Increased Short-chain Fatty Acids Production Research Articles

Effect of Black Glutinous Rice Fermented Beverage on Short-Chain Fatty Acid Levels in Metabolic Syndrome Rats

Metabolic Syndrome (MetS) represents a combination of metabolic factors that can elevate the likelihood of developing type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). The high prevalence of MetS results in a significant socio-economic burden. However, current management approaches have limitations, prompting the exploration of functional foods and nutraceuticals as promising alternatives. The primary objective of this study is to investigate the impact of Black Glutinous Rice Fermented Beverage (BGRFB) on Short Chain Fatty Acids (SCFA) concentration in a MetS rat model. Rats were induced with a high-fat diet (HFD) and streptozotocin (STZ)-nicotinamide (NA) to induce MetS conditions. BGRFB was administered as a treatment to the MetS rat group. The results showed that the Negative Control (NC) group exhibited a significant decrease in SCFA levels compared to the normal group (N). However, administration of BGRFB to the T2 group resulted in a significant increase in SCFA levels. The SCFA levels in the T2 group were higher but not significantly different from the Positive Control (PC) group treated with metformin. Increasing SCFA production could be an effective strategy in addressing Mets. This study demonstrates the potential of BGRFB as a therapy to enhance SCFA production and improve MetS. The outcomes of this investigation are anticipated to provide insights into novel dietary approaches for MetS management.

Butyrate interacts with the effects of 2'FL and 3FL to modulate in vitro ovalbumin-induced immune activation, and 2'FL lowers mucosal mast cell activation in a preclinical model for hen's egg allergy.

Early life provides a window of opportunity to prevent allergic diseases. With a prevalence of 0.5-2% in infants, hen's egg allergy is one of the most common food allergies. The immunomodulatory effects of human milk oligosaccharides (HMOs), 2'-fucosyllactose (2'FL), and 3-fucosyllactose (3FL) were studied in an in vitro mucosal immune model and an in vivo murine model for hen's egg (ovalbumin) allergy. Intestinal epithelial cell (IEC)/dendritic cell (DC) and DC/T cell cocultures were used to expose IECs to ovalbumin (OVA) in an in vitro mucosal immune model. The effects of epithelial pre-incubation with 0.1% 2'FL or 3FL and/or 0.5 mM butyrate were studied. Three- to four-weeks-old female C3H/HeOuJ mice were fed AIN93G diets containing 0.1-0.5% 2'FL or 3FL 2 weeks before and during OVA sensitization and challenge. Allergic symptoms and systemic and local immune parameters were assessed. Exposing IECs to butyrate in vitro left the IEC/DC/T cell cross-talk unaffected, while 2'FL and 3FL showed differential immunomodulatory effects. In 3FL exposed IEC-DC-T cells, the secretion of IFNγ and IL10 was enhanced. This was observed upon pre-incubation of IECs with 2'FL and butyrate as well, but not 2'FL alone. The presence of butyrate did not affect OVA activation, but when combined with 3FL, an increase in IL6 release from DCs was observed (p < 0.001). OVA allergic mice receiving 0.5% 3FL diet had a lower %Th2 cells in MLNs, but the humoral response was unaltered compared to control mice. OVA-allergic mice receiving 0.1 or 0.5% 2'FL diets had lower serum levels of OVA-IgG2a (p < 0.05) or the mast cell marker mMCP1, in association with increased concentration of cecal short-chain fatty acids (SCFAs) (p < 0.05). In vitro butyrate exposure promotes the development of a downstream type 1 and regulatory response observed after 2'FL exposure. 2'FL and 3FL differentially modulate ovalbumin-induced mucosal inflammation predominantly independent of butyrate. Mice receiving dietary 3FL during ovalbumin sensitization and challenge had lowered Th2 activation while the frequency of Treg cells was enhanced. By contrast, 2'FL improved the humoral immune response and suppressed mast cell activation in association with increased SCFAs production in the murine model for hen's egg allergy.

Activation of peroxymonosulfate by sewage sludge-derived biochar to promote short-chain fatty acid production during sludge anaerobic fermentation

