Fatty Acid Production Research Articles

Intestinal microflora dysbiosis and resistome in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)

The aim of the present study is to explore the bacterial diversity within the gut microbiome of chronic inflammatory demyelinating polyneuropathy patient. A stool sample was collected and analyzed to study the gut microbiota through bacterial 16S rRNA gene sequencing. The gut microbiota of chronic inflammatory demyelinating polyneuropathy patient exhibited a dominance of Firmicutes and Bacteroides phyla, with 58.19% and 33.31%, respectively. The data showed a notable abundance of Lachnospiraceae bacterium and Bacteroides sp species, 17.79% and 16.56%, respectively within the gut microbiota chronic inflammatory demyelinating polyneuropathy patient. Lachnospiraceae, a member of the Firmicutes phylum, plays a pivotal role in the production of short-chain fatty acids. At high concentration, short-chain fatty acids can trigger autoimmune leading to the chronic inflammatory demyelinating polyneuropathy. These findings strengthen the possible involvement of short-chain fatty acids in the chronic inflammatory demyelinating polyneuropathy pathogenesis process and could pave new paths in its diagnosis and therapies based on regulation of microbiota dysbiosis.

Effects of xylo-oligosaccharide supplementation on the production performance, intestinal morphology, cecal short-chain fatty acid levels, and gut microbiota of laying hens

This study investigated the effects of xylo-oligosaccharide supplementation on the production performance, intestinal morphology, cecal short-chain fatty acid levels, and gut microbiota of laying hens. A total of 800 Lohmann pink layers, each 48 wk old, were randomly divided into 5 dietary treatment groups, namely XOS at 0 (CON), 100 (XOS1), 200 (XOS2), 300 (XOS3) and 400 (X0S4) mg/kg. The experimental period was 24 wk. The results revealed that the egg production rate and the number of eggs laid by each layer between 1 to 12 wk increased as the XOS concentration increased (Plinear < 0.05). The sand-shell egg percentage decreased significantly from 1 to 12 wk in the XOS1, XOS2, and XOS3 groups (PANOVA < 0.05). Compared with the CON group, the 4 XOS dosage groups presented significant increases in the villus height and the ratio of villus height to crypt depth in the jejunum (PANOVA < 0.05), whereas a linear decrease in jejunal crypt depth (Plinear < 0.05) was noted. In addition, XOS supplementation significantly increased the concentrations of butyric acid and isovaleric acid in the caeca (PANOVA < 0.05). High-throughput sequencing analysis of bacterial 16S rRNA revealed that dietary XOS supplementation influenced the cecal microbiota. The alpha diversity analysis indicated that the richness of cecal bacteria was greater in the laying hens fed XOS. The modulation of the cecal microbiota composition upon the addition of XOS was characterized by an increased abundance of Firmicutes and Bifidobacteriaceae, and decreased abundance of Bacteroidetes. At the genus level, dietary XOS supplementation resulted in decreases in the abundances of Bacteroides and Rikenellaceae_RC9_gut_group and an increase in the abundance of Lactobacillus. In conclusion, dietary XOS supplementation improved the production performance of laying hens by increasing the production of short-chain fatty acids and improving their intestinal morphology, which was achieved mainly through changes in the composition of the intestinal microbiota. The recommended level of XOS in the diet of laying hens is 200 mg/kg.

Exploring the effect of lipid loading on acidogenic fermentation of food waste: Insights from microbiome, quorum sensing and carbon metabolic pathway

The high lipid loading in food waste (FW) is widely regarded as one of the main bottlenecks in the traditional anaerobic digestion, but the effect of lipid on FW acidogenic fermentation has been historically ignored. This study attempted to reveal the influence of lipid loading on volatile fatty acids (VFAs) production and the corresponding synthesis mechanisms during FW acidogenic fermentation. The VFAs production reached 27.10 ± 1.00 g COD/L when the lipid loading comprised 25 % of the FW dry weight, increasing by 36.88 % compared to the CK group. Lactobacillus, with a relative abundance of 59.43 %, was the predominant genus under lipid loading. In quorum sensing (QS) system, the relative abundance of luxS that is involved in the biosynthetic pathway of the Autoinducer-2 (AI-2) signal molecule increased from 0.066 % to 0.10 % in the presence of lipid. The relative abundance of Genetic Information Processing increased from 16.36 % to 24.25 % under lipid loading, with up-regulation of Translation and Replication and repair. Lipid loading not only promoted the conversion of acetyl-CoA to acetic acid, as evidenced by a 1.36-fold increase in pta gene abundance, but also concurrently suppressed the consumption of acetic acid, reflected in the 96.83 % and 77.16 % decreases in ALDH and aldB abundance, thus accumulating acetic acid. Carbon emission was also constrained under lipid loading, in which the conversion from formate to CO2 and passing Tricarboxylic acid (TCA) cycle were restricted over 60 %. Together, lipid loading in FW represents a potential strategy for enhancing VFAs production in FW acidogenic fermentation.

