Butyrate increases colonocyte protein synthesis in ulcerative colitis

Butyrate: More Than a Short Chain Fatty Acid

PURPOSE OF REVIEW

The mechanistic understanding of the importance and the potential benefits of the gut microbiome has exploded in potential roles in human health and disease. Short chain fatty acids (SCFAs), including butyrate, are one of the key metabolic end products that has been a major focus of microbiome understanding. This brief review aims to describe butyrate's relation to certain biological concepts and their clinical application.

RECENT FINDINGS

Butyrate has reportedly been described as a potent pro-resolution molecule that has a significant role in maintaining gut immunity, supporting gut barrier function, regulation of histone deacetylase (HDAC), and numerous systemic roles. Further research is needed to explore potential benefits of adding SCFAs for patients receiving total parenteral nutrition. Butyrate plays several biological roles in intestinal epithelium anti-inflammatory pathways with clear benefits in numerous acute and chronic disease states and overall human health helping to maintain homeostasis.

Gut Microbiota-Derived Short-Chain Fatty Acids Promote Poststroke Recovery in Aged Mice

RATIONALE

The elderly experience profound systemic responses after stroke, which contribute to higher mortality and more severe long-term disability. Recent studies have revealed that stroke outcomes can be influenced by the composition of gut microbiome. However, the potential benefits of manipulating the gut microbiome after injury is unknown.

OBJECTIVE

To determine if restoring youthful gut microbiota after stroke aids in recovery in aged subjects, we altered the gut microbiome through young fecal transplant gavage in aged mice after experimental stroke. Further, the effect of direct enrichment of selective bacteria producing short-chain fatty acids (SCFAs) was tested as a more targeted and refined microbiome therapy.

METHODS AND RESULTS

Aged male mice (18-20 months) were subjected to ischemic stroke by middle cerebral artery occlusion. We performed fecal transplant gavage 3 days after middle cerebral artery occlusion using young donor biome (2-3 months) or aged biome (18-20 months). At day 14 after stroke, aged stroke mice receiving young fecal transplant gavage had less behavioral impairment, and reduced brain and gut inflammation. Based on data from microbial sequencing and metabolomics analysis demonstrating that young fecal transplants contained much higher SCFA levels and related bacterial strains, we selected 4 SCFA-producers (Bifidobacterium longum, Clostridium symbiosum, Faecalibacterium prausnitzii, and Lactobacillus fermentum) for transplantation. These SCFA-producers alleviated poststroke neurological deficits and inflammation, and elevated gut, brain and plasma SCFA concentrations in aged stroke mice.

CONCLUSIONS

This is the first study suggesting that the poor stroke recovery in aged mice can be reversed via poststroke bacteriotherapy following the replenishment of youthful gut microbiome via modulation of immunologic, microbial, and metabolomic profiles in the host.

Indole-3-carbinol prevents colitis and associated microbial dysbiosis in an IL-22-dependent manner

Colitis, an inflammatory bowel disease, is caused by a variety of factors, but luminal microbiota are thought to play crucial roles in disease development and progression. Indole is produced by gut microbiota and is believed to protect the colon from inflammatory damage. In the current study, we investigated whether indole-3-carbinol (I3C), a naturally occurring plant product found in numerous cruciferous vegetables, can prevent colitis-associated microbial dysbiosis and attempted to identify the mechanisms. Treatment with I3C led to repressed colonic inflammation and prevention of microbial dysbiosis caused by colitis, increasing a subset of gram-positive bacteria known to produce butyrate. I3C was shown to increase production of butyrate, and when mice with colitis were treated with butyrate, there was reduced colonic inflammation accompanied by suppression of Th17 and induction of Tregs, protection of the mucus layer, and upregulation in Pparg expression. Additionally, IL-22 was increased only after I3C but not butyrate administration, and neutralization of IL-22 prevented the beneficial effects of I3C against colitis, as well as blocked I3C-mediated dysbiosis and butyrate induction. This study suggests that I3C attenuates colitis primarily through induction of IL-22, which leads to modulation of gut microbiota that promote antiinflammatory butyrate.

