Stearic acid prevent alcohol-induced liver damage by regulating the gut microbiota

Adherence to the planetary health diet index and metabolic dysfunction-associated steatotic liver disease: a cross-sectional study

Backgrounds

Adherence to the Planetary Health Diet Index (PHDI) has been shown to benefit both individual health and the planet. However, its impact on Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) remains unclear. This study aimed to investigate the relationship between PHDI adherence and the MASLD risk.

Methods

We analyzed a cohort of 15,865 adults (aged ≥18 years) using data from the National Health and Nutrition Examination Survey (NHANES, 2005-2018). The PHDI was derived from 24-h dietary assessments and comprised the scores of 15 food groups. Multivariate logistic regression was used to investigate the association between PHDI and MASLD, while restricted cubic spline (RCS) regression and threshold analysis were employed to explore potential non-linear relationship. Subgroup analyses were conducted to assess the influence of various demographic and clinical characteristics on the observed associations. Mediation analysis was performed to evaluate the indirect effect of PHDI on MASLD, and weighted quantile sum (WQS) regression was used to assess the influence of individual PHDI nutrients on MASLD.

Results

Among the cohort, 6,125 individuals were diagnosed with MASLD. Multivariate logistic regression revealed that a higher quintile of PHDI was significantly associated with reduced MASLD risk in the fully adjusted model (OR = 0.610, 95%CI 0.508-0.733, p < 0.001). Notably, nonlinear relationships between PHDI and MASLD risk were observed through RCS analysis (p = 0.002). Subgroup analyses indicated that PHDI was particularly effective in reducing MASLD risk among females, those with higher education attainment, and those living with a partner. WQS regression identified saturated fatty acids as the most significant factor contributing to MASLD risk (weight = 0.313). Additionally, BMI and waist circumference (81.47 and 87.66%, respectively) partially mediated the association between PHDI and MASLD risk, suggesting that the effect of PHDI on MASLD operates, in part, through its impact on BMI and waist circumference. The association between PHDI and MASLD remained robust across multiple sensitivity analyses.

Conclusion

Our findings indicate that adherence to PHDI is linked to a lower risk of MASLD, providing crucial insights for strategies aimed at mitigating the MASLD epidemic while simultaneously fostering environmental sustainability.

Ultrasound-assisted preparation of sweet corn cob polysaccharide selenium nanoparticles alleviates symptoms of chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is a long-term chronic condition that predisposes individuals to oxidative stress and disruption of the gut microbiota. In this study, sweet corn cob polysaccharide selenium nanoparticles (U-SCPSeNPs) with relatively small particle sizes were prepared using an ultrasound-assisted method. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV-Vis) were used to characterize the U-SCPSeNPs and determine the monosaccharide composition of the U-SCPSeNPs. The U-SCPSeNPs were used to improve the CFS of the mice. The results showed that the ultrasound-assisted method reduced the particle size of the SeNPs, and U-SCPSeNPs with a particle size of 76.74 nm and a selenium content of 186.83 ± 7.80 mg g-1 were obtained at an ultrasonication time of 40 min. Sweet corn cob (SCP) bound to the SeNPs through hydrogen bonding. In terms of energy production, the production capacity of Na+-K+-ATP, Mg2+-ATP, and Ca2+-ATP was enhanced by U-SCPSeSCP in CFS mice; In terms of oxidative stress, the levels of SOD and MDA were decreased and CAT and GSH-Px were increased by SCPSeSCP. U-SCPSeSCP improved the diversity and abundance of the gut microbiota in CFS mice, and decreasing the relative abundance of Firmicutes increased the relative abundance of Bacteroidota at the phylum level. This study provides a reference for synthesizing polysaccharide SeNPs and assessing the ability of U-SCPSeNPs to alleviate CFS.

Stearic acid metabolism in human health and disease

Named after the Greek term for "hard fat", stearic acid has gradually entered people's field of vision. As an important component of various physiological cellular functions, stearic acid plays a regulatory role in diverse aspects of energy metabolism and signal transduction. Its applications range from serving as a bodily energy source to participating in endogenous biosynthesis. Similar to palmitate, stearic acid serves as a primary substrate for the stearoyl coenzyme A desaturase, which catalyzes the conversion of stearate to oleate and is involved in the synthesis of triglyceride and other complex lipids. Additionally, stearic acid functions as a vital signaling molecule in pathological processes such as cardiovascular diseases, diabetes development, liver injury and even nervous system disorders. Therefore, we conduct a comprehensive review of stearic acid, summarizing its role in various diseases and attempting to provide a systematic overview of its homeostasis, physiological functions, and pathological process. From a medical standpoint, we also explore potential applications and discuss stearic acid as a potential therapeutic target for the treatment of human diseases.

