Gut microbiota promotes macrophage M1 polarization in hepatic sinusoidal obstruction syndrome via regulating intestinal barrier function mediated by butyrate.

BACKGROUND: The intestinal-liver axis is associated with various liver diseases. Here, we verified the role of the gut microbiota and macrophage activation in the progression of pyrrolizidine alkaloids-induced hepatic sinusoidal obstruction syndrome (PA-HSOS), and explored the possible mechanisms and new treatment options. METHODS: The HSOS murine model was induced by gavage of monocrotaline (MCT). An analysis of 16S ribosomal DNA (16S rDNA) of the feces was conducted to determine the composition of the fecal microbiota. Macrophage clearance, fecal microbiota transplantation (FMT), and butyrate supplementation experiments were used to assess the role of intestinal flora, gut barrier, and macrophage activation and to explore the relationships among these three variables. RESULTS: Activated macrophages and low microflora diversity were observed in HSOS patients and murine models. Depletion of macrophages attenuated inflammatory reactions and apoptosis in the mouse liver. Moreover, compared with control-FMT mice, the exacerbation of severe liver injury was detected in HSOS-FMT mice. Specifically, butyrate fecal concentrations were significantly reduced in HSOS mice, and administration of butyrate could partially alleviated liver damage and improved the intestinal barrier in vitro and in vivo. Furthermore, elevated lipopolysaccharides in the portal vein and high proportions of M1 macrophages in the liver were also detected in HSOS-FMT mice and mice without butyrate treatment, which resulted in severe inflammatory responses and further accelerated HSOS progression. CONCLUSIONS: These results suggested that the gut microbiota exacerbated HSOS progression by regulating macrophage M1 polarization via altered intestinal barrier function mediated by butyrate. Our study has identified new strategies for the clinical treatment of HSOS.

Exploring the butyrate metabolism-related shared genes in metabolic associated steatohepatitis and ulcerative colitis.

Metabolic-associated steatohepatitis (MASH) and ulcerative colitis (UC) exhibit a complex interconnection with immune dysfunction, dysbiosis of the gut microbiota, and activation of inflammatory pathways. This study aims to identify and validate critical butyrate metabolism-related shared genes between both UC and MASH. Clinical information and gene expression profiles were sourced from the Gene Expression Omnibus (GEO) database. Shared butyrate metabolism-related differentially expressed genes (sBM-DEGs) between UC and MASH were identified via various bioinformatics methods. Functional enrichment analysis was performed, and UC patients were categorized into subtypes using the consensus clustering algorithm based on sBM-DEGs. Key genes within sBM-DEGs were screened through Random Forest, Support Vector Machines-Recursive Feature Elimination, and Light Gradient Boosting. The diagnostic efficacy of these genes was evaluated using receiver operating characteristic (ROC) analysis on independent datasets. Additionally, the expression levels of characteristic genes were validated across multiple independent datasets and human specimens. Forty-nine shared DEGs between UC and MASH were identified, with enrichment analysis highlighting significant involvement in immune, inflammatory, and metabolic pathways. The intersection of butyrate metabolism-related genes with these DEGs produced 10 sBM-DEGs. These genes facilitated the identification of molecular subtypes of UC patients using an unsupervised clustering approach. ANXA5, CD44, and SLC16A1 were pinpointed as hub genes through machine learning algorithms and feature importance rankings. ROC analysis confirmed their diagnostic efficacy in UC and MASH across various datasets. Additionally, the expression levels of these three hub genes showed significant correlations with immune cells. These findings were validated across independent datasets and human specimens, corroborating the bioinformatics analysis results. Integrated bioinformatics identified three significant biomarkers, ANXA5, CD44, and SLC16A1, as DEGs linked to butyrate metabolism. These findings offer new insights into the role of butyrate metabolism in the pathogenesis of UC and MASH, suggesting its potential as a valuable diagnostic biomarker.

Butyrate induces higher host transcriptional changes to inhibit porcine epidemic diarrhea virus strain CV777 infection in porcine intestine epithelial cells.