Sodium butyrate ameliorates S100/FCA-induced autoimmune hepatitis through regulation of intestinal tight junction and toll-like receptor 4 signaling pathway

BACKGROUND AND AIM

Recent investigation revealed that dysbiosis in the gut flora and disruption of permeability of intestinal barrier are possible causes for the development of autoimmune hepatitis. Supplementation of sodium butyrate has been suggested to protect liver injury from disrupted permeability of small intestine. In current study, we employed S100/Freund's complete adjuvant induced autoimmune hepatitis to investigate therapeutic efficacy of sodium butyrate and its mechanism in the liver and upper small intestine.

METHODS

C57BL/6 mice were employed and divided into three groups - control group (n=8), autoimmune hepatitis group (n=12) and autoimmune hepatitis with treatment of sodium butyrate group (n=12). Histological staining and western blot analyses were employed to evaluate liver and upper small intestine morphology and gene expression respectively.

RESULTS

The findings revealed that S100/Freund's complete adjuvant caused liver injury and disruption of upper small intestine villi. Sodium butyrate attenuated the injuries and prevented migration of Escherichia coli into the liver. Moreover, the effect of sodium butyrate on protection of injuries of the liver and upper small intestine could be due to inhibition of toll-like receptor 4 signaling pathway, as well as its down-regulation of inflammatory cytokines - interleukin-6 and tumor necrosis factor-a.

CONCLUSIONS

Sodium butyrate can prevent liver injury by maintaining the integrity of small intestine and inhibiting inflammatory response in S100/Freund's complete adjuvant induced autoimmune hepatitis.

Orthogonal Comparison of GC-MS and 1H NMR Spectroscopy for Short Chain Fatty Acid Quantitation

Short chain fatty acids (SCFAs) are important regulators of host physiology and metabolism and may contribute to obesity and associated metabolic diseases. Interest in SCFAs has increased in part due to the recognized importance of how production of SCFAs by the microbiota may signal to the host. Therefore, reliable, reproducible, and affordable methods for SCFA profiling are required for accurate identification and quantitation. In the current study, four different methods for SCFA (acetic acid, propionic acid, and butyric acid) extraction and quantitation were compared using two independent platforms including gas chromatography coupled with mass spectrometry (GC-MS) and 1H nuclear magnetic resonance (NMR) spectroscopy. Sensitivity, recovery, repeatability, matrix effect, and validation using mouse fecal samples were determined across all methods. The GC-MS propyl esterification method exhibited superior sensitivity for acetic acid and butyric acid measurement (LOD < 0.01 μg mL-1, LOQ < 0.1 μg mL-1) and recovery accuracy (99.4%-108.3% recovery rate for 100 μg mL-1 SCFA mixed standard spike in and 97.8%-101.8% recovery rate for 250 μg mL-1 SCFAs mixed standard spike in). NMR methods by either quantitation relative to an internal standard or quantitation using a calibration curve yielded better repeatability and minimal matrix effects compared to GC-MS methods. All methods generated good calibration curve linearity (R2 > 0.99) and comparable measurement of fecal SCFA concentration. Lastly, these methods were used to quantitate fecal SCFAs obtained from conventionally raised (CONV-R) and germ free (GF) mice. Results from global metabolomic analysis of feces generated by 1H NMR and bomb calorimetry were used to further validate these approaches.

Cooperation between the bacterial-derived short-chain fatty acid butyrate and interleukin-22 detected in human Caco2 colon epithelial/carcinoma cells