Assessing the potential of olive mill solid waste as feedstock for methane and volatile fatty acids production via anaerobic bioprocesses

The extensive production of olive mill solid waste (OMSW) from olive oil industry in the Mediterranean basin claims effective treatments and valorization strategies. This study aims to elucidate the potential of anaerobic digestion (AD) and anaerobic fermentation (AF) to convert pre-treated OMSW into biogas (CH4) and volatile fatty acids (VFA), respectively. The two thermal treatment conditions (65 °C and 180 °C) that are being implemented in the industry that manages the OMSW were tested. Comparing the two treatments aims to demonstrate the influence on the AD process of the degree of solubilization and degradation of the metabolites produced from the same substrate. AD of OMSW treated at low-temperature (65 °C) exhibited similar methane yields (195 ± 8 mL CH4/g volatile solid (VS)) to raw OMSW. AD of the solid phase (SP) after high-temperature treatment with acid addition at 180 °C resulted in methane yields comparable to raw OMSW while the liquid phase (LP) exhibited low methane yields (85 ± 10 mL CH4/g VS). Nevertheless, LP/180 °C exhibited the highest VFA bioconversion at 27.6 %, compared to less than 10 % for SP/180 ºC, SP/65 °C, and raw OMSW. The VFA profile showed notable variations with thermal treatment temperatures. Propionic acid dominated at SP/65 °C, while acetic acid became the primary VFA at 180 °C. Furthermore, significant degradation rates of phenolic compounds and furans were observed during the final day of both anaerobic processes. Overall, these findings suggest that AD is more suitable for raw OMSW, treated at low temperature and SP at high temperature, while AF offers a promising alternative for high-temperature-treated LP.

Comparative study on static and dynamic digest characteristics of oat β-Glucan and β-Gluco-Oligosaccharides

Both oat β-glucans (OGs) and their hydrolyzed counterparts, oat β-gluco-oligosaccharides (OGOs), are dietary fibers indigestible by humans. They serve as substrates for the colonic intestinal flora, exhibiting potential prebiotic properties. This study, through in vitro digestion simulation, found that OGs and OGOs are not degraded and can safely pass through the upper digestive tract to reach the colon. Anaerobic fermentation was conducted using fecal microbiota in an anaerobic tube and gastrointestinal reactor to investigate their impact on the structure and metabolism of intestinal flora. The research revealed that OGs and OGOs distinctly influence the fermentation characteristics and the intestinal flora’s metabolic profile. Specifically, in static fermentation, OGs notably increased butyric acid production in both healthy individuals and those with type 2 diabetes, whereas OGOs more effectively enhanced acetic and propionic acid production in type 2 diabetics. Moreover, OGs and OGOs variably affected the composition of intestinal flora. In dynamic fermentation, there was a marked improvement in the production of short-chain fatty acids (SCFAs), with OGs significantly boosting butyric acid and OGOs enhancing acetic acid production. This study lays a theoretical foundation for employing specific dietary fibers to selectively improve intestinal flora and supports the development of functional ingredients that modulate intestinal microorganisms, utilizing in vitro research methodologies.

Harnessing the Power of Fermented Tea to Improve Gut Microbiota and Combat Obesity Epidemic.

The global rise in obesity rates has prompted a thorough evaluation of dietary strategies that may alleviate this metabolic issue. Fermented tea, a beverage rich in polyphenols and catechins, has emerged as a viable therapeutic option for obesity management. This review discusses the role of fermented tea in modulating the gut microbiome, a critical factor in energy regulation and obesity. We explore how the bioactive components in fermented tea influence gut health and their implications for metabolic health. Fermented tea may inhibit weight gain and fat accumulation in obese animal models, likely by promoting beneficial bacteria and suppressing harmful species. Changes in the production of short-chain fatty acids and improvements in gut barrier integrity are linked to enhanced insulin sensitivity and reduced inflammatory markers, essential for effective obesity management. However, barriers remain in applying these findings in clinical settings, such as the need for standardized fermentation techniques and accurate dosage assessments. This review underscores the therapeutic potential of fermented tea in obesity treatment and advocates for further research to enhance its integration with public health initiatives.

