Metabolism Of Short-chain Fatty Acids Research Articles

Altered Gut Microbiome Linked to Short Chain Fatty Acids Production in a Rat Model of Superimposed Preeclampsia

Preeclampsia (PE), a hypertensive disorder of pregnancy, is a leading cause of maternal and fetal morbidity. It affects 2–8% of all pregnancies, and its pathophysiology is not fully understood. Recent studies in preeclamptic patients have suggested a role for the gut microbiome (GM) in the disease. In addition, emerging evidence from both human and animal studies have reported that short‐chain fatty acids (SCFAs) and other gut‐derived metabolites such as lactate may modulate blood pressure (BP). We have characterized the Dahl salt‐sensitive (Dahl S) rat as a spontaneous rodent model of superimposed PE. The goal of our study was to determine if SCFAs production is impaired in PE. We hypothesized that preexisting chronic hypertension impairs maternal GM remodeling and maladaptation in SCFAs metabolism contributing to the development of superimposed PE. Female Sprague Dawley (SD) and Dahl S rats were maintained in conventional caging in the same room and on the same diet (Teklad 7034, 0.3% NaCl). Half of the rats of each strain were mated to have pregnant and virgin groups (n=7–9/group). Fecal samples were collected at baseline (BL), gestation day 20 (GD20) and one‐week postpartum (PP) to assess gut microbiome via 16S rRNA gene sequencing. Alpha diversity (Shannon index), beta diversity (Bray‐Curtis index), and linear discriminant analysis effect size (LEfSe) were determined from the sequenced data to assess microbial differences. PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states) was used to predict functional potential. At BL, Dahl S rats had higher alpha diversity (P<0.0001) and distinctly clustered beta diversity (p<0.001) compared to SD rats. Dahl S had higher Proteobacteria abundance (665,980 vs 51,240, p<0.05), a marker of dysbiosis. In response to pregnancy, we observed significant differences among groups in both alpha and beta diversity during late pregnancy. Also, Proteobacteria abundance in the SD rats rose from 0.56% (BL) to 13.46% (GD20) before subsiding to 7.36% (PP) suggesting that these changes may be a normal adaptation to pregnancy. The Dahl S, however, showed no change in proteobacteria: 5.29% (BL) to 6.35% (GD20) and 7.8% (PP). We found Dahl S groups to have significantly lower abundance of genera such as Odoribacter and Roseburia which are known to produce butyrate, a SCFA associated with lowering BP, compared to the SD rats. On the other hand, Dahl S rats were significantly enriched in lactate producing genera including Turibacter and Streptococcus. Increased lactate producers have been previously associated with increased BP. In addition, when comparing each pregnant group to its virgin counterpart of the same strain, we found that Dahl S rats had differentially regulated butanoate (33 hits, p=0.01 vs. 32 hits, p=0.43) and propanoate (31 hits, p=0.01 vs. 29 hits, p=0.57) metabolic pathways but not in SD groups. Altogether, these data suggest that superimposed PE may be associated with impaired pregnancy‐specific GM changes and dysregulation in SCFAs production. Future studies will assess the therapeutic potential of beneficial SCFAs supplementation for the treatment of PE in this model.Support or Funding InformationR01HL134711 ( J. M. Sasser) & funds to UMMC Molecular and Genomics Facility

Post-mortem tissue analyses in a patient with succinic semialdehyde dehydrogenase deficiency (SSADHD). I. Metabolomic outcomes.

Metabolomic characterization of post-mortem tissues (frontal and parietal cortices, pons, cerebellum, hippocampus, cerebral cortex, liver and kidney) derived from a 37 y.o. male patient with succinic semialdehyde dehydrogenase deficiency (SSADHD) was performed in conjunction with four parallel series of control tissues. Amino acids, acylcarnitines, guanidino- species (guanidinoacetic acid, creatine, creatinine) and GABA-related intermediates were quantified using UPLC and mass spectrometric methods that included isotopically labeled internal standards. Amino acid analyses revealed significant elevation of aspartic acid and depletion of glutamine in patient tissues. Evidence for disruption of short-chain fatty acid metabolism, manifest as altered C4OH, C5, C5:1, C5DC (dicarboxylic) and C12OH carnitines, was observed. Creatine and guanidinoacetic acids were decreased and elevated, respectively. GABA-associated metabolites (total GABA, γ-hydroxybutyric acid, succinic semialdehyde, 4-guanidinobutyrate, 4,5-dihydroxyhexanoic acid and homocarnosine) were significantly increased in patient tissues, including liver and kidney. The data support disruption of fat, creatine and amino acid metabolism as a component of the pathophysiology of SSADHD, and underscore the observation that metabolites measured in patient physiological fluids provide an unreliable reflection of brain metabolism.

