparable. However, the influence of gut microbiota on the efficacy of weight loss is dynamic. Specifically, the Fusobacteriota phylum significantly contributed to the early curative effects of LSG, while Actinobacteriota had a greater impact on the late curative effects. Additionally, Proteobacteria were found to mediate long-term efficacy through complex mechanisms.

Conclusion

This study analyzed the preoperative gut microbiota signature to predict the efficacy of LSG, potentially offering valuable insights for clinical applications. Preoperative assessment of gut microbiota profiles could assist patients in their decision-making processes, particularly regarding the potential outcomes of LSG and the long-term impact of the procedure on their health.

Probiotic interventions with highly acid-tolerant Levilactobacillus brevis strains improve lipid metabolism and gut microbial balance in obese mice

Many studies have shown that specific lactic acid bacteria (LAB) strains can delay obesity, offering a viable alternative to medications and surgeries. However, the mining and development of highly effective LAB strains for obesity control is still limited. In this study, the naturally highly acid-tolerant and gamma-aminobutyric acid-producing Levilactobacillus brevis D17 and its glnR deletion strain were used to investigate their anti-obesity effects. In an 8-week mouse experiment, L. brevis D17 and its glnR-deletion strain D17ΔglnR significantly reduced weight gain by 28.4% and 29.1%, respectively, improving abnormal serum indicators and glucose metabolism caused by a high-fat diet. Furthermore, L. brevis D17 and its glnR-deletion strain D17ΔglnR successfully colonized in the gut. Both D17 and D17ΔglnR interventions significantly restored the relative abundance of Muribaculaceae, Ileibacterium valens, Lactobacillus, Faecalibaculum, Bifidobacterium globosum, Akkermansia muciniphila, and Romboutsia ilealis, whereas they significantly reduced potentially harmful bacteria like Leptogranulimonas, Flintibacter, and Alistipes. Additionally, L. brevis intervention effectively decreased the levels of primary bile acids and increased secondary bile acids in the gut, thus balancing bile acid metabolism. The transcriptional analysis suggested that D17 and D17ΔglnR interventions may activate the AMPK signaling pathway in the liver to inhibit lipogenesis, activate the cAMP pathway to promote lipolysis, and inhibit pro-inflammatory macrophage infiltration to block inflammatory responses. These results indicate that L. brevis D17 and its glnR-deletion mutant strain D17ΔglnR show great potential in combating obesity. Moreover, these results also provide insights into the underlying mechanism behind their anti-obesity properties.

Dietary Influences on Gut Microbiota and Their Role in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major contributor to liver-related morbidity, cardiovascular disease, and metabolic complications. Lifestyle interventions, including diet and exercise, are first line in treating MASLD. Dietary approaches such as the low-glycemic-index Mediterranean diet, the ketogenic diet, intermittent fasting, and high fiber diets have demonstrated potential in addressing the metabolic dysfunction underlying this condition. The development and progression of MASLD are closely associated with taxonomic shifts in gut microbial communities, a relationship well-documented in the literature. Given the importance of diet as a primary treatment for MASLD, it is important to understand how gut microbiota and their metabolic byproducts mediate favorable outcomes induced by healthy dietary patterns. Conversely, microbiota changes conferred by unhealthy dietary patterns such as the Western diet may induce dysbiosis and influence steatotic liver disease through promoting hepatic inflammation, up-regulating lipogenesis, dysregulating bile acid metabolism, increasing insulin resistance, and causing oxidative damage in hepatocytes. Although emerging evidence has identified links between diet, microbiota, and development of MASLD, significant gaps remain in understanding specific microbial roles, metabolite pathways, host interactions, and causal relationships. Therefore, this review aims to provide mechanistic insights into the role of microbiota-mediated processes through the analysis of both healthy and unhealthy dietary patterns and their contribution to MASLD pathophysiology. By better elucidating the interplay between dietary nutrients, microbiota-mediated processes, and the onset and progression of steatotic liver disease, this work aims to identify new opportunities for targeted dietary interventions to treat MASLD efficiently.

