Increased Butyrate Production Research Articles

Saccharomyces cerevisiae derived postbiotic alters gut microbiome metabolism in the human distal colon resulting in immunomodulatory potential in vitro.

The yeast-based postbiotic EpiCor is a well-studied formulation, consisting of a complex mixture of bioactive molecules. In clinical studies, EpiCor postbiotic has been shown to reduce intestinal symptoms in a constipated population and support mucosal defense in healthy subjects. Anti-inflammatory potential and butyrogenic properties have been reported in vitro, suggesting a possible link between EpiCor's gut modulatory activity and immunomodulation. The current study used a standardized in vitro gut model, the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®), to obtain a deeper understanding on host-microbiome interactions and potential microbiome modulation following repeated EpiCor administration. It was observed that EpiCor induced a functional shift in carbohydrate fermentation patterns in the proximal colon environment. Epicor promoted an increased abundance of Bifidobacterium in both the proximal and distal colon, affecting overall microbial community structure. Co-occurrence network analysis at the phylum level provided additional evidence of changes in the functional properties of microbial community promoted by EpiCor, increasing positive associations between Actinobacteria with microbes belonging to the Firmicutes phylum. These results, together with a significant increase in butyrate production provide additional support of EpiCor benefits to gut health. Investigation of host-microbiome interactions confirmed the immunomodulatory potential of the applied test product. Specific microbial alterations were observed in the distal colon, with metabotyping indicating that specific metabolic pathways, such as bile acid and tryptophan metabolism, were affected following EpiCor supplementation. These results, especially considering many effects were seen distally, further strengthen the position of EpiCor as a postbiotic with health promoting functionality in the gut, which could be further assessed in vivo.

Lactiplantibacillus plantarum NKK20 Increases Intestinal Butyrate Production and Inhibits Type 2 Diabetic Kidney Injury through PI3K/Akt Pathway.

Nephropathy injury is a prevalent complication observed in individuals with diabetes, serving as a prominent contributor to end-stage renal disease, and the advanced glycation products (AGEs) are important factors that induce kidney injury in patients with diabetes. Addressing this condition remains a challenging aspect in clinical practice. The aim of this study was to explore the effects of Lactiplantibacillus plantarum NKK20 strain (NKK20) which protects against diabetic kidney disease (DKD) based on animal and cell models. The results showed that the NKK20 can significantly reduce renal inflammatory response, serum oxidative stress response, and AGE concentration in diabetic mice. After treatment with NKK20, the kidney damage of diabetic mice was significantly improved, and more importantly, the concentration of butyrate, a specific anti-inflammatory metabolite of intestinal flora in the stool of diabetic mice, was significantly increased. In addition, nontargeted metabolomics analysis showed a significant difference between the metabolites in the mouse serum contents of the NKK20 administration group and those in the nephropathy injury group, in which a total of 24 different metabolites that were significantly affected by NKK20 were observed, and these metabolites were mainly involved in glycerophospholipid metabolism and arachidonic acid metabolism. Also, the administration of butyrate to human kidney- (HK-) 2 cells that were stimulated by AGEs resulted in a significant upregulation of ZO-1, Occludin, and E-cadherin gene expressions and downregulation of α-SMA gene expression. This means that butyrate can maintain the tight junction structure of HK-2 cells and inhibit fibrosis. Butyrate also significantly inhibited the activation of PI3K/Akt pathway. These results indicate that NKK20 can treat kidney injury in diabetic mice by reducing blood glucose and AGE concentration and increasing butyrate production in the intestine. By inhibiting PI3K pathway activation in HK-2 cells, butyrate maintains a tight junction structure of renal tubule epithelial cells and inhibits renal tissue fibrosis. These results suggest that NKK20 is helpful to prevent and treat the occurrence and aggravation of diabetic kidney injury.