Effect of Berberine on Atherosclerosis and Gut Microbiota Modulation and Their Correlation in High-Fat Diet-Fed ApoE-/- Mice.

Atherosclerosis and its associated cardiovascular diseases (CVDs) are serious threats to human health and have been reported to be associated with the gut microbiota. Recently, the role of berberine (BBR) in atherosclerosis and gut microbiota has begun to be appreciated. The purposes of this study were to observe the effects of high or low doses of BBR on atherosclerosis and gut microbiota modulation, and to explore their correlation in ApoE–/– mice fed a high-fat diet. A significant decrease in atherosclerotic lesions was observed after treatment with BBR, with the effect of the high dose being more obvious. Both BBR treatments significantly reduced total cholesterol, APOB100, and very low-density lipoprotein cholesterol levels but levels of high/low-density lipoprotein cholesterol and lipoprotein (a) were only reduced by high-dose BBR. Decreased pro-inflammatory cytokines tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6 and increased anti-inflammatory IL-10 and adiponectin levels were observed in the high-dose BBR group, but no decrease in IL-6 or increase in IL-10 was evident using the low-dose of BBR. 16S rRNA sequencing showed that BBR significantly altered the community compositional structure of gut microbiota. Specifically, BBR enriched the abundance of Roseburia, Blautia, Allobaculum, Alistipes, and Turicibacter, and changed the abundance of Bilophila. These microbiota displayed good anti-inflammatory effects related to the production of short-chain fatty acids (SCFAs) and were related to glucolipid metabolism. Alistipes and Roseburia were significantly enriched in high-dose BBR group while Blautia and Allobaculum were more enriched in low-dose, and Turicibacter was enriched in both BBR doses. Metagenomic analysis further showed an elevated potential for lipid and glycan metabolism and synthesis of SCFAs, as well as reduced potential of TMAO production after BBR treatment. The findings demonstrate that both high and low-dose BBR can improve serum lipid and systemic inflammation levels, and alleviate atherosclerosis induced by high-fat diet in ApoE–/– mice. The effects are more pronounced for the high dose. This anti-atherosclerotic effect of BBR may be partly attributed to changes in composition and functions of gut microbiota which may be associated with anti-inflammatory and metabolism of glucose and lipid. Notably, gut microbiota alterations showed different sensitivity to BBR dose.

Clinical translation of 18F-fluoropivalate \u2013 a PET tracer for imaging short-chain fatty acid metabolism: safety, biodistribution, and dosimetry in fed and fasted healthy volunteers

BackgroundFatty acids derived de novo or taken up from the extracellular space are an essential source of nutrient for cell growth and proliferation. Radiopharmaceuticals including 11C-acetate, and 18F-FAC (2-18F-fluoroacetate), have previously been used to study short-chain fatty acid (SCFA) metabolism. We developed 18F-fluoropivalate (18F-FPIA; 3-18F-fluoro-2,2-dimethylpropionic acid) bearing a gem-dimethyl substituent to assert metabolic stability for studying SCFA metabolism. We report the safety, biodistribution, and internal radiation dosimetry profile of 18F-FPIA in 24 healthy volunteers and the effect of dietary conditions.Materials and methodsHealthy volunteer male and female subjects were enrolled (n = 24), and grouped into 12 fed and 12 fasted. Non-esterified fatty acids (NEFA) and carnitine blood measurements were assessed. Subjects received 159.48 MBq (range, 47.31–164.66 MBq) of 18F-FPIA. Radiochemical purity was > 99%. Safety data were obtained during and 24 h after radiotracer administration. Subjects underwent detailed multiple whole-body PET/CT scanning with sampling of venous bloods for radioactivity and radioactive metabolite quantification. Regions of interest were defined to derive individual and mean organ residence times; effective dose was calculated using OLINDA 1.1.ResultsAll subjects tolerated 18F-FPIA with no adverse events. Over 90% of radiotracer was present in plasma at 60 min post-injection. The organs receiving highest absorbed dose (in mGy/MBq) were the liver (0.070 ± 0.023), kidneys (0.043 ± 0.013), gallbladder wall (0.026 ± 0.003), and urinary bladder (0.021 ± 0.004); otherwise there was low tissue uptake. The calculated effective dose using mean organ residence times over all 24 subjects was 0.0154 mSv/MBq (SD ± 0.0010). No differences in biodistribution or dosimetry were seen in fed and fasted subjects, though systemic NEFA and carnitine levels reflected fasted and fed states.ConclusionThe favourable safety, imaging, and dosimetric profile makes 18F-FPIA a promising candidate radiotracer for tracing SCFA metabolism.

