Pattern Of Short-chain Fatty Acids Research Articles

Evaluation of synbiotic combinations of commercial probiotic strains with different prebiotics in in vitro and ex vivo human gut microcosm model.

Exploring probiotics for their crosstalk with the host microbiome through the fermentation of non-digestible dietary fibers (prebiotics) for their potential metabolic end-products, particularly short-chain fatty acids (SCFAs), is important for understanding the endogenous host-gut microbe interaction. This study was aimed at a systematic comparison of commercially available probiotics to understand their synergistic role with specific prebiotics in SCFAs production both in vitro and in the ex vivo gut microcosm model. Probiotic strains isolated from pharmacy products including Lactobacillus sporogenes (strain not labeled), Lactobacillus rhamnosus GG (ATCC53103), Streptococcus faecalis (T-110 JPC), Bacillus mesentericus (TO-AJPC), Bacillus clausii (SIN) and Saccharomyces boulardii (CNCM I-745) were assessed for their probiotic traits including survival, antibiotic susceptibility, and antibacterial activity against pathogenic strains. Our results showed that the microorganisms under study had strain-specific abilities to persist in human gastrointestinal conditions and varied anti-infective efficacy and antibiotic susceptibility. The probiotic strains displayed variation in the utilization of six different prebiotic substrates for their growth under aerobic and anaerobic conditions. Their prebiotic scores (PS) revealed which were the most suitable prebiotic carbohydrates for the growth of each strain and suggested xylooligosaccharide (XOS) was the poorest utilized among all. HPLC analysis revealed a versatile pattern of SCFAs produced as end-products of prebiotic fermentation by the strains which was influenced by growth conditions. Selected synbiotic (prebiotic and probiotic) combinations showing high PS and high total SCFAs production were tested in an ex vivo human gut microcosm model. Interestingly, significantly higher butyrate and propionate production was found only when synbiotics were applied as against when individual probiotic or prebiotics were applied alone. qRT-PCR analysis with specific primers showed that there was a significant increase in the abundance of lactobacilli and bifidobacteria with synbiotic blends compared to pre-, or probiotics alone. In conclusion, this work presents findings to suggest prebiotic combinations with different well-established probiotic strains that may be useful for developing effective synbiotic blends.

Methionine-choline deficient diet deteriorates DSS-induced murine colitis through disturbance of gut microbes and infiltration of macrophages.

Ulcerative colitis (UC) is associated with changed dietary habits and mainly linked with the gut microbiota dysbiosis, necroptosis of epithelial cells, and mucosal ulcerations. Liver dysfunction and abnormal level of liver metabolism indices were identified in UC patients, suggesting a close interaction between gut and liver disorders. Methionine-choline deficient diet (MCD) has been shown to induce persistent alterations of gut microbiota and metabolome during hepatitis. In this study we further explored the disease phenotypes in UC patients and investigated whether MCD functioned as a trigger for UC susceptibility. After assessing 88 serum specimens from UC patients, we found significant liver dysfunction and dyslipidemia including abnormal ALT, AST, TG, TC, LDL-c and HDL-c. Liver dysfunction and dyslipidemia were confirmed in DSS-induced colitis mice. We fed mice with MCD for 14 days to cause mild liver damage, and then treated with DSS for 7 days. We found that MCD intake significantly exacerbated the pathogenesis of mucosal inflammation in DSS-induced acute, progressive, and chronic colitis, referring to promotion of mucosal ulcers, colon shortening, diarrhea, inflammatory immune cell infiltration, cytokines release, and abnormal activation of inflammatory macrophages in colon and liver specimens. Intraperitoneal injection of clodronate liposomes to globally delete macrophages dramatically compromised the pathogenesis of MCD-triggering colitis. In addition, MCD intake markedly changed the production pattern of short-chain fatty acids (SCFAs) in murine stools, colons, and livers. We demonstrated that MCD-induced colitis pathogenesis largely depended on the gut microbes and the disease phenotypes could be transmissible through fecal microbiota transplantation (FMT). In conclusion, this study supports the concept that intake of MCD predisposes to experimental colitis and enhances its pathogenesis via modulating gut microbes and macrophages in mice.

