Butyrate Synthesis Research Articles

Strategies for enhancing short- and medium-chain fatty acids synthesis from corn stover-based sugar: A new perspective on co-culture

In this study, corn stover-based sugar served as the initial carbon source to investigate the impact of different co-culture strategies on the synthesis of short- and medium-chain fatty acids (SMCFAs) through carbon chain elongation (CCE). The results indicated that the sequential inoculation outperformed simultaneous inoculation in the M. elsdenii and Lactobacillus groups. The inclusion of Lactobacillus significantly enhanced substrate utilization, generating lactate that facilitated the integration of odd carbon carboxylates (such as propionate and valerate) into the CCE products. The caproate concentration in the M. elsdenii+L. pentosus group reached 3.4 g/L, which was 1.3 times that in the control group. Furthermore, the introduction of C. kluyveri effectively boosted the synthesis of butyrate and caproate through CCE using ethanol as an electron donor within the co-culture setup of the M. elsdenii+C. kluyveri group. Moreover, the carbon efficiency of the co-culture group increased by 10–21 % compared to the control group, and the cell protein titer was 1.5–2 times higher than that of the control group. This study has established a method for co-producing SMCFAs and cell proteins utilizing bio-sugars through a co-culture approach, offering implications for lignocellulose utilization and potential high-value applications of SMCFAs in the future.

The role of gut microbiota involved in prostate microenvironment and symptoms improvement in chronic prostatitis/chronic pelvic pain syndrome patients treated with low-intensity extracorporeal shock wave.

Low-intensity extracorporeal shockwave therapy (Li-ESWT) is emerging as a promising and safe treatment for Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). In this study, we aimed to investigate the role of the gut microbiota involved in the prostate microenvironment and symptom improvement during the Li-ESWT for CP/CPPS patients. CP/CPPS patients not taking antibiotics or other treatments were included. NIH-Chronic Prostatitis Symptom Index (NIH-CPSI), International Prostate Symptom Score (IPSS), and International Index of Erectile Function (IIEF-5) were used to evaluate the effectiveness of Li-ESWT at the end of treatment. Visual analogue scale/score was used to evaluate the pain during procedure. Stool and semen samples were collected before and after Li-ESWT. Shotgun metagenomics analyzed gut microbiota, while ELISA and other diagnostic kits detected biochemical changes in seminal plasma. Of the 60 enrolled patients, 52 completed treatment. Li-ESWT response rate was 78.8% (41/52) at end of treatment. Among responders, the subitems of the NIH-CPSI; IPSS; and IIEF-5 scores improved significantly, and the seminal plasma analysis showed decreased TNF-a and MDA levels and increased SOD and Zn2+ levels posttreatment. Gut microbiome analysis indicated that posttreatment, both α and β diversity increased, and the abundance of certain specific species significantly increased. Fifty-eight pathways significantly enriched posttreatment, notably in branched-chain amino acid synthesis and butyrate synthesis. The abundance of several specific species was found to be significantly higher in non-responders than responders. Among responders, at the species level, some bacteria associated with NIH-CPSI and its subscales, IPSS, IIEF-5, and prostate microenvironment markers (TNF-a, MDA, Zn2+, and SOD) were identified. Our study demonstrates for the first time that Li-ESWT improves the prostate microenvironment and gut microbiota in CP/CPPS patients. Treatment nonresponse may be associated with a high abundance of specific pathogens before treatment. The gut microbiota could have a significant impact on Li-ESWT response and the prostate microenvironment.

Synergistic role of carbon quantum dots on biohydrogen production

Biohybrid system has their distinct ability to improve microbial fermentation. This study demonstrates the role of surface-doped carbon quantum dots (CQDs) on dark fermentative biohydrogen production using lactobacillus organic-hybrid biocatalyst. Herein, nitrogen-doped carbon quantum dots (N-CQDs) with < 5 nm (having a surface charge of +2.6 mV) and un-doped carbon quantum dots (CQDs) (having a surface charge of −4.5 mV) were synthesized via chemical assisted process. Subsequently, the biohybrid systems were constructed via augmentation of N-CQDs and CQDs with Lactobacillus delbreuckii and assessed for biohydrogen production. The results revealed that both the biohybrid systems (N-CQDs- Lactobacillus delbreuckii and CQDs- Lactobacillus delbreuckii) provided improved hydrogen production than that of the native bacterial strain. Interestingly, the obtained N-CQDs- Lactobacillus delbreuckii system provided the maximum hydrogen yield of 2.01 mol/mol hexose, followed by 1.86 mol/mol hexose from CQDs- Lactobacillus delbreuckii, which is about 33 % and 19 % higher than the bare bacterial strain. The electron transfer and metabolic alteration of microbes by carbon quantum dots were assessed using cyclic voltammetry (CV) and VFA production. It was concluded that the improved bio-hydrogen production from N-CQDs- Lactobacillus delbreuckii is attributed to enhanced electron transfer, which regulates the central metabolic pathway of acetate and butyrate synthesis with the least production of lactate and other reduced end product formation.