Continuous biogas production from sugarcane as sole substrate

A German–Brazilian research project investigates sugarcane as an energy plant in anaerobic digestion for biogas production. The aim of the project is a continuous, efficient, and stable biogas process with sugarcane as the substrate. Tests are carried out in a fermenter with a volume of 10 l.In order to optimize the space–time load to achieve a stable process, a continuous process in laboratory scale has been devised. The daily feed in quantity and the harvest time of the substrate sugarcane has been varied. Analyses of the digester content were conducted twice per week to monitor the process: The ratio of inorganic carbon content to volatile organic acid content (VFA/TAC), the concentration of short-chain fatty acids, the organic dry matter, the pH value, and the total nitrogen, phosphate, and ammonium concentrations were monitored. In addition, the gas quality (the percentages of CO2, CH4, and H2) and the quantity of the produced gas were analyzed.The investigations have exhibited feasible and economical production of biogas in a continuous process with energy cane as substrate. With a daily feeding rate of 1.68 gVS /l*d the average specific gas formation rate was 0.5 m3/kgVS. The long-term study demonstrates a surprisingly fast metabolism of short-chain fatty acids. This indicates a stable and less susceptible process compared to other substrates.

P003 Metabolomics for improved patient stratification in inflammatory bowel disease: Characterisation of the ulcerative colitis metabolome

Abstract Background The onset of ulcerative colitis (UC) is characterised by a dysregulated mucosal immune response triggered by several genetic and environmental factors in the context of host-microbe interaction. This complexity makes UC ideal for metabolomic studies to unravel the disease pathobiology and to improve the patient stratification strategies toward personalised medicine. This study aims to explore the mucosal metabolomic profile in treatment-naïve and deep remission UC patients, and to define the metabolic signature of UC. Methods Treatment-naive UC patients (n = 18), UC patients in deep remission (n = 10), and healthy volunteers (n = 14) were recruited. Mucosa biopsies were collected during colonoscopy. The UC activity and the state of deep remission were assessed by endoscopy, histology, and by measuring TNF gene expression. Metabolomic analysis was performed by combined gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS) and ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS). In total, 177 metabolites from 50 metabolic pathways were identified. Results Multivariate data analysis revealed a distinct metabolomic profile in inflamed mucosa taken from treatment- naïve UC patients compared with non-inflamed mucosa taken from UC remission patients and healthy controls. The mucosal metabolome in UC remission patients differed to a lesser extent from the healthy controls. The most prominent metabolome changes among the study groups were in lysophosphatidylcholine, acylcarnitine, and amino acid profiles. Several metabolic pathways were perturbed, ranging from amino acid metabolism (such as tryptophan metabolism, and alanine, aspartate and glutamate metabolism) to antioxidant defence pathway (glutathione pathway). Furthermore, the pathway analysis revealed a disruption in the long-and short-chain fatty acid (LCFA and SCFA) metabolism, namely linoleic metabolism and butyrate metabolism. Conclusion The mucosal metabolomic profiling revealed a metabolic signature during the onset of UC, and reflected the homeostatic disturbance in the gut. The altered metabolic pathways highlight the importance of system biology approaches to identify key drivers of IBD pathogenesis which prerequisite personalised treatment.

Influence of the Mediterranean diet on the production of short-chain fatty acids in women at risk for breast cancer (LIBRE)

AbstractBackground: A number of small intervention studies suggested that a Mediterranean diet (MedD) and physical activity can lower the risk for breast cancer. LIBRE is the first large multicenter RCT to test the effect of these lifestyle factors on the incidence of breast cancer in women at risk because of BRCA mutations(1). LIBRE also offers to unravel underlying mechanisms such as the role of short-chain fatty acids (SCFA) for beneficial effects of such lifestyle interventions.Methods: We examined the effect of the lifestyle intervention on the production of SCFA measured in feces by gas chromatography. From the ongoing LIBRE trial we included all complete datasets (171 women; mean age 44 ± 11 years). Both women with and without previous breast cancer diagnosis were recruited (diseased; non-diseased). The participants were randomized into an intervention group (IG) trained for MedD and physical activity, and a usual care control group (CG). Adherence to the MedD was assessed at baseline and after 3 months (V1) using the validated Mediterranean Diet Adherence Screener (MEDAS) and the EPIC food frequency questionnaire (FFQ).Results: At baseline there was no difference in SCFA levels between the groups. In the IG the MEDAS score increased substantially by 2.5 points (p < 0.001), in the CG only mildly by 0.4 points (p < 0.05). Correspondingly, the intake of fibers increased solely in the IG. In the course of the study the amount of caproic acid decreased in the control group (p < 0.001). At V1 non-diseased women showed higher amounts of acetic acid (p = 0.042), n-butyric acid (p = 0.023), n-valeric acid (p = 0.018) and iso-valeric acid (p = 0.031). There were several correlations between the intake of different fibers and fecal SCFA. For example, the sum of poly- and oligosaccharides correlated with acetic acid (p = 0.001; r = 0.316), propionic acid (p = 0.034; r = 0,251), n-butyric acid (p = 0.010; r = 0.316) and iso-valeric acid (p = 0.012; r = 0.306). There was no correlation between the MEDAS and SCFA.Discussion: A lifestyle change towards a MedD and increased physical activity did not change the levels of SCFA in feces, although an increase of fiber intake was documented in the IG. To further analyze SCFA metabolism in this target population, gut microbiota composition and function (metabolites) are currently analyzed.