The integrated analysis of digestive physiology and gastrointestinal microbiota structure in Changle goose

Changle goose in Fujian, China is a rare genetic resource and in urgent need to be protected. Understanding the characteristics of digestive physiology and spatial variation of gastrointestinal microbiota is crucial for developing nutritional intervention strategies to improve intestinal health and production performance of goose. Hence, histomorphological assay was used for observing development status of proventriculus, jejunum, and cecum in 70-day-old Changle geese, whereas digesta from 6 alimentary canal locations (crop, proventriculus, gizzard, jejunum, cecum, and rectum) were collected for 16S rRNA gene sequencing and short chain fatty acids (SCFAs) quantitative analysis. The histomorphological observation indicated that the jejunum and cecum of Changle goose were well developed. The alpha diversity analysis revealed that, except rectum, microbiota in other noncecum sections were in high diversity as cecum. The Nonmetric MultiDimensional Scaling (NMDS) analysis showed that microbial community of proventriculus, gizzard, and jejunum formed a cluster, which distinctly discrete with the microbiota of the other gastrointestinal locations. Additionally, the proportions of Proteobacteria, Bacteroidota, and Campilobacterota at the phylum level and Lactobacillus, Streptococcus, Helicobacter, and Subdoligranulum at the genus level exhibited tremendous alternations among different gastrointestinal locations. The characteristic bacterial composition in each section was further disclosed by analyzing the core and feature Amplicon Sequence Variants (ASVs) and SCFAs pattern. Importantly, 7 body-weight-associated ASVs and 2 cecum-development-related ASVs were identified via correlation analysis. In a whole, our findings provided the first insights into the specialized digestive physiology of Changle geese and distinctive regional distribution of gastrointestinal microbiota, which laid the important foundation for improving growth performance through microbiota manipulation in geese.

Low Concentration of Fecal Valeric Acid at 1 Year of Age Is Linked with Eczema and Food Allergy at 13 Years of Age: Findings from a Swedish Birth Cohort

Background: Short-chain fatty acids (SCFAs) are abundant bacterial metabolites in the gut, with immunomodulatory properties. Hence, they may influence allergy development. Previous studies have linked fecal SCFA pattern during infancy with allergy. However, the association of SCFAs to allergic outcomes in adolescence is not well established. Here, we examined how the fecal SCFA pattern at 1 year of age related to allergy at 13 years of age. Methods: Levels of 8 SCFAs in fecal samples collected at 1 year of age from 110 children were quantified using gas chromatography. The same individuals were evaluated at 13 years of age for allergic symptoms, allergy diagnosis and allergy medication by questionnaire, and for sensitization using skin prick test against egg, milk, fish, wheat and soy, cat, dog, horse, birch, and timothy grass. Results: The concentration of fecal valeric acid at 1 year of age was inversely associated with eczema at 13 years of age (OR 0.6, 95% CI: 0.4–1.0, p = 0.049) and showed a trend for inverse association with food allergy at 13 years of age (OR 0.6, 95% CI: 0.4–1.0, p = 0.057). In a sub-group analysis of children with eczema at 1 year of age, a higher concentration of fecal valeric acid was linked with reduced risk of their eczema remaining at 13 years of age (OR 0.2, 95% CI: 0.0–1.5), although this latter analysis did not reach statistical significance (p = 0.12). Conclusions: Our findings lend further support to the notion of early childhood as a critical period when allergy may be programmed via the gut microbiota. Higher levels of fecal valeric acid may be characteristic of a protective gut microbiota and/or actively contribute to protection from eczema and food allergy.

Influence of Human Age on the Prebiotic Effect of Pectin-Derived Oligosaccharides Obtained from Apple Pomace

The aim of this study was to evaluate the prebiotic effect of pectin-derived oligosaccharides (POS) obtained from apple pomace on the growth and metabolism of microbiota from the human gastrointestinal tract as a function of the age of the host. The counts of major bacterial groups Bifidobacterium sp., lactobacilli, Clostridium sp., Bacteroides sp., Enterococcus sp. and Enterobacteria were assessed during long-term in vitro fermentation of mixed cultures in a prebiotic medium. Comparative assessment of bacterial diversity in the human fecal microbiota was performed relative to the age of the host, from childhood to old age, through younger years and middle age. The age group of the host was found to be an important factor that determined the prebiotic effect of POS, which was related to both the qualitative and quantitative composition of fecal microbiota and its metabolism. In contrast to the microbiota of elderly subjects, the child-derived intestinal microbiota underwent significantly different alterations in terms of the proportion and composition of lactic acid bacteria, leading to a more favorable pattern of short-chain fatty acids (SCFA) and lactic acid levels.