A probiotic Limosilactobacillus fermentum GR-3 mitigates colitis-associated tumorigenesis in mice via modulating gut microbiome

Bacterial therapy for colorectal cancer (CRC) represents a burgeoning frontier. The probiotic Limosilactobacillus fermentum GR-3, derived from traditional food “Jiangshui”, exhibited superior antioxidant capacity by producing indole derivatives ICA and IPA. In an AOM/DSS-induced CRC mouse model, GR-3 treatment alleviated weight loss, colon shortening, rectal bleeding and intestinal barrier disruption by reducing oxidative stress and inflammation. GR-3 colonization in distant colon induced apoptosis and reduced tumor incidence by 51.2%, outperforming the control strain and vitamin C. The beneficial effect of GR-3 on CRC was associated with gut microbiome modulation, increasing SCFA producer Lachnospiraceae NK4A136 group and suppressing pro-inflammatory strain Bacteroides. Metagenomic and metabolic analyses revealed that GR-3 intervention upregulated antioxidant genes (xseA, ALDH) and butyrate synthesis gene (bcd), while increasing beneficial metabolites (SCFAs, ICA, IPA, VB12 and VD3) and reducing harmful secondary bile acids. Overall, GR-3 emerges as a promising candidate in CRC therapy, offering effective gut microbiome remediation.

Diet, Microbiome, and Inflammation Predictors of Fecal and Plasma Short-Chain Fatty Acids in Humans

BackgroundGut microbes produce short-chain fatty acids (SCFAs), which are associated with broad health benefits. However, it is not fully known how diet and/or the gut microbiome could be modulated to improve SCFA production. ObjectivesThe objective of this study was to identify dietary, inflammatory, and/or microbiome predictors of SCFAs in a cohort of healthy adults. MethodsSCFAs were measured in fecal and plasma samples from 359 healthy adults in the United States Department of Agriculture Nutritional Phenotyping Study. Habitual and recent diet was assessed using a Food Frequency Questionnaire and Automated Self-Administered 24-h Dietary Assesment Tool dietary recalls. Markers of systemic and gut inflammation were measured in fecal and plasma samples. The gut microbiome was assessed using shotgun metagenomics. Using statistics and machine learning, we determined how the abundance and composition of SCFAs varied with measures of diet, inflammation, and the gut microbiome. ResultsWe show that fecal pH may be a good proxy for fecal SCFA abundance. A higher Healthy Eating Index for a habitual diet was associated with a compositional increase in fecal butyrate relative to acetate and propionate. SCFAs were associated with markers of subclinical gastrointestinal (GI) inflammation. Fecal SCFA abundance was inversely related to plasma lipopolysaccharide-binding protein. When we analyzed hierarchically organized diet and microbiome data with taxonomy-aware algorithms, we observed that diet and microbiome features were far more predictive of fecal SCFA abundances compared to plasma SCFA abundances. The top diet and microbiome predictors of fecal butyrate included potatoes and the thiamine biosynthesis pathway, respectively. ConclusionsThese results suggest that resistant starch in the form of potatoes and microbially produced thiamine provide a substrate and essential cofactor, respectively, for butyrate synthesis. Thiamine may be a rate-limiting nutrient for butyrate production in adults. Overall, these findings illustrate the complex biology underpinning SCFA production in the gut.This trial was registered at clinicaltrials.gov as NCT02367287.

Associations between gut microbiota and incident fractures in the FINRISK cohort

The gut microbiota (GM) can regulate bone mass, but its association with incident fractures is unknown. We used Cox regression models to determine whether the GM composition is associated with incident fractures in the large FINRISK 2002 cohort (n = 7043, 1092 incident fracture cases, median follow-up time 18 years) with information on GM composition and functionality from shotgun metagenome sequencing. Higher alpha diversity was associated with decreased fracture risk (hazard ratio [HR] 0.92 per standard deviation increase in Shannon index, 95% confidence interval 0.87–0.96). For beta diversity, the first principal component was associated with fracture risk (Aitchison distance, HR 0.90, 0.85–0.96). In predefined phyla analyses, we observed that the relative abundance of Proteobacteria was associated with increased fracture risk (HR 1.14, 1.07–1.20), while the relative abundance of Tenericutes was associated with decreased fracture risk (HR 0.90, 0.85–0.96). Explorative sub-analyses within the Proteobacteria phylum showed that higher relative abundance of Gammaproteobacteria was associated with increased fracture risk. Functionality analyses showed that pathways related to amino acid metabolism and lipopolysaccharide biosynthesis associated with fracture risk. The relative abundance of Proteobacteria correlated with pathways for amino acid metabolism, while the relative abundance of Tenericutes correlated with pathways for butyrate synthesis. In conclusion, the overall GM composition was associated with incident fractures. The relative abundance of Proteobacteria, especially Gammaproteobacteria, was associated with increased fracture risk, while the relative abundance of Tenericutes was associated with decreased fracture risk. Functionality analyses demonstrated that pathways known to regulate bone health may underlie these associations.

