Butyrate in Energy Metabolism: There Is Still More to Learn

Comparison analysis of bioactive metabolites in soybean, pea, mung bean, and common beans: reveal the potential variations of their antioxidant property

This study showed the significantly differences of basic nutrients and metabolite compounds in nine types of beans involved in soybean, mung bean, pea, and common beans. The metabolomics results showed that serval metabolites such as histidine, proline, 3-alanine, and myricetin which could be used to identify different beans. The random forest model showed that amino acid and fatty acid could be used as special indexes to distinguish different types of beans in practice. The different expressed metabolites among different types of beans were involved in various pathways including alanine, aspartate and glutamate metabolism, arginine and proline metabolism, and purine metabolism. The antioxidant activity was significantly different among different types of beans, and the contents of amino acid, coumarin, and polyphenol contributed the antioxidant activities of beans. Together, these results will provide a comprehensive understanding of metabolites in different types of beans and theoretical guideline for the future application of beans.

Metagenome-assembled genomes (MAGs) suggest an acetate-driven protective role in gut microbiota disrupted by Clostridioides difficile

Clostridioides difficile may have a negative impact on gut microbiota composition in terms of diversity and abundance, thereby triggering functional changes supported by the differential presence of genes involved in significant metabolic pathways, such as short-chain fatty acids (SCFA). This work has evaluated shotgun metagenomics data regarding 48 samples from four groups classified according to diarrhea acquisition site (community- and healthcare facility-onset) and positive or negative Clostridioides difficile infection (CDI) result. The metagenomic-assembled genomes (MAGs) obtained from each sample were taxonomically assigned for preliminary comparative analysis concerning differences in composition among groups. The predicted genes involved in metabolism, transport, and signaling remained constant in microbiota members; characteristic patterns were observed in MAGs and genes involved in SCFA butyrate and acetate metabolic pathways for each study group. A decrease in genera and species, as well as relative MAG abundance with the presence of the acetate metabolism-related gene, was evident in the HCFO/- group. Increased antibiotic resistance markers (ARM) were observed in MAGs along with the genes involved in acetate metabolism. The results highlight the need to explore the role of acetate in greater depth as a potential protector of the imbalances produced by CDI, as occurs in other inflammatory intestinal diseases.

Gut microbiota and metabolic changes in children with idiopathic short stature

BACKGROUND

Idiopathic short stature (ISS) is characterized by short stature with unknown causes. Recent studies showed different gut microbiota flora and reduced fecal short-chain fatty acids in ISS children. However, the roles of the microbiome and metabolites in the pathogenesis of ISS remains largely unknown.

METHODS

We recruited 51 Chinese subjects, comprising 26 ISS children and 25 normal-height control individuals. Untargeted metabolomics was performed to explore the fecal metabolic profiles between groups. A shotgun metagenomic sequencing approach was used to investigate the microbiome at the strains level. Mediation analyses were done to reveal correlations between the height standard deviation (SD) value, the gut microbiome and metabolites.

RESULTS

We detected marked differences in the composition of fecal metabolites in the ISS group, particularly a significant increase in erucic acid and a decrease in spermidine, adenosine and L-5-Hydroxytryptophan, when compared to those of controls. We further identified specific groups of bacterial strains to be associated with the different metabolic profile. Through mediation analysis, 50 linkages were established. KEGG pathway analysis of microbiota and metabolites indicated nutritional disturbances. 13 selected features were able to accurately distinguish the ISS children from the controls (AUC = 0.933 [95%CI, 79.9-100%]) by receiver operating characteristic (ROC) analysis.

CONCLUSION

Our study suggests that the microbiome and the microbial-derived metabolites play certain roles in children's growth. These findings provide a new research direction for better understanding the mechanism(s) underlying ISS.

The Bifidobacterium-dominated fecal microbiome in dairy calves shapes the characteristic growth phenotype of host

The dominant bacteria in the hindgut of calves play an important role in their growth and health, which could even lead to lifelong consequences. However, the identification of core probiotics in the hindgut and its mechanism regulating host growth remain unclear. Here, a total of 1045 fecal samples were analyzed by 16S rRNA gene sequencing from the 408 Holstein dairy calves at the age of 0, 14, 28, 42, 56, and 70 days to characterize the dynamic changes of core taxa. Moreover, the mechanisms of nutrient metabolism of calf growth regulated by core bacteria were investigated using multi-omics analyses. Finally, fecal microbiota transplantation (FMT) in mice were conducted to illustrate the potential beneficial effects of core bacteria. Four calf enterotypes were identified and enterotypes dominated by Bifidobacterium and Oscillospiraceae_UCG-005 were representative. The frequency of enterotype conversion shifted from variable to stable. The close relationship observed between phenotype and enterotype, revealing a potential pro-growth effect of Bifidobacterium, might be implemented by promoting the use of carbohydrate, activating the synthesis of volatile fatty acids, amino acids and vitamin B6, and inhibiting methane production in the hindgut. The FMT results indicated the beneficial effect of Bifidobacterium on host growth and hindgut development. These results support the notion that the Bifidobacterium-dominated fecal microbiome would be an important driving force for promoting the host growth in the early life. Our findings provide new insights into the potential probiotic mining and application strategies to promote the growth of young animals or improve their growth retardation.

Lysophosphatidylcholine trigger myocardial injury in diabetic cardiomyopathy via the TLR4/ZNF480/AP-1/NF-kB pathway

Background

Diabetic cardiomyopathy (DC), a frequent complication of type 2 diabetes mellitus (T2DM), is mainly associated with severe adverse outcomes. Previous research has highlighted the role of Lysophosphatidylcholine (LPC) in inducing myocardial injury; however, the specific mechanisms through which LPC mediate such injury in DC remain elusive. The existing knowledge gap underscores the need for additional clarification. Consequently, this study aimed to explore the impact and underlying mechanisms of LPC on myocardial injury in DC.

Methods

A total of 55 patients diagnosed with T2DM and 62 healthy controls were involved. A combination of 16s rRNA sequencing, metabolomic analysis, transcriptomic RNA-sequencing (RNA-seq), and whole exome sequencing (WES) was performed on fecal and peripheral blood samples collected from the participants. Following this, correlation analysis was carried out, and the results were further validated through the mouse model of T2DM.

Results

Four LPC variants distinguishing T2DM patients from healthy controls were identified, all of which were upregulated in T2DM patients. Specifically, Lysopc (16:0, 2 N isoform) and LPC (16:0) exhibited a positive correlation with nuclear factor kappa B subunit 2 (NFKB2) and a negative correlation with Zinc finger protein 480 (ZNF480) Furthermore, the expression levels of Toll-like receptor 4 (TLR4), c-Jun, c-Fos, and NFKB2 were upregulated in the peripheral blood of T2DM patients and in the myocardial tissue of T2DM mice, whereas ZNF480 expression level was downregulated. Lastly, myocardial injury was identified in T2DM mice.

Conclusions

The results indicated that LPC could induce myocardial injury in DC through the TLR4/ZNF480/AP-1/NF-kB pathway, providing a precise target for the clinical diagnosis and treatment of DC.

Sterile Diet Causes Gut Microbiome Collapse of Cancer Patients Post Hematopoietic Cell Transplantation, But Normal Diet Recovers Them

Though sterile diet, post-transplantation surgery is a clinical strategy for patient care to prevent the infiltration of gut pathogens, less is known about its effects on the gut microbiome. Here, the gut microbiome dynamics of leukemia patients following a 120-day "sterile-normal" diet strategy posthematopoietic cell transplantation are examined. In contrast to the traditional idea, a sterile diet leads to the lowest gut microbiota diversity (p < 0.05) and short-chain fatty acids, promoted the proliferation of potential pathogens such as Streptococcus (up by 16.93%) and Lactobacillus (up by 40.30%), and 43.32% reduction in nodes and an 85.33% reduction in edges within the microbial interaction's network. Interestingly, a normal diet allows the gut microbiome recovery and significantly promotes the abundance of beneficial bacteria. These results indicate that a sterile diet leads to a collapse of the patient's gut microbiome and promoted the proliferation of potential pathogens. This assay is a starting point for a more sophisticated assessment of the effects of a sterile diet. The work also suggests a basic principle for the re-establishment of microbial equilibrium that supplementation of microbial taxa may be the key to the restoration of the degraded ecosystem.

The Role of Short Chain Fatty Acids in Inflammation and Body Health

Short chain fatty acids (SCFAs), mainly including acetate, propionate and butyrate, are produced by intestinal bacteria during the fermentation of partially digested and indigestible polysaccharides. SCFAs play an important role in regulating intestinal energy metabolism and maintaining the homeostasis of the intestinal environment and also play an important regulatory role in organs and tissues outside the gut. In recent years, many studies have shown that SCFAs can regulate inflammation and affect host health, and two main signaling mechanisms have also been identified: the activation of G-protein coupled receptors (GPCRs) and inhibition of histone deacetylase (HDAC). In addition, a growing body of evidence highlights the importance of every SCFA in influencing health maintenance and disease development. In this review, we summarized the recent advances concerning the biological properties of SCFAs and their signaling pathways in inflammation and body health. Hopefully, it can provide a systematic theoretical basis for the nutritional prevention and treatment of human diseases.