Quorum quenching effects of linoleic and stearic acids on outer membrane vesicle-mediated virulence in Chromobacterium violaceum

Chromobacterium violaceum is a pathogenic bacterium that can infect humans and animals, yet the role of its outer membrane vesicles (OMVs) in mediating pathogenicity remains underexplored. This study evaluated the effects of linoleic acid (LA) and stearic acid (SA) on quorum sensing (QS)-mediated violacein production, biofilm formation, and OMV biogenesis in C. violaceum. Our findings revealed that 2 mM LA and 1 mM SA effectively quench QS, leading to a significant reduction in violacein production, biofilm formation, and OMV biogenesis. Gene expression analysis confirmed the downregulation of QS-related genes, including cviI, cviR, vioA, vioB, and vioC, in fatty acid-treated C. violaceum. Additionally, we assessed the antimicrobial activity of C. violaceum-derived OMVs on Rhizobium sp., a PGPR and observed a marked reduction in bactericidal activity in the treated OMVs. This study suggests that LA and SA have potential as anti-infective agents to mitigate OMV-mediated virulence and combat antibiotic resistance in pathogens.

Simultaneous Quantification of 66 Compounds in Two Tibetan Codonopsis Species Reveals Four Chemical Features by Database-Enabled UHPLC-Q-Orbitrap-MS/MS Analysis

Codonopsis canescens Nannf. (CoC) and Codonopsis nervosa Nannf. (CoN) are two traditional Tibetan medicinal herbs (Zangdangshen), which have been widely used in the treatment of various diseases. In this study, their aerial and underground parts were systematically analyzed using database-enabled UHPLC-Q-Orbitrap-MS/MS technology. This technology introduced three adduct ions, [M - H]-, [M + H]+, and [M + NH4]+, to putatively identify a total of 66 compounds. During the putative identification, at least 16 isomers were successfully differentiated, such as isochlorogenic acid A vs. isochlorogenic acid B vs. isochlorogenic acid C. Thereafter, all these identified compounds were further quantified for their contents based on a linear regression method. Their contents were observed to vary from 0.00 to 39,127.03 µg/g. Through multiple comparisons of these quantification results, the study found the following four chemical features: (1) Four sesquiterpenes (especially atractylenolide III) enriched mainly in CoC and rarely in CoN; (2) four quinic acid derivatives were abundant in the aerial part of two species; (3) sixteen flavonoids (particularly diosmetin and chrysoeriol) showed higher content in CoC than in CoN; and (4) lobetyolin was ubiquitously distributed in four parts of both CoC and CoN. Based on these features and the relevant principles, four compounds (lobetyolin, atractylenolide III, diosmetin, and chrysoeriol) are recommended as the quality markers of two Tibetan Codonopsis species. All these findings can facilitate the sustainable development and quality control of the two traditional Tibetan medicinal herbs.

Genetically predicted gut bacteria, circulating bacteria-associated metabolites and pancreatic ductal adenocarcinoma: a Mendelian randomisation study

Pancreatic ductal adenocarcinoma (PDAC) has high mortality and rising incidence rates. Recent data indicate that the gut microbiome and associated metabolites may play a role in the development of PDAC. To complement and inform observational studies, we investigated associations of genetically predicted abundances of individual gut bacteria and genetically predicted circulating concentrations of microbiome-associated metabolites with PDAC using Mendelian randomisation (MR). Gut microbiome-associated metabolites were identified through a comprehensive search of Pubmed, Exposome Explorer and Human Metabolome Database. Single Nucleotide Polymorphisms (SNPs) associated by Genome-Wide Association Studies (GWAS) with circulating levels of 109 of these metabolites were collated from Pubmed and the GWAS catalogue. SNPs for 119 taxonomically defined gut genera were selected from a meta-analysis performed by the MiBioGen consortium. Two-sample MR was conducted using GWAS summary statistics from the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case-Control Consortium (PanC4), including a total of 8,769 cases and 7,055 controls. Inverse variance-weighted MR analyses were performed along with sensitivity analyses to assess potential violations of MR assumptions. Nominally significant associations were noted for genetically predicted circulating concentrations of mannitol (odds ratio per standard deviation [ORSD] = 0.97; 95% confidence interval [CI]: 0.95-0.99, p = 0.006), methionine (ORSD= 0.97; 95%CI: 0.94-1.00, p = 0.031), stearic acid (ORSD= 0.93; 95%CI: 0.87-0.99, p = 0.027), carnitine = (ORSD=1.01; 95% CI: 1.00-1.03, p = 0.027), hippuric acid (ORSD= 1.02; 95%CI: 1.00-1.04, p = 0.038) and 3-methylhistidine (ORSD= 1.05; 95%CI: 1.01-1.10, p = 0.02). Two gut microbiome genera were associated with reduced PDAC risk; Clostridium sensu stricto 1 (OR: 0.88; 95%CI: 0.78-0.99, p = 0.027) and Romboutsia (OR: 0.87; 95%CI: 0.80-0.96, p = 0.004). These results, though based only on genetically predicted gut microbiome characteristics and circulating bacteria-related metabolite concentrations, provide evidence for causal associations with pancreatic carcinogenesis.