This study reports on the potential use of sewage sludge-derived biochar (SBC) as an activator for peroxymonosulfate (PMS) to improve the solubilization of waste activated sludge (WAS) and the production of short-chain fatty acids (SCFAs) during anaerobic digestion. The SBC produced by pyrolysis of WAS has active sites consisting of metals species and C = O groups, which can effectively activate PMS. SBC-activated PMS (PMS/SBC) can destroy cellular structures in WAS and release large amounts of organic matter, increasing the rate of hydrolysis and promoting subsequent SCFA production. Compared with the control, PMS/SBC treatment increased SCFA production by 801 % at a PMS dose of 0.14 g/g VSS (volatile suspended solids) and SBC dose of 0.24 g/g VSS. Moreover, PMS/SBC could degrade refractory organic pollutants in WAS (sulfamethoxazole removal efficiency >63 %), improving SCFA quality. Mechanistic investigations revealed that SBC activates PMS to produce •SO4−, 1O2, and •OH. The contributions of these species to sludge solubilization were 1O2 > •OH > •SO4−, with surface-bound radicals on SBC playing major roles. In addition, PMS/SBC treatment enriched hydrolysis and SCFA-forming bacteria and increased the expression of key genes for SCFA production during sludge anaerobic fermentation, which also contributed to SCFA accumulation. This work provides new insights into the mechanism of SBC activation of PMS and its potential applications in WAS resource utilization.

Human umbilical cord mesenchymal stem cells ameliorate colon inflammation via modulation of gut microbiota-SCFAs-immune axis

BackgroundInflammatory bowel disease (IBD) is a global health problem in which gut microbiota dysbiosis plays a pivotal pathogenic role. Mesenchymal stem cells (MSCs) therapy has emerged as a prospective novel tool for managing IBD, and which can also regulate the composition of gut microbiota. However, the functional significance of MSCs-induced changes in gut microbiome is poorly understood.MethodsHere, we investigated for the first time the role of gut microbiota in mediating the protective effect of human umbilical cord MSCs (HUMSCs) on DSS-induced colitis. Gut microbiota alteration and short-chain fatty acids (SCFAs) production were analyzed through 16S rRNA sequencing and targeted metabolomics. Spectrum antibiotic cocktail (ABX), fecal microbiota transplantation (FMT) and sterile fecal filtrate (SFF) were employed to evaluate the protective effect of intestinal flora and its metabolites. Cytokine microarray, Enzyme-linked immunosorbent assay (ELISA), and flow cytometry were conducted to assess the effect on CD4+T homeostasis.ResultsHere, we investigated for the first time the role of gut microbiota in mediating the protective effect of MSCs on DSS-induced colitis. By performing gut microbiota depletion and fecal microbiota transplantation (FMT) experiments, we revealed that MSCs derived from human umbilical cord ameliorated colon inflammation and reshaped T-cells immune homeostasis via remodeling the composition and diversity of gut flora, especially up-regulated SCFAs-producing bacterial abundance, such as Akkermansia, Faecalibaculum, and Clostridia_UCG_014. Consistently, targeted metabolomics manifested the increased SCFAs production with MSCs administration, and there was also a significant positive correlation between differential bacteria and SCFAs. Meanwhile, combined with sterile fecal filtrate (SFF) gavage experiments, the underlying protective mechanism was further associated with the improved Treg/Th2/Th17 balance in intestinal mucosa mediated via the increased microbiota-derived SCFAs production.ConclusionThe present study advances understanding of MSCs in the protective effects on colitis, providing evidence for the new role of the microbiome-metabolite-immune axis in the recovery of colitis by MSCs.

Gut Microbiota and Derived Short-Chain Fatty Acids Are Linked to Evolution of Heart Failure Patients.

There is a lack of direct evidence regarding gut microbiota dysbiosis and changes in short-chain fatty acids (SCFAs) in heart failure (HF) patients. We sought to assess any association between gut microbiota composition, SCFA production, clinical parameters, and the inflammatory profile in a cohort of newly diagnosed HF patients. In this longitudinal prospective study, we enrolled eighteen newly diagnosed HF patients. At admission and after 12 months, blood samples were collected for the assessment of proinflammatory cytokines, monocyte populations, and endothelial dysfunction, and stool samples were collected for analysis of gut microbiota composition and quantification of SCFAs. Twelve months after the initial HF episode, patients demonstrated improved clinical parameters and reduced inflammatory state and endothelial dysfunction. This favorable evolution was associated with a reversal of microbiota dysbiosis, consisting of the increment of health-related bacteria, such as genus Bifidobacterium, and levels of SCFAs, mainly butyrate. Furthermore, there was a decrease in the abundance of pathogenic bacteria. In vitro, fecal samples collected after 12 months of follow-up exhibited lower inflammation than samples collected at admission. In conclusion, the favorable progression of HF patients after the initial episode was linked to the reversal of gut microbiota dysbiosis and increased SCFA production, particularly butyrate. Whether restoring butyrate levels or promoting the growth of butyrate-producing bacteria could serve as a complementary treatment for these patients deserves further studies.