L-Theanine affects intestinal mucosal immunity by regulating short-chain fatty acid metabolism under dietary fiber feeding.

To investigate the effects of l-Theanine (LTA) on intestinal mucosal immunity and the regulation of short-chain fatty acid (SCFA) metabolism under dietary fiber feeding, a 28-day feeding experiment was performed in Sprague-Dawley rats. The results show that LTA increased the proportion of Prevotella, Lachnospira, and Ruminococcus while increasing the total SCFA, acetic acid, propionic acid, and butyric acid contents in the feces. LTA also increased IgA, IgE, and IgG levels in the ileum, and increased villi height and crypt depth. Moreover, LTA upregulated the mRNA and protein expression of acetyl-CoA carboxylase 1, sterol element-binding protein 1c, fatty acid synthase, and 3-hydroxy-3-methylglutaryl coenzyme A reductase in the liver, while downregulating the expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon. Our study suggests that LTA can affect intestinal mucosal immunity by regulating SCFA metabolism under dietary fiber feeding.

Gut Microbiota in Children With Cystic Fibrosis: A Taxonomic and Functional Dysbiosis

Intestinal dysbiosis has been observed in children with cystic fibrosis (CF), yet the functional consequences are poorly understood. We investigated the functional capacity of intestinal microbiota and inflammation in children with CF. Stool samples were collected from 27 children with CF and 27 age and gender matched healthy controls (HC) (aged 0.8–18 years). Microbial communities were investigated by iTag sequencing of 16S rRNA genes and functional profiles predicted using Tax4Fun. Inflammation was measured by faecal calprotectin and M2-pyruvate kinase. Paediatric CF gastrointestinal microbiota demonstrated lower richness and diversity compared to HC. CF samples exhibited a marked taxonomic and inferred functional dysbiosis when compared to HC. In children with CF, we predicted an enrichment of genes involved in short-chain fatty acid (SCFA), antioxidant and nutrient metabolism (relevant for growth and nutrition) in CF. The notion of pro-inflammatory GI microbiota in children with CF is supported by positive correlations between intestinal inflammatory markers and both genera and functional pathways. We also observed an association between intestinal genera and both growth z-scores and FEV1%. These taxonomic and functional changes provide insights into gastrointestinal disease in children with CF and future gastrointestinal therapeutics for CF should explore the aforementioned pathways and microbial changes.

Derivatization strategy combined with parallel reaction monitoring for the characterization of short-chain fatty acids and their hydroxylated derivatives in mouse

Short-chain fatty acids (SCFAs) and hydroxylated short-chain fatty acids (OH–SCFAs) are crucial intermediates related to a variety of diseases, such as bowel disease, cardiovascular disease, renal disease and cancer. A global profiling method to screen SCFAs and OH–SCFAs was developed by tagging these analytes with d0/d6-N, N-dimethyl-6,7-dihydro-5H-pyrrolo [3,4-d] pyrimidine-2-amine (d0/d6-DHPP) and using ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC-MS/MS) in parallel reaction monitoring (PRM) mode. The derivatization procedure was simple and rapid. The targeted compounds could be derivatized within 3 min under mild condition and analyzed without the need of further purification. The derivatization significantly improved the chromatographic performance and mass spectrometry response. The d6-DHPP tagged standards were used as internal standards, which remarkably reduced the matrix effects. The use of high resolution PRM mode made it possible to locate unknown SCFA and OH-SCFA species, and greatly reduced the false positive identification results. The developed method was successfully applied to the analysis of mouse fecal, serum, and liver tissue samples harvested from the breast cancer nude mice that had been exposed with 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47). Results showed that 40 analytes (10 SCFAs and 30 OH–SCFAs) were characterized. Semi-quantitative analysis indicated that the exposure of BDE-47 to the mice altered the SCFA and OH-SCFA metabolism, especially in the high dose group. This study provides a high-throughput method to characterize SCFAs and OH–SCFAs in mouse samples.