Glycerol and reuterin-producing Limosilactobacillus reuteri enhance butyrate production and inhibit Enterobacteriaceae in broiler chicken cecal microbiota PolyFermS model

BackgroundAdministering probiotic strains of Limosilactobacillus reuteri to poultry has been shown to improve poultry performance and health. Some strains of L. reuteri taxa can produce reuterin, a broad-spectrum antimicrobial compound from glycerol conversion, with high inhibitory activity against enterobacteria. However, little is known about the metabolism of glycerol in the complex chicken cecal microbiota nor the effect of glycerol, either alone or combined with L. reuteri on the microbiota. In this study, we investigated the effect of L. reuteri PTA5_F13, a high-reuterin-producing chicken strain and glycerol, alone or combined, on broiler chicken cecal microbiota composition and activity using the continuous PolyFermS model recently developed to mimic chicken cecal fermentation.MethodsThree independent PolyFermS chicken cecal microbiota models were inoculated with immobilized cecal microbiota from different animals and operated continuously. The effects of two additional levels of glycerol (50 and 100 mM) with or without daily supplementation of chicken-derived L. reuteri PTA5_F13 (107 CFU/mL final concentration) were tested in parallel second-stage reactors continuously inoculated with the same microbiota. We analyzed the complex chicken gut microbiota structure and dynamics upon treatment using 16S rRNA metabarcoding and qPCR. Microbiota metabolites, short-chain and branched-chain fatty acids, and glycerol and reuterin products were analyzed by HPLC in effluent samples from stabilized reactors.ResultsSupplementation with 100 mM glycerol alone and combined with L. reuteri PTA5_F13 resulted in a reproducible increase in butyrate production in the three modelled microbiota (increases of 18 to 25%). Glycerol alone resulted also in a reduction of Enterobacteriaceae in two of the three microbiota, but no effect was detected for L. reuteri alone. When both treatments were combined, all microbiota quantitatively inhibited Enterobacteriaceae, including in the last model that had very high initial concentrations of Enterobacteriaceae. Furthermore, a significant 1,3-PDO accumulation was measured in the effluent of the combined treatment, confirming the conversion of glycerol via the reuterin pathway. Glycerol supplementation, independent of L. reuteri addition, did not affect the microbial community diversity.ConclusionsGlycerol induced a stable and reproducible butyrogenic activity for all tested microbiota and induced an inhibitory effect against Enterobacteriaceae that was strengthened when reuterin-producing L. reuteri was spiked daily. Our in vitro study suggests that co-application of L. reuteri PTA5_F13 and glycerol could be a useful approach to promote chicken gut health by enhancing metabolism and protection against Enterobacteriaceae.

Prebiotic Mannan Oligosaccharide Attenuates Cognitive and Behavioral Disorders in HIV-1 gp120 Transgenic Mouse Via the Microbiota-Gut-Brain Axis

Background The prevalence of HIV-associated neurocognitive disorders (HAND) remains high among HIV-1 infected patients, despite significant advances in antiretroviral therapy (HAART). HAND is characterized by clinical symptoms such as motor and attention deficits, impaired learning and memory, and in severe cases, dementia. The HIV-1 envelope protein gp120 is believed to have a crucial role in the development of these disorders HIV-1-related neurocognitive dysfunction is strongly linked to the host inflammatory regulator α7 nicotinic acetylcholine receptor (A7R) and the signaling of highly reactive oxygen species (ROS). A7R plays a crucial role in regulating calcium ion exchange in nerve cells, immune cells, and endothelial cells. In the brain, antioxidants are present to control and prevent the formation of harmful ROS, which further contribute to the severity of neurodegeneration. Assessing ROS can help predict oxidative tissue damage, including modifications in proteins, lipids, or DNA. ROS tend to accumulate in the small and large intestines, leading to oxidative stress and affecting cognitive function. The prebiotic mangan oligosaccharide (MOS) has been reported to reshape the gut microbiome and increase short-chain fatty acid (SCFAs) production. This, in turn, alters neuronal redox status through the gut-brain axis. There may be a critical role for HIV-1 gp120 (Gp120) protein in these disorders. The microbiota-gut-brain (MGB) axis is bidirectional, and gut microbiota influence brain disorders including HAND, which could be targeted by nutritional interventions. Methods: The HIV-1 gp120 transgenic mice (Gp120 transgenic mice), and wild-type (WT) mice were randomly divided into 4 groups (9 months old, n=6 per group): WT group, WT+MOS group, Gp120 transgenic group, Gp120 transgenic + MOS group. All MOS group mice were administered the prebiotic MOS (0.12% w/v in the drinking water).The drinking water added MOS or was replaced twice a week for 8 weeks and recorded water intake. In the in vitro cell experiment, the cortex of neonatal Sprague-Dawley (SD) rats (1-3 days) was dissected to prepare astrocytes. Cells were identified using Cy3-conjugated GFAP immunostaining. Cultured astrocytes were treated with 300 pM Gp120 protein for 24 hours, and then 0.2, 2, 20 or 200 μM MOS was applied for 24 hours, and different proteins level of expression were detected by Western blot. The ROS level were then analyzed on FACS Calibur-Tangerine flow cytometry in 502 nm. The alteration in mitochondrial membrane potential in astrocytes was assessed through the utilization of the JC-1 Assay Kit in mPMs. Results: As a result of treatment with MOS, the redox status of the brain and the neuroinflammatory responses were significantly balanced. Through correlation analysis, it was observed that a modified gut microbiome and increased butyrate production had a significant impact on behavioral changes and brain oxidative status. Our findings suggest that MOS could mitigate cognitive and behavioral disorders in the Gp120 transgenic mouse. MOS achieves this by suppressing Gp120-induced chronic inflammation and dysregulated production of reactive oxygen species (ROS), thereby improving HIV-1-related neurocognitive dysfunction. This is achieved by targeting A7R and intestinal ROS signaling. Additionally, our results indicate that SCFA supplementation in the brain of HAND mice alleviated behavioral disorders and balanced the HPA-axis and redox status. Conclusion: Overall, the present study demonstrated that MOS significantly reduced cognitive and mental deficits in Gp120 transgenic mice. As prebiotics, MOS could be translated into novel microbiota-targeted approaches to manage metabolic and neurodegenerative diseases. ( Acknowledgements: Natural Science Foundation of Guangdong Province, No. 208059478058 to H.C.; Corresponding author: Hong Cao, gzhcao@smu.edu.cn ) Keywords：HIV-1 gp120, mangan oligosaccharide, α7nAChR, reactive oxygen species