Akkermansia muciniphila supplementation prevents cognitive impairment in sleep-deprived mice by modulating microglial engulfment of synapses

ABSTRACT The microbiome-gut-brain axis plays a crucial role in many neurological diseases, including mild cognitive impairment. Sleep deprivation (SD) induces cognitive decline accompanied by alterations in the gut microbiota. However, the role of gut microbiota alterations in SD-induced cognitive dysfunction and the underlying mechanisms remain unclear. Here, we found that dysbiosis of the gut microbiota following pretreatment with broad-spectrum antibiotics worsens SD-induced cognitive impairment in mice. Fecal microbiota transplantation from SD mice to healthy mice induced cognitive impairment. Additionally, the abundance of Akkermansia muciniphila (A. muciniphila) in the mouse gut microbiota was significantly reduced after 7 days of SD. A. muciniphila pretreatment alleviated cognitive dysfunction and prevented synaptic reduction in the hippocampus in SD mice. A. muciniphila pretreatment inhibited extensive microglial activation and synaptic engulfment in the hippocampus of SD mice. Metabolomics analysis revealed that A. muciniphila pretreatment increased the serum acetate and butanoic acid levels in SD mice. Finally, pretreatment with short-chain fatty acids (SCFAs) inhibited microglial synaptic engulfment and prevented neuronal synaptic loss in SD mice and primary microglia-neuron co-culture following LPS stimulation. Together, our findings illustrate that gut dysbiosis plays an essential role in SD-induced cognitive impairment by activating microglial engulfment at synapses. A. muciniphila supplementation may be a novel preventative strategy for SD-induced cognitive dysfunction, by increasing SCFAs production and maintaining microglial homeostasis.

Evaluating the effect of prebiotics on the gut microbiome profile and β cell function in youth with newly diagnosed type 1 diabetes: protocol of a pilot randomized controlled trial

IntroductionData show that disturbances in the gut microbiota play a role in glucose homeostasis, type 1 diabetes (T1D) risk and progression. The prebiotic high amylose maize starch (HAMS) alters the gut microbiome profile and metabolites favorably with an increase in bacteria producing short chain fatty acids (SCFAs) that have significant anti-inflammatory effects. HAMS also improves glycemia, insulin sensitivity, and secretion in healthy non-diabetic adults. Additionally, a recent study testing an acetylated and butyrylated form of HAMS (HAMS-AB) that further increases SCFA production prevented T1D in a rodent model without adverse safety effects. The overall objective of this human study will be to assess how daily HAMS-AB consumption impacts the gut microbiome profile, SCFA production, β cell heath, function, and glycemia as well as immune responses in newly diagnosed T1D youth.Methods and analysisWe hypothesize that HAMS-AB intake will improve the gut microbiome profile, increase SCFA production, improve β cell health, function and glycemia as well as modulate the immune system. We describe here a pilot, randomized crossover trial of HAMS-AB in 12 newly diagnosed T1D youth, ages 11–17 years old, with residual β cell function. In Aim 1, we will determine the effect of HAMS-AB on the gut microbiome profile and SCFA production; in Aim 2, we will determine the effect of HAMS-AB on β cell health, function and glycemia; and in Aim 3, we will determine the peripheral blood effect of HAMS-AB on frequency, phenotype and function of specific T cell markers. Results will be used to determine the effect-size estimate of using HAMS-AB. We anticipate beneficial effects from a simple, inexpensive, and safe dietary approach.Ethics and disseminationThe Institutional Review Board at Indiana University approved the study protocol. The findings of this trial will be submitted to a peer-reviewed pediatric journal. s will be submitted to relevant national and international conferences.Trial registrationNCT04114357; Pre-results.

Prebiotic and Anti-Adipogenic Effects of Radish Green Polysaccharide.

Radish (Raphanus sativus L.) greens are consumed as a source of nutrition, and their polysaccharides such as rhamnogalacturonan-I possess certain beneficial properties. This study investigated the prebiotic effects of a radish green polysaccharide (RGP) on gut health and obesity. The prebiotic activity of RGP was evaluated based on the pH changes and short-chain fatty acids (SCFAs) concentration. The results showed that 0.5% RGP had a higher prebiotic activity score than inulin and increased SCFAs production in all five prebiotic strains. Moreover, RGP inhibited fat accumulation in 3T3-L1 adipocytes, indicating its potential to reduce obesity. Overall, these findings suggested that the polysaccharide of radish greens has prebiotic effects and may serve as a beneficial prebiotic for gut health and obesity.