Polysaccharide from tuberous roots of Ophiopogon japonicus regulates gut microbiota and its metabolites during alleviation of high-fat diet-induced type-2 diabetes in mice

Abstract Ophiopogonis Radix (Maidong in Chinese), the tuberous roots of Ophiopogon japonicus having polysaccharide as the main active ingredient, is a traditional Chinese herb and popularly used as functional food additive in China. Here, a homogeneous polysaccharide fraction (OJP-W1) was isolated and characterized from Ophiopogonis Radix collected from Sichuan (Chuan-Maidong). The therapeutic effects of OJP-W1 in diabetes symptoms, gut microbiota and metabolism of short-chain fatty acids (SCFAs) in high-fat diet (HFD)-induced type-2 diabetes mice were investigated. Results showed that OJP-W1 significantly ameliorated HFD-induced insulin resistance and glucose tolerance. Meanwhile, OJP-W1 regulated the gut microbiota dysbiosis in HFD-fed mice, as indicated by increasing Actinobacteria and Bifidobacterium, decreasing Proteobacteria and type-2 diabetes-enriched taxa (e.g. Desulfovibrionaceae, Dorea and Ruminococcaceae). In addition, OJP-W1 could improve the metabolic disorder of SCFAs in HFD-fed mice. This study indicated that OJP-W1 might serve as a novel functional food in preventing diabetes-associated gut microbiota dysbiosis and SCFA metabolic disorder.

Antibiotic Exposure Disturbs the Gut Microbiota and Its Metabolic Phenotype Differently in Rats with Advanced-Stage Type 1 Diabetes and Age-Matched Controls.

Antibiotic-induced microbial perturbations alter host metabolism and affect host physiology. In this study, we aimed to investigate the effects of vancomycin (Vanc) and ciprofloxacin/metronidazole (CiMe) exposures on the gut microbiome and metabolome in the colonic content and tissue samples from advanced-stage type 1 diabetic (AST1D) rats and age-matched controls (AMCs) using 16S ribosomal RNA gene sequencing and nuclear magnetic resonance-based metabolomics. The results show that antibiotic effects on the gut microbiota were stronger in AMC rats relative to AST1D rats. These microbial alterations were accompanied by a series of metabolic changes, including energy metabolism, short-chain fatty acid metabolism, and amino acid metabolism. We found that AMC rats had a more notable metabolic response to antibiotic exposure than AST1D rats. Additionally, Vanc had a stronger impact on the gut microbiota and host metabolic phenotype versus CiMe. Therefore, our results reveal that antibiotic-induced shifts in the gut microbiome and metabolome are different between AST1D and AMC rats. If confirmed in human studies, these findings suggest that diabetic patients may need a specific strategy for antibiotic use in clinical practice.

Fecal metabonomics combined with 16S rRNA gene sequencing to analyze the changes of gut microbiota in rats with kidney-yang deficiency syndrome and the intervention effect of You-gui pill

Ethnopharmacological relevanceA myriad of evidence have shown that kidney-yang deficiency syndrome (KYDS) is associated with metabolic disorders of the intestinal microbiota, while TCMs can treat KYDS by regulating gut microbiota metabolism. However, the specific interplay between KYDS and intestinal microbiota, and the intrinsic regulation mechanism of You-gui pill (YGP) on KYDS’ gut microbiota remains largely unknown so far. Materials and methodsIn the present study, fecal metabonomics combined with 16S rRNA gene sequencing analysis were used to explore the mutual effect between KYDS and intestinal flora, and the intrinsic regulation mechanism of YGP on KYDS's gut microbiota. Rats' feces from control (CON) group, KYDS group and YGP group were collected, and metabolomic analysis was performed using 1H NMR technique combined with multivariate statistical analysis to obtain differential metabolites. Simultaneously, 16S rRNA gene sequencing analysis based on the Illumina HiSeq sequencing platform and ANOVA analysis were used to analyze the composition of the intestinal microbiota in the stool samples and to screen for the significant altered microbiota at the genus level. After that, MetaboAnalyst database and PICRUSt software were apply to conduct metabolic pathway analysis and functional prediction analysis of the screened differential metabolites and intestinal microbiota, respectively. What's more, Pearson correlation analysis was performed on these differential metabolites and gut microbiota. ResultsUsing fecal metabonomics, KYDS was found to be associated with 21 differential metabolites and seven potential metabolic pathways. These metabolites and metabolic pathways were mainly involved in amino acid metabolism, energy metabolism, methylamine metabolism, bile acid metabolism and urea cycle, and short-chain fatty acid metabolism. Through 16S rRNA gene sequencing analysis, we found that KYDS was related to eleven different intestinal microbiotas. These gut microbiota were mostly involved in amino acid metabolism, energy metabolism, nervous, endocrine, immune and digestive system, lipid metabolism, and carbohydrate metabolism. Combined fecal metabonomics and 16S rRNA gene sequencing analysis, we further discovered that KYDS was primarily linked to three gut microbiotas (i.e. Bacteroides, Desulfovibrio and [Eubacterium]_coprostanoligenes_group) and eleven related metabolites (i.e. deoxycholate, n-butyrate, valine, isoleucine, acetate, taurine, glycine, α-gluconse, β-glucose, glycerol and tryptophan) mediated various metabolic disorders (amino acid metabolism, energy metabolism, especially methylamine metabolism, bile acid metabolism and urea cycle, short-chain fatty acid metabolism. nervous, endocrine, immune and digestive system, lipid metabolism, and carbohydrate metabolism). YGP, however, had the ability to mediate four kinds of microbes (i.e. Ruminiclostridium_9, Ruminococcaceae_UCG-007, Ruminococcaceae_UCG-010, and uncultured_bacterium_f_Bacteroidales_S24-7_group) and ten related metabolites (i.e. deoxycholate, valine, isoleucine, alanine, citrulline, acetate, DMA, TMA, phenylalanine and tryptophan) mediated amino acid metabolism, especially methylamine metabolism, bile acid metabolism and urea cycle, short-chain fatty acid metabolism, endocrine, immune and digestive system, and lipid metabolism, thereby exerting a therapeutic effect on KYDS rats. ConclusionOverall, our findings have preliminary confirmed that KYDS is closely related to metabolic and microbial dysbiosis, whereas YGP can improve the metabolic disorder of KYDS by acting on intestinal microbiota. Meanwhile, this will lay the foundation for the further KYDS's metagenomic research and the use of intestinal microbiotas as drug targets to treat KYDS.

