Fecal short-chain fatty acid and dysbiosis in dogs with chronic enteropathy

Background: Short chain fatty acids (SCFAs) are the microbially-derived end products of dietary fiber fermentation. The SCFA butyrate is a signaling molecule shown to influence blood pressure (BP) in mouse models. The association of butyrate and other SCFAs on BP in humans is unclear, due in part to predominantly cross-sectional analyses and to differences in which biospecimens (blood vs. fecal) SCFAs were measured. Longitudinal studies including both circulating and fecal SCFAs are lacking. Objective: Investigate the cross-sectional and longitudinal associations of fecal and serum SCFAs with hypertension and changes in BP. Methods: We leveraged existing data from the SPIRIT trial, which randomized 121 adult cancer survivors with overweight/obesity to a behavioral weight loss intervention, metformin, or self-directed weight loss. Of participants with serum and fecal SCFAs measured at baseline (N=111), a subset also had serum (N=93) and fecal (N=89) SCFA measurements 12 months later. We used Poisson regression with robust error variance to estimate associations of serum or fecal SCFAs with hypertension at baseline (adjusting for age, sex, BMI, and fiber intake). In longitudinal analyses, we assessed the percent change in serum or fecal SCFAs from baseline with corresponding 12-month changes in BP (covariates listed in Table ). Results: Participants were aged 60.2±8.9 years, 78.4% female, and 46.9% identified as White. Higher baseline fecal butyrate was inversely associated with prevalent hypertension (standardized PR [95%CI]: 0.71 [0.54, 0.92]). In longitudinal analyses ( Table ), a 10% increase in fecal butyrate from baseline levels was significantly and inversely associated with systolic BP, and a 10% increase in serum butyrate was significantly and inversely associated with systolic and diastolic BPs. Associations of butyrate with BP were not modified by sex or race. Conclusion: Increased serum or fecal butyrate is associated with lowered BP. Butyrate may be a target for SCFA-centered BP-lowering interventions.

BackgroundProton pump inhibitors can cause diarrhea and a transient increase in fecal dysbiosis index in dogs. It is unknown if concurrent probiotic administration mitigates these effects.Objective/HypothesisTo assess the fecal Canine Microbial Dysbiosis Index (CMDI), fecal short chain fatty acid (SCFA), and fecal calprotectin concentrations in dogs administered esomeprazole with and without a probiotic.AnimalsEleven healthy dogs.MethodsProspective, within‐subjects before and after study. All dogs received 7‐day courses of esomeprazole (1 mg/kg PO q 24h) alone followed by esomeprazole with a probiotic (15 billion CFU/kg), separated by a 4‐week washout period. Data were compared between phases using mixed effects ANOVA or generalized estimating equations with post‐hoc Holm adjustment for 2‐way comparisons.ResultsCompared to baseline (mean CMDI −2.66, SD 3.04), fecal CMDI was not different with esomeprazole administration alone (mean CMDI −1.48, SD 3.32, P = .08), but there was a significant increase (Diff 3.05, 95% CI [1.37, 4.74], P < .001, Effect size 2.02) when esomeprazole and a probiotic were administered concurrently (mean CMDI 0.39, SD 2.83). CMDI was significantly higher when esomeprazole was administered with a probiotic than alone (Diff 1.87, 95% CI [0.19, 1.87], P = .02, Effect size 1.24). Fecal calprotectin and SCFA concentrations did not differ between phases. The occurrence of vomiting and diarrhea was not different from baseline when esomeprazole was administered alone (36%/27%) or with a probiotic (46%/9%).Conclusions and Clinical ImportanceIn healthy dogs, concurrent administration of a probiotic is unlikely to lessen adverse effects associated with esomeprazole administration.