By generating biologically active factors luminal microbiota shape the intestinal micro-milieu thereby regulating pathological processes such as inflammation and carcinogenesis. Preclinical data suggest that bacterial-derived butyrate and the signal transducer and activator of transcription (STAT)-3 activating cytokine interleukin (IL)-22 display concordant protective properties at the inflamed colonic epithelium. Herein, biochemical cooperation between the short-chain fatty acid butyrate and IL-22 was investigated by focusing on human Caco2 colon epithelial/carcinoma cells. We report that physiological levels of butyrate enhance IL-22 signaling thereby enforcing expression of the prototypic STAT3-downstrean target genes α1-antichymotrypsin and suppressor of cytokine signaling (SOCS)-3. A dual mode of butyrate action on the IL-22/STAT3 axis was identified. Butyrate acted by upregulating IL-22R1, the decisive chain of the heterodimeric IL-22 receptor, and, independent from that, has the potential to directly amplify STAT3-mediated gene activation as detected by chromatin immunoprecipitation analysis of STAT3 binding to the SOCS3 promoter. Since trichostatin A acted similarly, inhibition of histone deacetylases is likely at the root of these butyrate biological properties. The mutual benefit gained from interactions between the host and commensal intestinal bacteria-derived factors is an expanding field of research beginning to affect clinical practice. Data presented herein propose a supportive and fine-tuning role for butyrate in IL-22 signaling that might be therapeutically exploited by local butyrate administration or by increasing its bacterial production in the context of a fiber-rich diet. © 2016 BioFactors, 43(2):283-292, 2017.

Commensal 'trail of bread crumbs' provide pathogens with a map to the intestinal landscape

Growth of a microorganism in a host is essential for infection, and bacterial pathogens have evolved to utilize specific metabolites to enhance replication in vivo. Now, emerging data demonstrate that pathogens rely on microbiota-derived metabolites as a form of bacterial-bacterial communication to gain information about location within a host and modify virulence gene expression accordingly. Thus, metabolite-sensing is critical for pathogens to establish infection. Here, we highlight recent examples of how the foodborne pathogen enterohemorrhagic Escherichia coli O157:H7 (EHEC) exploits microbiota-derived metabolites to recognize the host intestinal environment and control gene expression that results in controlled expression of virulence traits.

From the gut to the peripheral tissues: the multiple effects of butyrate

Butyrate is a natural substance present in biological liquids and tissues. The present paper aims to give an update on the biological role of butyrate in mammals, when it is naturally produced by the gastrointestinal microbiota or orally ingested as a feed additive. Recent data concerning butyrate production delivery as well as absorption by the colonocytes are reported. Butyrate cannot be detected in the peripheral blood, which indicates fast metabolism in the gut wall and/or in the liver. In physiological conditions, the increase in performance in animals could be explained by the increased nutrient digestibility, the stimulation of the digestive enzyme secretions, a modification of intestinal luminal microbiota and an improvement of the epithelial integrity and defence systems. In the digestive tract, butyrate can act directly (upper gastrointestinal tract or hindgut) or indirectly (small intestine) on tissue development and repair. Direct trophic effects have been demonstrated mainly by cell proliferation studies, indicating a faster renewal of necrotic areas. Indirect actions of butyrate are believed to involve the hormono-neuro-immuno system. Butyrate has also been implicated in down-regulation of bacteria virulence, both by direct effects on virulence gene expression and by acting on cell proliferation of the host cells. In animal production, butyrate is a helpful feed additive, especially when ingested soon after birth, as it enhances performance and controls gut health disorders caused by bacterial pathogens. Such effects could be considered for new applications in human nutrition.

Butyrate specifically down-regulates salmonella pathogenicity island 1 gene expression

Invasion of intestinal epithelial cells by Salmonella enterica is decreased after exposure to butyric acid. To understand the molecular mechanisms of this phenomenon, a comparative transcriptomic analysis of Salmonella enterica serovar Enteritidis and Salmonella enterica serovar Typhimurium grown in medium supplemented with butyrate was performed. We found that butyrate down-regulated the expression of 19 genes common to both serovars by a factor of twofold or more, and 17 of these genes localized to the Salmonella pathogenicity island 1 (SPI1). These included the SPI1 regulatory genes hilD and invF. Of the remaining two genes, ampH has 91% homology to an Escherichia coli penicillin-binding protein and sopE2 encodes a type III-secreted effector protein associated with invasion but located at a separate site on the chromosome from SPI1.