Bacillus paralicheniformis, an acetate-producing probiotic, alleviates ulcerative colitis via protecting the intestinal barrier and regulating the NLRP3 inflammasome

Ulcerative colitis (UC) presents a challenging scenario in digestive health, characterized by recurrent inflammation that is often hard to manage. Bacteria capable of producing short-chain fatty acids (SCFAs) play a pivotal role in mitigating UC symptoms, rendering them promising candidates for probiotic therapy. In this investigation, we assessed the impact of Bacillus paralicheniformis HMPM220325 on dextran sodium sulfate (DSS)-induced UC in mice. Genomic analysis of the strain revealed the presence of protease genes associated with acetate and butyrate synthesis, with acetic acid detected in its fermentation broth. Administration of B. paralicheniformis HMPM220325 to UC mice ameliorated pathological manifestations of the condition and restored intestinal barrier function. Furthermore, B. paralicheniformis HMPM220325 suppressed the activation of the NLRP3 inflammasome signaling pathway and modulated the composition of the intestinal microbiota. These findings shed significant light on the potential of B. paralicheniformis as a probiotic candidate, offering a novel avenue for the prevention and therapeutic intervention of colitis.

Gut microbiota and its correlations with body mass index and age in patients with type 2 diabetes mellitus and thyroid dysfunction

Modern studies show that it is the transit microflora, the percentage of which is negligible compared to the total volume of the intestinal microbiota, that can cause severe damage and cause the appearance of chronic and acute diseases not only of the intestines but also of the immune, nervous, endocrine systems, etc. Instead, the obligate intestinal microbiota and even the opportunistic microbiota exhibit a number of beneficial properties, ranging from the synthesis of short-chain fatty acids, butyrate, and acetate to promoting the synthesis of vitamins and hormones such as dopamine, serotonin, etc. At the same time, the adverse effects of the gut microbiota cannot be discounted. The aim. The study aims to find correlations between gut microbiota, body mass index, and age in patients with type 2 diabetes and thyroid dysfunction..\ Materials and methods. The study included 84 patients with type 2 diabetes, obesity, and thyroid dysfunction. To analyze the composition of the intestinal microbiota, fecal samples were taken, and the quantitative and qualitative composition was calculated using the principle of PCR sequencing. Statistical methods of comparison and correlation of variables were used. Results. In patients, several significant correlations were found between the gut microbiota and the parameters studied. A negative correlation was found between body mass index and Bifidobacterium spp. and Escherichia coli, and a positive correlation was found between body mass index and some opportunistic pathogens. Thus, with Shigella spp. and Staphylococcus aureus, there is a direct weak reliable relationship, while an inverse reliable relationship with Helicobacter pylori. Interesting correlations were found with a tendency to confidence with Salmonella spp. and Bacteroides thetaiotaomicron direct weak and a tendency to probable feedback between BMI and Faecalibacterium prausnitzii and Candida spp. Conclusion. We found that body mass index has a greater impact on the gut microbiota than age. Also, the data obtained indicate that obesity negatively affects the number of some beneficial bacteria. We can assume that, like metformin, one of the most common drugs for the treatment of type 2 diabetes mellitus, it can affect the composition of the intestinal microbiota

Fermented Purslane (Portulaca oleracea L.) Supplementation Enhances Growth and Immune Function Parallel to the Regulation of Gut Microbial Butyrate Production in Weaned Piglets.