#3454 IMPACT OF SYMBIOTICS ON UREMIC TOXINS PRODUCTION, RENAL FUNCTION AND PEW SYNDROME IN SHIME AND CKD MICE MODELS

Abstract Background and Aims Alterations in gut microbiota in CKD patients have been linked to CKD progression, cachexia, and mortality. Gut dysbiosis is associated by modification of gut-microbiota-derived metabolites, including a decrease of short-chain fatty acids (SCFAs), an increase in gut-derived uremic toxins. Therefore, modulation of gut microbiota seems to be an attractive therapeutic approach. In silico studies led to the selection of bacterial species able to increase SCFAs production, improve gut function without having the enzymatic machinery for producing uremic toxins. The propose of this study is to indentify the impact of two different symbiotics containing the selected bacteria: 1) on both uremic toxins and SCFAs production using a Simulator of the Human Intestinal Microbial Ecosystem (SHIME) colonized with fresh feces from CKD or healthy controls (HC) and subsequently 2) on renal function, metabolic parameters, intestinal microbiota and gut-microbiota-derived metabolites in a mouse model of CKD (5/6 nephrectomy). Method 1) The SHIME® system manufactured by ProDigest (Ghent, Belgium) consists of systems comprising five double-wall biovessels simulating the stomach (ST), small intestine (SI), ascending colon (AC), transverse colon (TC), and descending colon (DC). The supernatant of the homogenized fecal slurry was inoculated into the AC (25 mL), TC (40 mL), and DC (30 mL), respectively. After fecal inoculation, SHIME system were fed in ST twice day with two different symbiotics (P1 or P2) for 10 days. After 7 days, we applied a diet amino acid (AA) challenge to all the groups. SCFAs and uremic toxins were quantified every day. 2) CKD mice received either P1 or P2 admix for 6 weeks. We measured food intake, body composition and renal function including renal fibrosis quantification. Plasma metabolomic and feces metagenomic analyses were performed. Results In vitro, the concentration of precursor of uremic toxins (indols and p-cresol) tended to be higher in DC colonized by feces from CKD patients and AA challenge increased uremic toxins production more significantly in CKD compared to HC. CKD microbiome showed a lower butyrate concentration at baseline and higher propionate and acetate production. Both P1 and P2 significantly limited uremic toxins production during AA challenge and increase SCFA production. In vivo, both symbiotics increased body weight (+14%) and food intake (+31%) compared to CKD mice on chow diet. Treatment did not impact lipid or glucose metabolism but fat accretion in epididymal was restored with P1. Both diets, but particularly P1, significantly reduced plasmatic urea, proteinuria, and kidney fibrosis. Symbiotics improved intestinal barrier with a greater expression of Occludin in the ileum. Metagenomic analyses of the gut microbiota indicated that the alfa-diversity was not different across groups while the beta-diversity was similar to the sham group if CKD mice were treated with symbiotics. Both symbiotics reduced significantly plasma levels of deleterious uremic toxins such as p-cresyl sulfate and indoxyl sulfate and symbiotics reduce fecal module of trypotophan degradation and other modules related to AA metabolism. Both diets increased fecal bacteria modules related to SCFAs production. Conclusion We have shown both in vitro and in vivo that a symbiotic association can reduce uremic toxins production and increase SCFA production by inducing a significant change in gut microbiota composition and function. These metabolic changes are associated with improved appetite, decreased uremic cachexia, and preserved renal function. This data needs be confirmed in a human clinical trial.

In vitro fermentation of epilactose and epilactitol by human faecal microbiota

To obtain new lactose-derived prebiotic, epilactose and its derivative epilactitol were synthesised with high purity (>98%), and their structural characteristics were investigated. To determine the prebiotic potential of epilactose and epilactitol, these two compounds were fermented in vitro with human faecal microbiota. Consequently, epilactose addition increased the relative abundance of Bifidobacterium, Megamonas, Blautia, and Phascolarctobacterium, whereas epilactitol addition enhanced the relative abundance of Anaerostipes, Megamonas, Blautia and Phascolarctobacterium after in vitro fermentation for 24 h. The two compounds increased the production of total amount of short-chain fatty acids (SCFAs); in particular, epilactose addition increased acetate and n-butyrate production (P < 0.05), and epilactitol addition increased propionate and n-butyrate production (P < 0.05) after in vitro fermentation for 24 h. In conclusion, epilactose and epilactitol can be utilised by human faecal microbiota, modify microbial community, increase SCFA production, they may serve as novel prebiotics to bring health benefits for humans.