Enhanced tolerance of Clostridium tyrobutyricum to furan derivatives for efficient butyric acid production by overexpressing native transporter genes

Furan aldehydes generated during the hydrolysis of lignocellulosic biomass are toxic to Clostridium tyrobutyricum, severely inhibiting its butyric acid production. This study confirmed that overexpression of the ABC-transporter gene CtAT2 in C. tyrobutyricum significantly increased furfural tolerance (> 3.0 g/L) and butyrate production (13.8 %). Conversely, overexpression of the MFS-transporter gene CtMT1 enhanced tolerance to HMF (> 4.0 g/L). However, co-expression of CtAT2 and CtMT1 in C. tyrobutyricum failed to improve the strain’s tolerance to furfural and HMF. Using undetoxified corncob acid hydrolysate as the carbon source, the recombinant strain ATCC 25755/AT2 exhibited excellent performance in butyric acid fermentation due to its heightened furfural tolerance and improved butyrate production. ATCC 25755/AT2 demonstrated impressive butyrate production and productivity in fed-batch fermentation, reaching 29.8 g/L and 0.23 g/L·h, respectively. These values represented a 22.6 % increase in butyrate production and a 27.8 % increase in productivity compared to the wild-type strain.

Evaluation of Four Multispecies Probiotic Cocktails in a Human Colonic Fermentation Model.

Bacteriotherapy represents an attractive approach for both prophylaxis and treatment of human diseases. However, combining probiotic bacteria in "cocktails" is underexplored, despite its potential as an alternative multi-target therapy. Herein, three-strain probiotic mixtures containing different combinations of Bacillus (Bc.) coagulans [ATB-BCS-042], Levilactobacillus (Lv.) brevis [THT 0303101], Lacticaseibacillus (Lc.) paracasei [THT 031901], Bacillus subtilis subsp. natto [ATB-BSN-049], Enterococcus faecium [ATB-EFM-030], and Bifidobacterium (Bf.) animalis subsp. lactis [THT 010802] were prepared. Four cocktails (PA: Bc. coagulans + Lv. brevis + Lc. paracasei, PB: Bc. subtilis subsp. natto + Lv. brevis + Lc. paracasei, PC: E. faecium + Lv. brevis + Lc. paracasei, PD: Bc. coagulans + Lv. brevis + Bf. animalis subsp. lactis) were tested using a short-term (72h) simulation of the human colonic microbiota in a final dose of 6 × 109CFU. All these probiotic mixtures significantly increased butyrate production compared to the parallel control experiment. PA and PB promoted a bifidogenic effect and facilitated lactobacilli colonization. Furthermore, reporter gene assays using the AhR_HT29-Lucia cell line revealed that fermentation supernatants from PA and PB notably induced AhR transactivity. Subsequent examination of the metabolic outputs of PA and PB in intestinal epithelial models using cell culture inserts suggested no significant impact on the transepithelial electricalresistance (TEER). Assessment of the expression of proinflammatory and anti-inflammatory cytokines, as well as AhR-related target genes in the Caco-2 cell monolayers indicated that PB's metabolic output upregulated most of the measured endpoints. Thisin vitro investigation evaluated the potential impact of four multispecies probiotic mixtures in the human colonic microbiota and identified a promising formulation comprising a combination of Bc. subtilis subsp. natto, Lv. brevis, and Lc. paracasei as a promising formulation for further study.