Microwave-assisted organic acids and green hydrogen production during mixed culture fermentation.

The integration of anaerobic digestion into bio-based industries can create synergies that help render anaerobic digestion self-sustaining. Two-stage digesters with separate acidification stages allow for the production of green hydrogen and short-chain fatty acids, which are promising industrial products. Heat shocks can be used to foster the production of these products, the practical applicability of this treatment is often not addressed sufficiently, and the presented work therefore aims to close this gap. Batch experiments were conducted in 5L double-walled tank reactors incubated at 37°C. Short microwave heat shocks of 25min duration and exposure times of 5-10min at 80°C were performed and compared to oven heat shocks. Pairwise experimental group differences for gas production and chemical parameters were determined using ANOVA and post-hoc tests. High-throughput 16SrRNA gene amplicon sequencing was performed to analyse taxonomic profiles. After heat-shocking the entire seed sludge, the highest hydrogen productivity was observed at a substrate load of 50g/l with 1.09molH2/molhexose. With 1.01molH2/molhexose, microwave-assisted treatment was not significantly different from oven-based treatments. This study emphasised the better repeatability of heat shocks with microwave-assisted experiments, revealing low variation coefficients averaging 29%. The pre-treatment with microwaves results in a high predictability and a stronger microbial community shift to Clostridia compared to the treatment with the oven. The pre-treatment of heat shocks supported the formation of butyric acid up to 10.8g/l on average, with a peak of 24.01g/l at a butyric/acetic acid ratio of 2.0. The results support the suitability of using heat shock for the entire seed sludge rather than just a small inoculum, making the process more relevant for industrial applications. The performed microwave-based treatment has proven to be a promising alternative to oven-based treatments, which ultimately may facilitate their implementation into industrial systems. This approach becomes economically sustainable with high-temperature heat pumps with a coefficient of performance (COP) of 4.3.

In Vitro Digestion and Fermentation of Cowpea Pod Extracts and Proteins Loaded in Ca(II)-Alginate Hydrogels.

Antioxidants derived from food by-products are known for their bioactive properties and impact on human health. However, the gastrointestinal behavior is often poor due to their degradation during digestion. The development of Ca(II)-alginate beads supplemented with biopolymers and enriched with cowpea (Vigna unguiculata) extract could represent a novel environmentally friendly technological solution to produce functional ingredients in the food industry. The present study evaluates the impact of in vitro digestion/fermentation by analyzing global antioxidant response (GAR), production of short-chain fatty acids (SCFAs) as a modulation of gut microbiota, and behavior of proton transverse relaxation times by low-field nuclear magnetic resonance (as an indicator of gelation state and characterization of microstructure). Results revealed that guar gum and cowpea protein preserved a high GAR of total phenolic compounds and antioxidant capacity by ABTS and FRAP methods after digestion/fermentation, promoting an adequate protection of the bioactives for their absorption. Alginate-based beads have great potential as prebiotics, with the guar gum-containing system contributing the most to SCFAs production. Finally, the overall higher mobility of protons observed in the intestinal phase agrees with structural changes that promote the release of phenolic compounds during this stage. Beads are excellent carriers of bioactive compounds (cowpea phenolic compounds and peptides) with potential capacities.

Increase in colonic PRopionate as a method of prEVENTing weight gain over 12 months in adults aged 20–40 years (iPREVENT): a multi-centre, double-blind, randomised, parallel-group trial