Seabuckthorn Wuwei Pulvis attenuates chronic obstructive pulmonary disease in rat through gut microbiota-short chain fatty acids axis

Ethnopharmacological relevanceSeabuckthorn Wuwei Pulvis (SWP) is a traditional Mongolian medicine used in China. It is composed of Hippophae rhamnoides (berries, 30 g), Aucklandiae costus Falc. (dry root, 25 g), Vitis vinifera F. Cordifolia (berries, 20 g), Glycyrrhiza uralensis Fisch. (dry root, 15 g), and Gardenia jasminoides J. Ellis (desiccative ripe fruit, 10 g). It is clinically applied in the treatment of chronic cough, shortness of breath and phlegm, and chest distress. Past studies demonstrated that Seabuckthorn Wuwei Pulvis improved lung inflammation and chronic bronchitis in mice. However, the effect of Seabuckthorn Wuwei Pulvis on chronic obstructive pulmonary disease (COPD) in rats and the underlying action mechanism is not fully understood. Aim of the studyTo evaluate the anti-COPD effect of Seabuckthorn Wuwei Pulvis and investigate whether its ameliorative effect is correlated with the composition of gut microbiota and its metabolites. Materials and methodsThe effects of Seabuckthorn Wuwei Pulvis on a COPD rat model were established by exposure to lipopolysaccharide (LPS) and smoking. These effects were then evaluated by monitoring the animal weight, pulmonary function, lung histological alteration, and the levels of inflammatory factors (tumor necrotic factor [TNF]-α, interleukin [IL]-8, IL-6, and IL-17). Furthermore, the serum LPS and fluorescein isothiocyanate-dextran levels were detected by using an enzyme-linked immunosorbent assay and fluorescence microplate reader, respectively. Tight junction proteins (ZO-1 and occludin-1) in the small intestine were detected by performing real-time quantitative polymerase chain reactions and Western blotting to evaluate the intestinal barrier function. The contents of short-chain fatty acids (SCFAs) in the feces of rats were determined by gas chromatography-mass spectrometry. 16S rDNA high throughput sequencing was used to investigate the effect of SWP on the gut microbiota of COPD rats. ResultsTreatment with low and median doses of SWP significantly increased the pulmonary function (forced expiratory volume [FEV] 0.3, forced vital capacity [FVC], and FEV0.3/FVC), decreased the levels of TNF-α, IL-8, IL-6, and IL-17 in the lung, and attenuated the infiltration of inflammatory cells into the lung. The low and median doses of SWP shaped the composition of gut microbiota, which increased the abundances of Ruminococcaceae, Christensenellaceae, and Aerococcaceae, increased the productions of acetic acid, propionic acid, and butyric acid, and upregulated the expression of ZO-1 and occludin-1 in the small intestine of COPD rats. ConclusionSWP improved pulmonary functions and inhibited the inflammatory response by shaping the gut microbiota, increasing SCFA production, and strengthening the intestinal barrier function in rats with COPD induced by LPS and smoking.

Age-Dependent Prebiotic Effects of Soluble Corn Fiber in M-SHIME® Gut Microbial Ecosystems

Soluble corn fiber (SCF) has demonstrated prebiotic effects in clinical studies. Using an in vitro mucosal simulator of the human intestinal microbial ecosystem (M-SHIME®) model, the effects of SCF treatment on colonic microbiota composition and metabolic activity and on host-microbiome interactions were evaluated using fecal samples from healthy donors of different ages (baby [≤ 2 years], n = 4; adult [18–45 years], n = 2; elderly [70 years], n = 1). During the 3-week treatment period, M-SHIME® systems were supplemented with SCF daily (baby, 1.5, 3, or 4.5 g/d; adult, 3 or 8.5 g/d; and elderly, 8.5 g/d). M-SHIME® supernatants were evaluated for their effect on the intestinal epithelial cell barrier and inflammatory responses in lipopolysaccharide. (LPS)-stimulated cells. Additionally, short-chain fatty acid (SCFA) production and microbial community composition were assessed. In the baby and adult models, M-SHIME® supernatants from SCF treated vessels protected Caco-2 membrane integrity from LPS-induced damage. SCF treatment resulted in the expansion of Bacteroidetes, Firmicutes, and Bifidobacterial, as well as increased SCFA production in all age groups. SCF tended to have the greatest effect on propionate production. These findings demonstrate the prebiotic potential of SCF in babies, adults, and the elderly and provide insight into the mechanisms behind the observed prebiotic effects.

Dietary fibers with low hydration properties exacerbate diarrhea and impair intestinal health and nutrient digestibility in weaned piglets