Weaning is a challenging period for piglets, characterized by stress-related growth checks, compromised immunity, and gut dysbiosis. Purslane (Portulaca oleracea L.), known for its rich content of antioxidants, has potential as a functional feed ingredient. This study investigates the effects of feeding fermented purslane (FP) on the growth performance, immune function, intestinal microbiota, and metabolic profiles of weaned piglets. Forty-eight weaned piglets were randomly divided into two groups, with eight pens in each group and three pigs in each pen: a control diet (CON group) and a diet supplemented with 0.20% FP (FP group). The experiment lasted 28 days. The results show that FP supplementation did not affect the average daily feed intake (ADFI) but significantly increased the average daily gain (ADG) during the initial 14 days post-weaning. FP supplementation decreased diarrhea occurrence, with a pronounced reduction from days 10 to 13 (p < 0.05). Immunologically, the FP group had a trend towards reduced serum IgA levels on day 14 (p < 0.10). Importantly, the serum concentrations of the pro-inflammatory cytokine IL-6 were significantly reduced on both days 14 and 28 post-weaning. The antioxidative analysis showed increased serum superoxide dismutase (SOD) and decreased catalase (CAT) activities on day 14 (p < 0.05). In addition, FP supplementation significantly decreased serum diamine oxidase (DAO) activity and D-lactate levels by day 28, indicating a potential improvement in gut integrity. Fecal microbiota assessment demonstrated a distinctive clustering of microbial communities between the FP and CON groups, with an increase in the abundance of Clostridium_sensu_stricto_1, Tyzzerella, and Prevotellaceae_NK3B31_group and a decrease in Lactobacillus, Bacillus, and Subdoligranulum in the FP group (p < 0.05). Functional predictions suggested that the relative abundance of microbial butyrate synthesis enzymes (EC 2.7.2.7 and EC 2.3.1.19) was significantly enhanced by FP treatment. This modulation was further corroborated by elevated fecal butyrate levels (p < 0.05). In summary, dietary supplementation with FP promotes early-growth performance and has beneficial effects on immune function and intestinal health in weaned piglets. The enhancements may be attributed to distinct microbiota compositional changes and targeted modulation of microbial butyrate metabolism, which are crucial for piglet post-weaning adaptation and overall health.

Synergistic effect of partially hydrolyzed guar gum on Clostridium butyricum in a synbiotic combination for enhanced butyrate production during in-vitro fermentation

Background: Clostridium butyricum is a butyrate-producing beneficial bacterium and is generally recognized as a significant indicator of appropriate gut microbial metabolism in human health. Objective: The synergistic effects of commercially available prebiotic partially hydrolyzed guar gum (PHGG) dietary fiber as a carbon source on a butyrate-producing bacterial strain were evaluated during in-vitro fermentation with Clostridium butyricum bacterial strain in a basal medium. Additionally, their prebiotic activities were compared to those of other dietary fibers. Methods: The examined functional dietary fiber substrates (PHGG, LMW-PHGG, indigestible dextrin, and inulin) demonstrated selective prebiotic effects on pH variation of a basal medium, leading to enhanced bacterial growth and butyrate production with Clostridium butyricum bacterial strains during in-vitro fermentation. Results: Prebiotic PHGG supplementation had the highest fermentability among dietary fibers, resulting in greater bacterial growth (OD660: 1.93 ± 0.01) of the Clostridium butyricum strain and enhanced butyrate generation (4.52 ± 2.09 mM) after cultivation in a basal medium. A significant difference in promoting bacterial growth (p &lt; 0.05), pH reduction (p &lt; 0.05), and butyrate production (p &lt; 0.05) compared to indigestible dextrin and inulin was observed. Mannose demonstrated the strongest butyrogenic effect and improved fermentability on the Clostridium butyricum, among the studied prebiotic monosaccharides (galactose, glucose, and starch). The order of bacterial growth and butyrate synthesis was mannose &gt; galactose &gt; glucose &gt; starch. The PHGG with a relatively lower molecular weight (LMW-PHGG) exhibited the improved bacterial growth of Clostridium butyricum and demonstrated the highest butyrate production after cultivation in a basal medium. A similar trend was observed when Clostridium butyricum was cultivated in-vitro using PHGG-supplemented artificial intestinal fluid containing MRS-agar medium. Conclusion: These findings suggest that the symbiotic combination of prebiotic PHGG and probiotic Clostridium butyricum could have major industrial applications as a therapeutic adjuvant for improved gastrointestinal health. Keywords: Partially hydrolyzed guar gum, synbiotic, prebiotic, probiotic, Clostridium butyricum, butyrate production

The giant panda gut harbors a high diversity of lactic acid bacteria revealed by a novel culturomics pipeline.

Some lactic acid bacteria (LAB) can provide significant health benefits, which are critically important for the conservation of endangered animals, such as giant pandas. However, little is known about the diversity and culturability of LAB in the giant panda gut microbiota. To understand the roles of LAB in giant panda conservation, it is critical to culture bacterial strains of interest. In this study, we established a pipeline to culture bacterial strains using enrichment of target bacteria with different liquid media and growth conditions. Then, the strains were isolated in solid media to study their functions. Using 210 samples from the culture enrichment method and 138 culture-independent samples, we obtained 1120 amplicon sequencing variants (ASVs) belonging to Lactobacillales. Out of the 1120 ASVs, 812 ASVs from the culture enrichment approach were twofold more diverse than 336 ASVs from the culture-independent approach. Many ASVs of interest were not detected in the culture-independent approach. Using this pipeline, we isolated many relevant bacterial strains and established a giant panda gut bacteria strain collection that included strains with low-abundance in culture-independent samples and included most of the giant panda LAB described by other researchers. The strain collection consisted of 60 strains representing 35 species of 12 genera. Thus, our pipeline is powerful and provides guidance in culturing gut microbiota of interest in hosts such as the giant panda.IMPORTANCECultivation is necessary to screen strains to experimentally investigate microbial traits, and to confirm the activities of novel genes through functional characterization studies. In the long-term, such work can aid in the identification of potential health benefits conferred by bacteria and this could aid in the identification of bacterial candidate strains that can be applied as probiotics. In this study, we developed a pipeline with low-cost and user-friendly culture enrichment to reveal the diversity of LAB in giant pandas. We compared the difference between culture-independent and culture enrichment methods, screened strains of interest that produced high concentrations of short-chain fatty acids (SCFAs), and we investigated the catalog of virulence factors, antibiotic resistance, butyrate and lactate synthesis genes of the strains at a genomic level. This study will provide guidance for microbiota cultivation and a foundation for future research aiming to understand the functions of specific strains.