Newborn piglets' health is seriously threatened by the porcine epidemic diarrhea virus (PEDV), which also has a significant effect on the pig industry. The gut microbiota produces butyrate, an abundant metabolite that modulates intestinal function through many methods to improve immunological and intestinal barrier function. The objective of this investigation was to ascertain how elevated butyrate concentrations impacted the host transcriptional profile of PEDV CV777 strain infection. Our findings showed that higher concentrations of butyrate have a stronger inhibitory effect on PEDV CV777 strain infection. According to RNA-seq data, higher concentrations of butyrate induced more significant transcriptional changes in IPEC-J2 cells, and signaling pathways such as PI3K-AKT may play a role in the inhibition of PEDV CV777 strain by high concentrations of butyrate. Ultimately, we offer a theoretical and experimental framework for future research and development of novel approaches to harness butyrate's antiviral infection properties.

The effect of hydroxy-selenomethionine on the productive and reproductive performance of old broiler breeders.

BACKGROUND: Selenium (Se) is a rare essential element that plays a vital role in the health and performance of animals. By interfering in the production of antioxidant enzymes such as glutathione peroxidase, thioredoxin reductase and methionine sulfoxide, Se plays a role in reducing the effects of oxidative stress and animal performance. OBJECTIVES: This study aimed to investigate the effect of hydroxy-selenomethionine (OH-SeMet) in the diet of broiler breeder and old broiler breeder roosters on productive performance, reproduction and sperm quality parameters. METHODS: For this purpose, 260 broiler breeders of the Ross 308 strain were used in a completely randomized design with four treatments and five replications (13 hens and one rooster in each replication). Experimental treatments included: (1) a basal diet without OH-SeMet (T1:control), (2) a broiler breeder diet without OH-SeMet and a rooster diet containing 0.1 mg/kg OH-SeMet (T2), (3) broiler breeder diet containing 0.1 mg/kg OH-SeMet and rooster diet without OH-SeMet (T3) and (4) broiler breeder and rooster diet contained 0.1 mg/kg OH-SeMet (T4). RESULTS: The results showed that T3 and T4 treatments improved egg production, egg weight, egg mass and feed conversion ratio (FCR) compared to the control treatment (p < 0.05). The fertility and hatchability percentages of T4 and T2 treatments increased compared to T1 and T3 treatments (p < 0.05). The rate of embryonic losses in T1 was higher than in other treatments. However, grade one chickens were higher in T4 than in other treatments (p < 0.05). Total motility and viability of sperms were significantly higher in T2 and T4 treatments than in T1 and T3 treatments. The sperm abnormality percentage and sperm MDA concentration decreased in T2 and T4 treatments. CONCLUSIONS: Therefore, using OH-SeMet may be a practical approach to help old broiler breeders' production and reproduction performance.

The Postbiotic Properties of Butyrate in the Modulation of the Gut Microbiota: The Potential of Its Combination with Polyphenols and Dietary Fibers.

The gut microbiota is a diverse bacterial community consisting of approximately 2000 species, predominantly from five phyla: Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Verrucomicrobia. The microbiota's bacterial species create distinct compounds that impact the host's health, including well-known short-chain fatty acids. These are produced through the breakdown of dietary fibers and fermentation of undigested carbohydrates by the intestinal microbiota. The main short-chain fatty acids consist of acetate, propionate, and butyrate. The concentration of butyrate in mammalian intestines varies depending on the diet. Its main functions are use as an energy source, cell differentiation, reduction in the inflammatory process in the intestine, and defense against oxidative stress. It also plays an epigenetic role in histone deacetylases, thus helping to reduce the risk of colon cancer. Finally, butyrate affects the gut-brain axis by crossing the brain-blood barrier, making it crucial to determine the right concentrations for both local and peripheral effects. In recent years, there has been a significant amount of attention given to the role of dietary polyphenols and fibers in promoting human health. Polyphenols and dietary fibers both play crucial roles in protecting human health and can produce butyrate through gut microbiota fermentation. This paper aims to summarize information on the key summits related to the negative correlation between intestinal microbiota diversity and chronic diseases to guide future research on determining the specific activity of butyrate from polyphenols and dietary fibers that can carry out these vital functions.