Salt stress altered anaerobic microbial community and carbon metabolism characteristics: The trade-off between methanogenesis and chain elongation

Discharge of saline organic wastewater is increasing worldwide, yet how salt stress disrupts the microbial community's structure and metabolism in bioreactors has not been systematically investigated. The non-adapted anaerobic granular sludge was inoculated into wastewater with varying salt concentration (ranging from 0% to 5%) to examine the effects of salt stress on the structure and function of the anaerobic microbial community. Result indicated that salt stress had a significant impact on the metabolic function and community structure of the anaerobic granular sludge. Specifically, we observed a notable reduction in methane production in response to all salt stress treatments (r = −0.97, p < 0.01), while an unexpected increase in butyrate production (r = 0.91, p < 0.01) under moderate salt stress (1–3%) with ethanol and acetate as carbon sources. In addition, analysis of microbiome structures and networks demonstrated that as the degree of salt stress increased, the networks exhibited lower connectance and increased compartmentalization. The abundance of interaction partners (methanogenic archaea and syntrophic bacteria) decreased under salt stress. In contrast, the abundance of chain elongation bacteria, specifically Clostridium kluyveri, increased under moderate salt stress (1–3%). As a consequence, the microbial carbon metabolism patterns shifted from cooperative mode (methanogenesis) to independent mode (carbon chain elongation) under moderate salt stress. This study provides evidence that salt stress altered the anaerobic microbial community and carbon metabolism characteristics, and suggests potential guidance for steering the microbiota to promote resource conversion in saline organic wastewater treatment.

Spent Tea Leaves and Coffee Grounds as Potential Biocathode for Improved Microbial Electrosynthesis Performance

Microbial electrosynthesis (MES) has emerged as a sustainable energy platform capable of simultaneous wastewater treatment and valuable chemical production. The performance of MES, like other bioelectrochemical systems, largely depends on its electrode (cathode), providing the platform for microbial growth as well as electron transfer. However, most of the electrodes are expensive, and their nonrenewable characteristics, cost, and poisoning nature are major bottlenecks in MES commercialization. Thus, several efforts have been made to explore the potential of waste carbon-based electrodes to reduce carbon footprints as well as electrode manufacturing costs. In this study, the feasibility of using spent tea leaves (STL) and spent coffee grounds (SCG) as MES biocathode was tested. Different bioelectrochemical tests suggested improved MES performance with STL and SCG biocathode along with reduced electrode resistance and improved current density. A 1.5- and 2.0-fold increase in cyclic voltammetry (CV) current output was observed for SCG and STL, respectively, with substantial mediator peaks of high intensity indicating enhanced electrocatalytic activity. Enrichment of some fermentative and exoelectrogenic microbial classes such as Clostridia, Bacteroidia, and Deltaproteobacteria led to a 1.3- and 1.4-fold increase in butyrate production for SCG and STL cathode, respectively. These results demonstrate the potential of STL and SCG as MES cathode for improved energy and chemical production.

UiO-66-Mediated Light-Driven Regeneration of Intracellular NADH in Clostridium tyrobutyricum to Strengthen Butyrate Production

With the increasing depletion of petroleum and fossil resources, the development of green, low-carbon recycling systems has become the main goal for achieving carbon neutrality. Biohybrid photosynthesis systems have been confirmed to reduce carbon loss and promote microbial metabolism to achieve high yields of chemicals. Here, we used UiO-66, an excellent photocatalyst, to increase the intracellular pool of reduced nicotinamide adenine dinucleotide hydrogen (NADH) for butyrate production in Clostridium tyrobutyricum. The NADH/NAD+ ratio increased by 62% in the UiO-66 and C. tyrobutyricum hybrid system compared to the other groups under illumination, which resulted in a 25% increase in butyrate production (11.71 ± 0.16 vs 9.36 ± 0.14 g/L). The system improved the utilization rate of carbon sources and reduced carbon loss. Proteomic analysis also revealed that UiO-66 enhanced the intracellular NADH supply under illumination, leading to an increase in butyrate production. Thus, this system provides an outstanding strategy for improving the conversion of organic carbon into useful chemicals that helps to achieve energy savings and reduce emissions.