Short chain fatty acids (SCFA) have been associated with improved glycemia and to reductions in inflammatory responses in cell and rodent models. Low grade inflammation has been associated with insulin resistance. We measured fecal and plasma SCFA and inflammatory biomarkers in response to a proprietary oligosaccharide intervention. 22 overweight and obese men and women participated in a three‐way crossover study that included 3 levels of oligosaccharide: 0, 15 and 30 g/d. for 3 weeks. During each treatment, a collection of 5 days' feces were combined and analyzed for SCFA. At the end of each treatment, a meal challenge protocol was employed in which participants consumed half their daily dose of oligosaccharide with breakfast followed by a standard lunch. We measured plasma acetate, propionate and butyrate in 12 blood draws over the course of a 9 hour test day and inflammatory cytokines at 3 time points, 0, 195 and 435 min following the breakfast test meal. All SCFA analyses were conducted by GC‐MS. Inflammatory cytokines were measured on an 8‐plex chemiluminescent MSD plate except for adiponectin and CRP which employed an Integra 400 bio‐analyzer. Breath hydrogen and methane were collected to characterize participants as either methane producers (MP) or non‐producers (NM). Adiponectin was positively associated with fecal SCFA (p&lt;0.05). TNF‐α and IL‐10 were negatively associated with various plasma SCFA AUC segments (p&lt;0.05). Neither CRP nor IL‐6 was associated with either fecal or plasma SCFA. Fecal SCFA concentrations did not correlate well with plasma SCFA AUCs. Fecal propionate and butyrate were lower in MP than NM. Breath methane was negatively associated with SCFA production in MP. Plasma and fecal SCFA may predict some inflammatory responses but differences in the time of collections and the span of collections may reflect different temporal relationships to cytokines.Support or Funding InformationFunding provided by USDA CRIS 2032‐51530‐022‐OOD and the West Coast Metabolomics Center (U24 DK097154)

Introduction: Fecal lactic acid (LA) and short chain fatty acids (SCFA) are produced from fermented unabsorbed carbohydrates by colonic bacterial flora. Recent studies show LA and SCFAs have anti-inflammatory and immunological effects on the gastrointestinal tract. It is known that the differences of intestinal microflora are reflected of the profile of fecal SCFAs. On the other hand, a previous study reported the colonic luminal concentration of butyric acid which is one of the SCFA might be a factor in the etiology of necrotizing enterocolitis (NEC). However, very few studies have been carried out about the beneficial effect of probiotics on fecal SCFA profile especially in premature infants. The aim of this study is to examine the effect of enteral administration of Bifidobacterium breve (B. breve) on fecal LA and SCFA profile in low birth weight infants (LBWI). Methods: Forty eight infants were enrolled in the study, who were divided into three groups depending on their birth weight; 11 term infants (Group I; mean birth weight, 3062g; mean gestational age, 39.5 weeks), 21 LBWI (Group II; mean birth weight, 1812g; mean gestational age, 33.7 weeks) and 16 very low birth weight infants (VLBWI) (Group III; mean birth weight, 1277g; mean gestational age, 31.1 weeks). Fecal samples were collected at three periods; 1–7, 8–14 and 21–35 days of age. LA and SCFA (aceteic acid; AA, propionic acid and butyric acid; BA) concentration were analyzed using high performance liquid chromatography. Additionally both of Group II and Group III were divided into two groups; B. breve administration group (B+; n= 11 in Group II, 11 in Group III) and control group (B− n=10 in Group II, 5 in Group III), respectively. A dose of 1.6×108 cells were administrated to B. breve group twice per day from 1 day of age before feeding. Results: Fecal AA concentrations on 21–35 days were significantly higher than those on 1–7 days in Group I and II. On 21–35 days of age, (1) fecal LA and AA concentrations of Group I were significantly higher than those of Group III (p<0.01, p<0.05, respectively); (2) the fecal AA ratio to total fecal SCFA in B+ infants was significantly higher than that in B− infants in Group II and Group III (p<0.05); (3) the concentration and ratio of fecal BA in B+ infants were significantly lower than those in B− infants in Group III (p<0.01). Conclusion: Our results indicated that enteral administration of B. breve augmented the fecal level of LA and AA in LBWI. Furthermore it reduced the level of BA in VLBWI but not in LBWI. These differences might be associated with the colonization by bifidobacteria in the gastrointestinal tract. Our study suggests that early administration of B. breve to VLBWI prevents them from the development of NEC.

