Fecal Short-chain Fatty Acids Research Articles

Alleviating D-Galactose-Induced Aging in Mice by Modulating Gut-Liver Axis Using Lactiplantibacillus plantarum TY-Y10

Oxidative stress is closely linked to aging. Probiotics, whether viable or heat-inactivated, have shown antioxidant properties; however, their effect and mechanism of action in reducing oxidative stress during aging remains underexplored. This study examined the effects of viable and heat-inactivated Lactiplantibacillus plantarum TY-Y10 (L. plantarum TY-Y10) on D-galactose (D-gal)-induced aging in mice, aiming to uncover potential anti-aging mechanisms. Mice were induced to age with D-gal injections, then treated with sodium ascorbate (positive control) or varying doses of L. plantarum TY-Y10 for eight weeks. After treatment, oxidative stress markers, gut microbiota, and liver health were analyzed. Results showed that L. plantarum TY-Y10 decreased malondialdehyde (MDA) and inflammatory markers while increasing antioxidant levels (glutathione, superoxide dismutase, catalase and glutathione peroxidase). Liver damage was reduced, and expression of Nrf2 and related antioxidant enzymes improved. Additionally, L. plantarum TY-Y10 enhanced the abundance of short-chain fatty acid-producing bacteria, boosting fecal short-chain fatty acid levels. In short, both viable and heat-inactivated L. plantarum TY-Y10 mitigated oxidative stress in aging mice by modulating gut microbiota and activating liver antioxidant pathways through the gut-liver axis.

Improvement of sleep quality and sub-health conditions through pasteurized fermented milk consumption: A human intervention study

The sub-health state refers to a transitional condition between optimal health and disease, impacting physical, psychological, and social well-being. In this 42-day human intervention trial, we investigated the effects of two pasteurized fermented milks on sub-health symptoms. These pasteurized fermented milks shared the same starter culture and probiotic strains (Lacticaseibacillus paracasei PC-01, Lactiplantibacillus plantarun Lp-6, Lactobacillus helveticus H9, and Bifidobacterium animalis subsp. lactis Probio-M8), differing only in the presence of inulin. Qualified subjects were randomly assigned to the probiotic group (received milk without inulin; n = 49 or synbiotic group (received milk with inulin; n = 51). Outcome measures included Sub-Health Measurement Scale (SHMS) and Pittsburgh Sleep Quality Index (PSQI) scores, fecal metagenomes, metabolomes, and short-chain fatty acids, and serum neurotransmitter levels at baseline, after a 4-week intervention (day 28), and a 2-week-follow-up period (day 42). Our results showed that both pasteurized fermented milks improved sleep quality and alleviated sub-health symptoms, with no significant added benefit from inulin. Fecal metagenome analysis revealed post-interventional changes in gut microbial composition, including increased Bifidobacterium longum and decreased potentially pro-inflammatory bacteria (Blautia sp. and Dorea sp.). Changes in Blautia sp. and B. longum correlated significantly with SHMS and PSQI scores, respectively. Fecal and serum metabolite analysis showed post-interventional modulation of fecal short-chain fatty acids, anti-inflammatory bioactive metabolites, and serum neurotransmitters such as gamma-aminobutyric and serotonin hydrochloride. In conclusion, pasteurized fermented milk intake alleviated sub-health symptoms, affected the gut microbiome, metabolome, and serum metabolites. These findings highlight the potential of pasteurized fermented milk for mitigating sub-health conditions.

Oral supplementation of heat-killed Enterococcus faecalis strain EC-12 relieves gastrointestinal discomfort and alters the gut microecology in academically stressed students.