Cellulose Butyrate as a Potent Fiber Supplement for Mono-Gastric Animals to Modulate Hindgut Microbiota and Fermentation: In Vitro Evaluations

To evaluate the function of cellulose butyrate (CB), a new synthetic, fibrous, candidate food additive, a series of batch culture study was carried out. Fecal cultures were prepared using fresh feces from human volunteers and swines, and anaerobically incubated to characterize the effect of CB on hindgut fermentation and microbial community, and thereby evaluate the potential use of CB as a food additive in mono-gastric animals. Three types of CB differing in the degree of substitution and in the carbon position of glucose residue where butyl groups are substituted were tested to proceed multiple comparisons for measured parameters. Among three types of CB tested, partially water-soluble CB3 was associated with the highest increase in butyrate production in human and swine fecal cultures. CB3 supplementation shifted fecal microbiota toward greater abundance of bacteria in the Bacteroidetes phylum, in particular the genus Parabacteroides, in which the increase of Parabacteroides distasonis was remarkable even with individual variations. CB3 also lowered putrefactive products, including ammonia, indole and skatole, in the cultures. Dietary use of partially water-soluble CB3 might be expected to have useful effects in humans and other mono-gastric animals, judging from the present results of enhanced butyrate production and lowered putrefactive products with CB3 addition to feces. The results might be partly attributable to a shift in hindgut microbiota, represented by the increased abundance of Bacteroidetes, especially Parabacteroides species. Therefore, CB3 can be considered as a functional additive candidate for the use in mono-gastric animals such as human and pigs.

Batch culture analysis to identify potent organic acids for suppressing ruminal methane production.

We performed an in vitro rumen batch culture study to screen 11 commercially available organic acids for methane-suppressing ability and analyzed the rumen microbiota to determine the mode of action of the acids that showed potent methane-suppressing activity. Nine of the 11 acids showed methane-suppressing activity. Maleic anhydride, itaconate, citrate, and fumarate, which showed the highest activity, were further examined. These four acids showed methane-suppressing activity irrespective of the hay-to-concentrate ratios of the substrate. Maleic anhydride and itaconate decreased total gas and short-chain fatty acid production. Maleic anhydride and fumarate increased propionate production, while itaconate increased butyrate production. Maleic anhydride, itaconate, and citrate increased lactate production. Fumarate increased the abundance of bacteria involved in propionate production. Maleic anhydride, itaconate, and citrate increased the abundance of bacteria involved in lactate production. Thus, the results indicate that maleic anhydride, itaconate, and citrate may decrease methane in part by stimulating the acrylate pathway.

Lactate and buyrate proportions, methanogen growth and gas production during in vitro dietary fibre fermentation all depend on fibre concentration

Dietary fibre (DF) concentration plays a critical role in the gas kinetics and short-chain fatty acid production profiles during in vitro human faecal fermentation. However, the mechanisms leading to concentration-dependent fermentation outcomes are unknown. In this study, fructo-oligosaccharides and pectin at three concentrations (0.2, 0.4 and 0.6g/44mL), were selected to investigate the effect of DF type and concentration on human gut microbiota. An absolute quantification method was applied to determine the microbial biomass and load for each genus. Additionally, the gas kinetics and fermentation metabolites (acetate, propionate, butyrate, i-butyrate, valerate, i-valerate, formate, succinate, methanol, ethanol and lactate) were measured. Results showed that DF type and concentration affected the microbial diversity, microbial loads and metabolite profiles to different extents. At high DF concentrations Methanobrevibacter , a genus of Archaea, was found to increase by ∼28 fold for FOS, and ∼93 fold for pectin. We propose three main pathways, dictated by DF type and concentration, driving the observed alterations in microbial loads and metabolite profiles. Firstly, the lactate cross-feeding pathway could lead to increased butyrate production. Secondly, methanogenesis from H 2 and CO 2 , and thirdly, reductive acetyl-CoA pathways resulted in the conversion of gases to increase microbial biomass. Understanding these underlying mechanisms allows for tailoring DF fermentation by varying their concentrations to control SCFA and gas production. • Higher DF concentration led to increased butyrate proportion via lactate cross-feeding. • Higher DF concentration led to more gas production, triggering gas cross-feeding. • Absolute quantification of microbiota revealed concentration-dependent biomass shifts. • Methanogenesis and reductive acetyl-CoA pathways led to biomass growth. • Cross-feeding of lactate and gases also depended on DF type.