Comparing the antioxidation and bioavailability of polysaccharides from extruded and unextruded Baijiu vinasses via in vitro digestion and fecal fermentation

Extrusion has been proven to be a novel approach for modifying the physicochemical characteristic of Baijiu vinasses (BV) to extract polysaccharides, contributing to the sustainable development of brewing industry. However, the comparison of the bioactivity and bioavailability of extruded (EX) and unextruded (UE) BV polysaccharides was unclear, which impended the determination of the efficacy of extrusion in BV resourcing. In this study, in vitro digestion and fecal fermentation experiments were conducted to investigate the bioavailability, and the results showed that EX exhibited less variation in the monosaccharide composition and molecular weight, while exhibiting a stronger antioxidant capacity compared to UE. Moreover, during fermentation EX increased the abundance of Parasutterella and Lachnospiraceae, while UE promoted the proliferation of Bacteroides, Faecalibacterium, and Dialister, resulting in variation in short-chain fatty acids. These findings indicate that extrusion can enhance the capacity of antioxidants and bioavailability of BV polysaccharides.

Primary goose kidney tubular epithelial cells for goose astrovirus genotype 2 infection: establishment and RNA sequencing analysis

Goose astrovirus genotype 2 (GAstV-2) mainly causes gout in goslings; therefore, it is a major pathogen threatening to goose flocks. However, the mechanisms underlying host-GAstV-2 interactions remain unclear because host cells suitable for GAstV-2 replication have been unavailable. We previously noted that GAstV-2 is primarily located in goose renal epithelial cells, where it causes kidney damage. Therefore, here, we derived goose primary renal tubular epithelial (RTE) cells (GRTE cells) from the kidneys of goose embryos after collagenase I digestion. After culture in Dulbecco's modified Eagle medium/Nutrient mixture F-12 with 10% fetal bovine serum (FBS), the isolated cells had polygonal with roadstone-like morphology; they were identified to be epithelial cells based on the presence of cytokeratin 18 expression detected through immunofluorescence assay (IFA). GAstV-2 infection in GRTE cells led to no obvious cytopathic effects; the maximum amounts of infectious virions were observed 48 h post infection through IFA and quantitative PCR. Next, RNA-seq was performed to identify and map post-GAstV-2 infection differentially expressed genes. The downregulated pathways were mainly related to metabolism, including tryptophan metabolism, drug metabolism by cytochrome P450, xenobiotic metabolism by cytochrome P450, retinol metabolism, butanoate metabolism, starch and sucrose metabolism, ascorbate and aldarate metabolism, and drug metabolism by other enzymes and peroxisome. In contrast, the upregulated pathways were mostly related to the host cell defense and proliferation, including extracellular matrix-receptor interaction, complement and coagulation cascades, phagosome, PI3K-Akt signaling pathway, human T-lymphotropic virus 1 infection, lysosome, and tumor necrosis factor signaling pathway. In conclusion, we developed a GRTE cell line for GAstV-2 replication and analyzed the potential host-GAstV-2 interactions through RNA-seq; our results may aid in further investigating the pathogenic mechanisms underlying GAstV-2 infection and provide strategies for its prevention and control.

Sodium butyrate ameliorates high glucose-suppressed neuronal mitophagy by restoring PRKN expression via inhibiting the RELA-HDAC8 complex

Damaged mitochondria accumulation in diabetes is one of the main features that contribute to increased incidence of cognitive impairment by inducing apoptosis. Butyrate is a major metabolite produced by microbiota that has neuroprotective effects by regulating mitochondrial function. However, detailed mechanisms underlying how butyrate can regulate neuronal mitophagy remain unclear. Here, we examined the regulatory effects of sodium butyrate (NaB) on high glucose-induced mitophagy dysregulation, neuronal apoptosis, and cognitive impairment and its underlying mechanisms in human-induced pluripotent stem cell-derived neurons, SH-SY5Ys, and streptozotocin (STZ)-induced diabetic mice. In our results, diabetic mice showed gut-microbiota dysbiosis, especially a decreased number of butyrate-producing bacteria and reduced NaB plasma concentration. NaB ameliorated high glucose-induced neuronal mitochondrial dysfunction by recovering PRKN/Parkin-mediated mitophagy. High glucose-induced reactive oxygen species (ROS) and -inhibited PRKAA/AMPKα stimulated the RELA/p65-HDAC8 complex, which downregulated PRKN protein expression by binding to the PRKN promoter region. NaB restored PRKN expression by blocking RELA nuclear translocation and directly inhibiting HDAC8 in the nucleus. In addition, HDAC8 overexpression inhibited the positive effect of NaB on high glucose-induced mitophagy dysfunction and neuronal apoptosis. Oral administration of NaB improved cognitive impairment in diabetic mice by restoring mitophagy in the hippocampus. Taken together, NaB ameliorates neuronal mitophagy through PRKN restoration by inhibiting RELA-HDAC8 complexes, suggesting that NaB is an important substance for protecting neuronal apoptosis in diabetes-associated cognitive impairment.

Modulating the Gut Microbiota and Metabolites with Traditional Chinese Medicines: An Emerging Therapy for Type 2 Diabetes Mellitus and Its Complications

Currently, an estimated 537 million individuals are affected by type 2 diabetes mellitus (T2DM), the occurrence of which is invariably associated with complications. Glucose-lowering therapy remains the main treatment for alleviating T2DM. However, conventional antidiabetic agents are fraught with numerous adverse effects, notably elevations in blood pressure and lipid levels. Recently, the use of traditional Chinese medicines (TCMs) and their constituents has emerged as a preferred management strategy aimed at curtailing the progression of diabetes and its associated complications with fewer adverse effects. Increasing evidence indicates that gut microbiome disturbances are involved in the development of T2DM and its complications. This regulation depends on various metabolites produced by gut microbes and their interactions with host organs. TCMs' interventions have demonstrated the ability to modulate the intestinal bacterial microbiota, thereby restoring host homeostasis and ameliorating metabolic disorders. This review delves into the alterations in the gut microbiota and metabolites in T2DM patients and how TCMs treatment regulates the gut microbiota, facilitating the management of T2DM and its complications. Additionally, we also discuss prospective avenues for research on natural products to advance diabetes therapy.

The association between gut microbiota and resting metabolic rate in overweight/obese women: a case-control study

Purpose

When examining the underlying processes of obesity, evaluation of gut flora and energy homeostasis can be crucial since disruption of the normal gut microbiota community and energy imbalances are significant factors in the development of obesity. Therefore, this study aimed to compare the relative abundance of important obesity modulator gut microbiota (including Firmicutes, Bacteroidetes, Bifidobactrium spp., Lactobacillus spp., Bacteroides fragilis, Faecalibacterium prausnitzii, Akkermansia muciniphila, and Escherichia coli) in fecal samples of normometabilic and hypometabolic overweight/obese individuals.

Methods

This matched case-control study conducted on 36 healthy women aged 18-50 years old. An indirect calorimeter and impedance body analyzer were used to assess resting metabolic rate (RMR) and body composition, respectively. Dietary intake and physical activity were assessed using questionnaires. To determine the abundance of the abovementioned gut microbiota, quantitative polymerase chain reaction (qPCR) method was performed. Moreover, ELISA kits were used to assess leptin, ghrelin, and insulin hormones.

Results

The results highlighted higher load of Firmicutes (p = 0.02), F. prausnitzii (p < 0.001), and B. fragilis (p = 0.02) in the normometabolic individuals compared to the hypometabolic ones. Besides, the positive correlation between the abundance of Firmicutes (β = 7.76 × 10-1, p = 0.01), F. prausnitzii (β = 1.29 × 10-5, p = 0.01), and B. fragilis (β = 4.13 × 10-6, p = 0.04) with the RMR have been shown. Whereas the abundance of Bacteroidetes, A. muciniphila, Lactobacillus spp., Bifidobactrium spp., and E. coli showed no significant difference (p > 0.05) and no significant correlation with the RMR except Lactobacillus spp. (β = 1.73 × 10-4, p = 0.01).

Conclusion

It seems that gut microbiota can be a potential target for refining host energy homeostasis and treating obesity and its consequences.

Spatial Distribution and Functional Impact of Human Scalp Hair Follicle Microbiota

Human hair follicles (HFs) constitute a unique microbiota habitat that differs substantially from the skin surface. Traditional HF sampling methods fail to eliminate skin microbiota contaminants or assess the HF microbiota incompletely, and microbiota functions in human HF physiology remain ill explored. Therefore, we used laser-capture microdissection, metagenomic shotgun sequencing, and FISH to characterize the human scalp HF microbiota in defined anatomical compartments. This revealed significant compartment-, tissue lineage-, and donor age-dependent variations in microbiota composition. Greatest abundance variations between HF compartments were observed for viruses, archaea, Staphylococcus epidermidis, Cutibacterium acnes, and Malassezia restricta, with the latter 2 being the most abundant viable HF colonizers (as tested by propidium monoazide assay) and, surprisingly, most abundant in the HF mesenchyme. Transfection of organ-cultured human scalp HFs with S. epidermidis-specific lytic bacteriophages ex vivo downregulated transcription of genes known to regulate HF growth and development, metabolism, and melanogenesis, suggesting that selected microbial products may modulate HF functions. Indeed, HF treatment with butyrate, a metabolite of S. epidermidis and other HF microbiota, delayed catagen and promoted autophagy, mitochondrial activity, and gp100 and dermcidin expression ex vivo. Thus, human HF microbiota show spatial variations in abundance and modulate the physiology of their host, which invites therapeutic targeting.