Decreased Intestinal Microbiome Diversity in Pediatric Sepsis: A Conceptual Framework for Intestinal Dysbiosis to Influence Immunometabolic Function.

The intestinal microbiome can modulate immune function through production of microbial-derived short-chain fatty acids. We explored whether intestinal dysbiosis in children with sepsis leads to changes in microbial-derived short-chain fatty acids in plasma and stool that are associated with immunometabolic dysfunction in peripheral blood mononuclear cells. Prospective observational pilot study. Single academic PICU. Forty-three children with sepsis/septic shock and 44 healthy controls. Stool and plasma samples were serially collected for sepsis patients; stool was collected once for controls. The intestinal microbiome was assessed using 16S ribosomal RNA sequencing and alpha- and beta-diversity were determined. We measured short-chain fatty acids using liquid chromatography, peripheral blood mononuclear cell mitochondrial respiration using high-resolution respirometry, and immune function using ex vivo lipopolysaccharide-stimulated whole blood tumor necrosis factor-α. Sepsis patients exhibited reduced microbial diversity compared with healthy controls, with lower alpha- and beta-diversity. Reduced microbial diversity among sepsis patients (mainly from lower abundance of commensal obligate anaerobes) was associated with increased acetic and propionic acid and decreased butyric, isobutyric, and caproic acid. Decreased levels of plasma butyric acid were further associated with lower peripheral blood mononuclear cell mitochondrial respiration, which in turn, was associated with lower lipopolysaccharide-stimulated tumor necrosis factor-α. However, neither intestinal dysbiosis nor specific patterns of short-chain fatty acids were associated with lipopolysaccharide-stimulated tumor necrosis factor-α. Intestinal dysbiosis was associated with altered short-chain fatty acid metabolites in children with sepsis, but these findings were not linked directly to mitochondrial or immunologic changes. More detailed mechanistic studies are needed to test the role of microbial-derived short-chain fatty acids in the progression of sepsis.

Key bacterial taxa and metabolic pathways affecting gut short-chain fatty acid profiles in early life

Infant gut microbiota development affects the host physiology throughout life, and short-chain fatty acids (SCFAs) are promising key metabolites mediating microbiota-host relationships. Here, we investigated dense longitudinally collected faecal samples from 12 subjects during the first 2 years (n = 1048) to identify early life gut SCFA patterns and their relationships with the microbiota. Our results revealed three distinct phases of progression in the SCFA profiles: early phase characterised by low acetate and high succinate, middle-phase characterised by high lactate and formate and late-phase characterised by high propionate and butyrate. Assessment of the SCFA–microbiota relationships revealed that faecal butyrate is associated with increased Clostridiales and breastfeeding cessation, and that diverse and personalised assemblage of Clostridiales species possessing the acetyl-CoA pathway play major roles in gut butyrate production. We also found an association between gut formate and some infant-type bifidobacterial species, and that human milk oligosaccharides (HMO)-derived fucose is the substrate for formate production during breastfeeding. We identified genes upregulated in fucose and fucosylated HMO utilisation in infant-type bifidobacteria. Notably, bifidobacteria showed interspecific and intraspecific variation in the gene repertoires, and cross-feeding of fucose contributed to gut formate production. This study provides an insight into early life SCFA–microbiota relationships, which is an important step for developing strategies for modulating lifelong health.

Fecal short chain fatty acids in children living on farms and a link between valeric acid and protection from eczema

Children growing up on farms have low rates of allergy, but the mechanism for this protective effect has not been fully elucidated. Short chain fatty acids (SCFAs) produced by the gut microbiota may play a role in protection from allergy. We measured fecal SCFA levels in samples collected from 28 farming and 37 control children over the first 3 years of life using gas chromatography. Data on diet and other host factors were recorded and allergy was diagnosed at 8 years of age. Among all children, median propionic and butyric acid concentration increased over the first 3 years, and longer SCFAs typically appeared by 1 year of age. Farm children had higher levels of iso-butyric, iso-valeric and valeric acid at 3 years of age than rural controls. In addition, children with elder siblings had higher levels of valeric acid at 3 years of age, and dietary factors also affected SCFA pattern. High levels of valeric acid at 3 years of age were associated with low rate of eczema at 8 years of age. The fecal SCFA pattern in farm children suggests a more rapid maturation of the gut microbiota. Valeric acid or associated microbes may have protective potential against eczema.