Modulatory effect of Lactobacillus acidophilus KLDS 1.0738 on intestinal short-chain fatty acids metabolism and GPR41/43 expression in β-lactoglobulin-sensitized mice.

We investigated the correlation between the beneficial effect of Lactobacillus acidophilus on gut microbiota composition, metabolic activities, and reducing cow's milk protein allergy. Mice sensitized with β-lactoglobulin (β-Lg) were treated with different doses of L. acidophilus KLDS 1.0738 for 4 weeks, starting 1 week before allergen induction. The results showed that intake of L. acidophilus significantly suppressed the hypersensitivity responses, together with increased fecal microbiota diversity and short-chain fatty acids (SCFAs) concentration (including propionate, butyrate, isobutyrate, and isovalerate) when compared with the allergic group. Moreover, treatment with L. acidophilus induced the expression of SCFAs receptors, G-protein-coupled receptors 41 (GPR41) and 43 (GPR43), in the spleen and colon of the allergic mice. Further analysis revealed that the GPR41 and GPR43 messenger RNA expression both positively correlated with the serum concentrations of transforming growth factor-β and IFN-γ (p < .05), but negatively with the serum concentrations of IL-17, IL-4, and IL-6 in the L. acidophilus-treated group compared with the allergic group (p < .05). These results suggested that L. acidophilus protected against the development of allergic inflammation by improving the intestinal flora, as well as upregulating SCFAs and their receptors GPR41/43.

Strain-specific ameliorating effect of Bifidobacterium longum on atopic dermatitis in mice

Abstract Atopic dermatitis (AD) is among the most common allergic diseases worldwide. This study evaluated differences in the abilities of Bifidobacterium longum strains to alleviate 2, 4-dinitrofluorobenzene-induced AD in mice. Of the 12 tested B. longum strains, CCFM1029 significantly relieved AD symptoms. This outcome was accompanied by the inhibition of inflammatory cells infiltration in AD-like skin lesions, decreases in serum IgE, and inflammatory cytokines levels in dorsal skin tissue, increases in IFN-γ and IL-10 levels, and a reduction in the cecal propionic acid level. B. longum CCFM1029 also reduced the proportions of unclassified Bacteroidales S24-7, Adlercreutzia, and Allobaculum spp., and restored the gut microbiota structure such that it resembled the control group structure. In conclusion, the administration of B. longum CCFM1029 helped to ameliorate AD by suppressing polarized Th2 immune responses and regulating the gut microbiota and short-chain fatty acids metabolism.

Antibiotic Exposure Has Sex-Dependent Effects on the Gut Microbiota and Metabolism of Short-Chain Fatty Acids and Amino Acids in Mice.