Gut Microbiota-Derived Butyrate Induces Epigenetic and Metabolic Reprogramming in Myeloid-Derived Suppressor Cells to Alleviate Primary Biliary Cholangitis

BACKGROUND & AIMS

Gut dysbiosis and myeloid-derived suppressor cells (MDSCs) are implicated in primary biliary cholangitis (PBC) pathogenesis. However, it remains unknown whether gut microbiota or their metabolites can modulate MDSCs homeostasis to rectify immune dysregulation in PBC.

METHODS

We measured fecal short-chain fatty acids levels using targeted gas chromatography-mass spectrometry and analyzed circulating MDSCs using flow cytometry in 2 independent PBC cohorts. Human and murine MDSCs were differentiated in vitro in the presence of butyrate, followed by transcriptomic, epigenetic (CUT&Tag-seq and chromatin immunoprecipitation-quantitative polymerase chain reaction), and metabolic (untargeted liquid chromatography-mass spectrometry, mitochondrial stress test, and isotope tracing) analyses. The in vivo role of butyrate-MDSCs was evaluated in a 2-octynoic acid-bovine serum albumin-induced cholangitis murine model.

RESULTS

Decreased butyrate levels and defective MDSC function were found in patients with incomplete response to ursodeoxycholic acid, compared with those with adequate response. Butyrate induced expansion and suppressive activity of MDSCs in a manner dependent on PPARD-driven fatty acid β-oxidation (FAO). Pharmaceutical inhibition or genetic knockdown of the FAO rate-limiting gene CPT1A abolished the effect of butyrate. Furthermore, butyrate inhibited HDAC3 function, leading to enhanced acetylation of lysine 27 on histone H3 at promoter regions of PPARD and FAO genes in MDSCs. Therapeutically, butyrate administration alleviated immune-mediated cholangitis in mice via MDSCs, and adoptive transfer of butyrate-treated MDSCs also displayed protective efficacy. Importantly, reduced expression of FAO genes and impaired mitochondrial physiology were detected in MDSCs from ursodeoxycholic acid nonresponders, and their impaired suppressive function was restored by butyrate.

CONCLUSIONS

We identify a critical role for butyrate in modulation of MDSC homeostasis by orchestrating epigenetic and metabolic crosstalk, proposing a novel therapeutic strategy for treating PBC.

Untargeted serum metabolic profiling of diabetes mellitus among Parkinson's disease patients

Type 2 diabetes mellitus (T2DM) is a common comorbidity among Parkinson's disease (PD) patients. Yet, little is known about dysregulated pathways that are unique in PD patients with T2DM. We applied high-resolution metabolomic profiling in serum samples of 636 PD and 253 non-PD participants recruited from Central California. We conducted an initial discovery metabolome-wide association and pathway enrichment analysis. After adjusting for multiple testing, in positive (or negative) ion mode, 30 (25) metabolic features were associated with T2DM in both PD and non-PD participants, 162 (108) only in PD participants, and 32 (7) only in non-PD participants. Pathway enrichment analysis identified 17 enriched pathways associated with T2DM in both the PD and non-PD participants, 26 pathways only in PD participants, and 5 pathways only in non-PD participants. Several amino acid, nucleic acids, and fatty acid metabolisms were associated with T2DM only in the PD patient group suggesting a possible link between PD and T2DM.

Improvement of functional dyspepsia with Suaeda salsa (L.) Pall via regulating brain-gut peptide and gut microbiota structure

PURPOSE

The traditional Chinese herbal medicine Suaeda salsa (L.) Pall (S. salsa) with a digesting food effect was taken as the research object, and its chemical composition and action mechanism were explored.

METHODS

The chemical constituents of S. salsa were isolated and purified by column chromatography, and their structures were characterized by nuclear magnetic resonance. The food accumulation model in mice was established, and the changes of the aqueous extract of S. salsa in gastric emptying and intestinal propulsion rate, colonic tissue lesions, serum brain-gut peptide hormone, colonic tissue protein expression, and gut microbiota structure were compared.

RESULTS

Ten compounds were isolated from S. salsa named as naringenin (1), hesperetin (2), baicalein (3), luteolin (4), isorhamnetin (5), taxifolin (6), isorhamnetin-3-O-β-D-glucoside (7), luteolin-3'-D-glucuronide (8), luteolin-7-O-β-D-glucuronide (9), and quercetin-3-O-β-D-glucuronide (10), respectively. The aqueous extract of S. salsa can improve the pathological changes of the mice colon and intestinal peristalsis by increasing the rate of gastric emptying and intestinal propulsion. By adjusting the levels of 5-HT, CCK, NT, SS, VIP, GT-17, CHE, MTL, and ghrelin, it can upregulate the levels of c-kit, SCF, and GHRL protein, and restore the imbalanced structure of gut microbiota, further achieve the purpose of treating the syndrome of indigestion. The effect is better with the increase of dose.

CONCLUSION

S. salsa has a certain therapeutic effect on mice with the syndrome of indigestion. From the perspective of "brain-gut-gut microbiota", the mechanism of digestion and accumulation of S. salsa was discussed for the first time, which provided an experimental basis for further exploring the material basis of S. salsa.

Metabolic trajectories of diabetic ketoacidosis onset described by breath analysis

Purpose

This feasibility study aimed to investigate the use of exhaled breath analysis to capture and quantify relative changes of metabolites during resolution of acute diabetic ketoacidosis under insulin and rehydration therapy.

Methods

Breath analysis was conducted on 30 patients of which 5 with DKA. They inflated Nalophan bags, and their metabolic content was subsequently interrogated by secondary electrospray ionization high-resolution mass spectrometry (SESI-HRMS).

Results

SESI-HRMS analysis showed that acetone, pyruvate, and acetoacetate, which are well known to be altered in DKA, were readily detectable in breath of participants with DKA. In addition, a total of 665 mass spectral features were found to significantly correlate with base excess and prompt metabolic trajectories toward an in-control state as they progress toward homeostasis.

Conclusion

This study provides proof-of-principle for using exhaled breath analysis in a real ICU setting for DKA monitoring. This non-invasive new technology provides new insights and a more comprehensive overview of the effect of insulin and rehydration during DKA treatment.

A serine-conjugated butyrate prodrug with high oral bioavailability suppresses autoimmune arthritis and neuroinflammation in mice

Butyrate-a metabolite produced by commensal bacteria-has been extensively studied for its immunomodulatory effects on immune cells, including regulatory T cells, macrophages and dendritic cells. However, the development of butyrate as a drug has been hindered by butyrate's poor oral bioavailability, owing to its rapid metabolism in the gut, its low potency (hence, necessitating high dosing), and its foul smell and taste. Here we report that the oral bioavailability of butyrate can be increased by esterifying it to serine, an amino acid transporter that aids the escape of the resulting odourless and tasteless prodrug (O-butyryl-L-serine, which we named SerBut) from the gut, enhancing its systemic uptake. In mice with collagen-antibody-induced arthritis (a model of rheumatoid arthritis) and with experimental autoimmune encephalomyelitis (a model of multiple sclerosis), we show that SerBut substantially ameliorated disease severity, modulated key immune cell populations systemically and in disease-associated tissues, and reduced inflammatory responses without compromising the global immune response to vaccination. SerBut may become a promising therapeutic for autoimmune and inflammatory diseases.

Butyrate and iso-butyrate: a new perspective on nutrition prevention of gestational diabetes mellitus

BACKGROUND

Dietary imbalance, such as a lower proportion of complex carbohydrates and a higher protein diet, may contribute to gestational diabetes mellitus (GDM) risks through their metabolisms. However, there is a lack of knowledge regarding the association between butyrate, iso-butyrate, and GDM, which are metabolisms of the two primary nutrients above. This study aimed to clarify the association of butyrate and iso-butyrate with GDM.

METHODS

A nested case-control study was conducted based on the Beijing Birth Cohort Study (BBCS) from 2017 to 2018. Totally, 99 singleton women were involved (GDM: n = 49, control: n = 50). All participants provided blood samples twice (in their first and second trimesters). Gas chromatography-mass spectrometry (GC-MS) was used for butyrate and iso-butyrate detection. Unconditional logistic regression and receiver operating characteristic (ROC) curve analysis were used for statistical analysis.

RESULTS

The results showed that butyrate in the first trimester was negatively correlated with GDM (odds ratio (OR): 0.00, 95% confidential interval (CI): 0.00-0.21, P = 0.008), and iso-butyrate in the second trimester was positively related to GDM (OR: 627.68, 95% CI: 40.51-9724.56, P < 0.001). The ratio (butyrate/iso-butyrate) was negatively associated with GDM, both in the first trimester (OR: 0.00, 95%CI: 0.00-0.05, P < 0.001) and in the second trimester (OR: 0.52, 95% CI: 0.34-0.80, P = 0.003). The area under the curve (AUC) using the ratio in the first trimester combined with clinical risk factors achieved 0.89 (95% CI: 0.83-0.95). Iso-butyrate in the second trimester combined with clinical risk factors achieved an AUC of 0.97 (95% CI: 0.92-1.00).