Impact of N-butyryl-l-homoserine lactone–mediated quorum sensing on acidogenic fermentation under saline conditions: Insights into volatile fatty acids production and microbial community

Anaerobic fermentation is often inhibited under high salinity conditions. This study discovered a strong, positive association between N-butyryl-l-homoserine lactone (C4-HSL)–mediated quorum sensing (QS) and the production of volatile fatty acids (VFAs) under saline conditions. N-acyl-homoserine lactones were identified during acidogenic fermentation for VFA production. Only C4-HSL was detected at all salt concentrations, and a maximum C4-HSL concentration of 0.49 μg/L was observed at a salt concentration of 15 g/L. C4-HSL secretion was closely related to salinity, and a strong correlation was observed between C4-HSL and VFAs (p < 0.01), especially butyrate. Further experiments with C4-HSL addition indicated that exogenous C4-HSL promoted substrate hydrolysis and increased butyrate production by 1.5 times at 15 g/L NaCl. Microbial community analysis indicated that unclassified_f__Enterobacteriaceae and Clostridium_sensu_stricto_1, associated with QS genes and butyrate production, were positively associated with C4-HSL. This study demonstrates the positive effect of C4-HSL–mediated QS on acidogenic fermentation.

Effect of DSS-Induced Ulcerative Colitis and Butyrate on the Cytochrome P450 2A5: Contribution of the Microbiome.

Several studies have indicated the beneficial anti-inflammatory effect of butyrate in inflammatory bowel disease (IBD) therapy implying attempts to increase butyrate production in the gut through orally administered dietary supplementation. Through the gut–liver axis, however, butyrate may reach directly the liver and influence the drug-metabolizing ability of hepatic enzymes, and, indirectly, also the outcome of applied pharmacotherapy. The focus of our study was on the liver microsomal cytochrome P450 (CYP) 2A5, which is a mouse orthologue of human CYP2A6 responsible for metabolism of metronidazole, an antibiotic used to treat IBD. Our findings revealed that specific pathogen-free (SPF) and germ-free (GF) mice with dextran sulfate sodium (DSS)-induced colitis varied markedly in enzyme activity of CYP2A and responded differently to butyrate pre-treatment. A significant decrease (to 50%) of the CYP2A activity was observed in SPF mice with colitis; however, an administration of butyrate prior to DSS reversed this inhibition effect. This phenomenon was not observed in GF mice. The results highlight an important role of gut microbiota in the regulation of CYP2A under inflammatory conditions. Due to the role of CYP2A in metronidazole metabolism, this phenomenon may have an impact on the IBD therapy. Butyrate administration, hence, brings promising therapeutic potential for improving symptoms of gut inflammation; however, possible interactions with drug metabolism need to be further studied.

Synergistic Effect of a Novel Combination of Pre-, Pro-, and Postbiotics on Microbial Fermentation and Metabolite Production In Vitro

Abstract Objectives To test the effect of probiotic strains (Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12; PS), a prebiotic (bacteriophage blend; BB), a postbiotic (tributyrin; TB), or a combination of all three (full mix; FM) on microbial fermentation and metabolite production in vitro. Methods Short term colonic incubation was performed under conditions representative of the proximal large intestine, using the fecal microbiota of a single healthy human donor. At the start of the experiment, treatments and a blank control (BC), were added to the reactors. Each reactor also received a carbohydrate-supplemented nutritional medium and freshly prepared fecal inoculum. Reactors were closed with a rubber septum, made anaerobic through flushing with nitrogen, and incubated for 48 hours. Each condition was run in triplicate. Overall fermentative activity (pH and gas production), changes in microbial metabolite production (short chain fatty acid, lactate, and ammonium analysis) were assessed. Results In the first 6 hours, microbial fermentation occurred in all treatments, indicated by pH shifts and production of gas and lactate. FM, PS, and BB stimulated production of lactate compared to BC (p &amp;lt; 0.05). After 24 hours, FM, PS and TB stimulated production of butyrate compared to BC (p &amp;lt; 0.05). FM and PS yielded more lactate than either BB or TB (p &amp;lt; 0.05). After 48 hours, FM, PS, BB, and TB each stimulated production of butyrate compared to BC (p &amp;lt; 0.05). Additionally, FM yielded significantly more butyrate than PS, TB, or BB (p &amp;lt; 0.05). Conclusions All treatments resulted in similar pH profiles and were representative of ideal conditions for bacterial growth and metabolism. The increased production of lactate in FM and PS was attributed to the fermentative activities of probiotics LGG and BB-12. Each treatment stimulated production of butyrate compared to BC but the largest increase in butyrate production was seen in FM, indicating a synergistic relationship between pre-, pro-, and postbiotics. Funding Sources The study was conducted by an independent lab, ProDigest, and funded and sponsored by Ritual (Natals, Inc.). Compound Solutions, Inc. also financially supported the study.