Obesity drives metabolic disease development. Preventing weight gain during early adulthood could mitigate later-life chronic disease risk. Increased dietary fibre intake, leading to enhanced colonic microbial fermentation and short-chain fatty acid (SCFA) production, is associated with lower body weight. Despite national food policy recommendations to consume 30g of dietary fibre daily, only 9% of adults achieve this target. Inulin-propionate ester (IPE) selectively increases the production of the SCFA propionate in the colon. In previous studies, IPE has prevented weight gain in middle-aged adults over 6 months, compared with the inulin control. IPE is a novel food ingredient that can be added to various commonly consumed foods with a potential health benefit. This 12-month study aimed to determine whether using IPE to increase colonic propionate prevents further weight gain in overweight younger adults. This multi-centre randomised-controlled, double-blind trial was conducted in London and Glasgow, UK. Recruited participants were individuals at risk of weight gain, aged between 20 and 40 years and had an overweight body mass index. Sealed Envelope Software was used to randomise participants to consume 10g of IPE or inulin (control), once per day for 12 months. The primary outcome was the weight gained from baseline to 12 months, analysed by an 'Intention to Treat' strategy. The safety profile and tolerability of IPE were monitored through adverse events and compliance. This study is registered with the International Standard Randomised Controlled Trials (ISRCT) Database (ISRCT number: 16299902). Participants (n=135 per study arm) were recruited from July 2019 to October 2021. At 12 months, there was no significant difference in baseline-adjusted mean weight gain for IPE compared with control (1.02kg, 95% CI:-0.37 to 2.41; p=0.15; n=226). Neither the IPE (+1.22kg) nor the control arm (+0.07kg) unadjusted mean gains in body weight reached the expected 2kg threshold. In the IPE arm, fat-free mass was greater by 1.07kg (95% CI: 0.21-1.93), and blood glucose elevated by 0.11mmol/L (95% CI: 0.01-0.21). Compliance, determined by intake of ≥50% sachets, was reached by 63% of IPE participants. There were no unexpected adverse events or safety concerns. Our study indicates that at 12 months, IPE did not differentially affect weight gain, compared with the inulin control, in adults between 20 and 40 years of age, at risk of obesity. NIHR EME Programme (15/185/16).

RIPK4 promotes oxidative stress and ferroptotic death through the downregulation of ACSM1

One of the most critical axes for cell fate determination is how cells respond to excessive reactive oxygen species (ROS)-oxidative stress. Extensive lipid peroxidation commits cells to death via a distinct cell death paradigm termed ferroptosis. However, the molecular mechanism regulating cellular fates to distinct ROS remains incompletely understood. Through siRNA against human receptor-interacting protein kinase (RIPK) family members, we found that RIPK4 is crucial for oxidative stress and ferroptotic death. Upon ROS induction, RIPK4 is rapidly activated, and the kinase activity of RIPK4 is indispensable to induce cell death. Specific ablation of RIPK4 in kidney proximal tubules protects mice from acute kidney injury induced by cisplatin and renal ischemia/reperfusion. RNA sequencing revealed the dramatically decreased expression of acyl-CoA synthetase medium-chain (ACSM) family members induced by cisplatin treatment which is compromised in RIPK4-deficient mice. Among these ACSM family members, suppression of ACSM1 strongly augments oxidative stress and ferroptotic cell death with induced expression of ACS long-chain family member 4, an important component for ferroptosis execution. Our lipidome analysis revealed that overexpression of ACSM1 leads to the accumulation of monounsaturated fatty acids, attenuation of polyunsaturated fatty acid (PUFAs) production, and thereby cellular resistance to ferroptosis. Hence, knockdown of ACSM1 resensitizes RIPK4 KO cells to oxidative stress and ferroptotic death. In conclusion, RIPK4 is a key player involved in oxidative stress and ferroptotic death, which is potentially important for a broad spectrum of human pathologies. The link between the RIPK4-ASCM1 axis to PUFAs and ferroptosis reveals a unique mechanism to oxidative stress-induced necrosis and ferroptosis.

The Role of Gut Microbiome Alterations in the Pathogenesis and Management of Sjögren's Syndrome

Sjögren’s syndrome (SS) is a systemic autoimmune disorder characterized by inflammation and damage to the exocrine glands, leading to symptoms such as ocular and oral dryness, and a range of extraglandular manifestations including polyneuropathies, lung and kidney dysfunction, and systemic vasculitis. Although the exact etiology of SS remains unclear, recent research has highlighted the significant role of gut microbiota in its pathogenesis. Alterations in the gut microbiome, known as dysbiosis, have been implicated in the onset and progression of autoimmune diseases, including SS. This review synthesizes current research on the impact of microbiota on SS, focusing on microbial dysbiosis, its impact on disease severity, and potential therapeutic interventions. Evidence indicates that specific microbial changes, such as reductions in beneficial bacteria and alterations in short-chain fatty acid (SCFA) production, correlate with increased disease activity and systemic inflammation. Microbiome-targeted therapies, including probiotics, prebiotics, and fecal microbiota transplantation, have shown promise in improving SS symptoms and modulating immune responses. Notably, butyrate and specific probiotic strains have demonstrated potential in reducing inflammation and enhancing salivary flow in preclinical studies. However, further research is needed to validate these findings and assess long-term efficacy. This review underscores the importance of gut microbiota in SS and suggests that microbiome-focused treatments could offer new avenues for managing this condition, improving patient outcomes, and potentially preventing disease onset.