CONCLUSIONS

High iso-butyrate and low butyrate levels may be associated with an increased risk of GDM. As they are produced through dietary nutrient formation by gut microbiota, further studies on the association of dietary intake and butyrate or iso-butyrate concentration in plasma may help find a novel approach to nutritional intervention for GDM.

Structural characteristics, digestion properties, fermentation properties, and biological activities of butyrylated starch: A review

Butyrylated starch is produced by the esterification of hydroxyl groups in starch with butyryl groups, which improves the structural diversity of starch and expands its function and biological activity. The paper summarizes the structural properties and digestive properties, fermentation properties, and biological activities of butyrylated starch and describes the conformational relationships generated by the butyryl groups to reveal the underlying mechanisms. The butyryl groups replace the hydroxyl groups in starch and break the hydrogen bonds, which consequently changes the molecular, crystal, and granular structures of starch, while the starch structure also affects the distribution of the butyryl groups. Binding to the butyryl groups gives starch efficacy in resisting digestion, lowering the glycaemic index, releasing butyric acid in the colon, and regulating intestinal flora and metabolites. Relationships between starch structural parameters and butyric acid production and intestinal flora were also concluded to provide guidance for the rational design of butyrylated starch to improve efficacy. Moreover, based on its digestive and fermentation properties, butyrylated starch has exhibited good therapeutic efficacy for intestinal diseases, diabetes, polycystic ovary syndrome, and chronic restraint stress-induced abnormalities. This review provides a valuable reference for butyrylated starch advancement and utilization.

Faecalibacterium prausnitzii Supplementation Prevents Intestinal Barrier Injury and Gut Microflora Dysbiosis Induced by Sleep Deprivation

Sleep deprivation (SD) leads to impaired intestinal barrier function and intestinal flora disorder, especially a reduction in the abundance of the next generation of probiotic Faecalibacterium prausnitzii (F. prausnitzii). However, it remains largely unclear whether F. prausnitzii can ameliorate SD-induced intestinal barrier damage. A 72 h SD mouse model was used in this research, with or without the addition of F. prausnitzii. The findings indicated that pre-colonization with F. prausnitzii could protect against tissue damage from SD, enhance goblet cell count and MUC2 levels in the colon, boost tight-junction protein expression, decrease macrophage infiltration, suppress pro-inflammatory cytokine expression, and reduce apoptosis. We found that the presence of F. prausnitzii helped to balance the gut microbiota in SD mice by reducing harmful bacteria like Klebsiella and Staphylococcus, while increasing beneficial bacteria such as Akkermansia. Ion chromatography analysis revealed that F. prausnitzii pretreatment increased the fecal butyrate level in SD mice. Overall, these results suggested that incorporating F. prausnitzii could help reduce gut damage caused by SD, potentially by enhancing the intestinal barrier and balancing gut microflora. This provides a foundation for utilizing probiotics to protect against intestinal illnesses.

Clostridium butyricum isolated from giant panda can attenuate dextran sodium sulfate-induced colitis in mice

Objective

Probiotics are beneficial to the intestinal barrier, but few studies have investigated probiotics from giant pandas. This study aims to explore the preventive effects of giant panda-derived Clostridium butyricum on dextran sodium sulfate (DSS)-induced colitis in mice.

Methods

Clostridium butyricum was administered to mice 14 days before administering DSS treatment to induce enteritis.

Results

Clostridium butyricum B14 could more effectively prevent colitis in mice than C. butyricum B13. C. butyricum B14 protected the mouse colon by decreasing the histology index and serum interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) levels, which improved intestinal inflammation-related symptoms. In addition, the treatment led to the regulation of the expression of Tifa, Igkv12-89, and Nr1d1, which in turn inhibited immune pathways. The expression of Muc4, Lama3, Cldn4, Cldn3, Ocln, Zo1, Zo2, and Snai is related the intestinal mucosal barrier. 16S sequencing shows that the C. butyricum B14 significantly increased the abundance of certain intestinal probiotics. Overall, C. butyricum B14 exerted a preventive effect on colitis in mice by inhibiting immune responses, enhancing the intestinal barrier and increasing the abundance of probiotic species. Thus, C. butyricum B14 administration helps regulate the balance of the intestinal microecology. It can suppress immune pathways and enhance barrier-protective proteins.

Overview on biotics development

Although probiotics have been used in food products and supplements for decades, there has been a considerable increase in their use more recently. Recent technological advances have thus led to major advances in knowledge of the gut microbiota, enabling a significant development of biotics. In this review, we discuss the uses of traditional probiotics but also the discovery of next-generation probiotics that could be used as live biotherapeutics. These novel preventive and therapeutic strategies hold promise for the treatment of numerous diseases such as inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. Probiotic bacteria can be consumed alone, or in combination with prebiotics as synbiotics, or mixed with other probiotic strains to form a consortium for enhanced effects. We also discuss the benefits of using postbiotics.

Colonic Dysregulation of Major Metabolic Pathways in Experimental Ulcerative Colitis

Inflammatory bowel disease (IBD) is multifactorial chronic inflammatory disease in the gastrointestinal tract, affecting patients' quality of life profoundly. The incidence of IBD has been on the rise globally for the last two decades. Because the molecular mechanisms underlying the disease remain not well understood, therapeutic development is significantly impeded. Metabolism is a crucial cellular process to generate the energy needed for an inflammatory response and tissue repair. Comprehensive understanding of the metabolic pathways in IBD would help to unravel the disease pathogenesis/progression and facilitate therapeutic discoveries. Here, we investigated four metabolic pathways altered in experimental colitis. C57BL/6J mice were treated with dextran sulfate sodium (DSS) in drinking water for 7 days to induce experimental ulcerative colitis (UC). We conducted proteomics analysis for the colon samples using LC/MS, to profile key metabolic intermediates. Our findings revealed significant alterations in four major metabolic pathways: antioxidative defense, β-oxidation, glycolysis, and TCA cycle pathways. The energy metabolism by β-oxidation, glycolysis, and TCA cycle pathways were downregulated under UC, together with reduced antioxidative defense pathways. These results reveal metabolic re-programming in intestinal cells under UC, showing dysregulation in all four major metabolic pathways. Our study underscores the importance of metabolic drivers in the pathogenesis of IBD and suggests that the modification of metabolism may serve as a novel diagnostic/therapeutic approach for IBD.

An Update on the Role and Potential Molecules in Relation to Ruminococcus gnavus in Inflammatory Bowel Disease, Obesity and Diabetes Mellitus

Ruminococcus gnavus (R. gnavus) is a gram-positive anaerobe commonly resides in the human gut microbiota. The advent of metagenomics has linked R. gnavus with various diseases, including inflammatory bowel disease (IBD), obesity, and diabetes mellitus (DM), which has become a growing area of investigation. The initial focus of research primarily centered on assessing the abundance of R. gnavus and its potential association with disease presentation, taking into account variations in sample size, sequencing and analysis methods. However, recent investigations have shifted towards elucidating the underlying mechanistic pathways through which R. gnavus may contribute to disease manifestation. In this comprehensive review, we aim to provide an updated synthesis of the current literature on R. gnavus in the context of IBD, obesity, and DM. We critically analyze relevant studies and summarize the potential molecular mediators implicated in the association between R. gnavus and these diseases. Across numerous studies, various molecules such as methylation-controlled J (MCJ), glucopolysaccharides, ursodeoxycholic acid (UDCA), interleukin(IL)-10, IL-17, and capric acid have been proposed as potential contributors to the link between R. gnavus and IBD. Similarly, in the realm of obesity, molecules such as hydrogen peroxide, butyrate, and UDCA have been suggested as potential mediators, while glycine ursodeoxycholic acid (GUDCA) has been implicated in the connection between R. gnavus and DM. Furthermore, it is imperative to emphasize the necessity for additional studies to evaluate the potential efficacy of targeting pathways associated with R. gnavus as a viable strategy for managing these diseases. These findings have significantly expanded our understanding of the functional role of R. gnavus in the context of IBD, obesity, and DM. This review aims to offer updated insights into the role and potential mechanisms of R. gnavus, as well as potential strategies for the treatment of these diseases.

Metabolites: a converging node of host and microbe to explain meta-organism

Meta-organisms encompassing the host and resident microbiota play a significant role in combatting diseases and responding to stress. Hence, there is growing traction to build a knowledge base about this ecosystem, particularly to characterize the bidirectional relationship between the host and microbiota. In this context, metabolomics has emerged as the major converging node of this entire ecosystem. Systematic comprehension of this resourceful omics component can elucidate the organism-specific response trajectory and the communication grid across the ecosystem embodying meta-organisms. Translating this knowledge into designing nutraceuticals and next-generation therapy are ongoing. Its major hindrance is a significant knowledge gap about the underlying mechanisms maintaining a delicate balance within this ecosystem. To bridge this knowledge gap, a holistic picture of the available information has been presented with a primary focus on the microbiota-metabolite relationship dynamics. The central theme of this article is the gut-brain axis and the participating microbial metabolites that impact cerebral functions.