Beneficial effects of Dendrobium officinale National Herbal Drink on metabolic immune crosstalk via regulate SCFAs-Th17/Treg

BACKGROUND

The development of gut-liver axis metabolic immune crosstalk is intimately associated with intestinal barrier disorder, intestinal SCFAs-Th17/Treg immunological imbalance, and disorders of the gut microbiota. Prior research has discovered that Dendrobium officinale National Herbal Drink (NHD), a traditional Chinese medicine drink with enhanced immunity, may enhance the immunological response in animals with impaired immune systems brought on by cyclophosphamide by repairing intestinal barrier function and controlling turbulence in the gut microbiota. However, whether NHD can further improve the gut-liver axis metabolic immune crosstalk and its related mechanisms need to be systematically studied.

OBJECTIVES

The purpose of this study is to clarify the function and mechanism of NHD in enhancing the gut-liver axis metabolic immunological crosstalk brought on by excessive alcohol intake.

METHODS

In this work, we set up a mouse model to analyze the metabolic and immunological crosstalk involving the gut-liver axis across 7 weeks of continuous, excessive drinking. At the same time, high and low doses (20,10 ml/kg) of NHD were given by gavage. The effect of NHD on improving the metabolism of gut-liver axis was evaluated by blood lipid, liver lipid deposition, liver function and intestinal pathophysiology. By measuring serum immunological indices, intestinal barrier, and intestinal immune barrier, the impact of NHD on enhancing immune and intestinal barrier function was assessed. Furthermore, immunohistochemistry, immunofluorescence, 16S rRNA, Western blot, q-PCR and other methods were used to detect gut microbiota, SCFAs-GPR41/43 pathway, intestinal Th17/Treg immune cells and PPAR-α-NPC1L1/SREBP1 pathway to elucidate the mechanism by which NHD enhances the gut-liver axis' metabolic immune crosstalk.

RESULTS

Our study demonstrated that NHD has the potential to improve the pathophysiological damage caused by gut-liver axis in model mice. NHD also ameliorated the disorder of lipid metabolism. In addition, it regulated the levels of peripheral blood T cell immunity and serum immune factors. And NHD can restore intestinal mechanical and immune barrier damage. NHD has a favorable impact on the quantity of beneficial bacteria, including uncultured_bacterium_g__norank_f__muribaculacea and uncultured_bacterium_g__Turicibacter. Additionally, it raised the model mice's levels of SCFAs (n-butyric acid, isovaleric acid, etc.). This resulted in the promotion of intestinal GPR41/43-ERK1/2 expression and the reshaping of intestinal CD4+T cell Th17/Treg homeostasis. As a consequence, colon IL-22 and IL-10 levels increased, while colon IL-17A levels decreased. Lastly, NHD raised the amount of intestinal IAP/LPS, regulated the development of PPAR-α-NPC1L1/SREBP1 pathway in gut-liver axis, and improve lipid metabolism disorder.

CONCLUSIONS

Our study found that NHD can improve the gut-liver axis metabolic immune crosstalk in model mice caused by excessive drinking. The mechanism might be connected to how NHD controls gut microbiota disorders in model mice, the activation of intestinal SCFAs-GPR41/43 pathway, the remodeling of Th17/Treg immune homeostasis of intestinal CD4+T cells, the improvement of IAP/LPS abnormality, and further mediating the PPAR-α-NPC1L1/SREBP1 pathway of lipid metabolism in gut-liver axis.