BackgroundSome probiotics have hypocholesterolemic effects in animal studies, which are mediated, in part, by increases in fecal short chain fatty acids (SCFAs). Clinical trials of probiotics on lipids/lipoproteins are inconsistent.ObjectiveWe examined the effects of Bifidobacterium animalis subsp. lactis BB-12® (BB-12®) (3.16 × 109 CFUs/day) on lipids and lipoproteins and fecal excretion of SCFAs in healthy adults.MethodsIn a randomized, partially blinded, 4-period, crossover study, 30 adults (11 men, 19 women) aged 18–40 years were randomly assigned to: 1) yogurt smoothie with no BB-12® (YS), 2) yogurt smoothie with BB-12® added pre-fermentation (PRE), 3) yogurt smoothie with BB-12® added post-fermentation (POST), 4) BB-12® containing capsule (CAP). We measured serum lipids/lipoproteins, glucose, insulin, C-reactive protein (CRP), and fecal SCFAs at baseline and after each treatment period.ResultsTotal cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides (TGs) did not differ after the PRE, POST, and CAP periods versus the YS or between treatments. Compared to baseline, fecal acetate was significantly increased after the YS (Δ = 211.89 ± 75.87 μg/g, P = 0.007) and PRE (Δ = 204.98 ± 75.70 μg/g, P = 0.009) periods. The percent increase in fecal acetate was significantly greater after the YS versus the POST period (52.2 ± 13.2% vs. 24.5 ± 13.2%, P = 0.023). Fecal total SCFAs, propionate and butyrate did not differ between treatment periods. Fecal total SCFAs were negatively associated with TC (r = -0.22, P = 0.01), LDL-C (r = -0.24, P = 0.004), age (r = -0.33, P < 0.001), and waist circumference (r = -0.25, P = 0.003).ConclusionsBB-12® supplementation did not improve lipids, lipoproteins and total and individual fecal SCFAs. Fecal SCFAs were negatively associated with TC, LDL-C, age, and waist circumference.Trial registrationThis trial was registered at clinicaltrials.gov as NCT01399996.

Age, Dietary Fiber, Breath Methane, and Fecal Short Chain Fatty Acids Are Interrelated in Archaea-Positive Humans1–3

Short-chain fatty acids (SCFA) in faeces were examined in 18 patients with the irritable bowel syndrome (IBS) during treatment with wheat bran or placebo. In the placebo period, the patients could be classified in accordance with the faecal concentrations of SCFA into one group with low concentrations (mean, 40 mmol/l; range, 19-77 mmol/l; 10 patients) and another with high concentrations (mean, 168 mmol/l; range, 145-187 mmol/l; 8 patients). The concentrations of SCFA differed (P less than 0.001) in both groups from concentrations found in faeces from a reference group of nine normal individuals (mean, 114 mmol/l; range, 93-155 mmol/l). Patients with low levels of SCFA had lower (P less than 0.001) mean stool mass and longer (P less than 0.05) transit times than those with high concentrations of SCFA in faeces. Ingestion of bran, although a precursor of SCFA, did not change faecal concentrations of SCFA. Abdominal pain, distension, and rumbling were not correlated to low or high concentrations of SCFA in faeces, nor did bran improve these symptoms when compared to placebo. The level of SCFA was rather constant intraindividually and independent of the variability of the daily faecal mass. It is concluded that patients with IBS apparently have continuously abnormal concentrations of SCFA in faeces, either high or low, which are unaffected by the treatment with bran and which hypothetically may be of pathophysiologic importance.

Construction of an ileal reservoir changes the fecal bacterial flora and the fecal composition of bile acids and short-chain fatty acids. We examined the relationships between pouch inflammation (pouchitis) and pouch content, as assessed by analysis of fecal bacteria, bile acids, and short chain fatty acids. Four groups were studied: ileal pouch-anal anastomosis (IPAA) for ulcerative colitis with pouchitis (N = 10), IPAA without pouchitis (N =5), IPAA for familial adenomatous polyposis without pouchitis (N = 5); and Brooke ileostomy for ulcerative colitis, which served as controls (N = 5). Pouchitis was defined as > or = 7 points on an 18-point pouchitis disease activity index. Aerobic and anaerobic bacteria were quantitatively cultured. Total aqueous-phase bile acids were measured by thin-layer chromatography and an enzymatic 3 alpha-OH hydroxysteroid dehydrogenase method. Fecal short chain fatty acids were measured by gas liquid chromatography. All patients with an IPAA had higher ratios of anaerobes/aerobes and concentrations of anaerobic gram-negative rods than did patients with an ileostomy. There were no other differences between patient groups with respect to bacteria, aqueous-phase total bile acids, or fecal short-chain fatty acids. Fecal concentrations of bacteria, bile acids, and short-chain fatty acids were similar in patients with and without pouchitis, indicating that these factors can not be the sole cause of pouchitis.