Pan-serotype dengue virus inhibitor JNJ-A07 targets NS4A-2K-NS4B interaction with NS2B/NS3 and blocks replication organelle formation.

Dengue fever represents a significant medical and socio-economic burden in (sub)tropical regions, yet antivirals for treatment or prophylaxis are lacking. JNJ-A07 was described as highly active against the different genotypes within each serotype of the disease-causing dengue virus (DENV). Based on clustering of resistance mutations it has been assumed to target DENV non-structural protein 4B (NS4B). Using a photoaffinity labeling compound with high structural similarity to JNJ-A07, here we demonstrate binding to NS4B and its precursor NS4A-2K-NS4B. Consistently, we report recruitment of the compound to intracellular sites enriched for these proteins. We further specify the mechanism-of-action of JNJ-A07, which has virtually no effect on viral polyprotein cleavage, but targets the interaction between the NS2B/NS3 protease/helicase complex and the NS4A-2K-NS4B cleavage intermediate. This interaction is functionally linked to de novo formation of vesicle packets (VPs), the sites of DENV RNA replication. JNJ-A07 blocks VPs biogenesis with little effect on established ones. A similar mechanism-of-action was found for another NS4B inhibitor, NITD-688. In summary, we unravel the antiviral mechanism of these NS4B-targeting molecules and show how DENV employs a short-lived cleavage intermediate to carry out an early step of the viral life cycle.

Rumen and hindgut microbiome regulate average daily gain of preweaning Holstein heifer calves in different ways.

BACKGROUND: The average daily gain (ADG) of preweaning calves significantly influences their adult productivity and reproductive performance. Gastrointestinal microbes are known to exert an impact on host phenotypes, including ADG. The aim of this study was to investigate the mechanisms by which gastrointestinal microbiome regulate ADG in preweaning calves and to further validate them by isolating ADG-associated rumen microbes in vitro. RESULTS: Sixteen Holstein heifer calves were selected from a cohort with 106 calves and divided into higher ADG (HADG; n = 8) and lower ADG (LADG; n = 8) groups. On the day of weaning, samples of rumen contents, hindgut contents, and plasma were collected for rumen metagenomics, rumen metabolomics, hindgut metagenomics, hindgut metabolomics, and plasma metabolomics analyses. Subsequently, rumen contents of preweaning Holstein heifer calves from the same dairy farm were collected to isolate ADG-associated rumen microbes. The results showed that the rumen microbes, including Pyramidobacter sp. C12-8, Pyramidobacter sp. CG50-2, Pyramidobacter porci, unclassified_g_Pyramidobacter, Pyramidobacter piscolens, and Acidaminococcus fermentans, were enriched in the rumen of HADG calves (LDA > 2, P < 0.05). Enrichment of these microbes in HADG calves' rumen promoted carbohydrate degradation and volatile fatty acid production, increasing proportion of butyrate in the rumen and ultimately contributing to higher preweaning ADG in calves (P < 0.05). The presence of active carbohydrate degradation in the rumen was further suggested by the negative correlation of the rumen microbes P. piscolens, P. sp. C12-8 and unclassified_g_Pyramidobacter with the rumen metabolites D-fructose (R < - 0.50, P < 0.05). Widespread positive correlations were observed between rumen microbes (such as P. piscolens, P. porci, and A. fermentans) and beneficial plasma metabolites (such as 1-pyrroline-5-carboxylic acid and 4-fluoro-L-phenylalanine), which were subsequently positively associated with the growth rate of HADG calves (R > 0.50, P < 0.05). We succeeded in isolating a strain of A. fermentans from the rumen contents of preweaning calves and named it Acidaminococcus fermentans P41. The in vitro cultivation revealed its capability to produce butyrate. In vitro fermentation experiments demonstrated that the addition of A. fermentans P41 significantly increased the proportion of butyrate in the rumen fluid (P < 0.05). These results further validated our findings. The relative abundance of Bifidobacterium pseudolongum in the hindgut of HADG calves was negatively correlated with hindgut 4-hydroxyglucobrassicin levels, which were positively correlated with plasma 4-hydroxyglucobrassicin levels, and plasma 4-hydroxyglucobrassicin levels were positively correlated with ADG (P < 0.05). CONCLUSIONS: This study's findings unveil that rumen and hindgut microbes play distinctive roles in regulating the preweaning ADG of Holstein heifer calves. Additionally, the successful isolation of A. fermentans P41 not only validated our findings but also provided a valuable strain resource for modulating rumen microbes in preweaning calves. Video Abstract.