Targeting Non-Alcoholic Fatty Liver Disease with Hawthorn Ethanol Extract (HEE): A Comprehensive Examination of Hepatic Lipid Reduction and Gut Microbiota Modulation

Recent studies have highlighted the lipid-lowering ability of hawthorn ethanol extract (HEE) and the role played by gut flora in the efficacy of HEE. Our study sought to explore the effects of HEE on non-alcoholic fatty liver disease (NAFLD) in normal flora and pseudo germ-free mice. The results showed that HEE effectively diminished hepatic lipid accumulation, ameliorated liver function, reduced inflammatory cytokine levels and blood lipid profiles, and regulated blood glucose levels. HEE facilitated triglyceride breakdown, suppressed fatty acid synthesis, and enhanced intestinal health by modulating the diversity of the gut microbiota and the production of short-chain fatty acids in the gut. In addition, HEE apparently helps to increase the presence of beneficial genera of bacteria, thereby influencing the composition of the gut microbiota, and the absence of gut flora affects the efficacy of HEE. These findings reveal the potential of hawthorn for the prevention and treatment of NAFLD and provide new perspectives on the study of functional plants to improve liver health.

Enterobacteriaceae in the Human Gut: Dynamics and Ecological Roles in Health and Disease

The human gut microbiota plays a crucial role in maintaining host health. Our review explores the prevalence and dynamics of Enterobacteriaceae, a bacterial family within the Proteobacteria phylum, in the human gut which represents a small fraction of the gut microbiota in healthy conditions. Even though their roles are not yet fully understood, Enterobacteriaceae and especially Escherichia coli (E. coli) play a part in creating an anaerobic environment, producing vitamins and protecting against pathogenic infections. The composition and residency of E. coli strains in the gut fluctuate among individuals and is influenced by many factors such as geography, diet and health. Dysbiosis, characterized by alterations in the microbial composition of the gut microbiota, is associated with various diseases, including obesity, inflammatory bowel diseases and metabolic disorders. A consistent pattern in dysbiosis is the expansion of Proteobacteria, particularly Enterobacteriaceae, which has been proposed as a potential marker for intestinal and extra-intestinal inflammatory diseases. Here we develop the potential mechanisms contributing to Enterobacteriaceae proliferation during dysbiosis, including changes in oxygen levels, alterations in mucosal substrates and dietary factors. Better knowledge of these mechanisms is important for developing strategies to restore a balanced gut microbiota and reduce the negative consequences of the Enterobacteriaceae bloom.

Immunology of gut microbiome and liver in non-alcoholic fatty liver disease (NAFLD): mechanisms, bacteria, and novel therapeutic targets

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Most important contributors to its development are diet and obesity. Gut microbiome's importance for immune system and inflammatory pathways more widely accepted as an important component in NAFLD and other liver diseases' pathogenesis. In this article we review potential mechanisms of microbiome alteration of local and systemic immune responses leading to NAFLD's development, and how can modulate them for the treatment. Our review mentions different immune system pathways and microorganisms regulating metabolism, liver inflammation and fibrosis. We specifically point out TLR-4 as a potential key immune pathway activated by bacterial lipopolysaccharides producing pro-inflammatory cytokines in NAFLD. Also, we discuss three endotoxin-producing strains (Enterobacter cloacae B29, Escherichia coli PY102, Klebsiella pneumoniae A7) that can promote NAFLD development via TLR4-dependent immune response activation in animal models and how they potentially contribute to disease progression in humans. Additionally, we discuss their other immune and non-immune mechanisms contributing to NAFLD pathogenesis. In the end we point out gut microbiome researches' future perspective in NAFLD as a potential new target for both diagnostic and treatment.

Urbanization associates with restricted gut microbiome diversity and delayed maturation in infants

Alterations of the microbiome are linked to increasingly common diseases such as obesity, allergy, and inflammatory bowel disease. Post-industrial lifestyles are thought to contribute to the gut microbiome alterations that cause or aggravate these diseases. Comparing communities across the industrialization spectrum can reveal associations between gut microbiome alterations and lifestyle and health, and help pinpoint which specific aspect of the post-industrial lifestyle is linked to microbiome alterations. Here, we compare the gut microbiomes of 60 mother and infant pairs from rural and urban areas of Senegal over two time points. We find that urban mothers, who were more frequently overweight, had different gut microbiome compositions than rural mothers, showing an expansion of Lachnospiraceae and Enterobacter. Urban infants, on the other hand, showed a delayed gut microbiome maturation and a higher susceptibility to infectious diseases. Thus, we identify new microbiome features associated with industrialization, whose association with disease may be further investigated.