Background: Short-chain fatty acids (SCFAs), mostly found in colon feces, is an important group of gut microbial metabolites from anaerobic fermentation of indigestible carbohydrates. Objectives: To develope an HPLC method to determined SCFAs in rat feces treated with resistant starch. Materials and methods: Sample is the rat feces fed with acetate wheat starch and normal starch; fatty acid hydrazides are derived from SCFAs in feces and measured by HPLC. After validated as guidance of US-FDA, method is applied to identify SCFAs in rat treated two types of starch. Results: the HPLC condition was optimized as follow: Eclipse XDB–C8 (4.6mmx150mm, 5µm) column; mobile phase: methanol, acetonitrile and 0,057 mM acid triflouroacetic (pH 4.5) (0:13:87 – 10:20:70 – 0:13:87, v/v/v) in 40 mins;, examinized wavelength: 396 nm. Method was validated with parameters: system suitability, specificity, linearity, precision, accuracy and stability. The result showed amount ratio of SCFAs in feces of mice group treated with acetate wheat starch containing resistant starch higher than from the diet containing normal starch significantly. Conclusion: This method can be used to investigate SCFAs in the gastrointestinal segments of the living organism. Key words: SCFAs, HPLC, resistant starch, feces

Short-chain fatty acids (SCFAs) produced by gut microbiota are reduced in feces but paradoxically increased in plasma of patients with Parkinson's disease (PD), which may stem from intestinal wall leakage. Gut function should be taken into consideration when conducting microbial-metabolite research. The objective was to investigate synchronous changes of SCFAs in feces and plasma of patients with PD, taking constipation as a confounder to better disentangle the SCFA metabolism exclusively associated with PD. The concentrations of fecal and plasma SCFAs in 33 healthy control subjects and 95 patients with PD were measured using liquid and gas chromatography mass spectrometry, respectively. Patients with PD were divided into patients with PD without constipation (n=35) and patients with PD with constipation (n=60). Gut-blood barrier (GBB) permeability was assessed by plasma/fecal ratio of SCFA concentrations and fecal α1-antitrypsin concentration. Patients with PD displayed decreased concentrations of fecal acetic, propionic, and butyric acid and increased concentrations of plasma acetic and propionic acid. Fecal acetic, isobutyric, and isovaleric acid were lower and plasma acetic and propionic acid were higher in patients with PD with constipation than in patients with PD without constipation. Constipation aggravated GBB permeability in patients with PD. Combined fecal and plasma SCFAs could discriminate patients with PD from healthy control subjects. Fecal SCFAs, except propionic acid, were negatively correlated with disease severity, while plasma acetic, propionic, and valeric acid showed a positive correlation. Our study showed alterations of fecal and plasma SCFAs in patients with PD that were associated with an impaired GBB and might be aggravated by constipation. © 2022 International Parkinson and Movement Disorder Society.

Short chain fatty acids (SCFAs) are generated by the degradation and fermentation of complex carbohydrates, (i.e., dietary fiber) by the gut microbiota relevant for microbe–host communication. Here, we present a method for the quantification of SCFAs in fecal samples by liquid chromatography tandem mass spectrometry (LC-MS/MS) upon derivatization to 3-nitrophenylhydrazones (3NPH). The method includes acetate, propionate, butyrate, and isobutyrate with a run time of 4 min. The reproducible (coefficients of variation (CV) below 10%) quantification of SCFAs in human fecal samples was achieved by the application of stable isotope labelled internal standards. The specificity was demonstrated by the introduction of a quantifier and qualifier ions. The method was applied to investigate the pre-analytic stability of SCFAs in human feces. Concentrations of SCFA may change substantially within hours; the degree and kinetics of these changes revealed huge differences between the donors. The fecal SCFA level could be preserved by the addition of organic solvents like isopropanol. An analysis of the colon content of mice either treated with antibiotics or fed with a diet containing a non-degradable and -fermentable fiber source showed decreased SCFA concentrations. In summary, this fast and reproducible method for the quantification of SCFA in fecal samples provides a valuable tool for both basic research and large-scale studies.

To determine the effect of olestra on microbial ecology of the gut, faecal short-chain fatty acids (SCFAs) and water content were assessed in 93 subjects in a 36 d parallel, placebo-controlled, double-blind study. Faecal SCFAs and water content were determined at the end of an 8 d low fibre baseline period and 28 d treatment period. The test meal consisted of either a moderate (7 g) or high (24 g) level of fibre and olestra (24 g) or an equivalent amount of conventional fat. Olestra had a significant effect on both faecal water content and SCFAs. The water content decreased and concentrations of some SCFAs increased. The effect of olestra on SCFA concentrations in faeces (mmol/kg) differed with different fibre content of the meal. When the SCFAs were expressed as mmol/1 faecal water, a similar pattern of changes (several SCFAs increased) was observed for both olestra groups. Although all individual SCFA values were within the range of a healthy population, the effects were consistent, and potential reasons for it are discussed. Keywords: olestra, SCFA, faeces, faecal water, microbial ecology.