Stress significantly affects gastrointestinal and mental health, and the gut microbiota plays a pivotal role in this process. Enterococcus faecalis strain EC-12 (EC-12) is a lactic acid bacterium that has several health benefits. To investigate the impact of oral supplementation with heat-killed EC-12 on the discomfort caused by stress, a randomised, double-blind, placebo-controlled trial was conducted with students under academic stress taking EC-12 (n= 14) or a placebo (n= 13) daily for one week. Improvement in the students' symptoms was assessed using the visual analogue scale. Faecal microbiota was characterised by next-generation sequencing of 16S rRNA genes, and faecal metabolites and short-chain fatty acids were analysed using a GC-MS metabolomics approach. Significant improvements in abdominal pain and rumbling of the stomach were found in the EC-12 group compared to the placebo group, but no changes were observed in mental symptoms or salivary cortisol levels. The relative abundance of E. faecalis significantly increased in the EC-12 group after the trial; however, the composition and diversity of the gut microbiota did not change significantly. Functional analysis of the gut microbiota suggested that EC-12 intake alters specific metabolic pathways. Although the levels of faecal short-chain fatty acids did not change between the groups before and after the trial, EC-12 intake altered the composition of faecal metabolites, with a significant increase in tryptamine levels. The ratio of students with improved symptoms to those with increased tryptamine levels was calculated based on the number of students with elevated faecal tryptamine levels who showed symptomatic improvements. The ratio of improved rumbling stomach was higher than that of other types of digestive discomfort. These results suggest that oral supplementation with EC-12 has a potentially beneficial effect on stress-induced gastrointestinal discomfort, which may occur through alterations in gut microbiota composition and metabolism. This study was registered at the University Hospital Medical Information Network Center (UMIN) under the UMIN ID: UMIN000048184.

Macroalgae and microalga blend in dogs' food: Effects on palatability, digestibility, and fecal metabolites and microbiota

The promotion of dogs' nutrition, health, and well-being are highly valued by pet owners, leading to an increasing interest in pet food with alternative, functional, and more sustainable supplements, such as algae. Few studies have assessed the supplementation of dog food with individual algae species, but no information exists on combined macro- and microalgae. This study evaluated the effects of dietary supplementation of a commercial algal blend, composed of two macroalgae (Ulva rigida and Fucus vesiculosus) and one microalga (Chlorella vulgaris) on palatability, intake, digestibility, metabolizable energy (ME), and fecal characteristics, metabolites, and microbiota of adult healthy Beagle dogs. Palatability was assessed by comparing a complete diet without (control) and with 1.5 % algae blend using twelve dogs. Then, six of these dogs were randomly selected for the digestibility trials. Following an initial trial to determine the control diet digestibility, a replicated Latin square was performed with three experimental periods of 10 days each, and three algal blend supplementation levels (0.5, 1.0, and 1.5 %). Dietary algal blend did not affect the first approach and first taste, but dogs preferred the control diet. Algal blend levels had no impact on intake, but organic matter, fiber, and energy digestibility increased with 1.5 % inclusion compared with 0.5 %. At the highest level, algae blend promoted fecal total short chain fatty acids and acetate while at lowest fecal propionate decreased and fecal production increased. Compared with the control diet, algal blend-supplemented diets promoted most nutrients and energy digestibility, diet ME content, and fecal quality, while reducing fecal butyrate. Fecal microbiota diversity and abundance were mostly unaffected by algae blend supplementation, with health-promoting genera Turicibacter and Blautia being the most abundant in all samples. Overall, results suggest algal blend as a promising alternative supplement for dog food, but further research is needed to unveil potential health-promoting effects.

Whole-Genome Metagenomic Analysis of Functional Profiles in the Fecal Microbiome of Farmed Sows with Different Reproductive Performances

Recent studies suggested an association between the reproductive performance of sows and their gut microbiota. To understand how the gut microbiota affect the reproductive performances of sows, we conducted a whole-genome metagenomic analysis on the fecal microbial functional profiles of sows with high and low reproductive performances. We used 60 sows from six farms (10 sows/farm), including 30 sows from three farms with higher reproductive performances (the mean number of weaned piglets/sow/year) (group H) and 30 sows from three farms with lower performances (group L). Fecal microbial DNA was subjected to a whole-genome metagenomic analysis. Biomarker exploration analysis identified “carbohydrate transport and metabolism” as the most discriminative function enriched in group H. Further analysis of carbohydrate-active enzymes revealed that the fecal microbiome of group H had a greater capacity to degrade dietary fiber, specifically cellulose and pectin. Group H also exhibited higher fecal short-chain fatty acid (SCFA) concentrations than group L, with the abundances of cellulose- and pectin-degrading genes showing significant positive correlations with fecal SCFA concentrations. Taxonomic analysis indicated greater contributions of Prevotella, Treponema, Ruminococcus, and Fibrobacter to cellulose and pectin degradation in the fecal microbiome in group H. In conclusion, higher reproductive performances of sows were, at least in part, associated with a greater microbial capacity for degrading cellulose and pectin, resulting in a higher SCFA production in the hindgut.

Effects of saccharomyces cerevisiae fermentation products on growth performance, fecal short chain fatty acids, and microbiota of pre-weaning calves.