Distinct patterns of short-chain fatty acids during flare in patients with ulcerative colitis under treatment with mesalamine or a herbal combination of myrrh, chamomile flowers, and coffee charcoal: secondary analysis of a randomized controlled trial.

Short-chain fatty acids are involved in the regulation of the gut immune system. In ulcerative colitis, short-chain fatty acids are often reduced, especially during flare. This study evaluated exploratively the pattern of butyrate and total short-chain fatty acids in patients with ulcerative colitis during flare treated either with mesalamine or a herbal preparation consisting of myrrh, chamomile flowers, and coffee charcoal which showed promising results in maintaining remission in a randomized double-blind, double-dummy, controlled clinical trial (EudraCT-Number 2007-007928-18). Patients were treated with the herbal preparation or mesalamine. Clinical activity was monitored by Clinical Colitis Activity Index. Using gas chromatography, we analyzed fecal samples of 38 patients who experienced a flare during treatment. Paired t-test showed a significant decline of total short-chain fatty acids [M before = 66.12, SD = 39.59; M after = 29.83, SD = 15.05; 95% bootstrap confidence interval (20.53-55.30); P = 0.01) and of butyrate [M before 11.35, SD = 7.56; M after = 6.50, SD = 3.55; 95% bootstrap confidence interval (2.06-8.11); P = 0.02] in the event of a flare for patients treated with mesalamine but not for patients treated with the herbal preparation. Patients who received the herbal preparation did not show a significant decline of total short-chain fatty acids in the event of a flare. Since a decline of short-chain fatty acids might lead to unfavorable health impairments, a combination of the two treatments should be further investigated.

Distribution of Short-chain Aliphatic Aldehydes in the Gastrointestinal Tract of Pigs (P06-033-19)

ObjectivesThe presence of short-chain aliphatic aldehydes (SCAAs), including acetaldehyde, propanal, butanal, and pentanal, in food has been detected. In addition, the production of SCAAs in the alimentary digestion of food has also been observed. However, the distribution of these SCAAs in the gastrointestinal tract (GIT) has not been defined previously. This study aimed to examine the distributions of SCAAs and their corresponding short chain fatty acids (SCFAs) in the GIT of pigs. MethodsDigesta samples were collected from the stomach, duodenum, jejunum, ileum, cecum, and rectum of 14 finishing barrows fed corn-soybean meal. The SCAAs and SCFAs in these samples were quantified by the liquid chromatography-mass spectrometry analysis, and their distribution in the GIT was further modeled by principal components analysis. ResultsSCAAs were far more abundant in the upper GIT than the lower GIT, with the highest concentrations of acetaldehyde and propanal in the stomach and the highest concentrations of butanal and pentanal in the duodenum and jejunum. In contrast, SCFAs were mainly present in the lower GIT, especially in the large intestine. ConclusionsThe digestive activities in the upper GIT can produce significant amounts of SCAAs, which were mostly eliminated in the lower GIT. The converse distribution patterns of SCAAs and SCFAs in the GIT suggested that some SCAAs may be oxidized into SCFAs in the large intestine through microbial metabolism. Funding SourcesThis study is partially supported by the AES project MIN-18-092.

Effect of Vancomycin, Tylosin, and Chlortetracycline on Vancomycin-Resistant Enterococcus faecium Colonization of Broiler Chickens During Grow-Out.

Broiler chickens may serve as reservoirs for human colonization by vancomycin-resistant Enterococcus (VRE). We examined the effects of vancomycin and two commonly used antimicrobial feed additives on VRE colonization in broiler chickens during grow-out. Chicks received unsupplemented feed or feed containing vancomycin, chlortetracycline, or tylosin from day of hatch to grow-out at 6 weeks. At 3 days of age, chicks received by crop gavage 107 colony-forming units (CFUs) of a human or poultry VRE isolate. Cecal contents were monitored weekly for VRE, short-chain fatty acids (SCFAs), and bacterial denaturing gradient gel electrophoresis (DGGE) profile methods. Vancomycin promoted persistent and high-level colonization with human- and poultry-derived VRE to grow-out in comparison with controls, while treatment with chlortetracycline and tylosin did not. Colonization by the poultry isolate in control, chlortetracycline, and tylosin groups persisted throughout the grow-out period with low concentrations present at 6 weeks, whereas the human isolate decreased to an undetectable level by week 6. Vancomycin resulted in significant reductions in cecal acetic acid and butyric acid in comparison with controls, but chlortetracycline and tylosin did not. DGGE profiles contained two main clusters with all vancomycin profiles in a smaller cluster and all other profiles in a larger cluster. These results demonstrate that vancomycin, but not chlortetracycline or tylosin, disrupted the indigenous microbiota and SCFA patterns of broiler chickens and promoted colonization by VRE.