Sodium butyrate ameliorated diabetic nephropathy-associated tubulointerstitial inflammation by modulating the tight junctions of renal tubular epithelial cells

As one of the most significant pathological changes of diabetic nephropathy (DN), tubulointerstitial fibrosis (TIF) had a close relationship with tubulointerstitial inflammation (TI), and the occurrence of TI could have resulted from the disrupted tight junctions (TJs) of renal tubular epithelial cells (RTECs). Studies have demonstrated that sodium butyrate (NaB), a typical short chain fatty acid (SCFA), played an important regulatory role in intestinal TJs and inflammation. In this study, our in vivo and in vitro results showed that accompanied by TI, renal tubular TJs were gradually disrupted in the process of DN-related TIF. In HG and LPS co-cultured HK-2 cells and db/db mice, NaB treatment regained the TJs of RTECs via the sphingosine 1-phosphate receptor-1 (S1PR1)/AMPK signaling pathway, relieving inflammation. Small interfering RNA of S1PR1, S1PR1 antagonist W146 and agonist SEW2871, and AMPK agonist AICAR were all used to further confirm the essential role of the S1PR1/AMPK signaling pathway in NaB's TJ protection in RTECs in vitro. Finally, NaB administration not only improved the renal function and TIF, but also relieved the TI of db/db mice. These findings suggested that the use of NaB might be a potential adjuvant treatment strategy for DN-associated TIF, and this protective effect was linked to the TJ modulation of RTECs via the S1PR1/AMPK signaling pathway, leading to the improvement of TI.

Two intestinal microbiota-derived metabolites, deoxycholic acid and butyrate, synergize to enhance host defense peptide synthesis and alleviate necrotic enteritis

BACKGROUND

Necrotic enteritis (NE) is a major enteric disease in poultry, yet effective mitigation strategies remain elusive. Deoxycholic acid (DCA) and butyrate, two major metabolites derived from the intestinal microbiota, have independently been shown to induce host defense peptide (HDP) synthesis. However, the potential synergy between these two compounds remains unexplored.

METHODS

To investigate the possible synergistic effect between DCA and butyrate in regulating HDP synthesis and barrier function, we treated chicken HD11 macrophage cells and jejunal explants with DCA and sodium butyrate (NaB), either individually or in combination, for 24 h. Subsequently, we performed RNA isolation and reverse transcription-quantitative PCR to analyze HDP genes as well as the major genes associated with barrier function. To further determine the synergy between DCA and NaB in enhancing NE resistance, we conducted two independent trials with Cobb broiler chicks. In each trial, the diet was supplemented with DCA or NaB on the day-of-hatch, followed by NE induction through sequential challenges with Eimeria maxima and Clostridium perfringens on d 10 and 14, respectively. We recorded animal mortality after infection and assessed intestinal lesions on d 17. The impact of DCA and NaB on the microbiota in the ileum and cecum was evaluated through bacterial 16S rRNA gene sequencing.

RESULTS

We found that the combination of DCA and NaB synergistically induced multiple HDP genes in both chicken HD11 cells and jejunal explants. Additionally, the gene for claudin-1, a major tight junction protein, also exhibited synergistic induction in response to DCA and NaB. Furthermore, dietary supplementation with a combination of 0.75 g/kg DCA and 1 g/kg NaB led to a significant improvement in animal survival and a reduction in intestinal lesions compared to either compound alone in a chicken model of NE. Notably, the cecal microbiota of NE-infected chickens showed a marked decrease in SCFA-producing bacteria such as Bacteroides, Faecalibacterium, and Cuneatibacter, with lactobacilli becoming the most dominant species. However, supplementation with DCA and NaB largely restored the intestinal microbiota to healthy levels.

CONCLUSIONS

DCA synergizes with NaB to induce HDP and claudin-1 expression and enhance NE resistance, with potential for further development as cost-effective antibiotic alternatives.

Influence of dietary status on the obesogenic effects of erythromycin antibiotic on Caenorhabditis elegans

As emerging pollutants, antibiotics were widely detected in water bodies and dietary sources. Recently, their obesogenic effects raised serious concerns. So far, it remained unclear whether their obesogenic effects would be influenced by water- and diet-borne exposure routes. In present study, Caenorhabditis elegans, nematodes free-living in air-water interface and feeding on bacteria, were exposed to water- and diet-borne erythromycin antibiotic (ERY). The statuses of the bacterial food, inactivated or alive, were also considered to explore their influences on the effects. Results showed that both water- and diet-borne ERY significantly stimulated body width and triglyceride contents. Moreover, diet-borne ERY's stimulation on the triglyceride levels was greater with alive bacteria than with inactivated bacteria. Biochemical analysis showed that water-borne ERY inhibited the activities of enzymes like adipose triglyceride lipase (ATGL) in fatty acid β-oxidation. Meanwhile, diet-borne ERY inhibited the activities of acyl-CoA synthetase (ACS) and carnitine palmitoyl transferase (CPT) in lipolysis, while it stimulated the activities of fatty acid synthase (FAS) in lipogenesis. Gene expression analysis demonstrated that water-borne ERY with alive bacteria significantly upregulated the expressions of daf-2, daf-16 and nhr-49, without significant influences in other settings. Further investigation demonstrated that ERY interfered with bacterial colonization in the intestine and the permeability of the intestinal barrier. Moreover, ERY decreased total long-chained fatty acids (LCFAs) in bacteria and nematodes, while it decreased total short-chained fatty acids (SCFAs) in bacteria but increased them in nematodes. Collectively, the present study demonstrated the differences between water- and diet-borne ERY's obesogenic effects, and highlighted the involvement of insulin and nhr-49 signaling pathways, SCFAs metabolism and also the interaction between intestinal bacteria and the host.

The gut microbiota composition and metabolites are different in women with hypertensive disorders of pregnancy and normotension: A pilot study

INTRODUCTION

Hypertensive disorders of pregnancy (HDP) are one of the main causes of perinatal morbidity. Gut microbiota influences host inflammatory pathways, glucose, and lipid metabolism. However, there is a lack of studies available on gut microbiota in HDP.

OBJECTIVES

We investigate the mechanistic and pathogenic role of microbiota in the development of HDP, and want to treat HDP with gut microbiota.

METHODS

We performed a case-control study to compare fecal samples of HDP and normotensive pregnant women by 16S ribosomal RNA sequencing. Fecal samples, collected from pregnant women, were divided into groups P and C (pregnant women with HDP and normotension, respectively). There were six pregnant women in group P and nine pregnant women in group C. Age of pregnant women is from 18 to 40 years and gestational age is from 27 to 40 weeks. DNA was extracted from fecal samples; a gene library was constructed and analyzed using bioinformatics. Finally, we determined the changes in the microbiome by alpha diversity, beta diversity, classification abundance, and taxonomic composition analyses.

RESULTS

Escherichia (10.48% in group P and 0.61% in group C) was the dominant bacterium in HDP patients by classification abundance analysis, which can lead to the development of preeclampsia through inflammatory response. We found that pregnant women with HDP had higher abundance of Rothia (p = 0.04984), Actinomyces (p = 0.02040), and Enterococcus (p = 0.04974) and lower abundance of Coprococcus (p = 0.04955) than pregnant women with normotension for the first time by taxonomic composition analysis. Based on the Kyoto Encyclopedia of Genes and Genomes database analysis, physiological and biochemical functions of HDP patients were significantly weakened, especially in energy metabolism.

CONCLUSIONS

We found the effect of changes in gut microbiota on the development of HDP. In comparison with group C, group P contained more harmful bacteria and less beneficial bacteria, which are associated with HDP. Our research further provides a basis for a clinical application for HDP treatment using antibiotics and probiotic supplementation.

Squid meal and shrimp hydrolysate as novel protein sources for dog food

The world's growing pet population is raising sustainability and environmental concerns for the petfood industry. Protein-rich marine by-products might contribute to mitigating negative environmental effects, decreasing waste, and improving economic efficiency. The present study evaluated two marine by-products, squid meal and shrimp hydrolysate, as novel protein sources for dog feeding. Along with the analysis of chemical composition and antioxidant activity, palatability was evaluated by comparing a commercial diet (basal diet) and diets with the inclusion of 150 g kg-1 of squid meal or shrimp hydrolysate using 12 Beagle dogs (2.2 ± 0.03 years). Two in vivo digestibility trials were conducted with six dogs, three experimental periods (10 days each) and three dietary inclusion levels (50, 100 and 150 g kg-1) of squid meal or shrimp hydrolysate in place of the basal diet to evaluate effects of inclusion level on apparent total tract digestibility (ATTD), metabolizable energy content, fecal characteristics, metabolites, and microbiota. Both protein sources presented higher protein and methionine contents than ingredients traditionally used in dog food formulation. Shrimp hydrolysate showed higher antioxidant activity than squid meal. First approach and taste were not affected by the inclusion of protein sources, but animals showed a preference for the basal diet. Effects on nutrient intake reflected the chemical composition of diets, and fecal output and characteristics were not affected by the increasing inclusion levels of both protein sources. The higher ATTD of dry matter, most nutrients and energy of diets with the inclusion of both by-products when compared to the basal diet, suggests their potential to be included in highly digestible diets for dogs. Although not affected by the inclusion level of protein sources, when compared to the basal diet, the inclusion of squid meal decreased butyrate concentration and shrimp hydrolysate increased all volatile fatty acids, except butyrate. Fecal microbiota was not affected by squid meal inclusion, whereas inclusion levels of shrimp hydrolysate significantly affected abundances of Oscillosperaceae (UCG-005), Firmicutes and Lactobacillus. Overall, results suggest that squid meal and shrimp hydrolysate constitute novel and promising protein sources for dog food, but further research is needed to fully evaluate their functional value.