The gut microbiota has the capability to regulate homeostasis of the host metabolism. Since antibiotic exposure can adversely affect the microbiome, we hypothesized that antibiotic effects on the gut microbiota and host metabolism are sex dependent. In this study, we examined the effects of antibiotic treatments, including vancomycin (Vanc) and ciprofloxacin-metronidazole (CiMe), on the gut microbiome and metabolome in colonic contents and tissues in both male and female mice. We found that the relative abundances and structural composition of Firmicutes were significantly reduced in female mice after both Vanc and CiMe treatments but in male mice only after treatment with Vanc. However, Vanc exposure considerably altered the relative abundances and structural composition of representatives of the Proteobacteria especially in male mice. The levels of short-chain fatty acids (SCFAs; acetate, butyrate, and propionate) in colonic contents and tissues were significantly decreased in female mice after both antibiotic treatments, while these reductions were detected in male mice only after Vanc treatment. However, another SCFA, formate, exhibited the opposite tendency in colonic tissues. Both antibiotic exposures significantly decreased the levels of alanine, branched-chain amino acids (BCAAs; leucine, isoleucine, and valine) and aromatic amino acids (AAAs; phenylalanine and tyrosine) in colonic contents of female mice but not in male mice. Additionally, female mice had much greater correlations between microbe and metabolite than male mice. These findings suggest that sex-dependent effects should be considered for antibiotic-induced modifications of the gut microbiota and host metabolism.IMPORTANCE Accumulating evidence shows that the gut microbiota regulates host metabolism by producing a series of metabolites, such as amino acids, bile acids, fatty acids, and others. These metabolites have a positive or negative effect on host health. Antibiotic exposure can disrupt the gut microbiota and thereby affect host metabolism and physiology. However, there are a limited number of studies addressing whether antibiotic effects on the gut microbiota and host metabolism are sex dependent. In this study, we uncovered a sex-dependent difference in antibiotic effects on the gut microbiota and metabolome in colonic contents and tissues in mice. These findings reveal that sex-dependent effects need to be considered for antibiotic use in scientific research or clinical practice. Moreover, this study will also give an important direction for future use of antibiotics to modify the gut microbiome and host metabolism in a sex-specific manner.

298-LB: GLP-1 Secretion Enhancement after H. Pylori Eradication Treatment Is Related to Gut Microbiota Modification

Introduction: Antibiotic treatments modify gut microbiota. Microbiota alterations (in composition and biodiversity) are fundamental pieces in the development of metabolic disorders (T2DM and obesity). Objective: To evaluate the relationship between microbiota changes due to antibiotic treatment in patients colonized by H. pylori and GLP-1 secretion. Methods: A prospective case control study was assessed. We evaluated a H. pylori positive patient model before and two months after a short-term eradication therapy and a control group. Anthropometric measurements, carbohydrate and lipid metabolisms, GLP-1 levels and fecal microbiota composition (determined by 16S rRNA gene (V3-V4) sequencing with an Illumina Miseq) were analyzed. Results: We studied 40 cases and 20 controls (60% women, respectively). Average age was 47.0±2 vs. 43.6±2.7 years. 42.5% vs. 40% had clinical history of gastrointestinal disease. After eradication treatment, we found significant changes in microbiota profile at phylum, family, genus and species levels. The Chao1 and Shannon indices showed a decreased in bacterial richness and diversity in patients (pre and post H. pylori eradication) compared to controls. GLP-1 secretion and carbohydrate metabolism were improved after antibiotic treatment. GLP-1 changes were related to microbial community disturbances through correlation analysis, specifically with Bifidobacterium adolescentis (r=0.354, p=0.034), Lachnobacterium (r=-0.332, p=0.048) and Coriobacteriaceae (r=0.372, p=0.026). Conclusions: Antibiotic treatment to eradicate H. pylori increased the secretion of GLP-1 and improved the carbohydrate metabolism. This GLP-1 secretion improvement was related to changes in microbial community because of the antibiotic treatment, particularly in Bifidobacterium adolescentis, Lachnobacterium and Coriobacteriaceae. These taxa could play their roles through the production of short chain fatty acids (SCFA) and/or bile acid metabolism. Disclosure I. Cornejo-Pareja: None. G. Martin-Nuñez: None. I. Moreno-Indias: None. F.F. Cardona-Díaz: None. M. Roca-Rodriguez: None. L. Coin-Arangüez: None. I. Mancha-Doblas: None. F. Tinahones: Advisory Panel; Self; Lilly Diabetes, Novo Nordisk A/S, Regeneron Pharmaceuticals, Sanofi-Aventis. Consultant; Self; AstraZeneca. Research Support; Self; AstraZeneca. Speaker’s Bureau; Self; Danone Nutricia Research, Lilly Diabetes, Novo Nordisk A/S, Regenerative Medical Solutions, Sanofi-Aventis.

Production of highly polarized [1-13 C]acetate by rapid decarboxylation of [2-13 C]pyruvate - application to hyperpolarized cardiac spectroscopy and imaging.