This research aims to explore the effects of incorporating saccharomyces cerevisiae fermentation products (SCFP) on growth performance, nutrient digestibility, antioxidant capacity, fecal SCFAs, and microbial composition of pre-weaning calves. Twenty Holstein calves, 10 days old and weighing an average of 48.63±0.91 kg, were randomly assigned to either the control group (CON) or the SCFP group, with 10 calves in each group. The CON group received only a basal diet, while the SCFP group received the starter diet supplemented with 5 g/head/d of SCFP products (NutriTek, Diamond V Cedar Rapids, IA 52404, United States). The pre-trial period lasted for 5 days, followed by a main experimental period of 45 days. The SCFP group had significantly higher final weight, ADG, and FE compared to the control group (p < 0.05). Moreover, the SCFP group exhibited increased apparent digestibility of DM, CP, EE, ADF, Ca, and P (p < 0.05). Additionally, supplementation with SCFP led to elevated content of GH, IGF-1, and GLP-1 in serum. The inclusion of SCFP also raised serum CAT content and reduced serum MDA content in pre-weaning calves. Furthermore, SCFP supplementation influenced the composition of intestinal microflora by decreasing Actinobacteriota abundance and increasing the abundance of Ruminococcus, Lachnospiraceae_AC2044_group, Parabacteroides, and Butyricimonas. The addition of SCFP has a positive impact on the growth performance, nutrient digestibility, antioxidant capacity, and intestinal microflora composition of pre-weaning calves.

The gut microbiota metabolite trimethylamine-N-oxide in children with β-thalassemia: potential implication for iron-induced renal tubular dysfunction.

Renal tubular dysfunction is common in transfusion-dependent β thalassemia (β-TM). Iron overload, chronic anemia, and hypoxia are precipitating factors for renal insult. However, gut microbiota engagement in the renal insult has not been explored. Our work aimed to assess the potential link between iron overload, gut leakage/dysbiosis, and kidney dysfunction in these children. We enrolled 40 children with β-TM and 40 healthy controls. Gut leakage/dysbiosis biomarkers (trimethylamine-N-oxide [TMAO] and fecal short-chain fatty acids [SCFAs]), oxidative stress and inflammatory biomarkers, TMAO-regulated proteins such as serum sirtuin 1 (S.SIRT1) and serum high mobility box group-1 (S.HMGB1), and tubular dysfunction biomarkers were assessed. Correlations and regression analysis were performed to assess the relation between different parameters. Iron overload, redox imbalance, and generalized inflammation were evident in children with β-TM. Renal tubular dysfunction biomarkers and S.TMAO were significantly elevated in the patient group. Furthermore, fecal SCFAs were significantly lower with upregulation of the investigated genes in the patient group. The correlation studies affirmed the close relationship between circulating ferritin, TMAO, and renal dysfunction and strongly implicated SIRT1/HMGB1 axis in TMAO action. Gut dysbiosis may have a role in the pathogenesis of renal injury in children with β-TM. Renal tubular dysfunction is a prominent health issue in β thalassemia major (β-TM). Iron overload, chronic anemia, and hypoxia are known precipitating factors. However, gut microbiota engagement in renal insult in these patients has not yet been explored. We aimed to assess potential link between iron overload, gut leakage/dysbiosis, and kidney dysfunction in β-TM children and to highlight the SIRT1/HMGB1 axis, a signal motivated by the gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO), involvement in such insults. We found that gut leakage/dysbiosis may have a role in kidney dysfunction in β-TM children by exacerbating the iron-motivated oxidative stress, inflammation, ferroptosis, and modulating SIRT1/HMGB1 axis.

Effectiveness and safety study of formula containing probiotics, prebiotics, synbiotics on fullterm infants' growth - a systematic review and meta-analysis of randomized controlled study.