The gut-brain axis in individuals with alcohol use disorder: Anexploratory study of associations among clinical symptoms, brain morphometry, and the gut microbiome.

Alcohol use disorder (AUD) is commonly associated with distressing psychological symptoms. Pathologic changes associated with AUD have been described in both the gut microbiome and brain, but the mechanisms underlying gut-brain signaling in individuals with AUD are unknown. This study examined associations among the gut microbiome, brain morphometry, and clinical symptoms in treatment-seeking individuals with AUD. We performed a secondary analysis of data collected during inpatient treatment for AUD in subjects who provided gut microbiome samples and had structural brain magnetic resonance imaging (MRI; n = 16). Shotgun metagenomics sequencing was performed, and the morphometry of brain regions of interest was calculated. Clinical symptom severity was quantified using validated instruments. Gut-brain modules (GBMs) used to infer neuroactive signaling potential from the gut microbiome were generated in addition to microbiome features (e.g., alpha diversity and bacterial taxa abundance). Bivariate correlations were performed between MRI and clinical features, microbiome and clinical features, and MRI and microbiome features. Amygdala volume was significantly associated with alpha diversity and the abundance of several bacteria including taxa classified to Blautia, Ruminococcus, Bacteroides, and Phocaeicola. There were moderate associations between amygdala volume and GBMs, including butyrate synthesis I, glutamate synthesis I, and GABA synthesis I & II, but these relationships were not significant after false discovery rate (FDR) correction. Other bacterial taxa with shared associations to MRI features and clinical symptoms included Escherichia coli and Prevotella copri. We identified gut microbiome features associated with MRI morphometry and AUD-associated symptom severity. Given the small sample size and bivariate associations performed, these results require confirmation in larger samples and controls to provide meaningful clinical inferences. Nevertheless, these results will inform targeted future research on the role of the gut microbiome in gut-brain communication and how signaling may be altered in patients with AUD.

Investigation of the human-gut-kidney axis by fecal proteomics, highlights molecular mechanisms affected in CKD

ObjectiveThe interplay of gut microbiota with the kidney system in chronic kidney disease (CKD), is characterized by increased concentrations of uric acid in the gut, which in turn, may increase bacterial uricase activity and may lead to the generation of uremic toxins. Nevertheless, knowledge on these underlying bidirectional molecular mechanisms is still limited. MethodsIn this exploratory study, proteomic analysis was performed on fecal samples, targeting to investigate this largely unexplored biological material as a source of information reflecting the gut-kidney axis. Specifically, fecal suspension samples from patients with CKD1 (n = 12) and CKD4 (n = 17) were analysed by LC-MS/MS, using both the Human and Bacterial UniProt RefSeq reviewed databases. ResultsThis fecal proteomic analysis collectively identified 701 human and 1011 bacterial proteins of high confidence. Differential expression analysis (CKD4/CKD1) revealed significant changes in human proteins (n = 8, including proteins such as galectin-3-binding protein and prolactin-inducible protein), that were found to be associated with inflammation and CKD. The differential protein expression of pancreatic alpha-amylase further suggested plausible reduced saccharolytic fermentation in CKD4/CKD1. Significant changes in bacterial proteins (n = 9, such as glyceraldehyde-3-phosphate dehydrogenase and enolase), participating in various carbohydrate and metabolic pathways important for the synthesis of butyrate, in turn suggested differential butyrate synthesis in CKD4/CKD1. Further, targeted quantification of fecal pancreatic alpha-amylase and butyrate in the same fecal suspension samples, supported these hypotheses. ConclusionCollectively, this exploratory fecal proteomic analysis highlighted changes in human and bacterial proteins reflecting inflammation and reduced saccharolytic fermentation in CKD4/CKD1, plausibly affecting the butyrate synthesis pathways in advanced stage kidney disease. Integrative multi-omics validation is planned.