Lipidomics Investigation Reveals the Reversibility of Hepatic Injury by Silica Nanoparticles in Rats After a 6-Week Recovery Duration

Given the inevitable human exposure owing to its increasing production and utilization, the comprehensive safety evaluation of silica nanoparticles (SiNPs) has sparked concerns. Substantial evidence indicated liver damage by inhaled SiNPs. Notwithstanding, few reports focused on the persistence or reversibility of hepatic injuries, and the intricate molecular mechanisms involved remain limited. Here, rats are intratracheally instilled with SiNPs in two regimens (a 3-month exposure and a subsequent 6-week recovery after terminating SiNPs administration) to assess the hepatic effects. Nontargeted lipidomics revealed alterations in lipid metabolites as a contributor to the hepatic response and recovery effects of SiNPs. In line with the functional analysis of differential lipid metabolites, SiNPs activated oxidative stress, and induced lipid peroxidation and lipid deposition in the liver, as evidenced by the elevated hepatic levels of ROS, MDA, TC, and TG. Of note, these indicators showed great improvements after a 6-week recovery, even returning to the control levels. According to the correlation, ROC curve, and SEM analysis, 11 lipids identified as potential regulatory molecules for ameliorating liver injury by SiNPs. Collectively, the work first revealed the reversibility of SiNP-elicited hepatotoxicity from the perspective of lipidomics and offered valuable laboratory evidence and therapeutic strategy to facilitate nanosafety.

Solanum nigrum L. berries extract ameliorated the alcoholic liver injury by regulating gut microbiota, lipid metabolism, inflammation, and oxidative stress

Solanum nigrum L. (SN) berry is an edible berry containing abundant polyphenols and bioactive compounds, which possess antioxidant and antiinflammatory properties. However, the effects of SN on alcohol-induced biochemical changes in the enterohepatic axis remain unclear. In the current study, a chronic ethanol-fed mice ALD model was used to test the protective mechanisms of SN berries. Microbiota composition was determined via 16S rRNA sequencing, we found that SN berries extract (SNE) improved intestinal imbalance by reducing the Firmicutes to Bacteroides ratio, restoring the abundance of Akkermansia microbiota, and reducing the abundance of Allobaculum and Shigella. SNE restored the intestinal short-chain fatty acids content. In addition, liver transcriptome data analysis revealed that SNE primarily affected the genes involved in lipid metabolism and inflammatory responses. Furthermore, SNE ameliorated hepatic steatosis in alcohol-fed mice by activating AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), peroxisome proliferator-activated receptor α (PPAR-α). SNE reduced the expression of toll-like receptor 4 (TLR4), myeloid differentiation factor-88 (MyD88) nuclear factor kappa-B (NF-κB), which can indicate that SNE mainly adjusted LPS/TLR4/MyD88/NF-κB pathway to reduce liver inflammation. SNE enhanced hepatic antioxidant capacity by regulating NRF2-related protein expression. SNE alleviates alcoholic liver injury by regulating of gut microbiota, lipid metabolism, inflammation, and oxidative stress. This study may provide a reference for the development and utilization of SN resources.

Bifidobacterium longum S3 alleviates loperamide-induced constipation by modulating intestinal acetic acid and stearic acid levels in mice

Constipation is a major gastrointestinal (GI) symptom worldwide, with diverse causes of formation, and requires effective and safe therapeutic measures. In the present study, we used loperamide hydrochloride to establish a constipation model and assessed the effect of Bifidobacterium on constipation and its possible mechanism of relief. The results showed that B. longum S3 exerted a constipation-relieving effect primarily by improving the gut microbiota, enriching genera including Lactobacillus, Alistipes, and Ruminococcaceae UCG-007, and decreasing the bacteria Lachnospiraceae NK4B4 group. These changes may thereby increase acetic acid and stearic acid (C18:0) levels, which significantly increase the expression levels of ZO-1 and MUC-2, repair intestinal barrier damage and reduce inflammation (IL-6). Furthermore, it also inhibited oxidative stress levels (SOD and CAT), decreased the expression of water channel proteins (AQP4 and AQP8), significantly elevated the Gas, 5-HT, PGE2, and Ach levels, and reduced nNOS and VIP levels to improve the intestinal luminal transit time and fecal water content. Collectively, these changes resulted in the alleviation of constipation.