Increased Butyrate Production in Clostridium saccharoperbutylacetonicum from Lignocellulose-Derived Sugars.

Butyrate is produced by chemical synthesis based on crude oil, produced by microbial fermentation, or extracted from animal fats (M. Dwidar, J.-Y. Park, R. J. Mitchell, and B.-I. Sang, The Scientific World Journal, 2012:471417, 2012, https://doi.org/10.1100/2012/471417). Butyrate production by anaerobic bacteria is highly favorable since waste or sustainable resources can be used as the substrates. For this purpose, the native hyper-butanol producer Clostridium saccharoperbutylacetonicum N1-4(HMT) was used as a chassis strain due to its broad substrate spectrum. BLASTp analysis of the predicted proteome of C. saccharoperbutylacetonicum N1-4(HMT) resulted in the identification of gene products potentially involved in acetone-butanol-ethanol (ABE) fermentation. Their participation in ABE fermentation was either confirmed or disproven by the parallel production of acids or solvents and the respective transcript levels obtained by transcriptome analysis of this strain. The genes encoding phosphotransacetylase (pta) and butyraldehyde dehydrogenase (bld) were deleted to reduce acetate and alcohol formation. The genes located in the butyryl-CoA synthesis (bcs) operon encoding crotonase, butyryl-CoA dehydrogenase with electron-transferring protein subunits α and β, and 3-hydroxybutyryl-CoA dehydrogenase were overexpressed to channel the flux further towards butyrate formation. Thereby, the native hyper-butanol producer C. saccharoperbutylacetonicum N1-4(HMT) was converted into the hyper-butyrate producer C. saccharoperbutylacetonicum ΔbldΔpta [pMTL83151_BCS_PbgaL]. The transcription pattern following deletion and overexpression was characterized by a second transcriptomic study, revealing partial compensation for the deletion. Furthermore, this strain was characterized in pH-controlled fermentations with either glucose or Excello, a substrate yielded from spruce biomass. Butyrate was the main product, with maximum butyrate concentrations of 11.7 g·L-1 and 14.3 g·L-1, respectively. Minimal amounts of by-products were detected. IMPORTANCE Platform chemicals such as butyrate are usually produced chemically from crude oil, resulting in the carry-over of harmful compounds. The selective production of butyrate using sustainable resources or waste without harmful by-products can be achieved by bacteria such as clostridia. The hyper-butanol producer Clostridium saccharoperbutylacetonicum N1-4(HMT) was converted into a hyper-butyrate producer. Butyrate production with very small amounts of by-products was established with glucose and the sustainable lignocellulosic sugar substrate Excello extracted from spruce biomass by the biorefinery Borregaard (Sarpsborg, Norway).

Reprogramming microbial populations using a programmed lysis system to improve chemical production

Microbial populations are a promising model for achieving microbial cooperation to produce valuable chemicals. However, regulating the phenotypic structure of microbial populations remains challenging. In this study, a programmed lysis system (PLS) is developed to reprogram microbial cooperation to enhance chemical production. First, a colicin M -based lysis unit is constructed to lyse Escherichia coli. Then, a programmed switch, based on proteases, is designed to regulate the effective lysis unit time. Next, a PLS is constructed for chemical production by combining the lysis unit with a programmed switch. As a result, poly (lactate-co-3-hydroxybutyrate) production is switched from PLH synthesis to PLH release, and the content of free PLH is increased by 283%. Furthermore, butyrate production with E. coli consortia is switched from E. coli BUT003 to E. coli BUT004, thereby increasing butyrate production to 41.61 g/L. These results indicate the applicability of engineered microbial populations for improving the metabolic division of labor to increase the efficiency of microbial cell factories.

An Intervention With Michigan-Grown Wheat in Healthy Adult Humans to Determine Effect on Gut Microbiota: Protocol for a Crossover Trial.