Oral Lichen Planus and Features in the Short Chain Fatty Acid Pattern Produced by Colonic Fermentation

Oral Lichen Planus and Features in the Short Chain Fatty Acid Pattern Produced by Colonic Fermentation

The effects of oats on the function of gut microflora in children with coeliac disease

Faecal short chain fatty acids (SCFAs) are produced by the gut microflora. We have previously reported high faecal SCFA levels in children with coeliac disease (CD), indicating alteration in gut microfloral metabolism. Data accumulated over recent decades by us and others suggest that wheat-free oats can safely be included in a gluten-free diet (GFD). However, concerns have been raised with respect to the safety of oats in a subset of coeliacs. To describe faecal SCFA patterns in children with newly diagnosed CD treated for 1 year with a GFD with or without oats. This report is part of a randomised, double-blind study on the effect of a GFD containing oats (GFD-oats) vs. a standard GFD (GFD-std). Faecal samples were received from 34 children in the GFD-oats group and 37 in the GFD-std group at initial diagnosis and/or after 1 year on a GFD. Faecal SCFAs were analysed. The GFD-std group had a significantly lower total faecal SCFA concentration at 12 months compared with 0 months (P < 0.05). In contrast, total SCFA in the GFD-oats group remained high after 1 year on the GFD. The children in the GFD-oats group had significantly higher acetic acid (P < 0.05), n-butyric acid (P < 0.05) and total SCFA concentration (P < 0.01) after 1-year diet treatment compared to the GFD-std group. Our results indicate that oats do affect the gut microflora function, and that some coeliac children receiving oats may develop gut mucosal inflammation, that may present a risk for future complications.

High-Fat Diet Reduces the Formation of Butyrate, but Increases Succinate, Inflammation, Liver Fat and Cholesterol in Rats, while Dietary Fibre Counteracts These Effects

IntroductionObesity is linked to type 2 diabetes and risk factors associated to the metabolic syndrome. Consumption of dietary fibres has been shown to have positive metabolic health effects, such as by increasing satiety, lowering blood glucose and cholesterol levels. These effects may be associated with short-chain fatty acids (SCFAs), particularly propionic and butyric acids, formed by microbial degradation of dietary fibres in colon, and by their capacity to reduce low-grade inflammation.ObjectiveTo investigate whether dietary fibres, giving rise to different SCFAs, would affect metabolic risk markers in low-fat and high-fat diets using a model with conventional rats for 2, 4 and 6 weeks.Material and MethodsConventional rats were administered low-fat or high-fat diets, for 2, 4 or 6 weeks, supplemented with fermentable dietary fibres, giving rise to different SCFA patterns (pectin – acetic acid; guar gum – propionic acid; or a mixture – butyric acid). At the end of each experimental period, liver fat, cholesterol and triglycerides, serum and caecal SCFAs, plasma cholesterol, and inflammatory cytokines were analysed. The caecal microbiota was analysed after 6 weeks.Results and DiscussionFermentable dietary fibre decreased weight gain, liver fat, cholesterol and triglyceride content, and changed the formation of SCFAs. The high-fat diet primarily reduced formation of SCFAs but, after a longer experimental period, the formation of propionic and acetic acids recovered. The concentration of succinic acid in the rats increased in high-fat diets with time, indicating harmful effect of high-fat consumption. The dietary fibre partly counteracted these harmful effects and reduced inflammation. Furthermore, the number of Bacteroides was higher with guar gum, while noticeably that of Akkermansia was highest with the fibre-free diet.

Faecal short-chain fatty acid pattern in childhood coeliac disease is normalised after more than one year's gluten-free diet.