N1F(Improved-Nephropathy 1 Formula) Ameliorates Renal Interstitial Fibrosis via Inhibiting Extracellular Matrix Deposition and Regulating the FGF23/P38MAPK/Wnt Pathway

BACKGROUND

Renal fibrosis is the primary pathway in the progression of chronic kidney disease (CKD) towards end-stage renal failure. The currently used drugs currently are ineffective, and their mechanisms of action remain unclear. This study aims to investigate the nephroprotective effect of Improved-Nephropathy 1 Formula (N1F) in a rat model of unilateral ureteral obstruction (UUO) and explore the potential mechanisms of N1F-containing serum in treating TGF-ß1-induced human renal tubular epithelial cells (HK-2).

METHODS

SD rats received 2-week continuous N1F gavage starting on day 2 after UUO. HK-2 cells were pretreated with a P38MAPK inhibitor for 1 h in vitro, followed by induction of the cells with TGF-ß1 and treatment with N1F 48 h later. The chemical composition of N1F was analyzed using high-performance liquid chromatography-Q-Orbitrap high-resolution liquid mass spectrometry. Renal function was assessed by measuring serum creatinine (Scr), blood urea nitrogen (BUN) and urine protein (Upro) levels. Hematoxylin and eosin (HE) and Masson's trichrome (Masson) staining were used to evaluate the extent of renal tissue damage and fibrosis. Western blotting, immunohistochemistry, and immunofluorescence were used to detect the protein levels of relevant indices. The RNA levels of the relevant indices were detected using real-time fluorescence quantitative PCR (RT-qPCR).

RESULTS

We identified 361 chemical components in the water extract of N1F. These chemical components of N1F significantly reduced the area associated with interstitial fibrosis in the kidneys of UUO rats and the levels of serum creatinine, urea nitrogen, and urinary protein. Additionally, N1F decreased the protein levels of FGF23, Wnt1, ß-catenin and p-P38MAPK/P38MAPK, along with the expression of renalfibrosis-associated proteins, α-SMA, FN, Collagen III, and Vimentin in the renal tissues of the UUO rats, while enhancing klotho and DKK1 protein levels. In vitro experiments revealed that inhibition of P38MAPK signaling significantly suppressed the expression of proteins related to the Wnt signaling pathway, with a concomitant decrease in the expression of FGF23 and an increase in the expression of Klotho. Notably, the P38MAPK inhibitor (SB203580) had similar effects to N1F in altering the above-mentioned indices in vitro.

CONCLUSIONS

N1F may exhibit potential therapeutic efficacy against renal fibrosis by inhibiting the FGF23/P38MAPK/Wnt signaling pathway, consequently inhibiting extracellular matrix deposition due to renal injury.

Network medicine-based analysis of the hepatoprotective effects of Amomum villosum Lour. on alcoholic liver disease in rats

Alcoholic liver disease (ALD) is characterized by high morbidity and mortality, and mainly results from prolonged and excessive alcohol use. Amomum villosum Lour. (A. villosum), a well-known traditional Chinese medicine (TCM), has hepatoprotective properties. However, its ability to combat alcohol-induced liver injury has not been fully explored. The objective of this study was to investigate the hepatoprotective effects of A. villosum in a rat model of alcohol-induced liver disease, thereby establishing a scientific foundation for the potential preventive use of A. villosum in ALD. We established a Chinese liquor (Baijiu)-induced liver injury model in rats. Hematoxylin and eosin (HE) staining, in combination with biochemical tests, was used to evaluate the protective effects of A. villosum on the liver. The integration of network medicine analysis with experimental validation was used to explore the hepatoprotective effects and potential mechanisms of A. villosum in rats. Our findings showed that A. villosum ameliorated alcohol-induced changes in body weight, liver index, hepatic steatosis, inflammation, blood lipid metabolism, and liver function in rats. Network proximity analysis was employed to identify 18 potentially active ingredients of A. villosum for ALD treatment. These potentially active ingredients in the blood were further identified using mass spectrometry (MS). Our results showed that A. villosum plays a hepatoprotective role by modulating the protein levels of estrogen receptor 1 (ESR1), anti-nuclear receptor subfamily 3 group C member 1 (NR3C1), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α). In conclusion, the results of the current study suggested that A. villosum potentially exerts hepatoprotective effects on ALD in rats, possibly through regulating the protein levels of ESR1, NR3C1, IL-6, and TNF-α.