Unravelling the effects of short-term starvation and pH disturbances in stable volatile fatty acids production

The successful upscaling of anaerobic fermentation (AF) still relies on ensuring the stable production of volatile fatty acids (VFAs) in high concentrations and yields. The unforeseen events taking place at industrial scale can compromise the AF stability, thereby decreasing the cost-effectiveness of the process. To assess process stability against disturbances and identify AF failure indicators, this investigation explored the effect of starvation and pH control failure in a continuous reactor. The starvation disturbance did not affect AF performance and methanogenesis was not restored, confirming the relevance of selecting proper conditions (25 °C and pH 6.5) to ensure methanogenesis suppression. By contrast, the uncontrolled pH provoked a pH drop to 4.5, limiting the acidogenesis metabolisms and modifying the metabolites profile due to microbiome reshape. Lactobacillus, and members of Lactobacillaceae, Lactobacillales, and Bifidobacteriaceae dominated the microbiome in the pH disturbance, revealing lactic, succinic and oxalic acids as warning indicators of the acidogenesis failure. Nevertheless, the AF was completely recovered after the disturbances evidencing the microbiome robustness against pH range between 4.5 and 5.

Enhancing medium-chain fatty acids production via alkyl polyglucose modulation of electron acceptor generation, microbial community and metabolic traits in anaerobic fermentation of waste activated sludge

Production of medium chain fatty acids (MCFAs) through anaerobic fermentation is an essential pathway for efficient resource recovery and utilization of waste activated sludge (WAS). In this study, a novel strategy utilizing polyglucose (APG) to enhance MCFAs production from WAS by anaerobic fermentation was proposed. The results showed that the maximum MCFAs production reached 14745.0 mg COD/L with 0.3 g APG/g TSS, which was 20.2 times of that without APG treatment. The transformation of intermediates demonstrated that APG promoted the generation of electron acceptors (i.e., short-chain fatty acids) and conversion of substrate to MCFAs. Microbial community analysis indicated that APG selectively enriched microbe involved in hydrolysis, acidogenesis and chain elongation (CE). Also, the presence of APG had a negative impact on methanogens and potential excessive ethanol oxidation (EEO) microbe, which were competitors of CE bacteria in mixed-culture system. Metagenomic analysis showed an increase in relative abundance of genes encoding metabolic functions responsible for hydrolysis, acidogenesis, CE and energy generation, thus maintained high microbial activity in MCFAs biosynthesis. These enhanced metabolic functions were accompanied by a reduction in relative abundance of genes encoding methanogenesis and EEO metabolism, which together result in boosting the efficiency of substrate and energy flow to MCFAs production. This study presents a promising approach to improve the biotransformation of polysaccharides and proteins from WAS into MCFAs.

Yeast β-glucan attenuates dextran sulfate sodium-induced colitis: Involvement of gut microbiota and short-chain fatty acids

Yeast β-glucan intervention offers a promising strategy for managing colitis; however, the mechanisms remain unknown. In the present work, the protective effects of yeast β-glucan on DSS-induced colitis in mice was evaluated, focusing on its interaction with gut microbiota. The result showed yeast β-glucan significantly alleviated colitis symptoms, evidenced by reduced weight loss, lower disease activity index (DAI) scores, and minimized intestinal damage. It enhanced intestinal barrier integrity via upregulation of tight junction proteins, suppressed lipopolysaccharide (LPS) release, and decreased pro-inflammatory cytokines production. Additionally, yeast β-glucan boosted short-chain fatty acids (SCFAs) production, and activated their receptors, increased the relative abundances of beneficial microbes like Lactobacillus and Lachnospiraceae_UCG-006. Transcriptomic analyses suggest that yeast β-glucan mitigates inflammation by downregulating gene expression related to IL-17 pathway. Our findings highlight potential of yeast β-glucan as a therapeutic agent for colitis through modulation of gut microbiota and inflammatory responses.