Facile synthesis of elastin nanogels encapsulated decursin for castrated resistance prostate cancer therapy.

Nanogels offer hope for precise drug delivery, while addressing drug delivery hurdles is vital for effective prostate cancer (PCa) management. We developed an injectable elastin nanogels (ENG) for efficient drug delivery system to overcome castration-resistant prostate cancer (CRPC) by delivering Decursin, a small molecule inhibitor that blocks Wnt/ßcatenin pathways for PCa. The ENG exhibited favourable characteristics such as biocompatibility, flexibility, and low toxicity. In this study, size, shape, surface charge, chemical composition, thermal stability, and other properties of ENG were used to confirm the successful synthesis and incorporation of Decursin (DEC) into elastin nanogels (ENG) for prostate cancer therapy. In vitro studies demonstrated sustained release of DEC from the ENG over 120 h, with a pH-dependent release pattern. DU145 cell line induces moderate cytotoxicity of DEC-ENG indicates that nanomedicine has an impact on cell viability and helps strike a balance between therapeutics efficacy and safety while the EPR effect enables targeted drug delivery to prostate tumor sites compared to free DEC. Morphological analysis further supported the effectiveness of DEC-ENG in inducing cell death. Overall, these findings highlight the promising role of ENG-encapsulated decursin as a targeted drug delivery system for CRPC.

Phenylalanine Butyramide: A Butyrate Derivative as a Novel Inhibitor of Tyrosinase.

Metabolites resulting from the bacterial fermentation of dietary fibers, such as short-chain fatty acids, especially butyrate, play important roles in maintaining gut health and regulating various biological effects in the skin. However, butyrate is underutilized due to its unpleasant odor. To circumvent this organoleptic unfavorable property, phenylalanine butyramide (PBA), a butyrate precursor, has been synthesized and is currently available on the market. We evaluated the inhibition of mushroom tyrosinase by butyrate and PBA through in vitro assays, finding IC50 values of 34.7 mM and 120.3 mM, respectively. Docking calculations using a homology model of human tyrosinase identified a putative binding mode of PBA into the catalytic site. The anti-aging and anti-spot efficacy of topical PBA was evaluated in a randomized, double-blind, parallel-arm, placebo-controlled clinical trial involving 43 women affected by photo-damage. The results of this study showed that PBA significantly improved skin conditions compared to the placebo and was well tolerated. Specifically, PBA demonstrated strong skin depigmenting activity on both UV and brown spots (UV: -12.7% and -9.9%, Bs: -20.8% and -17.7% after 15 and 30 days, respectively, p < 0.001). Moreover, PBA brightened and lightened the skin (ITA°: +12% and 13% after 15 and 30 days, respectively, p < 0.001). Finally, PBA significantly improved skin elasticity (Ua/Uf: +12.4% and +32.3% after 15 and 30 days, respectively, p < 0.001) and firmness (Uf: -3.2% and -14.9% after 15 and 30 days, respectively, p < 0.01).

Effects of short-chain fatty acid-butyrate supplementation on expression of circadian-clock genes, sleep quality, and inflammation in patients with active ulcerative colitis: a double-blind randomized controlled trial.