Resistant starch modulates in vivo colonic butyrate uptake and its oxidation in rats with dextran sulfate sodium-induced colitis

We previously demonstrated improvements of colonic lesions due to dextran sulfate sodium (DSS) in rats after 7 d of supplementation with resistant starch (RS) type 3, a substrate yielding high levels of butyrate (C(4)), a colonic cell fuel source. In the present study, we hypothesized that if inflammation is related to decreased C(4) utilization by the colonic mucosa, RS supplementation should restore C(4) use simultaneously with an increase in the amount of C(4) present in the digestive tract. Hence, we compared, in vivo, the cecocolonic uptake of C(4) and its oxidation into CO(2) and ketone bodies in control and DSS-treated rats fed a fiber-free basal diet (BD) or a RS-supplemented diet. Sprague-Dawley rats (n = 60) were used. DSS treatment was performed to induce acute colitis and then to maintain chronic colitis. After cecal infusion of [1-(13)C]-C(4) (20 micro mol in 1 h), concentrations and (13)C-enrichment of C(4), ketone bodies, and CO(2) were quantified in the abdominal aorta and portal vein. Portal blood flow was recorded. During acute colitis, (13)C(4) uptake and (13)CO(2) production were lower in DSS rats than in controls. During chronic colitis, DSS rats did not differ from controls. After 7 d of chronic colitis, RS-DSS rats exhibited the same C(4) uptake as BD-DSS rats in spite of higher C(4) cecocolonic disposal. After 14 d, C(4) uptake was higher in RS-DSS than in BD-DSS rats. Thus, the increased utilization of C(4) by the mucosa is subsequent to evidence of healing and appears to be a consequence rather than a cause of this RS healing effect.

Restoration of the integrity of rat caeco-colonic mucosa by resistant starch, but not by fructo-oligosaccharides, in dextran sulfate sodium-induced experimental colitis

Butyrate is recognised as efficient in healing colonic inflammation, but cannot be used as a long-term treatment. Dietary fibre that produces a high-butyrate level when fermented represents a promising alternative. We hypothesised that different types of dietary fibre do not have the same efficiency of healing and that this could be correlated to their fermentation characteristics. We compared short-chain fructo-oligosaccharides (FOS) and type 3 resistant starch (RS) in a previously described dextran sulfate sodium (DSS)-induced colitis model. Seventy-two Sprague-Dawley rats received water (control rats) or DSS (50 g DSS/l for 7 d then 30 g DSS/l for 7 (day 7) or 14 (day 14) d). The rats were fed a basal diet (BD), or a FOS or RS diet creating six groups: BD-control, BD-DSS, FOS-control, FOS-DSS, RS-control and RS-DSS. Caeco-colonic inflammatory injuries were assessed macroscopically and histologically. Short-chain fatty acids (SCFA) were quantified in caeco-colon, portal vein and abdominal aorta. At days 7 and 14, caecal and distal macroscopic and histological observations were improved in RS-DSS compared with BD-DSS and also with FOS-DSS rats. Caeco-colonic SCFA were reduced in FOS-DSS and RS-DSS groups compared with healthy controls. The amount of butyrate was higher in the caecum of the RS-DSS rats than in the BD-DSS and FOS-DSS rats, whereas distal butyrate was higher in FOS-DSS rats. Partially explained by higher luminal levels of SCFA, especially butyrate, the healing effect of RS confirms the involvement of some types of dietary fibre in inflammatory bowel disease. Moreover, the ineffectiveness of FOS underlines the importance of the type of dietary substrate.

Butyrate and the cytokine-induced alpha1-proteinase inhibitor release in intestinal epithelial cells

BACKGROUND

Alpha1-proteinase inhibitor (alpha1-PI), an anti-inflammatory protein thought to play a role in the intestinal inflammation, is synthesised by and released from the intestinal epithelial cells. IL-1beta is a key proinflammatory cytokine in the abnormal immune response that occurs in inflammatory bowel disease. Butyrate is a normal luminal constituent in the colon, known to be of benefit in preventing inflammatory bowel disease. Direct modes of action of butyrate in intestinal inflammation have been poorly studied so far. The aim of this study was to investigate the effects of butyrate on cytokine-mediated alpha1-PI release in intestinal epithelial cells.