In situ immobilization of Cal B enzyme in mesoporous materials of the MCM-48 type using different ionic solids: synthesis and application in esterification reactions

The ionic solids [C16MI]Cl and [C14MI]Cl were used as structure directors on MCM-48 mesoporous support with immobilized CALB lipase for the synthesis of esters from geraniol. Significant results were obtained in the synthesis of geranyl acetate and geranyl butyrate. Enzyme concentration, temperature and molar ratio of substrates were parameters that affect the synthesis yield. The highest temperature (60°C) and highest enzyme concentration (13%) conditions showed the best ester conversion results. For both esters, the ionic liquid [C16MI]Cl showed better conversion results and reached a value above 38% of conversion. Furthermore, the support tested in the present study for application in ester synthesis is cost-effective. In addition, the enzymatic route to obtain the esters presents mild reaction conditions and the results show potential for application in industrial applications.

Abstract CT030: Randomized placebo-controlled, biomarker-stratified phase 1b microbiome modulation trial for metastatic melanoma demonstrates impact of antibiotic pre-conditioning regimen on the microbiome and immunity

Abstract Background: Gut microbiota modulation shows promise in improving immune checkpoint blockade (ICB) response; however, precision biomarker-driven trials using rationally-designed consortia are lacking. To address this, we performed a multi-center, randomized placebo-controlled, biomarker-stratified phase 1 trial in patients with ICB-naïve unresectable or metastatic melanoma using SER-401, a bacterial consortia enriched for Firmicutes spores and Ruminococcaceae. Methods: MCGRAW was a multi-center, randomized, blinded, and placebo-controlled phase 1b study in patients with advanced melanoma. Patients were randomized 2:1 to the SER-401 active or placebo arm, respectively, and stratified by baseline stool Ruminococcaceae abundance. Patients received an oral vancomycin (vanco) preparative regimen+SER-401 (vanco+SER-401 arm), versus placebo antibiotic+placebo (Placebo arm), followed by nivolumab. Stool, blood and tumor samples were collected at baseline and on treatment. The primary endpoint was safety, with additional secondary endpoints (SER-401 microbiome engraftment, overall response rate (ORR), disease control rate (DCR), and other translational endpoints). The study was not powered for comparison between arms. Results: 14 patients were randomized (n=8 vanco+SER-401, n=6 placebo). In the vanco+SER-401 arm, ORR was 25.0% and DCR was 37.5%, with no Grade 3-4 treatment-related adverse events (TRAE); in the placebo arm, ORR was 66.7% and DCR was 83.3%, with 1 (17%) TRAE. Notably, pre-conditioning with vanco was associated with significant shift in the microbiome taxonomic composition, with depletion of target families such as Ruminococcaceae (p=0.008, Wilcoxon signed-rank test), and other spore-formers, followed by their recovery post dosing with SER-401. There was a significant increase in multiple ICB-resistance associated pathways (e.g. butyrate synthesis, p&amp;lt;0.0001), and a decrease in response-associated pathways after vanco preconditioning; these changes did normalize by nivolumab initiation. There was corresponding increase in systemic proteomic markers of inflammation after vanco, which also normalized by first dose of immunotherapy. Conclusions: This first-of-its-kind, placebo-controlled, randomized biomarker-driven microbiome modulation trial demonstrated that SER-401 and anti-PD1 are a safe combination in melanoma patients. The study was limited by poor accrual during the COVID-19 pandemic. Nonetheless, important insights were gained via translational analyses, suggesting that antibiotic preconditioning and interventional drug dosing regimens should be carefully considered when designing such trials. Additional placebo-controlled biomarker-driven microbiome trials are needed in this age of precision medicine. Trial registration: ClinicalTrials.gov (NCT03817125) Citation Format: Isabella C. Glitza Oliva, Yongwoo David Seo, Christine N. Spencer, Jennifer R. Wortman, Elizabeth M. Burton, Farah A. Alayli, Christopher Loo, Shikha Gautam, Ashish V. Damania, Julie Densmore, Justin Fairchild, Christopher Cabanski, Matthew C. Wong, Christine B. Peterson, Brian Weiner, Nathan Hicks, John Aunins, Christopher McChalicher, Michael T. Tetzlaff, Omid Hamid, Patrick A. Ott, Genevieve M. Boland, Ryan J. Sullivan, Kenneth F. Grossmann, Nadim J. Ajami, Theresa M. LaVallee, Matthew R. Henn, Hussein A. Tawbi, Jennifer A. Wargo. Randomized placebo-controlled, biomarker-stratified phase 1b microbiome modulation trial for metastatic melanoma demonstrates impact of antibiotic pre-conditioning regimen on the microbiome and immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT030.