BACKGROUND: The regulation of the circadian clock genes, which coordinate the activity of the immune system, is disturbed in inflammatory bowel disease (IBD). Emerging evidence suggests that butyrate, a short-chain fatty acid produced by the gut microbiota is involved in the regulation of inflammatory responses as well as circadian-clock genes. This study was conducted to investigate the effects of sodium-butyrate supplementation on the expression of circadian-clock genes, inflammation, sleep and life quality in active ulcerative colitis (UC) patients. METHODS: In the current randomized placebo-controlled trial, 36 active UC patients were randomly divided to receive sodium-butyrate (600 mg/kg) or placebo for 12-weeks. In this study the expression of circadian clock genes (CRY1, CRY2, PER1, PER2, BMAl1 and CLOCK) were assessed by real time polymerase chain reaction (qPCR) in whole blood. Gene expression changes were presented as fold changes in expression (2^-ΔΔCT) relative to the baseline. The faecal calprotectin and serum level of high-sensitivity C-reactive protein (hs-CRP) were assessed by enzyme-linked immunosorbent assay method (ELIZA). Moreover, the sleep quality and IBD quality of life (QoL) were assessed by Pittsburgh sleep quality index (PSQI) and inflammatory bowel disease questionnaire-9 (IBDQ-9) respectively before and after the intervention. RESULTS: The results showed that sodium-butyrate supplementation in comparison with placebo significantly decreased the level of calprotectin (-133.82 ± 155.62 vs. 51.58 ± 95.57, P-value < 0.001) and hs-CRP (-0.36 (-1.57, -0.05) vs. 0.48 (-0.09-4.77), P-value < 0.001) and upregulated the fold change expression of CRY1 (2.22 ± 1.59 vs. 0.63 ± 0.49, P-value < 0.001), CRY2 (2.15 ± 1.26 vs. 0.93 ± 0.80, P-value = 0.001), PER1 (1.86 ± 1.77 vs. 0.65 ± 0.48, P-value = 0.005), BMAL1 (1.85 ± 0.97 vs. 0.86 ± 0.63, P-value = 0.003). Also, sodium-butyrate caused an improvement in the sleep quality (PSQI score: -2.94 ± 3.50 vs. 1.16 ± 3.61, P-value < 0.001) and QoL (IBDQ-9: 17.00 ± 11.36 vs. -3.50 ± 6.87, P-value < 0.001). CONCLUSION: Butyrate may be an effective adjunct treatment for active UC patients by reducing biomarkers of inflammation, upregulation of circadian-clock genes and improving sleep quality and QoL.

Dietary Fiber-Derived Microbial Butyrate Suppresses ILC2-Dependent Airway Inflammation in COPD.

Group 2 innate lymphoid cells (ILC2) strongly modulate COPD pathogenesis. However, the significance of microbiota in ILC2s remains unelucidated. Herein, we investigated the immunomodulatory role of short-chain fatty acids (SCFAs) in regulating ILC2-associated airway inflammation and explores its associated mechanism in COPD. In particular, we assessed the SCFA-mediated regulation of survival, proliferation, and cytokine production in lung sorted ILC2s. To elucidate butyrate action in ILC2-driven inflammatory response in COPD models, we administered butyrate to BALB/c mice via drinking water. We revealed that SCFAs, especially butyrate, derived from dietary fiber fermentation by gut microbiota inhibited pulmonary ILC2 functions and suppressed both IL-13 and IL-5 synthesis by murine ILC2s. Using in vivo and in vitro experimentation, we validated that butyrate significantly ameliorated ILC2-induced inflammation. We further demonstrated that butyrate suppressed ILC2 proliferation and GATA3 expression. Additionally, butyrate potentially utilized histone deacetylase (HDAC) inhibition to enhance NFIL3 promoter acetylation, thereby augmenting its expression, which eventually inhibited cytokine production in ILC2s. Taken together, the aforementioned evidences demonstrated a previously unrecognized role of microbial-derived SCFAs on pulmonary ILC2s in COPD. Moreover, our evidences suggest that metabolomics and gut microbiota modulation may prevent lung inflammation of COPD.