Effects of Glucagon-Like Peptide-1 Receptor Agonists on Gut Microbiota in Dehydroepiandrosterone-Induced Polycystic Ovary Syndrome Mice: Compared Evaluation of Liraglutide and Semaglutide Intervention

Purpose

Polycystic ovary syndrome (PCOS) is a frequent cause of infertility in reproductive-age women. Our work aims to evaluate the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on gut microbiota, with metabolic parameters including body weight and the hormone profile in PCOS.

Patients and Methods

Dehydroepiandrosterone (DHEA)-induced PCOS mice were established and then treated with two GLP-1RAs: liraglutide and novel form semaglutide for four weeks. Changes in body weight and metabolic parameters were measured. Fecal samples were collected and analyzed using metagenomic sequencing.

Results

Liraglutide and semaglutide modulated both alpha and beta diversity of the gut microbiota in PCOS. Liraglutide increased the Bacillota-to-Bacteroidota ratio through up-regulating the abundance of butyrate-producing members of Bacillota like Lachnospiraceae. Moreover, liraglutide showed the ability to reverse the altered microbial composition and the disrupted microbiota functions caused by PCOS. Semaglutide increased the abundance of Helicobacter in PCOS mice (p < 0.01) which was the only bacteria found negatively correlated with body weight. Moreover, pathways involving porphyrin and flavonoids were increased after semaglutide intervention.

Conclusion

Liraglutide and semaglutide improved reproductive and metabolic disorders by modulating the whole structure of gut microbiota in PCOS. The greater efficacy in weight loss compared with liraglutide observed after semaglutide intervention was positively related with Helicobacter. The study may provide new ideas in the treatment and the underlying mechanisms of GLP-1RAs to improve PCOS.

Environmentally relevant concentrations of chemically complex shale gas wastewater led to reduced fitness of water fleas (Daphnia carinata): Multiple lines of evidence approach

Shale gas hydraulic fracturing generates flowback waters that pose a threat to aquatic organisms if released into the environment. In order to prevent adverse effects on aquatic ecosystems, multiple lines of evidence are needed to guide better decisions and management actions. This study employed a multi-disciplinary approach, combining direct toxicity assessment (DTA) on the water flea Daphnia carinata and LC-MS metabolomics analysis to determine the impact of a major ion salinity control (SC) and a cumulative flowback shale gas wastewater (SGW) from a well in the Beetaloo Sub-basin, Northern Territory, Australia. The exposures included a culture water control, simply further referred to as 'control', SC at 1% and 2% (v/v) and SGW at 0.125, 0.25, 0.5, 1% and 2% (v/v). The results showed that reproduction was significantly increased at SGW 0.5%, and significantly decreased when exposed to SC 2%. SGW 2% was found to be acutely toxic for the D. carinata (< 48-h). Second generation (F1) of D. carinata exposed to 0.125-1% SGW generally saw reduced activity in four oxidative biomarkers: glutathione S-transferase, lipid peroxidation, reactive oxygen species, and superoxide dismutase. At the metabolomics level, we observed significant changes in 103 metabolites in Daphnia exposed to both SGW and elevated salinity, in comparison to the control group. These changes indicate a range of metabolic disturbances induced by SGW and salinity, such as lipid metabolism, amino acid metabolism, nucleotide synthesis, energy production, and the biosynthesis of crucial molecules like hormones and pigments. These multiple lines of evidence approach not only highlights the complexities of SGW's impact on aquatic ecosystems but also underscores the importance of informed decision-making and management practices to safeguard the environment and its inhabitants.

Multi-copy expression of a protease-resistant xylanase with high xylan degradation ability and its application in broilers fed wheat-based diets

The acidic thermostable xylanase (AT-xynA) has great potential in the feed industry, but its low activity is not conductive to large-scale production, and its application in poultry diets still needs to be further evaluated. In Experiment1, AT-xynA activity increased 3.10 times by constructing multi-copy strains, and the highest activity reached 10,018.29 ± 91.18 U/mL. AT-xynA showed protease resistance, high specificity for xylan substrates, xylobiose and xylotriose were the main hydrolysates. In Experiment2, 192 broilers were assigned into 3 treatments including a wheat-based diet, and the diets supplemented with AT-xynA during the entire period (XY-42) or exclusively during the early stage (XY-21). AT-xynA improved growth performance, while the performance of XY-21 and XY-42 was identical. To further clarify the mechanism underlying the particular effectiveness of AT-xynA during the early stage, 128 broilers were allotted into 2 treatments including a wheat-based diet and the diet supplemented with AT-xynA for 42 d in Experiment3. AT-xynA improved intestinal digestive function and microbiota composition, the benefits were stronger in younger broilers than older ones. Overall, the activity of AT-xynA exhibiting protease resistance and high xylan degradation ability increased by constructing multi-copy strains, and AT-xynA was particularly effective in improving broiler performance during the early stage.

Butyrate functions as a histone deacetylase inhibitor to protect pancreatic beta cells from IL-1β-induced dysfunction

Butyrate, a gut microbial metabolite, has beneficial effects on glucose homeostasis and has become an attractive drug candidate for type 2 diabetes (T2D). Recently, we showed that butyrate protects pancreatic beta cells against cytokine-induced dysfunction. In this study, we explored the underlying mechanisms of butyrate action. Pancreatic mouse islets were exposed to a non-cytotoxic concentration of interleukin-1β (IL-1β) for 10 days to mimic low-grade inflammation in T2D. Similar to the effect of butyrate, an isoform-selective histone deacetylase 3 (HDAC3) inhibitor normalized IL-1β-reduced glucose-stimulated insulin secretion and insulin content. In contrast, free fatty acid receptor 2 and 3 (FFAR2/3) agonists failed to normalize IL-1β-induced beta cell dysfunction. Furthermore, butyrate inhibited HDAC activity and increased the acetylation of histone H3 and H4 by 3- and 10-fold, respectively. Genome-wide analysis of histone H3 lysine 27 acetylation (H3K27ac) revealed that butyrate mainly increased H3K27ac at promoter regions (74%), while H3K27ac peaks regulated by IL-1β were more equally distributed at promoters (38%), introns (23%) and intergenic regions (23%). Gene ontology analysis showed that butyrate increased IL-1β-reduced H3K27ac levels near several genes related to hormone secretion and reduced IL-1β-increased H3K27ac levels near genes associated with inflammatory responses. Butyrate alone increased H3K27ac near many genes related to MAPK signaling, hormone secretion, and differentiation, and decreased H3K27ac at genes involved in cell replication. Together, these results suggest that butyrate prevents IL-1β-induced pancreatic islet dysfunction by inhibition of HDACs resulting in changes in H3K27ac levels at genes relevant for beta cell function and inflammatory responses.

Butyrate Alleviates High-Fat-Induced Metabolic Disorders Partially through Increasing Systematic Glutamine

Obesity has emerged as a worldwide epidemic. Both butyrate and glutamine counteract obesity-related metabolic disorders; however, whether and how they synergistically cooperate with each other remains a mystery. In the study, a high-fat diet (HFD, 60% calories from fat) was used to develop a model of obesity-related metabolic disorder and compared with administrated saline and sodium butyrate (SB, 300 mg/kg body weight) daily by gavage. Compared with HFD counterparts, oral administration of SB in mice exhibited significantly reduced body weight and fat mass and decreased hepatic triglyceride content. The targeted mass spectrum revealed that SB restored serum contents of glutamine, which were significantly decreased by HFD. Furthermore, SB significantly elevated the expression of glutamine synthetase (GS, encoded by GLUL) in the liver, accompanied by more enrichment of H3K27ac modifications within its promoter. In summary, the study verified the contribution of elevated glutamine to the beneficial effects of butyrate on metabolic disorders induced by a high-fat diet, providing a novel pathway for understanding how butyrate benefits metabolic homeostasis.

Ginsenoside F2-Mediated Intestinal Microbiota and Its Metabolite Propionic Acid Positively Impact the Gut-Skin Axis in Atopic Dermatitis Mice

Atopic dermatitis (AD) is a complex inflammatory skin disease induced by multiple factors. AD can also cause intestinal inflammation and disorders of the gut microbiota. Ginseng is a kind of edible and medicinal plant; its main active components are ginsenosides. Ginsenosides have a variety of anti-inflammatory effects and regulate the gut microbiota; however, their role in AD and the underlying mechanisms are unclear. In this study, we found that intragastric administration of ginsenoside F2 improved AD-like skin symptoms and reduced inflammatory cell infiltration, serum immunoglobulin E levels, and mRNA expression of inflammatory cytokines in AD mice. 16s rRNA sequencing analysis showed that ginsenoside F2 altered the intestinal microbiota structure and enriched the short-chain fatty acid-producing microbiota in AD mice. Metabolomic analysis revealed that ginsenoside F2 significantly increased the propionic acid (Pa) content of feces and serum in AD mice, which was positively correlated with significant enrichment of Parabacteroides goldsteinii and Lactobacillus plantarum in the intestines. Pa inhibits inflammatory responses in the gut and skin of AD mice through the G-protein-coupled receptor43/NF-κB pathway, thereby improving skin AD symptoms. These results revealed, for the first time, the mechanism by which ginsenoside F2 improves AD through the Pa (a metabolite of intestinal microbiota)-gut-skin axis.