METHODS

Differentiated Caco-2 cells were incubated with IL-1beta in the presence or absence of 2 mM butyrate. Alpha1-PI expression in the cells was evaluated by Western blot analysis and alpha1-PI release by ELISA.

RESULTS

Treatment with butyrate alone had no effect on alpha1-PI expression in differentiated Caco-2 cells. However, treatment of the cells with 2 mM butyrate significantly reduced the alpha1-PI level in IL-1beta-treated cells. In the cell culture medium, the presence of butyrate impaired the IL-1beta-induced alpha1-PI release to 17-35%. The treatment induced no change in the number of detached cells or the percentage of viable cells.

CONCLUSION

Our data show that butyrate inhibits alpha1-PI release from Caco-2 colonocytes treated with IL-1beta. It is therefore likely that anti-inflammatory actions of butyrate occur via a mechanism that does not involve direct regulation of cytokine-induced anti-inflammatory protein expression in intestinal epithelial cells.

Searching for the magic bullet against cancer: the butyrate saga

n-Butyric acid and its "polymorphic" derivatives have been largely but somehow "blindly" studied in oncology and in red cell diseases with consistent results through decades indicating a strong maturative effect determined by enhancement of gene transcription. Although these effects have been observed mainly in vitro, the relative absence of systemic toxicity of butyrates render these compounds appealing as specific therapeutic agents. More interestingly, their specific mechanism of action, i.e. inhibition of histone deacetylase and de-repression of transcription represents at present an unique tool for diseases such as acute leukemias which are characterised by a disregulation of co-repressors and co-activators of gene transcription. More insight into specificity and modalities of action of different butyrate derivatives may be a guarantee for excellent tailored antileukemic therapy in the future.

Role of butyric acid and its derivatives in the treatment of colorectal cancer and hemoglobinopathies

Butyric acid, a short chain fatty acid (SCFA), is a natural component of the animal metabolism. Physiological concentrations induce multiple and reversible biological effects. They concern regulatory mechanisms of gene expression conducing to promote markers of cell differentiation, apoptosis and cell growth control. The described hyperacetylation of histones and the induction of several immune or non-immune cell-activating mediators are consistent with the pleiotropic stimulatory effect of the agent. Butyric acid is considered as a biological response modifier (BRM) and is an interesting tool for biological studies. The history of butyric acid as a putative medication in human health is spanning since 60 years and is confusing in part because of conflicting data between exciting experimental results and clinical trials. In light of minimal impact of systemic therapy and the short half-life of the saline molecule used, it is evident that continuous infusions of butyrate are required to improve the efficacy of the treatment. Butyric acid has been viewed with skepticism because of less convenient for long-term chronic therapy. New experimental data from several studies conduced within the past decade with butyric derivatives, delivery systems, and long-acting prodrugs, have demonstrated the practical value of the therapeutic concept. To support issues regarding clinical development, it was of interest to evaluate the recent information, showing butyric acid currently considered as therapeutic purposes in the treatment of colorectal cancer and hemoglobinopathies.

Sodium butyrate upregulates Kupffer cell PGE2 production and modulates immune function

The immunosuppressive effect of portal venous blood transfusions in organ transplantation has been well established and may be mediated by increased Kupffer cell production of the immunosuppressive arachidonic acid metabolite prostaglandin E2 (PGE2). In this study, butyrate, a short-chain fatty acid known to enhance gene transcription, is hypothesized to enhance Kupffer cell PGE2 production by altering cyclooxygenase or phospholipase A2 (PLA2) activity, thus augmenting the immunosuppressive effect of portal venous transfusion. Lewis rats were given a portal venous transfusion of Wistar-Firth blood or saline 1 h prior to Kupffer cell harvest. The in vitro effects of butyrate on Kupffer cell PGE2 production, cyclooxygenase, and PLA2 activity were assessed. Kupffer cell tumor necrosis factor-alpha (TNFalpha) production was also assessed due to its sensitivity to PGE2 and its proinflamatory effects. Kupffer cells from portally transfused animals produced significantly more PGE2 than saline-transfused controls. Addition of butyrate to the culture medium further increased PGE2 production by as much as sevenfold in Kupffer cells of portally transfused animals. Other short-chain fatty acids, propionate and hexanoate, did not increase PGE2 production. Butyrate added to Kupffer cells from transfused animals slightly upregulated inducible cyclooxygenase (COX-2) mRNA levels as measured by both Northern blot and reverse-transcriptase polymerase chain reaction and increased PLA2 activity fivefold as measured by Western blot. Kupffer cell immune function was also affected by in vitro butyrate treatment with a significant decrease in the production of TNFalpha. Thus, butyrate may be a useful immunoregulatory agent in organ transplantation protocols which seek to enhance transcription of immunosuppressive molecules.