ObjectiveRecent work indicates that the gut microflora is altered in patients with coeliac disease (CD). Faecal short-chain fatty acids (SCFAs) are produced by the gut microflora. We have previously reported a high SCFA output in children with symptomatic and asymptomatic CD at presentation, as well as in CD children on a gluten-free diet (GFD) for less than 1 year, indicating deviant gut microfloral function. In this report, we focus on faecal SCFA production in coeliacs on GFD for more than 1 year.Materials and methodsFaecal samples were collected from 53 children with CD at presentation, 74 coeliac children on GFD for less than 1 year, and 25 individuals diagnosed with CD in childhood and on GFD for more than 1 year. The control group comprised 54 healthy children (HC). The faecal samples were analysed to show the SCFA pattern taken as a marker of gut microflora function. We applied a new fermentation index, reflecting the inflammatory activity of the SCFAs (amount of acetic acid minus propionic acid and n-butyric acid, together divided by the total amount of SCFAs).ResultsIn coeliacs on GFD for more than 1 year, the individual SCFAs, total SCFA, and fermentation index did not differ significantly from the findings in controls. In contrast, the faecal SCFA level was clearly higher in coeliacs treated with GFD for less than 1 year compared to those more than 1 year.ConclusionsThis is the first study on SCFA patterns in faecal samples from individuals with CD on GFD for more than 1 year. Our study indicates that the disturbed gut microflora function in children with CD at presentation and after less than 1 year of GFD, previously demonstrated by us, is normalised on GFD for more than 1 year.

Increase of Faecal Tryptic Activity Relates to Changes in the Intestinal Microbiome: Analysis of Crohn's Disease with a Multidisciplinary Platform

ObjectiveTo investigate—by molecular, classical and functional methods—the microbiota in biopsies and faeces from patients with active Crohn's disease (CD) and controls.DesignThe microbiota in biopsies was investigated utilizing a novel molecular method and classical cultivation technology. Faecal samples were investigated by classical technology and four functional methods, reflecting alterations in short chain fatty acids pattern, conversion of cholesterol and bilirubin and inactivation of trypsin.ResultsBy molecular methods we found more than 92% similarity in the microbiota on the biopsies from the two groups. However, 4.6% of microbes found in controls were lacking in CD patients. Furthermore, NotI representation libraries demonstrate two different clusters representing CD patients and controls, respectively. Utilizing conventional technology, Bacteroides (alt. Parabacteroides) was less frequently detected in the biopsies from CD patients than from controls. A similar reduction in the number of Bacteroides was found in faecal samples. Bacteroides is the only group of bacteria known to be able to inactivate pancreatic trypsin. Faecal tryptic activity was high in CD patients, and inversely correlated to the levels of Bacteroides.ConclusionsCD patients have compositional and functional alterations in their intestinal microbiota, in line with the global description hypothesis rather than the candidate microorganism theory. The most striking functional difference was high amount of faecal tryptic activity in CD patients, inversely correlated to the levels of Bacteroides in faeces.

Effect of exclusive enteral nutrition on gut microflora function in children with Crohn's disease

Objective.Exclusive enteral nutrition (EEN) is a first-line treatment in children with active Crohn's disease (CD) but is seldom used in adults with active disease. The mode of action of EEN in suppressing mucosal inflammation is not fully understood, but modulation of intestinal microflora activity is one possible explanation. The aim of this study was to investigate the effect of 6-week EEN in children with active CD, with special reference to intestinal microflora function. Materials and methods.Fecal samples from 18 children (11 boys, 7 girls; median age 13.5 years) with active CD (13 children with small bowel/colonic and 5 with perianal disease) were analyzed for short chain fatty acid (SCFA) pattern as marker of gut microflora function. The children were studied before and after EEN treatment. Results from 12 healthy teenagers were used for comparison. Results.Eleven (79%) of the children with small bowel/colonic CD responded clinically positively to EEN treatment showing decreased levels of pro-inflammatory acetic acid as well as increased concentrations of anti-inflammatory butyric acids and also of valeric acids, similar to the levels in healthy age-matched children. In children with active perianal CD, however, EEN had no positive effect on clinical status or inflammatory parameters. Conclusions.The authors present new data supporting the hypothesis that the well-documented anti-inflammatory effect of EEN in children with active small bowel/colonic CD is brought about by modulation of gut microflora activity, resulting in an anti-inflammatory SCFA pattern. By contrast, none of the children with perianal disease showed clinical or biochemical improvement after EEN treatment.