Characteristics of Gut Microbiota in Small for Gestational Age Infants with Very Low Birth Weight

Small for gestational age (SGA) birth is associated with high rates of mortality and morbidity in preterm infants. The aim of this preliminary observational study was to investigate the difference in gut microbiota between SGA and appropriate for gestational age (AGA) preterm infants with very low birth weight (VLBW). We included 20 VLBW preterm infants (SGA, n = 10; AGA, n = 10) in this study. Stool samples were collected on days 7, 14, and 30 after birth. We performed 16S ribosomal DNA sequencing to compare microbiota composition between both groups. The SGA group exhibited a lower abundance of Klebsiella on day 14 (SGA, 0.57%; AGA, 7.42%; p = 0.037). On day 30, the SGA group exhibited a lower abundance of Klebsiella (SGA 3.76% vs. AGA 16.05%; p = 0.07) and Enterobacter (SGA 5.09% vs. AGA 27.25%; p = 0.011) than the AGA group. Beta diversity demonstrated a separation of the bacterial community structure between both groups on day 30 (p = 0.019). The present study revealed that a distinct gut microbiota profile gradually develops in SGA preterm infants with VLBW during the early days of life. The role of changes in gut microbiota structure warrants further investigation.

Gut microbial community differentially characterizes patients with nonalcoholic fatty liver disease

BACKGROUND AND AIM

Discordant reports of the signature gut microbes involved in nonalcoholic fatty liver disease (NAFLD) have hampered understanding of the pathogenesis of the disease, and thus its diagnosis. Thus, we investigated diagnostic factors and the potential mechanisms for heterogenous NAFLD based on the gut environment, including microbes and functional pathways.

METHODS

Stools from 16 biopsy-proven NAFLD patients were analyzed for bacterial taxonomy and functional pathways based on 16s rRNA gene sequencing. Data from the physical examination, serum biochemistry, and the gut environment were subjected to a decision tree classifier to identify diagnostic markers.

RESULTS

We identified two NAFLD subpopulations: those with and without a gut microbiota similar to health controls (HCs), defined as P_HC-like and P patients, respectively. Stools of P_HC-like patients were significantly populated with Enterobacteriaceae and were inferred to be rich in metabolites degraded from dicarboxylic acid sugars. Significant colonization of Prevotella was observed in the stools of P patients, in parallel with enrichment of metabolites from heme b biosynthesis and sulfate reduction. As a potential mechanism, we suggest that protoporphyrin IX and/or protoheme from Prevotella participates in hepatic injury, and that endogenous hydrogen sulfide increases serum IL-6 level in P patients. However, endotoxin-producing Enterobacteriaceae are thought to produce glycerate, triggering a peroxisome proliferator- activated receptor-alpha-mediated decrease in IL-6 level and fat accumulation in P_HC-like patients.

CONCLUSIONS

Heterogenous NAFLD subpopulations were identified, defined according to gut microbial composition and their potential underlying pathogenic mechanisms; our results raise the possibility of personalized treatment for NALFD patients.

Changes in the Mucosa-Associated Microbiome and Transcriptome across Gut Segments Are Associated with Obesity in a Metabolic Syndrome Porcine Model

Obesity is a major risk factor for metabolic syndrome, which is the most common cause of death worldwide, especially in developed countries. The link between obesity and gut mucosa-associated microbiota is unclear due to challenges associated with the collection of intestinal samples from humans.

Effects of Low-Carbohydrate Diet and Exercise Training on Gut Microbiota

Objective

This study was aimed to evaluate the effects of low-carbohydrate diet (LC) and incorporated high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on gut microbiota, and the associations between changes in gut microbiota and cardiometabolic health-related profiles.

Methods

Fifty overweight/obese Chinese females (age 22.2 ± 3.3 years, body mass index 25.1 ± 3.1 kg/m–2) were randomized to the groups of LC, LC and HIIT (LC-HIIT, 10 repetitions of 6-s sprints and 9-s rest), and LC and MICT group (LC-MICT, cycling at 50–60% V̇O2peak for 30 min). The LC-HIIT and LC-MICT experienced 20 training sessions over 4 weeks.