Dietary Fiber-Derived Butyrate Alleviates Piglet Weaning Stress by Modulating the TLR4/MyD88/NF-κB Pathway.

During weaning, piglets are susceptible to intestinal inflammation and impairment in barrier function. Dietary fiber (DF) plays an active role in alleviating weaning stress in piglets. However, the effects of different sources of dietary fiber on the performance of weaned piglets are inconsistent, and the mechanisms through which they affect intestinal health need to be explored. Therefore, in this study, sixty weaned piglets were randomly divided into three treatment groups: basal diet (control, CON), beet pulp (BP), and alfalfa meal (AM) according to the feed formulation for a 28-day trial. The results showed that both AM and BP groups significantly reduced diarrhea rate and serum inflammatory factors (IL-1ß and TNF-α) and increased antioxidant markers (T-AOC and SOD), in addition to decreasing serum MDA and ROS concentrations in the AM group. At the same time, piglets in the AM group showed a significant reduction in serum intestinal permeability indices (LPS and DAO) and a substantial increase in serum immunoglobulin levels (IgA, IgG, and IgM) and expression of intestinal barrier-associated genes (Claudin1, Occludin, ZO-1, and MUC1), which resulted in an improved growth performance. Interestingly, the effect of DF on intestinal inflammation and barrier function can be attributed to its modulation of gut microbes. Fiber-degrading bacteria enriched in the AM group (Christensenellaceae_R-7_group, Pediococcus and Weissella) inhibited the production of TLR4- through the promotion of SCFAs (especially butyrate). MyD88-NF-κB signaling pathway activation reduces intestinal inflammation and repairs intestinal barrier function. In conclusion, it may provide some theoretical support and rationale for AM to alleviate weaning stress and improve early intestinal dysfunction, which may have implications for human infants.

Long-Term pemafibrate treatment exhibits limited impact on body fat mass in patients with hypertriglyceridemia accompanying NAFLD.

Aim: Short-term use of pemafibrate (PEM), a selective modulator of peroxisome proliferator-activated receptor alpha, has been reported to improve abnormal liver function in patients with nonalcoholic fatty liver disease with hypertriglyceridemia (HTG-NAFLD). This study aimed to clarify the effects and predictive factors of long-term 72-week PEM administration on body composition, and laboratory tests in HTG-NAFLD patients. Methods: Fifty-three HTG-NAFLD patients receiving a 72-week PEM regimen were retrospectively enrolled. Routine blood and body composition results were analyzed immediately before and at the end of the study period. Results: PEM treatment significantly improved liver enzyme levels such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, and gamma-glutamyl transferase, along with lipid profiles including triglyceride, total cholesterol, and low-density lipoprotein cholesterol. PEM did not have any detectable impact on body composition parameters. The factors of female, higher AST (≥ 46 U/L) and fat mass (≥ 31.9%), as well as lower soft lean mass (< 61.6%), skeletal muscle mass (< 36%), and skeletal muscle mass index (< 6.9 kg/m2) were significantly associated with the treatment response status of a > 30% decrease in ALT. All patients completed the treatment without any adverse effects. Conclusions: Long-term PEM treatment had a positive impact on liver enzymes and lipid profiles, but it did not result in significant changes in body composition among HTG-NAFLD patients. In predicting the response to PEM treatment, the evaluation of AST and body composition may be useful.

Microbial metabolite butyrate modulates granzyme B in tolerogenic IL-10 producing Th1 cells to regulate intestinal inflammation.