Fads2 knockout mice reveal that ALA prevention of hepatic steatosis is dependent on delta-6 desaturase activity

The production of the omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from alpha-linolenic acid (ALA) relies on the delta-6 desaturase (D6D) enzyme encoded by the Fads2 gene. While EPA and DHA reduce hepatic triacylglycerol (TAG) storage and regulate lipogenesis, the independent impact of ALA is less understood. To address this gap in knowledge, hepatic fatty acid metabolism was investigated in male wild-type (WT) and Fads2 knockout (KO) mice fed diets (16% kcal from fat) containing either lard (no n-3 LCPUFA), flaxseed oil (ALA-rich), or menhaden oil (EPA/DHA rich) for 21 weeks. Fat content and composition, as well as markers of lipogenesis, glyceroneogenesis, and TAG synthesis, were analyzed using histology, gas chromatography, and reverse transcription quantitative PCR (RT-qPCR). Mice fed the menhaden diet had significantly lower hepatic TAG compared to both lard- and flax-fed mice, concomitant with changes in n-3 and n-6 LCPUFA in both TAG and phospholipid (PL) fractions (all P < 0.05). Flax-fed WT mice had lower liver TAG content compared to their KO counterparts. Menhaden-fed mice had significantly lower expression of key lipogenic (Scd1, Srebp-1c, Fasn, Fads1, and Fads2), glyceroneogenic (Pck1), and TAG synthesis (Agpat3) genes compared to lard, with flax-fed mice showing some intermediate effects. Gene expression effects were independent of D6D activity, since no differences were detected between WT and KO mice fed the same diet. This study demonstrates that EPA/DHA and not ALA itself is critical for the prevention of hepatic steatosis.

Baicalein ameliorates SEB-induced acute respiratory distress syndrome in a microbiota-dependent manner

BackgroundAcute respiratory distress syndrome (ARDS) is characterized by sudden and extensive pulmonary inflammation, with a mortality rate of approximately 40 %. Presently, there is no effective treatment to prevent or reverse its severe consequences. Baicalein (BAI) is a natural vicinal trihydroxyflavone and has been identified as the core quality marker of Scutellariae baicalensis for its effect on lung inflammation. However, its oral bioavailability is limited. The majority of studies that investigate BAI's in vivo mechanisms use injection techniques. Currently, there is no clear understanding of the mechanisms by which low-bioavailable BAI functions orally. PurposeThis study aimed to evaluate the efficiency of BAI in ARDS mice and its underlying mechanisms. Study design and methodsBehavioral experiments, histological analysis, immunofluorescence staining, flow cytometry of immune cells, qRT-PCR, and ELISA analysis were performed to evaluate the efficiency of BAI in ARDS mice. Lung tissues transcriptomic-based analyses were performed to detect the differentially expressed genes and biological pathways. Fecal samples were subjected to microbial 16S rRNA analysis and untargeted metabolomics analysis in order to identify the specific flora and metabolites associated with BAI. Furthermore, antibiotic cocktail treatment and fecal microbiota transplantation were used to elucidate the gut microbiota-mediated effects on ARDS. ResultsIn our study, we first find that oral administration of BAI effectively mitigates staphylococcal enterotoxin B-induced ARDS. BAI can alleviate gut dysbiosis and regulate the Toll-like signaling pathway and amino acid metabolism. The protective effects of BAI against ARDS are gut microbiota dependent. Modulation of gut microbiota increases the production of short-chain fatty acids and enhances lung barrier function, which is consistent with the therapeutic interventions with BAI. Notably, BAI greatly enriches the abundance of Prevotellaceae, a butyrate-producing bacterial family, exhibiting a positive correlation with key differentially expressed genes in the TLR4/MyD88 signaling cascades. ConclusionBAI emerges as a potential prebiotic agent to attenuate ARDS, and targeting specific microbial species may offer an innovative therapeutic approach to investigate other flavonoids with limited bioavailability.

The short-chain fatty acid receptors Gpr41/43 regulate bone mass by promoting adipogenic differentiation of mesenchymal stem cells.