BackgroundDaily fiber intake can increase the diversity of the human gut microbiota as well as the abundance of beneficial microbes and their metabolites. Whole-grain wheat is high in fiber.ObjectiveThis manuscript presents a study protocol designed to understand the effects of different types of wheat on gastrointestinal tract microbes.MethodsHuman adults will consume crackers made from three types of wheat flour (refined soft white wheat, whole-grain soft white wheat, and whole-grain soft red wheat). In this study, participants will alternate between crackers made from refined soft white wheat flour to those made from whole-grain soft white wheat and whole-grain soft red wheat flour. Survey and stool sample collection will occur after 7-day treatment periods. We will assess how wheat consumption affects gastrointestinal bacteria by sequencing the V4 region of 16S rRNA gene amplicons and the inflammatory state of participants’ intestines using enzyme-linked immunosorbent assays. The butyrate production capacity of the gut microbiota will be determined by targeted quantitative real-time polymerase chain reaction.ResultsWe will report the treatment effects on alpha and beta diversity of the microbiota and taxa-specific differences. Microbiota results will be analyzed using the vegan package in R. Butyrate production capacity and biomarkers of intestinal inflammation will be analyzed using parametric statistical methods such as analysis of variance or linear regression. We expect whole wheat intake to increase butyrate production capacity, bacterial alpha diversity, and abundance of bacterial taxa responsive to phenolic compounds. Soft red wheat is also expected to decrease the concentration of inflammatory biomarkers in the stool of participants.ConclusionsThis protocol describes the methods to be used in a study on the impact of wheat types on the human gastrointestinal microbiota and biomarkers of intestinal inflammation. The analysis of intestinal responses to the consumption of two types of whole wheat will expand our understanding of how specific foods affect health-associated outcomes.International Registered Report Identifier (IRRID)DERR1-10.2196/29046

Effects of fish protein with glycation extent on gut microbiota and colonic barrier function in mice fed a high-fat diet

• The glycated fish protein diets increased the accumulation of AGEs in mice. • The fish protein with low or medium glycation extent improved colonic barrier function. • The intake of fish protein with high glycation extent was potentially harmful to gut health. This study aimed to investigate how fish protein with glycation extent affects gut microbiota and colonic barrier function in mice fed a high-fat diet. The mice were fed a fish protein (MP) diet, fish protein with low, medium and high glycation extent (L-GE, M-GE and H-GE) diet for 15 weeks. The glycated fish protein diets greatly increased butyrate production, which was related to the genes expression of butyryl-CoA: acetate CoA-transferase (BUT) and butyrate kinase (BUK), and also considerably improved insulin resistance, but increased the expression of AGEs receptor (RAGE). Among the four diets, the L-GE diet markedly increased occudin and zonulin-1 (ZO-1), lowered inflammation markers, and enhanced butyrate-producing bacteria Lachnospiraceae_UCG-006 and Allobaculum , while H-GE diet decreased Bifidobacterium and Lactobacillus . Overall, these biological effects were greatly affected by the glycation extent of fish protein, and the fish protein with low glycation extent may provide more potentially positive effects to gut health.

Could the use of butyric acid have a positive effect on microbiota and treatment of type 2 diabetes?

This review focuses on the role of butyrate as one of the key metabolites of gut microbiota. Butyrate along with other short-chain fatty acids, acetate and propionate, is one of the most important regulators of human metabolism. In this review, we discuss how changes in gut microbiota triggered by type 2 diabetes mellitus and its treatment (e.g., metformin) affect butyrate synthesis, how to increase butyrate production and whether there is robust evidence for the positive effects of sodium butyrate in the treatment of diabetes mellitus. Literature review was conducted by all authors. Studies published until 27/03/2020 were included. Search words were: ("butyric acid" OR "butyrate") AND ("type 2 diabetes "OR "T2DM"). The articles selected for the study were not chosen in a systematic manner, so the evidence may not be comprehensive. Butyrate was found to effectively reduce inflammation and plays a prominent role in the function of the intestinal barrier. To date the use of sodium butyrate in the treatment of patients with T2DM is not very popular. Meanwhile, butyric acid can beneficially modulate intestinal functions, counteracting the negative effects of the disease as well as the drugs used to treat diabetes. T2DM is a widespread chronic disease. Understanding role of microbiota in type 2 diabetes and the mechanisms connecting T2DM and alterations in gut microbiota could be the key to improved treatment of T2DM.