CD4+ T cells play a critical role in regulating autoimmune diseases, and intestinal microbial metabolites control various immune responses. Granzyme B (GzmB)-producing CD4+ T cells have been recently reported to participate in the pathogenesis of autoimmune diseases. Here, we found that GzmbB-deficient CD4+ T cells induced more severe colitis in Rag1-/- mice than wild-type (WT) CD4+ T cells. Germ-free (GF) mice exhibited a lower expression of GzmB in intestinal CD4+ T cells compared to specific pathogen-free (SPF) mice. Intestinal microbial metabolite butyrate increased GzmB expression in CD4+ T cells, especially in IL-10-producing Th1 cells, through HDAC inhibition and GPR43, but not GPR41 and GPR109a. Butyrate-treated GzmB-deficient CD4+ T cells demonstrated more severe colitis compared to butyrate-treated WT CD4+ T cells in the T cell transfer model. Butyrate altered intestinal microbiota composition, but altered microbiota did not mediate butyrate induction of intestinal CD4+ T cell expression of GzmB in mice. Blimp1 was involved in the butyrate induction of GzmB in IL-10-producing Th1 cells. Glucose metabolism, including glycolysis and pyruvate oxidation, mediated butyrate induction of GzmB in Th1 cells. In addition, we found that IKZF3 and NR2F6 regulated GzmB expression induced by butyrate. Together, our studies underscored the critical role of GzmB in mediating gut bacterial metabolite butyrate regulation of T cell tolerance at the mucosal surface.

A synbiotic of Anaerostipes caccae and lactulose prevents and treats food allergy in mice.

Depletion of beneficial microbes by modern lifestyle factors correlates with the rising prevalence of food allergies. Re-introduction of allergy-protective bacteria may be an effective treatment strategy. We characterized the fecal microbiota of healthy and food-allergic infants and found that the anaerobe Anaerostipes caccae (A. caccae) was representative of the protective capacity of the healthy microbiota. We isolated a strain of A. caccae from the feces of a healthy infant and identified lactulose as a prebiotic to optimize butyrate production by A. caccae in vitro. Administration of a synbiotic composed of our isolated A. caccae strain and lactulose increased luminal butyrate in gnotobiotic mice colonized with feces from an allergic infant and in antibiotic-treated specific pathogen-free (SPF) mice, and prevented or treated an anaphylactic response to allergen challenge. The synbiotic's efficacy in two models and microbial contexts suggests that it may be a promising approach for the treatment of food allergy.

Butyrate inhibits the malignant biological behaviors of breast cancer cells by facilitating cuproptosis-associated gene expression.

BACKGROUND: Butyrate is a common short-chain fatty acids (SCFA), and it has been demonstrated to regulate the development of breast cancer (BC), while the underlying mechanism is still unreported. METHODS: Gas chromatography was used to measure the amounts of SCFA (acetate, propionate, and butyrate) in the feces. Cell viability was measured by the CCK-8 assay. The wound healing assay demonstrated cell migration, and the transwell assay demonstrated cell invasion. The levels of protein and gene were determined by western blot assay and RT-qPCR assay, respectively. RESULTS: The levels of SCFA were lower in the faecal samples from BC patients compared to control samples. In cellular experiments, butyrate significantly suppressed the cell viability, migration and invasion of T47D in a dose-dependent manner. In animal experiments, butyrate effectively impeded the growth of BC tumors. Toll like receptor 4 (TLR4) was highly expressed in the tumors from BC patients. Butyrate inhibited the expression of TLR4. In addition, butyrate promoted the expression of cuproptosis-related genes including PDXK (pyridoxal kinase) and SLC25A28 (solute carrier family 25 member 28), which was lowly expressed in BC tumors. Importantly, overexpression of TLR4 can reverses the promotion of butyrate to PDXK and SLC25A28 expression and the prevention of butyrate to the malignant biological behaviors of T47D cells. CONCLUSION: In summary, butyrate inhibits the development of BC by facilitating the expression of PDXK and SLC25A28 through inhibition of TLR4. Our investigation first identified a connection among butyrate, TLR4 and cuproptosis-related genes in BC progression. These findings may provide novel target for the treatment of BC.