Bone is a dynamic tissue that is constantly remodeled throughout adult life. Recently, it has been shown that bone turnover decreases shortly after food consumption. This process has been linked to the fermentation of non-digestible food ingredients such as inulin by gut microbes, which results in the production of the short-chain fatty acids (SCFAs) acetate, propionate and butyrate. SCFAs exert various metabolic functions, which in part can be explained by activation of G protein-coupled receptors (Gpr) 41 and 43. However, the potential relevance of a SCFA-Gpr41/43 signaling axis for bone metabolism has not been established. The aim of our study is to investigate the role of Gpr41/43 in bone metabolism and osteogenic differentiation of mesenchymal stem cells. For this purpose, we analyzed the skeletal phenotype of wild type controls (WT) and Gpr41/43 double knockout (Gpr41/43 dKO) mice fed either a chow or an inulin-enriched diet. In addition, we isolated bone marrow derived mesenchymal stem cells from WT and Gpr41/43 dKO mice and differentiated them into osteoblasts in the absence or presence of acetate. MicroCT scanning of femoral bones of Gpr41/43 dKO mice revealed a significant increase of trabecular bone volume and trabecular compared to WT controls. Treatment of WT bone marrow-derived osteoblasts with acetate resulted in decreased mineralization and substantial downregulation of bone formation markers such as Phex, Ptgs2 and Col1a1. Notably, this effect was strongly attenuated in differentiated osteoblasts lacking Gpr41/43. Inversely, acetate supplementation resulted in higher levels of adipocyte marker genes including Pparg, Lpl and Adipoq in bone marrow-derived cells from WT mice, an effect blunted in differentiated cells isolated from Gpr41/43 dKO mice. Overall, these data indicate that acetate regulates bone architecture via SCFA-Gpr41/43 signaling by modulating the osteogenic versus adipogenic differentiation of mesenchymal stem cells.

Volatile Fatty Acid Production through Arresting Methanogenesis by Electro-Synthesized Hydrogen Peroxide in Anaerobic Digestion and Subsequent Recovery by Electrodialysis

Volatile Fatty Acid Production through Arresting Methanogenesis by Electro-Synthesized Hydrogen Peroxide in Anaerobic Digestion and Subsequent Recovery by Electrodialysis

Genomic analysis and functional properties of Lactobacillus johnsonii GJ231 isolated from healthy beagles.

Probiotics are one of the management tools to improve the host's healthy microbiota. The positive effects of probiotics on host health are species-specific, so probiotics isolated from host's own gut may be most beneficial. Many of the metabolites (e.g., short-chain fatty acids, bacteriocins, and hydrogen peroxide) produced by Lactobacillus johnsonii have specific inhibitory profiles against invading pathogens. In this study, we isolated L. johnsonii GJ231 from the intestinal tract of healthy female beagles. The genome size of 1.763 M encoded a total of 1,691 predicted genes. Many carbohydrate-active enzymes responsible for carbohydrate degradation and the production of short-chain fatty acids were also predicted. The metabolic profile of short-chain fatty acids in L. johnsonii GJ231 was determined using LC-MS/MS. The bacteriocin-producing gene bacteriocin (lactacin F) in L. johnsonii GJ231 was also predicted. In vitro, experiments demonstrated that GJ231 can thrive in weak acids, 0.3% bile salts, and artificial gastrointestinal fluid models. It was tolerant of to high temperatures up to 70°C, was non- hemolytic, inhibited pathogenic bacteria, and had a high antioxidant capacity. In vivo safety experiments conducted in mice revealed that oral administration of GJ231 not only had no toxic side effect but also increased their antioxidant capacity. In conclusion, combining the above test results, which collectively demonstrate that canine-derived L. johnsonii GJ231 was a non-pathogenic, acid-tolerant and bile-salt-tolerant probiotic strain that inhibits pathogenic bacteria and improves host antioxidant function. This may make it a promising candidate for the development of innovative functional foods for pets.

The Gut Microbiota characterization of a World-Class Mountain Trail runner during a complete competition season: a case report.

In the present case study, the gut microbiota (GM) profile of a male Elite Mountain Runner (34 years, 171cm, 59 kg, VO2max: 92 mL·min-1 ·kg-1) was analyzed over 5 months competitive period (6 samples). The GM diversity increased through the season coinciding higher levels to the peak performance and shorter and longer race (42 vs. 172 km) produced different phenotypic GM changes. Shorter race promoted the elevation of protective bacteria related to positive benefits (higher production of short-chain fatty acids (SCFAs), lactate resynthesis, mucin degraders). In contrast, longer race promoted an elevation of opportunistic pathogenic bacteria while reducing protective commensal bacteria. The present findings indicate that a higher resilience of the GM after competitions may support rapid recovery from maximal exercise. The GM analyses pre- and post-competition could represent a rapid indicator for the (patho)physiological impact of exercise and provide information on gut health and recovery time needed.