The Role of Oxidative Stress in Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies

Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD+/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1β, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.

The Contribution of Microorganisms to the Quality and Flavor Formation of Chinese Traditional Fermented Meat and Fish Products

Guizhou sour meat and sour fish, Chaoshan fish sauce, Sichuan sausage and bacon, Cantonese sausage, Jinhua ham, and Xinjiang air-dried beef are eight representatives of Chinese traditional fermented meat and fish products (FMFPs), which are favored by Chinese consumers due to their high nutritional value and quality. The quality of the spontaneously fermented Chinese traditional FMFP is closely correlated with microorganisms. Moreover, the dominant microorganisms are significantly different due to regional differences. The effects of microorganisms on the texture, color, flavor, nutrition, functional properties, and safety of Chinese traditional FMFPs have not been not fully described. Additionally, metabolic pathways for flavor formation of Chinese traditional FMFPs have not well been summarized. This article describes the seven characteristic Chinese traditional FMFPs and correlated dominant microorganisms in different regions of China. The effects of microorganisms on the texture, color, and flavor of Chinese traditional FMFPs are discussed. Furthermore, the metabolic pathways of microbial regulation of flavor formation in Chinese traditional FMFPs are proposed. This work provides a theoretical basis for improvement of Chinese traditional FMFPs by inoculating functional microorganisms isolated from Chinese traditional fermented foods.

The interplay between dietary fatty acids and gut microbiota influences host metabolism and hepatic steatosis

Dietary lipids can affect metabolic health through gut microbiota-mediated mechanisms, but the influence of lipid-microbiota interaction on liver steatosis is largely unknown. We investigate the impact of dietary lipids on human gut microbiota composition and the effects of microbiota-lipid interactions on steatosis in male mice. In humans, low intake of saturated fatty acids (SFA) is associated with increased microbial diversity independent of fiber intake. In mice, poorly absorbed dietary long-chain SFA, particularly stearic acid, induce a shift in bile acid profile and improved metabolism and steatosis. These benefits are dependent on the gut microbiota, as they are transmitted by microbial transfer. Diets enriched in polyunsaturated fatty acids are protective against steatosis but have minor influence on the microbiota. In summary, we find that diets enriched in poorly absorbed long-chain SFA modulate gut microbiota profiles independent of fiber intake, and this interaction is relevant to improve metabolism and decrease liver steatosis.

Helicobacter pylori infection altered gastric microbiota in patients with chronic gastritis

Objective

The present study aims to investigate the effect of Helicobacter pylori (Hp) infection on gastric mucosal microbiota in patients with chronic gastritis.

Methods

Here recruited a population of 193 patients with both chronic gastritis and positive rapid urease, including 124 patients with chronic atrophic gastritis (CAG) and 69 patients with chronic non-atrophic gastritis (nCAG). Immunoblotting was used to detect four serum Hp antibodies (UreA, UreB, VacA and CagA) to determine the types of virulent Hp-I and avirulent Hp-II infections. Gastric microbiota was profiled by 16S rRNA gene V3-V4 region, and R software was used to present the relationship between the microbial characteristics and the type of Hp infection.

Results

In the stomach of patients with Hp-positive gastritis, the dominant gastric bacterial genera included Ralstonia (23.94%), Helicobacter (20.28%), Pseudonocardia (9.99%), Mesorhizobium (9.21%), Bradyrhizobium (5.05%), and Labrys (4.75%). The proportion of Hp-I infection was significantly higher in CAG patients (91.1%) than in nCAG patients (71.0%) (P < 0.001). The gastric microbiota richness index (observed OTUs, Chao) was significantly lower in CAG patients than in nCAG patients (P <0.05). Compared with avirulent Hp-II infection, virulent Hp-I infection significantly decreased the Shannon index in CAG patients (P <0.05). In nCAG patients, Hp-I infected patients had lower abundances of several dominant gastric bacteria (Aliidiomarina, Reyranella, Halomonas, Pseudomonas, Acidovorax) than Hp-II infected patients. Meanwhile, in CAG patients, Hp-I infected patients occupied lower abundances of several dominant oral bacteria (Neisseria, Staphylococcus and Haemophilus) than Hp-II infected patients. In addition, bile reflux significantly promoted the colonization of dominant oral microbiota (Veillonella, Prevotella 7 and Rothia) in the stomach of CAG patients. There was no significant symbiotic relationship between Helicobacter bacteria and non-Helicobacter bacteria in the stomach of nCAG patients, while Helicobacter bacteria distinctly linked with the non-Helicobacter bacteria (Pseudolabrys, Ralstonia, Bradyrhizobium, Mesorhizobium and Variovorax) in CAG patients.