Probiotics, prebiotics, and synbiotics, are hot topics of research and have been shown to improve the body's disease state and promote health. Analysis of whether infant formula containing probiotcs, prebiotics, synbiotics is beneficial to infant and child growth. We systematically searched multiple electronic databases (PubMed, Web of Science, The Cochrane Library, Embase) to identify eligible studies published from 1966 to December 25, 2022. Included studies were randomized controlled trials (RCTs) studying the influence of milk powder containing probiotcs, prebiotics, synbiotics on infants and children's growth. RevMan 5.4 was used to analyze the data. A total of 55 RCTs with a total sample size of 8868 participants met the inclusion criteria. Milk powder with probiotics, prebiotics, synbiotics does not significantly improve the growth of infants and children (Weight, height, BMI, and Head Circumference); The incidence of minor adverse events (OR 0.88, 95% CI 0.70-1.11 P = 0.28) and serious adverse events (OR 0.92, 95% CI 0.62-1.36 P = 0.67) was also comparable to the control group; The intestinal microbial diversity of infants consuming probiotcs, prebiotics, synbiotics supplemented formula was lower than that of infants consuming formula without probiotcs, prebiotics, synbiotics (SMD -0.88, 95% CI -1.66- -0.1 P = 0.03), but the abundance of individual beneficial flora was increased. (SMD 1.62, 95%CI 0.61-2.62 P = 0.002). In particular, the abundance of Lactobacillus (SMD 1.62, 95% CI 0.61-2.62 P = 0.002). For metabolites, synbiotics increased fecal antibody concentrations (SMD 0.47, 95% CI 0.08-0.86 P = 0.02), but fecal short-chain fatty acid concentrations remained balanced in both groups (SMD 0.05 95% CI -0.17-0.28 P = 0.64). Compared to the control group, infants who consumed formula with prebiotics had softer stools (SMD -1.47, 95% CI -2.23 to -0.7 P = 0.002) and lower stool pH (SMD -0.82, 95% CI -1.15- -0.5 P < 0.00001), there is also more frequency of bowel movements (SMD 0.27, 95% CI 0.09-0.44 P = 0.002). Probiotcs, prebiotics, synbiotics supplemented formulas significantly increased abundance of individual probiotics, alter intestinal antibody secretion, and improve bowel movements. Incidence of adverse reactions did not differ between the two groups. So we can choose formula-supplemented probiotcs, prebiotics, synbiotics to maintain the intestinal health of infants.

Yeast β-glucan supplementation lowers insulin resistance without altering microbiota composition compared to placebo in subjects with Type II diabetes: a phase I exploratory study.

The increased global prevalence of type II diabetes mellitus (T2DM) is associated with consumption of low fibre "Western diets". Characteristic metabolic parameters of these individuals include insulin resistance, high fasting and postprandial glucose, as well as low-grade systemic inflammation. Gut microbiota composition is altered significantly in these cohorts suggesting a causative link between diet, microbiota and disease. Dietary fibre consumption has been shown to alleviate these changes and improve glucose parameters in individuals with metabolic disease. We previously reported that yeast β-glucan (yeast beta-1,3/1,6-D-glucan; Wellmune) supplementation ameliorated hyperinsulinemia and insulin resistance in a murine model. Here we conducted a randomised, placebo-controlled, two-armed dietary fibre phase I exploratory intervention study in patients with T2DM. The primary outcome measure was alteration to microbiota composition while the secondary outcome measures included markers of glycaemic control, inflammation as well as metabolomics. Patients were supplemented with 2.5g/day of maltodextrin (placebo) or yeast β-1,3/1,6-D-glucan (treatment). Yeast β-glucan (Wellmune) lowered insulin resistance (HOMA-IR) compared to the placebo maltodextrin after 8 weeks of consumption. TNFα was significantly lower after 4 weeks of β-glucan supplementation. Significantly higher faecal concentrations of several bile acids were detected in the treatment group when compared to the placebo after 8 weeks. These included tauroursodeoxycholic acid (TUDCA) which was previously shown to improve glucose control and lower insulin resistance. Interestingly, the hypoglycaemic and anti-inflammatory effect of yeast β-glucan was independent of any changes in faecal microbiota composition or short-chain fatty acid (SCFA) levels. Our findings highlight the potential of yeast β-glucan to lower insulin resistance in patients with T2DM.

Beneficial Role of Heat-Treated Lactobacillus sakei HS-1 on Growth Performance, Nutritional Status and Gut Microbiota in Weaned Piglets.