Results

The 4-week LC intervention with/without additional training failed to change the Shannon, Chao 1, and Simpson indexes (p > 0.05), LC increased Phascolarctobacterium genus, and LC-HIIT reduced Bifidobacterium genus after intervention (p < 0.05). Groups with extra exercise training increased short-chain fatty acid-producing Blautia genus (p < 0.05) and reduced type 2 diabetes-related genus Alistipes (p < 0.05) compared to LC. Sutterella (r = −0.335) and Enterobacter (r = 0.334) were associated with changes in body composition (p < 0.05). Changes in Ruminococcus, Eubacterium, and Roseburia genera were positively associated with blood pressure (BP) changes (r = 0.392–0.445, p < 0.05), whereas the changes in Bacteroides, Faecalibacterium, and Parabacteroides genera were negatively associated with BP changes (r = −0.567 to −0.362, p < 0.05).

Conclusion

LC intervention did not change the α-diversity and overall structure of gut microbiota. Combining LC with exercise training may have additional benefits on gut physiology. Specific microbial genera were associated with LC- and exercise-induced regulation of cardiometabolic health.

Gut microbiota and gestational Diabetes Mellitus: A systematic review

BACKGROUND

Gestational Diabetes Mellitus (GDM) is one of the most prevalent complications of pregnancy and can cause adverse maternal and fetal outcomes. The maternal gut microbiota is involved in several metabolic functions, but it is not yet known its role in GDM physiopathology. This study aims to review the role of gut microbiota in pregnancies that evolved with GDM.

METHODS

Systematic search of the PubMed, Embase, and Scopus databases was performed to identify articles published until 18th August 2021 involving the assessment of gut microbiota in pregnancy.

RESULTS

A total of 23 articles were selected for this review. Seventeen studies investigated differences in the gut microbiota of healthy and GDM pregnant women and showed differences in alfa and beta diversity. Six prospective studies found that microbiota changes during pregnancy and showed that some particularities in the microbiome in are associated with the risk of GDM.

CONCLUSION

This systematic review showed that there is a relationship between intestinal microbiota and GDM. Gut microbiota could be a biomarker for early detection of GDM and could be considered a potential target for modification to reduce the risk of GDM.

Gut Microbiota: Novel Therapeutic Target of Ginsenosides for the Treatment of Obesity and Its Complications

Obesity, generally characterized by excessive lipid accumulation, is a metabolic threat worldwide due to its rapid growth in global prevalence. Ginsenosides are crucial components derived from natural plants that can confer metabolic benefits for obese patients. Considering the low bioavailability and degradable properties of ginsenosides in vivo, it should be admitted that the mechanism of ginsenosides on anti-obesity contribution is still obscure. Recently, studies have indicated that ginsenoside intervention has beneficial metabolic effects on obesity and its complications because it allows for the correction of gut microbiota dysbiosis and regulates the secretion of related endogenous metabolites. In this review, we summarize the role of gut microbiota in the pathogenetic process of obesity, and explore the mechanism of ginsenosides for ameliorating obesity, which can modulate the composition of gut microbiota by improving the metabolism of intestinal endogenous substances and alleviating the level of inflammation. Ginsenosides are expected to become a promising anti-obesity medical intervention in the foreseeable clinical settings.

The Effects of Erchen Decoction on Gut Microbiota and Lipid Metabolism Disorders in Zucker Diabetic Fatty Rats