Exploring the intestinal ecosystem: from gut microbiota to associations with subtypes of inflammatory bowel disease

Objective

Significant differences have been discovered between subtypes of Crohn's disease (CD) and ulcerative colitis (UC). The role of gut microbiota in promoting the onset of UC and CD is established, but conclusions regarding subtype-specific analyses remain limited.

Methods

This study aims to explore the influence of gut microbiota on subtypes of UC and CD, offering novel insights into the pathogenesis and treatment of UC and CD.Two-sample Mendelian randomization (MR) analysis was employed to examine the causal relationship between subtypes of UC and CD and gut microbiota composition. Gut microbiota data were sourced from the International Consortium MiBioGen, while UC and CD data were obtained from FINNGEN. Eligible single nucleotide polymorphisms (SNPs) were selected as instrumental variables. Multiple analytical approaches such as inverse variance-weighted (IVW), MR-Egger regression, weighted median, weighted mode, and MR-RAPS were utilized. Sensitivity analyses including MR-Egger intercept test, Cochran's Q test, and leave-one-out analysis were conducted for quality control. Subsequently, we employed multivariable IVW, MR-Egger, weighted median, and LASSO regression methods to identify independently significant genera or families and conducted sensitivity analyses.

Results

We have determined that Hungatella, Acidaminococcaceae, and 15 other microbial taxa act as protective factors for various CD and UC subtypes, while Terrisporobacter, Anaerostipes, and 23 other microbial taxa are associated with increased risk for different CD and UC subtypes. Furthermore, through multivariable MR analysis, we have identified significant genera or families with independent effects.

Conclusion

Our study confirms a causal relationship between dysbiosis of gut microbiota and the occurrence of CD and UC subtypes. Furthermore, it validates etiological distinctions among different subtypes of CD and UC. A novel approach to adjunctive therapy involving distinct UC or CD subtypes may involve the use of probiotics and represents a potential avenue for future treatments.

Butyrate affects bacterial virulence: a new perspective on preventing enteric bacterial pathogen invasion

Enteric bacterial pathogens are a major threat to intestinal health. With the widespread use of antibiotics, bacterial resistance has become a problem, and there is an urgent need for a new treatment to reduce dependence on antibiotics. Butyrate can control enteric bacterial pathogens by regulating the expression of their virulence genes, promoting the posttranslational modification of their proteins, maintaining an anaerobic environment, regulating the host immune system and strengthening the intestinal mucosal barrier. Here, this review describes the mechanisms by which butyrate regulates the pathogenicity of enteric bacterial pathogens from various perspectives and discusses the prospects and limitations of butyrate as a new option for the control of pathogenic bacteria.

Structural property of extractable proteins and polysaccharides in wheat bran following a dual-enzymatic pretreatment and corresponding functionality

The current study applied dual-enzymatic treatment via alcalase and Bacillus velezensis hydrolase for enhancing extraction of proteins and polysaccharides from wheat bran and modifying their corresponding structure. Results indicated the aqueous extract by enzymatic pretreatment (referred as EHWB) had an increased content of soluble substance, in which 18.5 % increased for carbohydrates and 11.4 % increased for proteins in the extract compared to the aqueous extract without enzymes (labeled as AEWB). Furthermore, compositions with lower molecular weight of 130 kDa and < 21.1 kDa for polysaccharides and proteins, respectively, were found in EHWB. Interestingly, EHWB had a twice higher radicals scavenging than that of AEWB, and digestive property indicated EHWB had a greater peptides production although glucose release was lower in gastric phase. Importantly, this is the first study to reveal that gut microbiota fermentation of EHWB resulted in faster generation of short-chain fatty acids at initial fermentation stage (6 h), followed a higher generation of butyrate at final fermentation stage (24 h). This fermentation property might be associated with its presence of lower molecular weight substrates and even the changes in the molecular structure induced by the enzymes. This study highlights a novel approach for developing a value-added product from wheat bran.

Enhancing social behavior in an autism spectrum disorder mouse model: investigating the underlying mechanisms of Lactiplantibacillus plantarum intervention

Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting over 1% of the global population. Individuals with ASD often exhibit complex behavioral conditions, including significant social difficulties and repetitive behaviors. Moreover, ASD often co-occurs with several other conditions, including intellectual disabilities and anxiety disorders. The etiology of ASD remains largely unknown owing to its complex genetic variations and associated environmental risks. Ultimately, this poses a fundamental challenge for the development of effective ASD treatment strategies. Previously, we demonstrated that daily supplementation with the probiotic Lactiplantibacillus plantarum PS128 (PS128) alleviates ASD symptoms in children. However, the mechanism underlying this improvement in ASD-associated behaviors remains unclear. Here, we used a well-established ASD mouse model, induced by prenatal exposure to valproic acid (VPA), to study the physiological roles of PS128 in vivo. Overall, we showed that PS128 selectively ameliorates behavioral abnormalities in social and spatial memory in VPA-induced ASD mice. Morphological examination of dendritic architecture further revealed that PS128 facilitated the restoration of dendritic arborization and spine density in the hippocampus and prefrontal cortex of ASD mice. Notably, PS128 was crucial for restoring oxytocin levels in the paraventricular nucleus and oxytocin receptor signaling in the hippocampus. Moreover, PS128 alters the gut microbiota composition and increases the abundance of Bifidobacterium spp. and PS128-induced changes in Bifidobacterium abundance positively correlated with PS128-induced behavioral improvements. Together, our results show that PS128 treatment can effectively ameliorate ASD-associated behaviors and reinstate oxytocin levels in VPA-induced mice, thereby providing a promising strategy for the future development of ASD therapeutics.

Erchen Decoction alleviates obesity-related hepatic steatosis via modulating gut microbiota-drived butyric acid contents and promoting fatty acid β-oxidation

ETHNOPHARMACOLOGICAL RELEVANCE

Erchen decoction (ECD) is a traditional Chinese medicine formula comprising six distinct herbs and has been documented to possess a protective effect against obesity. The study conducted previously demonstrated that ECD has the potential to effectively modulate the composition of gut microbiota and levels of short-chain fatty acids (SCFAs) in obese rat. However, the regulatory mechanism of ECD on gut microbiota and SCFAs and further improvement of obesity have not been thoroughly explained.

AIM OF THE STUDY

The objective of this study was to examine the therapeutic effect and molecular mechanism of ECD in a rat model of high-fat diet (HFD) feeding.

MATERIALS AND METHODS

Rats with HFD-induced obesity were treated with ECD. Upon completion of the study, serum and liver samples were procured to conduct biochemical, pathological, and Western blotting analyses. The investigation of alterations in the gut microbiota subsequent to ECD treatment was conducted through the utilization of 16S rRNA sequencing. The metabolic alterations in the cecal contents were examined through the utilization of mass spectrometry-ultraperformance liquid chromatography.

RESULTS

ECD treatment improved lipid metabolic disorders and reduced hepatic steatosis in HFD-induced obese rats. Obese rat treated with ECD showed a higher abundance of SCFA-producing bacteria, including Lactobacillus, Bifidobacterium, and Butyricicoccus, and lower abundance of disease-related bacteria, such as Bacteroides, Parabacteroides, and Sediminibacterium. Additionally, ECD caused an increase in total SCFAs levels; in particular, butyric acid was dramatically increased in the HFD group. Rats treated with ECD also exhibited significantly increased butyric acid concentrations in the serum and liver. The subsequent reduction in histone deacetylase 1 expression and increase in acetyl-histone 3-lysine 9 (H3K9ac) levels contributed to the promotion of fatty acid β-oxidation (FAO) in liver by ECD.

CONCLUSION

This study demonstrates that ECD regulates the gut microbiota and promotes butyric acid production to ameliorate obesity-related hepatic steatosis. The mechanism might be related to the promotion of FAO via a butyric acid-mediated increase in H3K9ac levels in the liver.

Metabolic mechanisms in physiological and pathological cardiac hypertrophy: new paradigms and challenges

Cardiac metabolism is vital for heart function. Given that cardiac contraction requires a continuous supply of ATP in large quantities, the role of fuel metabolism in the heart has been mostly considered from the perspective of energy production. However, the consequence of metabolic remodelling in the failing heart is not limited to a compromised energy supply. The rewired metabolic network generates metabolites that can directly regulate signalling cascades, protein function, gene transcription and epigenetic modifications, thereby affecting the overall stress response of the heart. In addition, metabolic changes in both cardiomyocytes and non-cardiomyocytes contribute to the development of cardiac pathologies. In this Review, we first summarize how energy metabolism is altered in cardiac hypertrophy and heart failure of different aetiologies, followed by a discussion of emerging concepts in cardiac metabolic remodelling, that is, the non-energy-generating function of metabolism. We highlight challenges and open questions in these areas and finish with a brief perspective on how mechanistic research can be translated into therapies for heart failure.