Conclusions

Virulent Hp infection alters the gastric microbiota, reduces microbial diversity, and enhances the symbiotic relationship between the Helicobacter bacteria and non-Helicobacter bacteria in patients with chronic gastritis. The data provides new evidence for treating Hp infection by improving the gastric microbiota.

E Se tea extract ameliorates CCl4 induced liver fibrosis via regulating Nrf2/NF-κB/TGF-β1/Smad pathway

BACKGROUND

Liver fibrosis is a crucial progress to deteriorate liver disease. E Se tea (ES) is an ethnic herbal tea in China that has various biological activities for human beings. However, the traditional application on the treatment of liver disease is not studied.

PURPOSE

This study is firstly performed to explore the chemical constituents of ES extract together with its anti-hepatic fibrosis effect and potential mechanism on CCl₄ treated mice.

STUDY DESIGN AND METHODS

The chemical constituents of ethanol-aqueous extract from ES (ESE) were analyzed by UPLC-ESI-MS/MS. The anti-hepatic fibrosis effect of ESE was determined by measuring ALT and AST activities, antioxidative indexes, inflammatory cytokines and collagen protein levels on CCl₄ treated mice. Moreover, H&E, Masson staining and immunohistochemical analysis were performed for evaluating the protective effect of ESE on histopathological changes of liver tissues.

RESULTS

UHPLCHRESI-MS/MS analysis showed that the ESE was rich in flavonoids such as phlorizin, phloretin, quercetin and hyperoside. ESE could significantly reduce the plasma AST and ALT activities. The cytokines (IL-6, TNF-α, IL-1β) expressions were inhibited after ESE administration via suppressing NF-κB pathway. In addition, ESE could decrease MDA accumulation for alleviating CCl₄ induced liver oxidative stress via regulating Nrf2 pathway to promote the expressions of antioxidant enzymes (SOD, HO-1, CAT and NQO1). Moreover, ESE could inhibit the expressions of TGF-β1, Smad2, α-SMA, and collagens Ⅰ and III proteins, thereby effectively alleviate the liver fibrosis.

CONCLUSION

This study demonstrated that ESE could alleviate liver fibrosis through enhancing antioxidant and anti-inflammatory abilities by Nrf2/NF-κB pathway and reducing deposition of liver fibrosis via suppressing TGF-β/Smad pathway.

Health and Disease: Akkermansia muciniphila, the Shining Star of the Gut Flora

Akkermansia muciniphila (A. muciniphila) has drawn much attention as an important gut microbe strain in recent years. A. muciniphila can influence the occurrence and development of diseases of the endocrine, nervous, digestive, musculoskeletal, and respiratory systems and other diseases. It can also improve immunotherapy for some cancers. A. muciniphila is expected to become a new probiotic in addition to Lactobacillus and Bifidobacterium. An increase in A. muciniphila abundance through direct or indirect A. muciniphila supplementation may inhibit or even reverse disease progression. However, some contrary findings are found in type 2 diabetes mellitus and neurodegenerative diseases, where increased A. muciniphila abundance may aggravate the diseases. To enable a more comprehensive understanding of the role of A. muciniphila in diseases, we summarize the relevant information on A. muciniphila in different systemic diseases and introduce regulators of A. muciniphila abundance to promote the clinical transformation of A. muciniphila research.

The role of human milk fats in shaping neonatal development and the early life gut microbiota

Human breast milk (HBM) is the main source of nutrition for neonates across the critical early-life developmental period. The highest demand for energy is due to rapid neurophysiological expansion post-delivery, which is largely met by human milk lipids (HMLs). These HMLs also play a prebiotic role and potentially promote the growth of certain commensal bacteria, which, via HML digestion, supports the additional transfer of energy to the infant. In tandem, HMLs can also exert bactericidal effects against a variety of opportunistic pathogens, which contributes to overall colonisation resistance. Such interactions are pivotal for sustaining homeostatic relationships between microorganisms and their hosts. However, the underlying molecular mechanisms governing these interactions remain poorly understood. This review will explore the current research landscape with respect to HMLs, including compositional considerations and impact on the early life gut microbiota. Recent papers in this field will also be discussed, including a final perspective on current knowledge gaps and potential next research steps for these important but understudied breast milk components.