Obesity is a chronic metabolic disease caused by genetic and environmental factors that has become a serious global health problem. There is evidence that gut microbiota is closely related to the occurrence and development of obesity. Erchen Decoction (ECD), a traditional Chinese medicine, has been widely used for clinical treatment and basic research of obesity and related metabolic diseases in recent years. It can significantly improve insulin resistance (IR) and lipid metabolism disorders. However, there is no microbiological study on its metabolic regulation. In this study, we investigated the effects of ECD on obesity, especially lipid metabolism and the composition and function of gut microbiota in Zucker diabetic fatty (ZDF) rats, and explored the correlation between the biomarkers of gut microbiota and metabolite and host phenotype. The results showed that ECD could reduce body weight, improve IR and lipid metabolism, and reduce the concentration of free fatty acids (FFA) released from white adipose tissue (WAT) due to excessive lipolysis by interfering with the insulin receptor substrate 1 (IRS1)/protein kinase B (AKT)/protein kinase A (PKA)/hormone-sensitive triglyceride lipase (HSL) signaling pathway in ZDF rats. Additionally, ECD gradually adjusted the overall structure of changed gut microbiota, reversed the relative abundance of six genera, and changed the function of gut microbiota by reducing the content of propionic acid, a metabolite of gut microbiota, in ZDF rats. A potentially close relationship between biomarkers, especially Prevotella, Blautia, and Holdemania, propionic acid and host phenotypes were demonstrated through correlation analysis. The results suggested that the beneficial effects of ECD on obesity, especially lipid metabolism disorders, are related to the regulation of gut microbiota in ZDF rats. This provides a basis for further research on the mechanism and clinical application of ECD to improve obesity via gut microbiota.

Comparison of overfeeding effects on gut physiology and microbiota in two goose breeds

To have a better understanding of how the “gut–liver axis” mediates the lipid deposition in the liver, a comparison of overfeeding influence on intestine physiology and microbiota between Gang Goose and Tianfu Meat Goose was performed in this study. After force-feeding, compared with Gang Goose, Tianfu Meat Goose had better fat storage capacity in liver (397.94 vs. 166.54 for foie gras weight (g), P < 0.05; 6.37 vs. 2.92% for the ratio of liver to body, P < 0.05; 60.01 vs. 46.64% for fat content, P < 0.05) and the less subcutaneous adipose tissue weight (1240.96 g vs. 1440.46 g, P < 0.05). After force-feeding, the digestion–absorption capacity of Tianfu Meat Goose was higher than that of Gang Goose (5.56 vs. 3.64 and 4.63 vs. 3.68 for the ratio of villus height to crypt depth in duodenum and ileum, respectively, P < 0.05; 1394.96 vs. 782.59 and 1314.76 vs. 766.17 for the invertase activity (U/mg-prot), in duodenum and ileum, respectively, P < 0.05; 6038.36 vs. 3088.29 and 4645.29 vs. 3927.61 for the activity of maltase (U/mg-prot), in duodenum and ileum, respectively, P < 0.05). Force-feeding decreased the gene expression of Escherichia coli in the ileum of Tianfu Meat Goose; force-feeding increased the number of gut microbiota Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction band in Tianfu Meat Goose and decreased the number in Gang Goose. In conclusion, compared with Gang Goose, the lipid deposition in the liver and the intestine digestion–absorption capacity and stability were higher in Tianfu Meat Goose. Thereby, Tianfu Meat Goose is the better breed for foie gras production for prolonged force-feeding; Gang Goose possesses better fat storage capacity in subcutaneous adipose tissue. However, Gang Goose has lower gut stability responding to force-feeding, so Gang Goose is suited to force-feeding in a short time to gain the body weight and subcutaneous fat as an overfed duck for roast duck.

Homeostasis of gut microbiota protects against polychlorinated biphenyl 126-induced metabolic dysfunction in liver of mice

Polychlorinated biphenyls (PCBs) exposure is closely associated with the prevalence of metabolic diseases, including fatty liver and dyslipidemia. Emerging literature suggests that disturbance of gut microbiota is related to PCB126-induced metabolic disorders. However, the causal role of dysbiosis in PCB126-induced fatty liver is still unknown. To clarify the role of the gut microbiome in the detoxification of PCB126 in intestine or PCB126-induced toxicity in liver, mice were administrated with drinking water containing antibiotics (ampicillin, vancomycin, neomycin, and metronidazole) or Inulin. We showed that PCB126 resulted in significant hepatic lipid accumulation, inflammation, and fibrosis. PCB126, Antibiotics, and Inulin significantly affected the structure and shifted community membership of gut microbiome. 7 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways at level 2 and 39 KEGG pathways at level 3 were significantly affected. Antibiotics alleviated PCB126-induced fibrosis in the liver but increased inflammation. Inulin treatment ameliorated both inflammation and fibrosis in the liver of PCB126-treated mice. Neither Antibiotics nor Inulin had significant effect on PCB126-induced hepatic steatosis. The more specific intervention of gut microbiota is needed to alleviate PCB126-induced fatty liver. These data demonstrate that homeostasis of gut microbiota is critical for the defense against PCB126 toxicity and dysbiosis plays a fundamental role in the development of inflammation and fibrosis in liver of PCB126-treated mice.