In the swine industry, there is a strong need to replace an antibiotic growth promoter (AGP) used as feed additives in weaned piglets to enhance nutrient utilization in their diets and improve growth performance. Lactobacillus sakei HS-1 strain is a microbial preparation isolated from pickles. The study aim is to investigate the effectiveness of heat-treated L. sakei HS-1 strain (HT-LS) as a growth promoter in weaned piglets compared to colistin (CS), a widely used AGP. Eighteen crossbred weaned piglets (Landrace × Yorkshire × Duroc) of 21 days (average body weight [BW]: 7.06 ± 0.59 kg) were divided into three groups: fed the control diet (CT group), fed a diet supplemented with 30 ppm colistin sulphate (CS group), fed a diet supplemented with HT-LS at a concentration of 2.0 × 105 cells/g (LS group) until 49 days. The results indicated that LS group exhibited significantly higher average daily gain (p < 0.05) and higher BW (p < 0.1) compared with CT group, even higher than CS group. CS group showed higher growth performance compared to CT group but the differences were not statistically significant. In addition, LS group had higher (p < 0.05) or tended to higher (p < 0.1) concentrations of several plasma amino acids than the other two groups at 35 and 49 days. Faecal acetate concentration was higher (p < 0.1) in LS group than in CT group at 35 days. Blood immunoglobulin G concentration in LS group was significantly lower (p < 0.05) than in CT group at 35 and 49 days, and blood immunoglobulin A tended to be lower (p < 0.1) at 35 days than in CT group. LS group showed an increased abundance of g_Prevotella 7, g_Streptococcus and g_Lactobacillus (linear discriminant analysis [LDA] score ≥ 2.0). Predictive metagenomic analysis revealed an enrichment of the mixed acid fermentation pathway (LDA score ≥ 2.0). Furthermore, several gut microbes exhibited correlations with plasma amino acids (p < 0.01) and short-chain fatty acids in faeces (p < 0.01). These findings demonstrate that HT-LS improves the growth performance of weaned piglets by enhancing the efficient utilization of nutrients through gut microbiota modification.

GC-MS quantification of fecal short-chain fatty acids and spectrophotometric detection of indole: Do rectal swabs produce comparable results as stool samples? - A pilot study.

The exploration of the gut microbiome and related metabolites holds an exciting future in health science. The challenges associated with fecal sample testing are proper sample collection, sterile transportation, optimal transport conditions, and processing as all these factors could potentially change the microbiome composition, further exacerbated by the patient's customary discomfort regarding feces samples. The study aimed to compare the usage of rectal swabs and stool samples for short-chain fatty acid estimation using gas chromatography-mass spectrometry (GC-MS) and indole estimation using spectrophotometry. From May 2022 to June 2022, three women were recruited from the Department of Obstetrics and Gynecology (OBG) in a secondary care hospital in coastal Karnataka. During their clinical visit, a rectal swab was collected, and the stool sample was transported to the hospital from the patient's home in sterile containers provided. After the extraction, short-chain fatty acids (acetate, propionate, and butyrate) were quantified using GC-MS. The fecal indole concentration was determined using a hydroxylamine-based assay. The GC-MS analysis failed to detect the concentrations of short-chain fatty acids in rectal swab samples. Indole concentrations in stool and swab samples were significantly different. The study's findings do not support the use of rectal swabs to analyze gut metabolites.

Optimization of a gelatin/carboxymethylcellulose-based probiotic microcapsule and its application in preventing dextran sodium sulfate-induced colitis in mice.

Oral administration of probiotics has demonstrated substantial potential in alleviating colitis. However, most of the ingested microorganisms struggle to survive the harsh conditions of the gastrointestinal tract, leading to decreased efficacy. In the present study, using double emulsification (W1/O/W2) and complex coacervation methods, we developed a gelatin/carboxymethyl cellulose (CMC)-based probiotic microcapsule and analyzed the efficacy of encapsulated probiotics in preventing dextran sodium sulfate (DSS)-induced colitis in mice. Our results reveal that nearly 90% of the encapsulated probiotics remained viable after 30-day storage at 4°C and approximately 38.1% of viable bacteria (4.0 × 108 cfu/g) survived after 4-h simulated gastrointestinal digestion. In a DSS-induced colitis model, pretreatment with probiotics exerted significant protective effects, with the bacterial microcapsule-treated group having superior outcomes to those of the bacterial suspension plus empty carrier group. Probiotic treatments, especially those administered in the encapsulated form, significantly increased fecal short-chain fatty acid contents, and altered the intestinal microbial composition. The family Muribaculaceae, dominant bacteria in the mouse gut, may be the key microorganism involved in the BM regulation process. Our study presents an alternative approach to treating colitis using probiotics. PRACTICAL APPLICATION: The encapsuled probiotic showed remarkable storage stability at 4°C, maintained good vitality after simulated digestion, and gained superior outcomes in preventing colitis. Our results offer an alternative approach for the probiotic preparations aiming to prevent the intestinal inflammation.