BackgroundThis study aimed to investigate the hydration properties of different-source fibrous materials by comparing their water-binding capacity (WBC), water swelling capacity (WSC), viscosity, and in vivo effects of selected samples on growth performance, nutrient digestibility, diarrhea, and intestinal health in weaned piglets.MethodsA total of 13 commercially available fibrous materials were first compared in chemical composition and in vitro hydration property. Subsequently, 40 weaned piglets were randomized to five experimental dietary groups (8 piglets per group): control diet (a basal diet without dietary fiber, CON), basal diet supplemented with 5% microcrystalline cellulose (MCC), 5% wheat bran (WB), 5% Moringaoleifera leaf powder (MOLP), or 5% sugar beet pulp (SBP), followed by analyzing their growth performance and diarrhea rate in a 28-d experiment. After the feeding experiment, anaesthetized piglets were killed, and their intestinal and colon content or plasma samples were analyzed in nutrient digestibility, intestinal morphology, intestinal barrier, short-chain fatty acids (SCFAs), and bacterial population.ResultsIn vitro studies showed low hydration properties for WB and MCC, while medium hydration properties for MOLP and SBP. In vivo studies indicated that compared with medium hydration property groups, low hydration property groups showed (1) exacerbated diarrhea, impaired intestinal health, and reduced apparent fecal digestibility of dry matter, gross energy, acid detergent fiber, and neutral detergent fiber; (2) decreased SCFAs concentration and relative levels of Lactobacillus and Bifidobacterium, but increased levels of Escherichia coli and Brachyspira hyodysenteriae in colon contents. Additionally, SBP showed optimal performance in reducing diarrhea and increasing SCFAs production. Correlation analysis revealed a positive correlation of fiber hydration properties with in vitro SCFAs production, and diarrhea index and nutrient digestibility were negatively and positively correlated with SCFAs levels in the colon contents of weaned piglets, respectively.ConclusionsDifferent-source dietary fibers varied in their hydration properties and impacts on diarrhea, microbial composition and SCFAs production in weaned piglets. WB and MCC could exacerbate diarrhea and impair nutrient digestibility, probably because their low hydration properties were detrimental to gut microbial homeostasis and fermentation. Our findings provide new ideas for rational use of fiber resources in weaned piglets.

Diet-Related Changes of Short-Chain Fatty Acids in Blood and Feces in Obesity and Metabolic Syndrome.

Obesity-related illnesses are one of the leading causes of death worldwide. Metabolic syndrome has been associated with numerous health issues. Short-chain fatty acids (SCFAs) have been shown to have multiple effects throughout the body, both directly as well as through specific G protein-coupled receptors. The main SCFAs produced by the gut microbiota are acetate, propionate, and butyrate, which are absorbed in varying degrees from the large intestine, with some acting mainly locally and others systemically. Diet has the potential to influence the gut microbial composition, as well as the type and amount of SCFAs produced. High fiber-containing foods and supplements increase the production of SCFAs and SCFA-producing bacteria in the gut and have been shown to have bodyweight-lowering effects. Dietary supplements, which increase SCFA production, could open the way for novel approaches to weight loss interventions. The aim of this review is to analyze the variations of fecal and blood SCFAs in obesity and metabolic syndrome through a systematic search and analysis of existing literature.

Proanthocyanidins in grape seeds and their role in gut microbiota-white adipose tissue axis

Several factors can impact the gut microbiota, affecting host metabolism and immunity. It implies intestinal barrier disruption and translocation of gut microbiota metabolites to the bloodstream, such as lipopolysaccharides (LPS). LPS is an endotoxin from gram-negative gut bacteria that trigger the activation of the Toll-like receptor-4 (TLR-4) inflammatory pathway and can modulate white adipose tissue (WAT) metabolism. Dietary components, including diets rich in fiber and polyphenols, contribute to intestinal environment homeostasis. Grape seed proanthocyanidins extract (GSPE) may improve intestinal permeability and microbial diversity and increase short-chain fatty acids production. Furthermore, GSPE has been involved in LPS reduction, down-regulating the TLR-4 pathway, decreasing the WAT metainflammatory profile, and preventing adipocyte hypertrophy. Studies have pointed out strategies to promote health and control obesity by modulating the gut microbiota environment. Therefore, this review aims to summarize the potential effects of GSPE on the gut microbiota-white adipose tissue axis against obesity.

Synergistic improvement of short-chain fatty acid production from waste activated sludge via anaerobic fermentation by combined plasma-calcium peroxide process

In this study, the combination of dielectric barrier discharge plasma (DBD) with calcium peroxide (CaO2) achieved significant synergistic effects in promoting hydrolysis of waste activated sludge (WAS) and short-chain fatty acid (SCFA) production during anaerobic fermentation. Compared with the control, DBD/CaO2 pretreatment increased SCFA production by 116 %, acetic acid ratio by 39 %, and sludge reduction by 30 % under the optimal conditions (discharge power = 76.5 W, CaO2 dosage = 0.05 g/g VSS). Mechanism investigations elucidated that DBD/CaO2 enhanced the generation of •OH, 1O2, and •O2−, synergistically promoted decomposing extracellular polymeric substances (EPS), lysing cells, releasing biodegradable substances, and enhancing acetic acid-enriched SCFA accumulation from fermentation. Meanwhile, Illumina MiSeq sequencing analysis revealed that the enrichment of hydrolytic and SCFAs-forming bacteria and the decrease in SCFAs-consuming bacteria by DBD/CaO2 treatment also contributed. This work provides an effective method to boost the SCFA production from WAS fermentation.