Swapping white for high-fibre bread exceeds fibre target and improves microbiome diversity

A majority of Australians consume a limited range of different dietary fibres and insufficient total dietary fibre(1). This contributes to low intestinal microbial diversity and impaired microbial function, such as capability in producing beneficial metabolites like short-chain fatty acids (SCFA). This diet-induced dysbiosis is associated with poor gastrointestinal health and a broad range of non-communicable diseases(2). Our study aimed to determine whether one dietary change, substitution of white bread with a high fibre bread improves faecal microbial diversity and butyrate-producing capability. Twenty-six healthy adults completed a randomised, cross-over, single-blinded intervention. Over the two intervention phases separated with a 4-wk washout, participants consumed either 3 slices of a high fibre bread (Prebiotic Cape Seed Loaf with BARLEYmax®) or control white bread as part of the usual diet, each for 2 weeks. At the beginning and end of each intervention period, participants completed a 24-h diet recall, a gut symptoms rating questionnaire and provided a faecal sample for microbiome analysis. The composition of faecal microbiome was characterised using 16S rRNA amplicon sequencing (V3-V4) and a marker of butyrate synthesis capability, the faecal content of butyryl-CoA:acetate CoA-transferase (BCoAT) gene was assessed using Real-time PCR. The high fibre bread intervention increased the servings of whole grain from 1.5 to 4 per day and increased total dietary fibre intake to 40 g/d which was double the amount of fibre consumed by participants at baseline or during the white bread intervention. Compared to white bread, the high fibre bread increased richness and evenness (Shannon, p = 0.014) of the gut microbiota and increased the relative abundance of SCFA producing taxa Lachnospiracae ND3007 group (p &lt;0.001, FDR = 0.019). In addition, the high-fibre bread tended to increase relative abundance of butyrate-producing genus Roseburia, and microbial BCoAT gene content compared to white bread. In conclusion, the substitution of white bread with high-fibre bread improved the diversity of gut microbiota, specific microbes involved in SCFA production and may enhance the butyrate production capability of gut microbiota in healthy adults.

Postbiotic butyrate: role and its effects for being a potential drug and biomarker to pancreatic cancer.

Postbiotics are produced by microbes and have recently gained importance in the field of oncology due to their beneficial effects to the host, effectiveness against cancer cells, and their ability to suppress inflammation. In particular, butyrate dominates over all other postbiotics both in quantity and anticancer properties. Pancreatic cancer (PC), being one of the most malignant and lethal cancers, reported a decreased 5-year survival rate in less than 10% of the patients. PC causes an increased mortality rate due to its inability to be detected at an early stage but still a promising strategy for its diagnosis has not been achieved yet. It is necessary to diagnose Pancreatic cancer before the metastatic progression stage. The available blood biomarkers lack accurate and proficient diagnostic results. Postbiotic butyrate is produced by gut microbiota such as Rhuminococcus and Faecalibacterium it is involved in cell signalling pathways, autophagy, and cell cycle regulation, and reduction in butyrate concentration is associated with the occurrence of pancreatic cancer. The postbiotic butyrate is a potential biomarker that could detect PC at an early stage, before the metastatic progression stage. Thus, this review focused on the gut microbiota butyrate's role in pancreatic cancer and the immuno-suppressive environment, its effects on histone deacetylase and other immune cells, microbes in major butyrate synthesis pathways, current biomarkers in use for Pancreatic Cancer.

Butyrate's (a short-chain fatty acid) microbial synthesis, absorption, and preventive roles against colorectal and lung cancer.

Butyrate, a short-chain fatty acid (SCFA) produced by bacterial fermentation of fiber in the colon, is a source of energy for colonocytes. Butyrate is essential for improving gastrointestinal (GI) health since it helps colonocyte function, reduces inflammation, preserves the gut barrier, and fosters a balanced microbiome. Human colonic butyrate producers are Gram-positive firmicutes, which are phylogenetically varied. The two most prevalent subgroups are associated with Eubacterium rectale/Roseburia spp. and Faecalibacterium prausnitzii. Now, the mechanism for the production of butyrate from microbes is a very vital topic to know. In the present study, we discuss the genes encoding the core of the butyrate synthesis pathway and also discuss the butyryl-CoA:acetate CoA-transferase, instead of butyrate kinase, which usually appears to be the enzyme that completes the process. Recently, butyrate-producing microbes have been genetically modified by researchers to increase butyrate synthesis from microbes. The activity of butyrate as a histone deacetylase inhibitor (HDACi) has led to several clinical trials to assess its effectiveness as a potential cancer treatment. Among various significant roles, butyrate is the main energy source for intestinal epithelial cells, which helps maintain colonic homeostasis. Moreover, people with non-small-cell lung cancer (NSCLC) have distinct gut microbiota from healthy adults and frequently have dysbiosis of the butyrate-producing bacteria in their guts. So, with an emphasis on colon and lung cancer, this review also discusses how the microbiome is crucial in preventing the progression of certain cancers through butyrate production. Further studies should be performed to investigate the underlying mechanisms of how these specific butyrate-producing bacteria can control both colon and lung cancer progression and prognosis.