Alleviation of Alcoholic Fatty Liver by Dendrobium officinale Flower Extracts due to Regulation of Gut Microbiota and Short-Chain Fatty Acids in Mice Exposed to Chronic Alcohol

Alcoholic fatty liver disease (AFLD) is caused by long-term heavy alcohol consumption; therefore, useful and practical methods for the prevention of AFLD are urgently needed. The edible flower of Dendrobium officinale contains diverse flavonoids, and has shown antioxidant activity as well as antihypertensive and anti-inflammatory effects. In this study, an AFLD model was established, the protective effect of D. officinale flower (DOF) ethanol extract on AFLD was evaluated, and its mechanisms were investigated by analyzing gut microbiota and short-chain fatty acids (SCFAs). DOF extract (DOFE) supplementation promoted alcohol metabolism, restored hepatic antioxidant capacity, alleviated oxidative stress, reduced inflammatory factor levels, and inhibited dyslipidemia induced by alcohol intake in chronic alcohol-exposed mice, especially in the high DOFE group. Moreover, DOFE supplementation increased the diversity, structure, and composition of the gut microbiota in mice, restored some of the abnormal SCFA levels caused by AFLD, and helped restore intestinal function. DOFE supplementation significantly increased the relative abundance of Akkermansia, suggesting that Akkermansia may be a potential target of the protective effect of DOFE. Therefore, DOFE supplementation to improve the composition of the gut microbiota may be an effective therapeutic strategy for the prevention of AFLD.

Theragra chalcogramma Hydrolysates, Rich of Fragment Gly-Leu-Pro-Ser-Tyr-Thr, Ameliorate Alcohol-Induced Cognitive Impairment via Attenuating Neuroinflammation and Enhancing Neuronal Plasticity in Sprague-Dawley Rats

Chronic alcohol abuse induces the cognitive deficits and is associated with low-grade inflammation and neurodegeneration. Currently, by virtue of the immunomodulatory and neuroprotective properties, nutrients represent a promising strategy to attenuate cognitive impairments. We previously prepared the hydrolysates from Theragra chalcogramma skin (TCH), and this study aims to evaluate the neuroprotection of TCH on alcohol-induced cognitive impairment (AICI) and to elucidate the associated mechanism. Behavioral results showed that TCH effectively ameliorated AICI and this amelioration was highly associated with the decrease of IL-1β and the increase of BDNF, CREB, and PSD95 in AICI rats (P < 0.05). Furthermore, TCH restored the histopathological impairment in hippocampus by reactivating extracellular signal-regulated kinase and suppressing Caspase-3 apoptosis signal pathways and modulating the abnormality of neurotransmitters acetylcholine and γ-aminobutyric acid(P < 0.05 or 0.01). Therefore, TCH exhibits potent attenuation of neuroinflammation and represents a potential ingredient for prevention of AICI.

Role of gut bacterial and non-bacterial microbiota in alcohol-associated liver disease: Molecular mechanisms, biomarkers, and therapeutic prospective

Alcohol-associated liver disease (ALD) comprises a spectrum of liver diseases that include: steatosis to alcohol-associated hepatitis, cirrhosis, and ultimately hepatocellular carcinoma. The pathophysiology and potential underlying mechanisms for alcohol-associated liver disease are unclear. Moreover, the treatment of ALD remains a challenge. Intestinal microbiota include bacteria, fungi, and viruses, that are now known to be important in the development of ALD. Alcohol consumption can change the gut microbiota and function leading to liver disease. Given the importance of interactions between intestinal microbiota, alcohol, and liver injury, the gut microbiota has emerged as a potential biomarker and therapeutic target. This review focuses on the potential mechanisms by which the gut microbiota may be involved in the pathogenesis of ALD and explains how this can be translated into clinical management. We discuss the potential of utilizing the gut microbiota signature as a biomarker in ALD patients. Additionally, we present an overview of the prospect of modulating the intestinal microbiota for the management of ALD.

Walnut protein hydrolysates ameliorate alcohol-induced cognitive impairment (AICI) by alleviating oxidative stress and inflammation in the brain and improving hippocampal synaptic plasticity in Sprague–Dawley rats

Walnut protein hydrolysate (WPH) ameliorates Alcohol-induced cognitive impairment (AICI) via alleviating oxidative stress and inflammation in brain tissue and improving the hippocampal synaptic plasticity.