Supplemental Clostridium butyricum Modulates Lipid Metabolism Through Shaping Gut Microbiota and Bile Acid Profile of Aged Laying Hens

Probiotic Clostridium butyricum could affect lipid metabolism in broilers. However, it is not clear whether C. butyricum could improve lipid metabolism through shaping gut microbiota and bile acid (BA) profile of laying hens. We aimed to evaluate the contributions of gut microbiota and BA profile to the potential effect of C. butyricum on lipid metabolism of aged laying hens. A total of 192 60-week-old Hy-Line Brown laying hens were divided into two groups (eight replicates per group). Birds were fed a basal diet supplemented with 0 or 2.7 g/kg C. butyricum (1.0 × 10⁹ CFU/g). Samples were collected at the end of week 8 of the experiment. The results showed elevated (P < 0.05) concentrations of glucagon-like peptide 1, insulin and thyroid hormones in serum responded to C. butyricum addition, which also decreased (P < 0.05) hepatic free fatty acids contents, as well as increased (P < 0.05) the expression of hepatic acyl-CoA oxidase, farnesoid X receptor (FXR) and PPARα. C. butyricum addition increased (P < 0.05) Bacteroidetes abundance but tended to decrease (P < 0.10) Firmicutes abundance in the ileum. Besides, C. butyricum addition resulted in higher (P < 0.05) abundances of Clostridia (Clostridiales) and Prevotellaceae, concurrent with an increasing trend (P < 0.10) of Bifidobacteriaceae abundance and decreased the abundances of several harmful bacteria such as Klebsiella (P < 0.05). Regarding ileal BA profile, there was a reduced (P < 0.05) content of tauro-α-muricholic acid, increased (P < 0.05) contents of tauroursodeoxycholic acid and lithocholic acid, along with increasing trends (P < 0.10) of glycochenodeoxycholic acid and hyodeoxycholic acid contents due to C. butyricum addition, which also increased (P < 0.05) ileal FXR expression. Collectively, supplemental C. butyricum accelerated hepatic fatty acid oxidation, and shaped gut microbiota and BA profile, thus reducing fat deposition in the liver of aged laying hens.

Ranitidine and finasteride inhibit the synthesis and release of trimethylamine N-oxide and mitigates its cardiovascular and renal damage through modulating gut microbiota

Trimethylamine N-oxide (TMAO) leads to the development of cardiovascular and chronic kidney diseases, but there are currently no potent drugs that inhibit the production or toxicity of TMAO. In this study, high-fat diet-fed ApoE-/- mice were treated with finasteride, ranitidine, and andrioe. Subsequently, the distribution and quantity of gut microbiota in the faeces of the mice in each group were analysed using 16S rRNA sequencing of the V3+V4 regions. Pathological examination confirmed that both ranitidine and finasteride reduced atherosclerosis and renal damage in mice. HPLC analysis also indicated that ranitidine and finasteride significantly reduced the synthesis of TMAO and the TMAO precursor delta-Valerobetaine in their livers. The 16S rRNA sequencing showed that all 3 drugs significantly increased the richness and diversity of gut microbiota in the model mice. Bioinformatic analysis revealed that the faeces of mice treated with ranitidine and finasteride, had significant increases in the number of microbes in the families g_Helicobacter, f_Desulfovibrionaceae, Mucispirillum_schaedleri_ASF457, and g_Blautia, whereas the relative abundances of microbes in the families Enterobacter_sp._IPC1-8 and g_Bacteroides were significantly reduced. The microbiota metabolic pathways, such as nucleotide and cofactor and vitamin metabolism were also significantly increased, whereas the activities of metabolic signalling pathways related to glycan biosynthesis and metabolism and cardiovascular diseases were significantly reduced. Therefore, our study indicates that in addition to their known pharmacological effects, ranitidine and finasteride also exhibit potential cardiovascular and renal protective effects. They inhibit the synthesis and metabolism of TMAO and delay the deposition of lipids and endotoxins through improving the composition of the gut microbiota.