Nutrient pharmacotherapy for gut mucosal diseases

The use of nutrients for pharmacotherapy is a recent advance in the treatment of gastrointestinal disorders or alterations of gut function and structure. Nutrients may have a direct effect on the gut, or may enhance the response to medications. Alternatively, pharmacologic agents may improve the absorption of nutrients. Potentially, pharmacotherapy may be an adjunct to the traditional approach used in the treatment of compromised patients.

Sulfides impair short chain fatty acid beta-oxidation at acyl-CoA dehydrogenase level in colonocytes: implications for ulcerative colitis

The disease process of ulcerative colitis (UC) is associated with a block in beta-oxidation of short chain fatty acid in colonic epithelial cells which can be reproduced by exposure of cells to sulfides. The aim of the current work was to assess the level in the beta-oxidation pathway at which sulfides might be inhibitory in human colonocytes. Isolated human colonocytes from cases without colitis (n = 12) were exposed to sulfide (1.5 mM) in the presence or absence of exogenous CoA and ATP. Short chain acyl-CoA esters were measured by a high performance liquid chromatographic assay. 14CO2 generation was measured from [1-14C]butyrate and [6-14C]glucose. 14CO2 from butyrate was significantly reduced (p < 0.001) by sulfide. When colonocytes were incubated with hydrogen sulfide in the presence of CoA and ATP, butyryl-CoA concentration was increased (p < 0.01), while crotonyl-CoA (p < 0.01) and acetyl-CoA (p < 0.01) concentrations were decreased. These results show that sulfides inhibit short chain acyl-CoA dehydrogenase. As oxidation of n-butyrate governs the epithelial barrier function of colonocytes the functional activity of short chain acyl-CoA dehydrogenase may be critical in maintaining colonic mucosal integrity. Maintaining the functional activity of dehydrogenases could be an important determinant in the expression of ulcerative colitis.

Dexpanthenol enemas in ulcerative colitis: a pilot study

OBJECTIVE

To test the hypothesis that topical administration of pantothenic acid, a precursor of coenzyme A, might result in increased tissue levels of coenzyme A, improvement of fatty acid oxidation, and amelioration of ulcerative colitis.

MATERIAL AND METHODS

In an open-label pilot study, three patients with active left-sided ulcerative colitis received nightly enemas that contained 1,000 mg of dexpanthenol for 4 weeks. Before and after the study, patients submitted stool specimens for short-chain fatty acid analysis and urine collections for measurement of pantothenic acid and dicarboxylic acids; they also underwent flexible sigmoidoscopy for procurement of biopsy specimens for histologic examination and measurement of colonic coenzyme A activity. A clinical disease activity index and histologic disease activity index were used to assess response.

RESULTS

Despite increases in urinary pantothenic acid, no significant changes were found in colonic tissue coenzyme A concentrations, fecal short-chain fatty acid concentrations, or urinary dicarboxylic acid concentrations. Moreover, no significant changes in clinical or histologic disease activity were noted. Although stool frequency and rectal bleeding remained unchanged, all patients noted increased abdominal cramping, and one patient had an increased extent of disease.

CONCLUSION

Topically administered dexpanthenol seems to be absorbed, but at the dose used in this study, it did not influence concentrations of colonic coenzyme A activity, fecal short-chain fatty acids, or clinical response in patients with active left-sided ulcerative colitis.