Phaseolus vulgaris L. Leaves Increase Short-Chain Fatty Acid (SCFA) Production, Ameliorating Early Metabolic Alterations.

High-fat/high-fructose diets promote early metabolic disorders in weight and lipid and glucose metabolism. Bioactive compounds such as polyphenols and fiber present in plant-based food prevent the development of metabolic disorders. The objective of the present study was to evaluate the effect of Phaseolus vulgaris L. Flor de Mayo Eugenia (FME) bean leaves on early metabolic alterations in male Wistar rats fed a high-fat/high-fructose diet. After proximate and chemical analysis of FME bean leaves, thirty-six male Wistar rats (ethical approval 06FCN2019 and 77FCN2019) were randomly assigned to one of four groups: 1) standard diet (S) fed with Rodent Laboratory Chow 5001®; 2) standard diet + 10% dry FME bean leaves (SBL); 3) high-fat (lard) and high-fructose diet (H); and 4) high-fat/high-fructose diet + 10% dry FME bean leaves (HBL). The study was carried out for sixweeks. Group H exhibited early metabolic alterations compared to Group S: final weight gain (↑15%), abdominal fat accumulation (waist circumference, ↑11%), triglycerides (↑30%), glucose (↑16%), insulin resistance (HOMA-IR, ↑32%), and fecal triglycerides (↑284%) and decreased total short-chain fatty acids (SCFAs, ↓17%). FME bean leavesupplementation (HBL) prevented body weight gain (↓12%), abdominal fat accumulation (waist circumference, ↓10%), and early insulin resistance (glucose area under the curve, ↓6%) compared to Group H. The supplementary bean leave diet increased SCFA production (↑54%), most likely mediated by the fiber and polyphenols present in the leaves. Therefore, bean leaves are a low-cost alternative for human nutritional care and prevention of early metabolic alterations.

Puerarin improves skeletal muscle strength by regulating gut microbiota in young adult rats.

BackgroundSarcopenia is an age-related skeletal muscle dysfunction syndrome that is lacking validated treatments. Maximizing muscle strength in young adulthood may be a promising way to prevent sarcopenia in the elderly. The phytomolecule puerarin has been extensively used in clinical practice and reported to increase energy metabolism in skeletal muscle by directly targeting the skeletal muscle fiber. However, the bioavailability of puerarin is very poor, and almost 93% of puerarin stays in the intestine until excretion. Therefore, we hypothesize that puerarin may regulate gut microbiota to improve skeletal muscle strength and/or mass in adults.MethodsTwenty three-month old male Sprague Dawley rats were divided into two groups according to average weights, puerarin group (puerarin dissolved in 0.5% CMC-Na, 150 ​mg/kg/day, N ​= ​10), and control group (equal volume 0.5% CMC-Na, N ​= ​10). The treatment lasted for 8 weeks. Muscle weight, muscle fiber types and cross-sectional area (CSA), ex vivo muscle contraction test and grip strength were measured. 16S rDNA sequencing was employed to evaluate the gut microbiota composition in the sample of cecal content. Short-chain fatty acids (SCFAs) in cecal and serum were analyzed by gas chromatography-mass spectrometry. Adenosine triphosphate (ATP) concentration in skeletal muscle was also detected. Pearson's correlation was used to analyze the relations between SCFAs, ATP concentration and muscle function.ResultsAfter puerarin treatment, grip strength, the specific twitch force, and the tetanic forces in the soleus (SOL) and extensor digitorum longus (EDL) muscle were significantly higher than those of the control group. The percentage and CSA of type II muscle fiber in EDL was higher in the puerarin group than those in the control group. Puerarin treatment significantly changed the gut microbial constitutes. Two SCFAs-productive microbiota, the families Peptococcaceae and Closteridiales, were significantly higher in the puerarin group than those in the control group, while the ratio of Prevotellaceae/Bacteroidaceae (P/B), a muscle atrophy indicator, was lower in the puerarin group. As expected, there were significant linear correlations between the concentrations of SCFAs, including cecal total SCFAs, serum n-butyric acid and total SCFAs, and skeletal muscle strength and function, including the twitch force and tetanic force of SOL and EDL, as well as the forelimb grip strength.ConclusionIn conclusion, puerarin improved the forelimb grip strength and muscle contraction function in young adult rats. The underlying mechanism may include that puerarin increased SCFAs production by regulating gut microbiota, augmented ATP synthesis and skeletal muscle strength.The translational potential of this article: Our study finds that a clinical used phytomolecule puerarin has the potential of improving skeletal muscle strength in young adult rats. As puerarin has long-term clinical experience and shows good safety, it might be a potential candidate for developing muscle strengthening agents.