Targeting the Adipose Tissue-Liver-Gut Microbiota Crosstalk to Cure MASLD

The gut microbiota is a complex system, playing a peculiar role in regulating innate and systemic immunity. Increasing evidence links dysfunctional gut microbiota to metabolic dysfunction-associated steatotic liver disease (MASLD) due to the activation of multiple pathways in the gut and in the liver, including those mediated by Toll-like receptors (TLRs), that sustain hepatic inflammation. Thus, many efforts have been made to unravel the role of microbiota-associated dysfunction in MASLD, with the final aim of finding novel strategies to improve liver steatosis and function. Moreover, recent evidence underlines the role of adipose tissue in sustaining hepatic inflammation during MASLD development. In this review, we focus on the recently discovered strategies proposed to improve the alteration of gut microbiota observed in MASLD patients, with a particular insight into those known to modulate gut microbiota-associated dysfunction and to affect the complex crosstalk between the gut, the adipose tissue, and the liver.

Phosphate-solubilizing bacteria: Their agroecological function and optimistic application for enhancing agro-productivity

Phosphorus (P) is a limiting nutrient in the soil-plant nutrient cycling. Although the exogenous application of chemical P fertilizers can satisfy crop P requirements during critical growth phases. While excessive P fertilizers use results in low phosphorus acquisition efficiency (PAE), it has serious environmental consequences and hastens the depletion of P mineral reserves. Phosphate-solubilizing bacteria (PSB) have the potential to make insoluble phosphate available to plants through solubilization and mineralization, increasing crop yields while maintaining environmental sustainability. Existing reviews mainly focus on the beneficial effects of PSB on crop performance and related mechanisms, while few of them elucidate the action mechanisms of PSB in soil-microbe-plant interactions for crop cultivation with high yield efficiency. Hence, this study provides a comprehensive review of the physicochemical and molecular mechanisms (e.g., root exudates, extracellular polysaccharides, organic acids, phosphatases, and phosphate-specific transport systems) of PSB to facilitate the P cycle in the soil-plant systems. Further, the potential of commercial applications of PSB (e.g., genetic engineering, seed priming and coating) are also discussed in order to highlight their contribution to sustainable agriculture. Finally, existing challenges and future prospects in agricultural applications are proposed. In conclusion, we firmly believe that PSB represent a highly significant biotechnological tool for enhancing agricultural productivity and offers a wide range of extensive potential applications.

Butyrate Inhibits Dendritic Cell Activation and Alleviates Periodontitis

Dendritic cells (DCs) can mediate inflammation-related bone resorption that is crucial in the development of periodontitis. Butyrate is a critical by-product of microbes with antibacterial and anti-inflammatory properties. Here, we found that butyrate inhibited the activation of lipopolysaccharide (LPS)-induced DCs and generation of inflammatory cytokines by DCs. Moreover, butyrate regulated glycolysis in LPS-induced DCs via the G-protein-coupled receptor/hypoxia-inducible factor-1α pathway. In addition, butyrate inhibited the maturation of CD11c+MHC-II+ DCs in vivo, suppressing local inflammatory infiltration and ultimately alleviating bone resorption in a periodontitis model. Our results imply that butyrate suppresses the activation of LPS-induced DCs by modulating their metabolism, highlighting its potential as a therapeutic agent for inflammatory diseases.

High temperature stress induced oxidative stress, gut inflammation and disordered metabolome and microbiome in tsinling lenok trout

Tsinling lenok trout (Brachymystax lenok tsinlingensis Li) is a species of cold-water salmon that faces serious challenges due to global warming. High temperature stress has been found to damage the gut integrity of cold-water fish, impacting their growth and immunity. However, limited research exists on the causal relationship between gut microbial disturbance and metabolic dysfunction in cold-water fish induced by high temperature stress. To address this gap, we conducted a study to investigate the effects of high temperature stress (24 °C) on the gut tissue structure, antioxidant capacity, gut microorganisms, and metabolome reactions of tsinling lenok trout. Our analysis using 16 S rDNA gene sequencing revealed significant changes in the gut microbial composition and metabolic profile. Specifically, the abundance of Firmicutes and Gemmatimonadetes decreased significantly with increasing temperature, while the abundance of Bacteroidetes increased significantly. Metabolic analysis revealed a significant decrease in the abundance of glutathione, which is synthesized from glutamate and glycine, under high temperature stress. Additionally, there was a notable reduction in the levels of adenosine, inosine, xanthine, guanosine, and deoxyguanosine, which are essential for DNA/RNA synthesis. Conversely, there was a significant increase in the abundance of D-glucose 6 P. Furthermore, high temperature stress adversely affects intestinal structure and barrier function. Our findings provide valuable insights into the mechanism of high temperature stress in cold-water fish and serve as a foundation for future research aimed at mitigating the decline in production performance caused by such stress.

Metabolic engineering of commensal bacteria for gut butyrate delivery and dissection of host-microbe interaction

An overwhelming number of studies have reported the correlation of decreased abundance of butyrate-producing commensals with a wide range of diseases. However, the molecular-level mechanisms whereby gut butyrate causally affects the host mucosal immunity and pathogenesis were poorly understood, hindered by the lack of efficient tools to control intestinal butyrate. Here we engineered a facultative anaerobic commensal bacterium to delivery butyrate at the intestinal mucosal surface, and implemented it to dissect the causal role of gut butyrate in regulating host intestinal homeostasis in a model of murine chronic colitis. Mechanistically, we show that gut butyrate protected against colitis and preserved intestinal mucosal homeostasis through its inhibiting effect on the key pyroptosis executioner gasdermin D (GSDMD) of colonic epithelium, via functioning as an HDAC3 inhibitor. Overall, our work presents a new avenue to build synthetic living delivery bacteria to decode causal molecules at the host-microbe interface with molecular-level insights.

Association analysis of the gut microbiota in predicting outcomes for patients with acute ischemic stroke and H-type hypertension

Introduction

H-type hypertension (HHTN) is a subtype of hypertension that tends to worsen the prognosis of acute ischemic stroke (AIS). Recent studies have highlighted the vital role of gut microbiota in both hypertension and AIS, but there is little available data on the relationship between gut microbiota and the progression of AIS patients with HHTN. In this study, we investigated the microbial signature of AIS patients with HHTN and identified characteristic bacteria as biomarkers for predicting prognosis.

Methods

AIS patients with HHTN (n = 150) and without HHTN (n = 50) were enrolled. All patients received a modified Rankin Scale (mRS) assessment at 3 months after discharge. Fecal samples were collected from the participants upon admission, including 150 AIS patients with HHTN, 50 AIS patients with non-HHTN, and 90 healthy subjects with HHTN. These samples were analyzed using 16S rRNA sequencing to characterize the bacterial taxa, predict functions, and conduct correlation analysis between specific taxa and clinical features.

Results

Our results showed that the composition of the gut microbiota in HHTN patients differed significantly from that in non-HHTN patients. The abundance of the genera Bacteroides, Escherichia-Shigella, Lactobacillus, Bifidobacterium, and Prevotella in AIS patients with HHTN was significantly increased compared to AIS patients without HHTN, while the genus Streptococcus, Faecalibacterium, and Klebsiella were significantly decreased. Moreover, Bacteroides, Lactobacillus, Bifidobacterium, and Klebsiella in AIS patients with HHTN were more abundant than healthy subjects with HHTN, while Escherichia-Shigella, Blautia, and Faecalibacterium were less abundant. Moreover, the genera Butyricicoccus, Rothia, and Family_XIII_UCG-001 were negatively connected with the NIHSS score, and the genera Butyricicoccus and Rothia were observed to be negatively associated with the mRS score. The genera Butyricicoccus, Romboutsia, and Terrisporobacter were associated with a poor prognosis, whereas the increase in Butyricimonas and Odoribacter was correlated with good outcomes. Generated by eight genera and clinical indexes, the area under the curve (AUC) value of the receiver operating characteristic (ROC) curve achieved 0.739 to effectively predict the prognosis of AIS patients with HHTN.

Conclusion

These findings revealed the microbial signature of AIS patients with HHTN and further provided potential microbial biomarkers for the clinical diagnosis of AIS patients with HHTN.

Endocrine, genetic, and microbiome nexus of obesity and potential role of postbiotics: a narrative review

Obesity is a public health crisis, presenting a huge burden on health care and the economic system in both developed and developing countries. According to the WHO's latest report on obesity, 39% of adults of age 18 and above are obese, with an increase of 18% compared to the last few decades. Metabolic energy imbalance due to contemporary lifestyle, changes in gut microbiota, hormonal imbalance, inherent genetics, and epigenetics is a major contributory factor to this crisis. Multiple studies have shown that probiotics and their metabolites (postbiotics) supplementation have an effect on obesity-related effects in vitro, in vivo, and in human clinical investigations. Postbiotics such as the SCFAs suppress obesity by regulating metabolic hormones such as GLP-1, and PPY thus reducing feed intake and suppressing appetite. Furthermore, muramyl di-peptides, bacteriocins, and LPS have been tested against obesity and yielded promising results in both human and mice studies. These insights provide an overview of targetable pharmacological sites and explore new opportunities for the safer use of postbiotics against obesity in the future.