Caesarean section (CS) interrupts mother-to-newborn microbial transfer at birth. Beyond the neonatal period, the impact of CS on offspring gut microbiota and their short-chain fatty acids (SCFAs) remains unclear. Here, we examine birth delivery mode (CS versus vaginal delivery) with the infant gut microbiota and faecal SCFAs measured 3 and 12months after birth. Longitudinal study. North Carolina. In 2013-15, we enrolled pregnant women and followed up their offspring for 12months. We asked a subset of participants, enrolled over a 3-month period, to provide faecal samples at the 3- and 12-month follow-up visits. We sequenced the 16S rRNA V4 region with Illumina MiSeq and quantified SCFA concentrations using gas chromatography. We examined delivery mode with differential abundance of microbiota amplicon sequence variants (ASVs) using beta-binomial regression and faecal SCFAs using linear regression. We adjusted models for confounders. Of the 70 infants in our sample, 25 (36%) were delivered by CS. Compared with vaginal delivery, CS was associated with differential abundance of 14 infant bacterial ASVs at 3months and 13 ASVs at 12months (all FDR P < 0.05). Of note, CS infants had a higher abundance of the potential pathobionts Clostridium neonatale (P=0.04) and Clostridium perfringens (P=0.04) and a lower abundance of potentially beneficial Bifidobacterium and Bacteroides spp. (both P < 0.05) at 3 months. Other ASVs were differentially abundant at 12 months. Infants delivered by CS also had higher faecal butyrate concentration at 3months (P<0.005) but not at 12 months. Caesarean section was associated with increased butyrate excretion, decreased Bifidobacterium and Bacteroides spp., and more colonisation of the infant gut by pathobionts at 3 months of age. CS was also associated with altered gut microbiota composition, but not faecal SCFAs, at 12 months. Caesarean section delivery was associated with increased butyrate excretion, decreased Bifidobacterium, and increased colonisation of the infant gut by pathobionts at 3months of age.

The gut microbiota and metabolome could play a role in primary biliary cholangitis (PBC) progression. We aimed to assess fecal microbiota and fecal short-chain fatty acids (SCFAs) in PBC according to fibrosis. In a cross-sectional study of 23 PBC patients, fecal microbiota and SCFAs were determined using 16S rRNA sequencing and nuclear magnetic resonance spectroscopy, respectively. Fecal acetate and SCFAs were higher in advanced fibrosis. Advanced fibrosis microbiota exhibited decreased alpha diversity, increased Weisella and a distinct community composition. SCFAs correlated with individual taxa in non-advanced fibrosis. Fecal microbiota and SCFAs correspond to fibrosis in PBC.

Circadian rhythm disturbances induced by rotating shift work contribute to development of metabolic disorders. However, their effects on intestinal parameters such as epithelial permeability and fecal short chain fatty acid (SCFA) levels have not been established yet. This study was planned to investigate the changes in intestinal integrity, fecal SCFA levels, gut microbiota and nutritional intake of rotational shift workers. The study was conducted on ten male rotational shift workers, 25–40 years old. Circadian rhythm disruption was assumed to have occurred after 14 days in the night shift. Dietary data which was obtained by using 24 h record for 7 days, physical activity data, anthropometric measurements, fecal and blood samples were collected during day and night shift. Changes in dietary consumption, anthropometric measurements, blood chemistry and intestinal epithelial permeability indicator according to day and night shifts were not significant (p > .05). Additionally, acetic, propionic and total SCFA were associated with the intestinal permeability biomarker in night shift, but not in day shift (p < .05). Consumption of dark green vegetables and beans and peas was positively associated with fecal isobutyric acid and fecal total SCFA concentration (r = 0.685, p = .029; r = 0.695, p = .026, respectively). The proportions of the genus including Blautia, Bifidobacterium, Dialister, and Ruminococcus gnavus group increased when individuals shifted to the night shift. Gut microbiota changes responding to circadian rhythm disruption became more prominent when consumed high sugar diet. So, changes have been observed in the gut microbiota of rotational shift workers, especially in individuals with certain dietary pattern. Moreover, in individuals with the circadian rhythm disruption SCFAs levels have been demonstrated to be associated with intestinal barrier integrity. A better understanding of the relation among fecal SCFAs, gut microbiota, intestinal epithelial permeability and circadian rhythm disruption is necessary for the development of new dietary strategies for gut health.