Improved biocatalytic activity of steapsin lipase in supercritical carbon dioxide medium for the synthesis of benzyl butyrate: A commercially important flavour compound

Enzymatic synthesis of flavours, fragrances and food additives compounds have great demand and market value. Benzyl butyrate is commercially important flavour and food additive compound having global use around 100 metric tons/year and widely used in various industrial sectors. However, industrial synthesis of food additive benzyl butyrate is carried out by conventional chemical process which demands for the green biobased sustainable synthetic process. The present work reports steapsin catalyzed synthesis of benzyl butyrate for the first time in supercritical carbon dioxide (Sc-CO2) reaction medium. All reaction variables are optimized in details to obtain competent conversion of 99% in Sc-CO2 reaction medium. The developed steapsin catalyzed synthesis in Sc-CO2 medium offered almost four-fold higher conversion to benzyl butyrate than organic (conventional) solvent. The steapsin biocatalyst was effectually recycled up to five reaction cycles in Sc-CO2 medium. Moreover, the developed steapsin catalyzed protocol in Sc-CO2 medium was extended to synthesize different TEN industrially significant flavour fragrance compounds that offers 99% conversion and three to five-folds higher conversion than organic (conventional) medium. Thus, the present steapsin catalyzed protocol offered improved synthesis of various commercially significant flavour compounds in Sc-CO2. medium.

Effects of a multistrain Bacillus-based direct-fed microbial on gastrointestinal permeability and biomarkers of inflammation during and following feed restriction in mid-lactation Holstein cows

Objectives were to evaluate the effects of a multistrain Bacillus-based (Bacillus subtilis and Bacillus pumilus blend) direct-fed microbial (DFM) on production, metabolism, inflammation biomarkers and gastrointestinal tract (GIT) permeability during and following feed restriction (FR) in mid-lactation Holstein cows. Multiparous cows (n = 36; 138 ± 53 DIM) were randomly assigned to 1 of 3 dietary treatments: (1) control (CON; 7.5 g/d rice hulls; n = 12), (2) DFM10 (10 g/d Bacillus DFM, 4.9 × 109 cfu/d; n = 12) or 3) DFM15 (15 g/d Bacillus DFM, 7.4 × 109 cfu/d; n = 12). Before study initiation, cows were fed their respective treatments for 32 d. Cows continued to receive treatments during the trial, which consisted of 3 experimental periods (P): P1 (5 d) served as baseline for P2 (5 d), during which all cows were restricted to 40% of P1 DMI, and P3 (5 d), a "recovery" where cows were fed ad libitum. On d 4 of P1 and on d 2 and 5 of P2, GIT permeability was evaluated in vivo using the oral paracellular marker Cr-EDTA. As anticipated, FR decreased milk production, insulin, glucagon, and BUN but increased nonesterified fatty acids. During recovery, DMI rapidly increased on d 1 then subsequently decreased (4.9 kg) on d 2 before returning to baseline, whereas milk yield slowly increased but remained decreased (13%) relative to P1. The DFM10 cows had increased DMI and milk yield relative to DFM15 during P3 (10%). Overall, milk lactose content was increased in DFM cows relative to CON (0.10 percentage units), and DFM10 cows tended to have increased lactose yield relative to CON and DFM15 during P3 (8% and 10%, respectively). No overall treatment differences were observed for other milk composition variables. Circulating glucose was quadratically increased in DFM10 cows compared with CON and DFM15 during FR and recovery. Plasma Cr area under the curve was increased in all cows on d 2 (9%) and 5 (6%) relative to P1. Circulating LPS binding protein (LBP), serum amyloid A (SAA), and haptoglobin (Hp) increased in all cows during P2 compared with baseline (31%, 100%, and 9.0-fold, respectively). Circulating Hp concentrations continued to increase during P3 (274%). Overall, circulating LBP and Hp tended to be increased in DFM15 cows relative to DFM10 (29% and 81%, respectively), but no treatment differences were observed for SAA. Following feed reintroduction during P3, fecal pH initially decreased (0.62 units), but returned to baseline levels whereas fecal starch markedly increased (2.5-fold) and remained increased (82%). Absolute quantities of a fecal Butyryl-CoA CoA transferase (but) gene associated with butyrate synthesis, collected by fecal swab were increased in DFM10 cows compared with CON and DFM15 cows. In summary, FR increased GIT permeability, caused inflammation, and decreased production. Feeding DFM10 increased some key production and metabolism variables and upregulated a molecular biomarker of microbial hindgut butyrate synthesis, while DFM15 appeared to augment immune activation.