Gut microbiome composition and intestinal immunity in antiphospholipid syndrome patients versus healthy controls.

The gut microbiome is recognized as a factor that could potentially contribute to the persistent antibodies of antiphospholipid syndrome (APS). Gut microbial interventions can both induce and mitigate APS in mice. In human APS patients, anti-beta-2-glycoprotein I (β2GP-1) titers correlate with antibody titers against a gut commensal protein homologous to β2GP-1. To investigate the effect of the intestinal microenvironment on human APS. Methods We cross-sectionally compared intestinal microbiota composition quantified by shotgun sequencing; fecal short chain fatty acids (SCFAs), bacterial metabolites known to affect autoimmune processes; and fecal calprotectin, an intestinal inflammatory marker, in APS patients and healthy controls. Neither alpha nor beta diversity of the gut microbiota differed between APS patients (n = 15) and controls (n = 16) and no taxa were differentially abundant. Moreover, fecal SCFAs and fecal calprotectin, did not differ between the groups. Gut microbiome effects on the APS phenotype are likely not driven by bacterial overabundance, SCFA production or intestinal inflammation.

Soy protein β-conglycinin ameliorates pressure overload-induced heart failure by increasing short-chain fatty acid (SCFA)-producing gut microbiota and intestinal SCFAs

Soybeans and their ingredients have antioxidant and anti-inflammatory effects on cardiovascular diseases. β-Conglycinin (β-CG), a major constituent of soy proteins, is protective against obesity, hypertension, and chronic kidney disease, but its effects on heart failure remain to be elucidated. We tested the effects of β-CG on left ventricular (LV) remodeling in pressure overload-induced heart failure. A transverse aortic constriction (TAC)-induced pressure overload was applied to the heart in 7-week-old C57BL6 male mice that were treated with β-CG, GlcNAc, or sodium propionate. Gut microbiota was analyzed by 16S rRNA sequencing. Fecal short-chain fatty acids (SCFAs) were quantified by GC-MS. The effects of oral antibiotics were examined in β-CG-fed mice. β-CG ameliorated impaired cardiac contractions, cardiac hypertrophy, and myocardial fibrosis in TAC-operated mice. As β-CG is a highly glycosylated protein, we examined the effects of GlcNAc. GlcNAc had similar but less efficient effects on LV remodeling compared to β-CG. β-CG increased three major SCFA-producing intestinal bacteria, as well as fecal concentrations of SCFAs, in sham- and TAC-operated mice. Oral administration of antibiotics nullified the effects of β-CG in TAC-operated mice by markedly reducing SCFA-producing intestinal bacteria and fecal SCFAs. In contrast, oral administration of sodium propionate, one of SCFAs, ameliorated LV remodeling in TAC-operated mice to a similar extent as β-CG. β-CG was protective against TAC-induced LV remodeling, which was likely to be mediated by increased SCFA-producing gut microbiota and increased intestinal SCFAs. Modified β-CG and/or derivatives arising from β-CG are expected to be developed as prophylactic and/or therapeutic agents to ameliorate devastating symptoms in heart failure.

Effects of single-dose ruminal infusions of high or low short-chain fatty acid concentrations and high or low pH on apparent total tract digestibility and hindgut fermentation of pre-weaned dairy calves