Determination of the short–chain fatty acid pattern in biodiesel using high throughput syringe solvent extraction and ion exclusion chromatography

A simple, robust, and sensitive technique to determine the distribution of short–chain fatty acids (SCFA) in biodiesel and their relative contribution to the total acid number (TAN) was developed. The method is based on miniaturized volume extractions in order to (1) remove the diesel background and transfer the acids to an aqueous phase for robust ion exclusion chromatography with conductivity detection, and (2) regulate the sensitivity of the method so that it fits the concentrations for both aged and un aged biodiesel down to trace levels. The quick extraction (10s) resulted in extraction recoveries from 90% to 100% for the six acids evaluated and the overall method precision from extraction to detection was at most 2.3% (relative standard deviation) for the tested acids (lactic–valeric). The suggested standard method covers SCFA concentrations from 0.1mg/kg to ∼985mg/kg but can be extended to 2μg/kg by alteration of the extraction properties and sample loop size (injection volume). In order to demonstrate the usefulness of the method, unaged and aged rapeseed (B100) biodiesel were analyzed. The inherent characteristic short–chain fatty acid pattern for unaged biodiesel include lactic, formic acetic and propionic acid that all together initially constituted 33mol% of the TAN in the specific rape seed biodiesel tested in this study. After 14days of aging in 80°C freely exposed to dry air, lactic acid concentration in the biodiesel was unaltered while formic, acetic and propionic acids increased altogether to reach over 50mol% of the TAN. Formic acid alone contributed 42mol% of the TAN which corresponded to an increase in absolute terms of 15mg/kg to >300mg/kg after aging. Longer acids such as butyric and valeric acids as well as branched isomers were not found in the tested biodiesel sample but will be detected by the proposed method if present.

Screening-detected and symptomatic untreated celiac children show similar gut microflora-associated characteristics

Objective. The aim of this study was to investigate the metabolic function of intestinal microflora in children with screening-detected celiac disease (CD) to see if there is an aberrant gut flora in screening-detected CD similar to symptomatic CD and contrary to healthy controls. Materials and methods. As part of a Swedish multicenter screening for CD, 912 12-year-old children were screened with serum anti-human tissue transglutaminase-IgA. Small bowel biopsy specimens from children with positive serology revealed 17 individuals with CD. The functional status of the intestinal microflora was evaluated by gas–liquid chromatography of short chain fatty acids (SCFAs) in fecal samples. Our previously published findings in children with symptomatic CD and healthy controls were used as comparison. Results. The children with screening-detected CD had a similar fecal SCFA profile to children with symptomatic CD, but differed significantly from that in healthy children. Conclusions. This is the first study on SCFA patterns in fecal samples from children with screening-detected CD. The similarity of the fecal SCFA profile in screening-detected and symptomatic CD indicates common pathogenic mechanisms. This could open the way for new therapeutic or prophylactic measures based on novel biological principles.

Probiotic therapy to men with incipient arteriosclerosis initiates increased bacterial diversity in colon: A randomized controlled trial

Objective This study aimed to clarify the microbial change in the intestinal microbiota in patients, with cardiovascular disease, consuming a drink with high numbers of live Lactobacillus plantarum. Methods Sixteen males, with atherosclerotic plaque on the carotid wall, were randomly selected from a larger cohort and included in this double blind, placebo controlled study. Colonic biopsies, taken before and after four weeks of probiotic treatment, were analysed with Terminal Restriction Fragment Length Polymorphism, including digestion with MspI and HaeIII. Microbial diversity was calculated, short-chain fatty acids in faeces, and blood markers were analysed. Results Consumption of one probiotic strain of L. plantarum (DSM 9843) increased intestinal microbial diversity. The probiotic group had an increased diversity after consumption of the probiotic drink compared to the change in the placebo group when Shannon and Weaner diversity index ( MspI and HaeIII, p = 0.026) and Simpson index of diversity ( MspI, p = 0.044 and HaeIII, p = 0.026) were calculated. The fermentation pattern of short-chain fatty acids in faeces were unaffected for most acids, but the probiotic group had decreased concentration of isovaleric acid ( p = 0.006) and valeric acid ( p = 0.029). Viable count of lactobacilli increased in the probiotic group ( p = 0.001), but no significant changes in blood markers were observed. Conclusion Administration of a single-strain probiotic increases the bacterial diversity in the gut, and affects the concentration of some short-chain fatty acids. Consumption of the single strain L. plantarum DSM 9843 might be a strategy to favour a diverse intestinal microbiota, which is beneficial for the host.