The objective of the present work was to develop and implement an efficient approach to hyperpolarize [1-13 C]acetate and apply it to in vivo cardiac spectroscopy and imaging. Rapid hydrogen peroxide induced decarboxylation was used to convert hyperpolarized [2-13 C]pyruvate into highly polarized [1-13 C]acetate employing an additional step following rapid dissolution of [2-13 C]pyruvate in a home-built multi-sample dissolution dynamic nuclear polarization system. Phantom dissolution experiments were conducted to determine optimal parameters of the decarboxylation reaction, retaining polarization and T1 of [1-13 C]acetate. In vivo feasibility of detecting [1-13 C]acetate metabolism is demonstrated using slice-selective spectroscopy and multi-echo imaging of [1-13 C]acetate and [1-13 C]acetylcarnitine in the healthy rat heart. The first in vivo signal was observed ~23 s after dissolution. At the corresponding time point in the phantom experiments, 97.9 ± 0.4% of [2-13 C]pyruvate were converted into [1-13 C]acetate by the decarboxylation reaction. T1 and polarization of [1-13 C]acetate was determined to be 29.7 ± 1.9% and a 47.7 ± 0.5 s. Polarization levels of [2-13 C]pyruvate and [1-13 C]acetate were not significantly different after transfer to the scanner. In vivo, [1-13 C]acetate and [1-13 C]acetylcarnitine could be detected using spectroscopy and imaging. Decarboxylation of hyperpolarized [2-13 C]pyruvate enables the efficient production of highly polarized [1-13 C]acetate that is applicable to study short-chain fatty acid metabolism in the in vivo heart.

Fecal Microbiota and Its Correlation With Fatty Acids and Free Amino Acids Metabolism in Piglets After a Lactobacillus Strain Oral Administration.

Lactobacillus has a positive effect on the host intestinal microbiota. In piglets, dietary supplementation with Lactobacillus affects general health and plays an important role in nutrient digestion and fermentation. However, this association requires further investigation. Here, we studied newborn piglets from 12 litters. The nursed piglets were given a creep feed beginning on day 10 post-partum and weaned at day 30. Piglets were fed either a control basic diet or a diet including supplementation with Lactobacillus reuteri ZLR003 at 6.0 × 106 CFU/g feed. At day 30 and 60, feces samples were taken and used for sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. At day 60, feces samples and serum samples were also taken and used to measure the short chain fatty acids (SCFAs) and to detect long chain fatty acids (LCFAs) and free amino acids (FAAs), respectively. The results revealed that L. reuteri ZLR003 could improve piglet fecal microbiota composition, especially at the end of weaned period. The concentrations of lactic acid and butyric acid in feces were higher, and acetic acid concentration was lower in the L. reuteri ZLR003 group compared with the control group (P < 0.05). The serum polyunsaturated fatty acids C18:2n6c, C18:3n3, C20:4n6, and C22:6n3 were significantly higher (P < 0.05), as were the serum FAAs Gly, Ala, Val, Iso, Asn, Asp, Glu, Met, Phe, and Leu (P < 0.05), in the L. reuteri group compared with the control group. A correlation analysis revealed that the genera Ruminococcaceae_UCG-010 and Ruminococcaceae_UCG-014 had a negative correlation with the SCFAs content in feces, the genus Prevotella_9 had a higher positive correlation with C18:2n6c, and the genera Megasphaera and Mitsuokella had a more positive significant effect on the serum FAAs content in weaned piglets in the L. reuteri ZLR003 group compared with the control group. In conclusion, L. reuteri ZLR003 influenced the fecal microbiota composition of piglets, and its effects were related to the metabolism of SCFAs, LCFAs, and FAAs. Our findings will help facilitate the application of Lactobacillus strains in pig production.

Genetic risk scores demonstrate the cumulative association of single nucleotide polymorphisms in gut microbiome-related genes with obesity phenotypes in preschool age children.

Childhood obesity is a nutrition-related disease with multiple underlying aetiologies. While genetic factors contribute to obesity, the gut microbiome is also implicated through fermentation of nondigestible polysaccharides to short-chain fatty acids (SCFA), which provide some energy to the host and are postulated to act as signalling molecules to affect expression of gut hormones. To study the cumulative association of causal, regulatory, and tagged single nucleotide polymorphisms (SNPs) within genes involved in SCFA recognition and metabolism with obesity. Study participants were non-Hispanic White (NHW, n=270) and non-Hispanic Black (NHB, n=113) children (2-5years) from the Synergistic Theory and Research on Obesity and Nutrition Group (STRONG) Kids 1 Study. SNP variables were assigned values according to the additive, dominant, or recessive inheritance models. Weighted genetic risk scores (GRS) were constructed by multiplying the reassigned values by independently generated β-coefficients or by summing the β-coefficients. Ethnicity-specific SNPs were selected for inclusion in GRS by cohort. GRS were directly associated with body mass index (BMI) z-score. The models explained 3.75%, 12.9%, and 26.7% of the variance for NHW/NHB, NHW, and NHB (β=0.89 [CI: 0.43-1.35], P=0.0002; β=0.78 [CI: 0.54-1.03], P<0.0001; β=0.74 [CI: 0.51-0.97], P<0.0001). This analysis supports the cumulative association of several candidate genetic variants selected for their role in SCFA signalling, transport, and metabolism with early-onset obesity. These data strengthen the concept that microbiome influences obesity development through host genes interacting with SCFA.