Phenothiazines Enhance the Hypothermic Preservation of Liver Grafts: A Pilot in Vitro Study

In vitro liver conservation is an issue of ongoing critical importance in graft transplantation. In this study, we investigated the possibility of augmenting the standard pre-transplant liver conservation protocol (University of Wisconsin (UW) cold solution) with the phenothiazines chlorpromazine and promethazine. Livers from male Sprague-Dawley rats were preserved either in UW solution alone, or in UW solution plus either 2.4, 3.6, or 4.8 mg chlorpromazine and promethazine (C+P, 1:1). The extent of liver injury following preservation was determined by alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, the ratio of AST/ALT, morphological changes as assessed by hematoxylin-eosin staining, apoptotic cell death as determined by ELISA, and by expression of the apoptotic regulatory proteins BAX and Bcl-2. Levels of glucose (GLU) and lactate dehydrogenase (LDH) in the preservation liquid were determined at 3, 12, and 24 h after incubation to assess glucose metabolism. Oxidative stress was assessed by levels of superoxide dismutase (SOD), reactive oxygen species (ROS), and malondialdehyde (MDA), and inflammatory cytokine expression was evaluated with Western blotting. C+P augmentation induced significant reductions in ALT and AST activities; the AST/ALT ratio; as well as in cellular swelling, vacuolar degeneration, apoptosis, and BAX expression. These changes were associated with lowered levels of GLU and LDH; decreased expression of SOD, MDA, ROS, TNF-α, and IL-1β; and increased expression of Bcl-2. We conclude that C+P augments hypothermic preservation of liver tissue by protecting hepatocytes from ischemia-induced oxidative stress and metabolic dysfunction. This result provides a basis for improvement of the current preservation strategy, and thus for the development of a more effective graft conservation method.

Role of intestinal microecology in the regulation of energy metabolism by dietary polyphenols and their metabolites

Background

Polyphenols are a class of plant secondary metabolites with a variety of physiological functions. Polyphenols and their intestinal metabolites could greatly affect host energy metabolism via multiple mechanisms.

Objective

The objective of this review was to elaborate the role of intestinal microecology in the regulatory effects of dietary polyphenols and their metabolites on energy metabolism.

Methods

In this review, we illustrated the potential mechanisms of energy metabolism regulated by the crosstalk between polyphenols and intestinal microecology including intestinal microbiota, intestinal epithelial cells, and mucosal immune system.

Results

Polyphenols can selectively regulate the growth of susceptible microorganisms (eg. reducing the ratio of Firmicutes to Bacteroides, promoting the growth of beneficial bacteria and inhibiting pathogenic bacteria) as well as alter bacterial enzyme activity. Moreover, polyphenols can influence the absorption and secretion of intestinal epithelial cells, and alter the intestinal mucosal immune system.

Conclusion

The intestinal microecology play a crucial role for the regulation of energy metabolism by dietary polyphenols.

Regulation of Microbiota by Vitamin D Receptor: A Nuclear Weapon in Metabolic Diseases

Metabolic syndrome is a multi-faceted disease. The microbiota, as a newly discovered organ, contributes to the pathogenesis and progression of metabolic syndrome. Recent studies have demonstrated that nuclear receptors play critical roles in metabolic diseases. In the current review, we discuss the general role of the microbiome in health and metabolic syndrome. We summarize the functions of the nuclear receptor vitamin D receptor (VDR) in metabolism. The focus of this review is the novel roles of vitamin D/VDR signaling in regulating inflammation and the microbiome, especially in obesity. Furthermore, we extend our discussion of potential gut-liver axis mediated by VDR signaling and microbiota in obesity. Finally, we discuss the potential clinical application of probiotics and fecal microbiota transplantation in prevention and treatment of metabolic syndrome. Insights into nuclear receptors in metabolism and metabolic diseases will allow us to develop new strategies for fighting metabolic diseases.