Extruded Wheat Bran Consumption Increases Serum Short-Chain Fatty Acids but Does Not Modulate Psychobiological Functions in Healthy Men: A Randomized, Placebo-Controlled Trial

BackgroundIncorporation of wheat bran (WB) into food products increases intake of dietary fiber, which has been associated with improved mood and cognition and a lower risk for psychiatric disorders such as depression, with short-chain fatty acids (SCFAs) as candidate mediators of these effects. Modifying WB using extrusion cooking increases SCFA production in vitro relative to unmodified WB.ObjectiveThe aim of this study was to evaluate the effects of extruded WB on psychobiological functioning and the mediating role of SCFAs.MethodsIn a randomized, triple-blind, placebo-controlled trial, 69 healthy male participants consumed 55 g of breakfast cereal containing either extruded WB or placebo daily for 28 days. At pre- and post-intervention visits, the cortisol response to experimentally induced stress was measured as a primary outcome. In addition, serum SCFAs and brain-derived neurotrophic factors were quantified as potential mediators. Secondary psychobiological outcomes included subjective stress responses, responses to experimentally induced fear, cortisol awakening response, heart rate variability, and retrospective subjective mood ratings. Intestinal permeability, fecal SCFAs, and stool consistency were measured as secondary biological outcomes.ResultsExtruded WB increased serum acetate and butyrate (p < 0.05). None of the primary or secondary outcomes were affected by the intervention. Participants who consumed a placebo exhibited an increase in the percentage of fecal dry weight but did not report increased constipation. Despite these statistically significant effects, these changes were small in magnitude.ConclusionsExtruded WB consumption increased serum short-chain fatty acids but did not modulate psychobiological functions in healthy men. Effective modulation of psychobiological functions may require greater increases in SCFAs than those achieved following extruded WB consumption. Rather than attempting to induce health benefits with a single fiber-rich food, combinations of different fibers, particularly highly fermentable ones, might be needed to further increase SCFA production and uptake in the systemic circulation to observe an effect on psychobiological processes.

Endurance exercise ameliorates Western diet\u2013induced atherosclerosis through modulation of microbiota and its metabolites

The World Health Organization determined cardiovascular disease to be the leading cause of death globally; atherosclerosis is the primary cause of the high morbidity and mortality rates. Regular physical activity is an effective strategy for maintaining endothelial health and function to prevent the development of atherosclerosis. Obesity is also a crucial risk factor for atherosclerotic progression in combination with various complications and systemic inflammation. Physiological homeostasis is modulated by the intestinal microbiota, but the mechanisms through which exercise attenuates atherosclerosis through the microbiota have not been elucidated. Therefore, we investigated the effects of endurance exercise on atherosclerosis induced by a Western diet (WD) and apolipoprotein E (ApoE) knockout in terms of microbiota parameters and metabolites. Genetically modified ApoE knockout mice (C57BL/6-Apoeem1Narl/Narl, ApoEKO) and wild-type mice (C57BL6/J) were divided into the following four groups (n = 6), namely, wild-type mice fed a chow diet (WT CD), ApoEKO mice fed a chow diet (ApoE CD), ApoEKO mice fed a WD (ApoE WD), and ApoEKO mice fed a WD and performing endurance exercise (ApoE WD EX), for a 12-week intervention. The WD significantly induced obesity and atherosclerotic syndrome in the ApoE WD group. Severe atherosclerotic lesions and arterial thickness were significantly elevated and accompanied by increases in VCAM-1, MCP-1, TNF-α, and IL-1β for immune cell chemotaxis and inflammation during atherosclerotic pathogenesis in the ApoE WD group. In addition, dysbiosis in the ApoE WD group resulted in the lowest short-chain fatty acid (SCFA) production. Endurance exercise intervention (ApoE WD EX) significantly alleviated atherosclerotic syndrome by reducing obesity, significantly inhibiting VCAM-1, MCP-1, TNF-α, and IL-1β expression, and increasing the production of SCFAs. Modulation of the microbiota associated with inflammation, such as Desulfovibrio, Tyzzerella, and Lachnospiraceae_ge, and increased SCFA production, particularly through an abundance of Rikenellaceae and Dubosiella, were also observed after exercise intervention. Endurance exercise can alleviate WD-induced atherosclerosis through the amelioration of obesity, inflammation, and chemotaxis signaling, which are modulated by the microbiota and derived SCFAs.