Methanol as a co-substrate with CO2 enhances butyrate production in microbial electrosynthesis.

Methanol is a promising feedstock for the bio-based economy as it can be derived from organic waste streams or produced electrochemically from CO2. Acetate production from CO2 in microbial electrosynthesis (MES) has been widely studied, while more valuable compounds such as butyrate are currently attracting attention. In this study, methanol was used as a co-substrate with CO2 to enhance butyrate production in MES. Feeding with CO2 and methanol resulted in the highest butyrate production rates and titres of 0.36 ± 0.01 g L-1 d-1 and 8.6 ± 0.2 g L-1, respectively, outperforming reactors with only CO2 feeding (0.20 ± 0.03 g L-1 d-1 and 5.2 ± 0.1 g L-1, respectively). Methanol acted as electron donor and as carbon source, both of which contributed ca. 50% of the carbon in the products. Eubacterium was the dominant genus with 52.6 ± 2.5% relative abundance. Thus, we demonstrate attractive route for the use of the C1 substrates, CO2 and methanol, to produce mainly butyrate. KEY POINTS: • Butyrate was the main product from methanol and CO2 in MES • Methanol acted as both carbon and electron source in MES • Eubacterium dominating microbial culture was enriched in MES.

Targeted microbial collaboration to enhance key flavor metabolites by inoculating Clostridium tyrobutyricum and Saccharomyces cerevisiae in the strong-flavor Baijiu simulated fermentation system.

Ethyl hexanoate and ethyl butyrate are indispensable flavor metabolites in strong-flavor Baijiu (SFB), but batch production instability in fermenting grains can reduce the quality of distilled Baijiu. Biofortification of the fermentation process by designing a targeted microbial collaboration pattern is an effective method to stabilize the quality of Baijiu. In this study, we explored the metabolism under co-culture liquid fermentation with Clostridium tyrobutyricum DB041 and Saccharomyces cerevisiae YS219 and investigated the effects of inoculation with two functional microorganisms on physicochemical factors, flavor metabolites, and microbial communities in solid-state simulated fermentation of SFB for the first time. The headspace solid-phase microextraction-gas chromatography-mass spectrometry results showed that ethyl butyrate and ethyl hexanoate significantly increased in fermented grain. High-throughput sequencing analysis showed that Pediococcus, Lactobacillus, Weissella, Clostridium_sensu_stricto_12, and Saccharomyces emerged as the dominant microorganisms at the end of fermentation. Co-occurrence analysis showed that ethyl hexanoate and ethyl butyrate were significantly correlated (|r| > 0.5, P < 0.05) with a cluster of interactions dominated by lactic acid bacteria (Pediococcus, Lactobacillus, Weissella, and Lactococcus), which was driven by the functional C. tyrobutyricum and S. cerevisiae. Mantel test showed that moisture and reducing sugars were the main physicochemical factor affecting microbial collaboration (|r| > 0.7, P < 0.05). Taken together, the collaborative microbial pattern of inoculation with C. tyrobutyricum and S. cerevisiae showed positive results in enhancing typical flavor metabolites and the synergistic effects of microorganisms in SFB.

Structural changes and degradation mechanism of type 3 resistant starch during in vitro fecal fermentation.

The colonic fermentation metabolites of resistant starch (RS) are recognized to have various health benefits. However, the relationship between the structural variation of RS and the colonic fermentation properties, remains inadequately studied, especially for type 3 resistant starch. The in vitro fecal fermentation properties with multi-structure evolution of A- and B-type polymorphic resistant starch spherulites (RSS) were investigated. Both polymorphic types of RSS showed similar fermentation rate and total short-chain fatty acid profiles, while the butyrate concentration of the A-type RSS subjected to 24 h of fermentation was significantly higher compared to B-type RSS. In the case of recrystallized starch spherulites, irrespective of the polymorphic type, gut bacteria preferentially degraded the intermediate chains and crystalline regions, as the local molecule-ordered area potentially serves as suitable attachment sites or surfaces for microbial enzymes.