While the importance of pH and short-chain fatty acids (SCFA) on rumen development are well-known, their impact on the small and large intestine are unclear. This study investigated how single-dose ruminal infusions with high or low short-chain fatty acid concentrations and high or low pH affect calves' productivity as well as physiological parameters associated with hindgut acidosis at 3-time points in 49 d. Holstein bull calves (n = 32) were individually housed and fed milk replacer (900 g/d) twice daily and calf starter and water ad libitum. At d 10 ± 3 of life, the rumens were fistulated and cannulated. At d 14 of life, calves were grouped by body weight and assigned in a 2 × 2 factorial arrangement of treatments: high or low SCFA concentration (285 vs. 10 mM) and high or low pH (6.2 vs. 5.2), creating 4 treatment groups: high SCFA concentration, high pH (HS-HP); high SCFA concentration, low pH (HS-LP); low SCFA concentration, high pH (LS-HP); and low SCFA concentration, low pH (LS-LP). On d 21, 35, 49, feces were sampled to calculate apparent total-tract digestibility, determinate organic acid concentrations (i.e., SCFA, BCFA and lactic acid), and pH. Afterward, the rumen was evacuated and underwent a single-dose infusion for 4 h with one of 4 treatment buffers. After completion of rumen infusion on d 49, calves were harvested, and the tissue weight and length, and digesta pH of the rumen, cecum, colon, and rectum were recorded along with the digesta pH of duodenum, jejunum, and ileum only at d 49 after dissection. Data were analyzed with main factors as fixed effects and repeated measures for weekly measurements. Treatments did not affect performance parameters such as feed intake, ADG, apparent total-tract digestibility and gut measurements. In the duodenum, jejunum, and ileum, HS-HP had a greater digesta pH than LS-HP, while the hindgut digesta pH was only affected by the SCFA concentration. High SCFA concentration increased the concentration of colonic isovaleric acid and fecal BCFA, while only colonic acetic acid and fecal lactic acid concentrations were affected by treatment. Fecal SCFA and BCFA concentrations increased mainly on d 35. In summary, 4 h of physiological buffer infusion in the rumen does not change apparent total-tract digestibility and gut measurements but does affect hindgut fermentation parameters (i.e., organic acid concentrations and digesta pH). In addition, calves can experience increased risks of hindgut acidosis around 35 d of life.

Quality and quantity of carbohydrates, fecal short-chain fatty acids and gastrointestinal symptoms - results from a randomized, controlled trial (CARBFUNC)

Quality and quantity of carbohydrates, fecal short-chain fatty acids and gastrointestinal symptoms - results from a randomized, controlled trial (CARBFUNC)

Integrative microbiomics, proteomics and lipidomics studies unraveled the preventive mechanism of Shouhui Tongbian Capsules on cerebral ischemic stroke injury

Ethnopharmacological relevanceCerebral ischemic stroke (CIS) is one of the most important factors leading to death and disability, which seriously threaten the survival and health of patients. The intentional flora and its derived metabolites are demonstrated to play vital roles in the physiology and onset of CIS. Shouhui Tongbian Capsules (SHTB), a Traditional Chinese Medicine, could regulate gut microbiota and metabolites. Study has found that SHTB has protective effect on CIS, but the mechanism is still unclear. Aim of studyThis study was designed to evaluate the preventive effects and the mechanism of SHTB on CIS injury. Materials and methodsThe rats were pretreated with SHTB for 5 days, then the middle cerebral artery occlusion/reperfusion (MCAO/R) was established. Neurological deficit score, TTC staining, brain water content, H&E and Nissl staining were preformed to evaluate the preventive effects of SHTB on CIS. The Occludin and ZO-1 were analyzed to evaluate the blood-brain barrier (BBB). 16S rDNA sequencing and LC-ESI-MS/MS-based metabolomics profiling were performed to analyze the gut microbiota composition and short chain fatty acids (SCFAs) profile in gut. Serum lipopolysaccharide specific IgA antibody (LPS-SIgA) and diamine oxidase (DAO), as well as colon Claudin 5 and ZO-1 were analyzed to evaluate the intestinal barrier. Proteomics was used to evaluated the proteins profile in brain. Lipidomics were used to evaluate the brain SCFAs as well as medium and long chain fatty acids (MCFAs and LCFAs). Malondialdehyde (MDA), Total Superoxide dismutase (T-SOD), Glutathione (GSH), Glutathione peroxidase (GSH-Px), Catalase (CAT) and reactive oxygen species (ROS) were assayed to evaluate the oxidative stress in brain. Western blot was performed to evaluate the expression of PPARγ, Nrf2, SLC3A2, SCL7A11, GPX4, ACSL4 and LOX. ResultsSHTB prevented rats from MCAO/R injury, which was confirmed by lower cerebral infarct rate, brain water content, neurological deficit score and nissl body loss, and improved brain pathology. Meanwhile, SHTB upregulated the expression of ZO-1 and Occludin to maintain the integrity of BBB. 16S rDNA sequencing and LC-ESI-MS/MS-based targeted metabolomics found that SHTB increased the abundance of gut microbiota, regulated the numbers of intestinal bacteria to increase the production of Acetic acid, Propionic acid, and Butyric acid, as well as decrease the production of Valeric acid and Hexanoic acid in the gut. Meanwhile, SHTB improved the intestinal barrier by upregulating the protein levels of Claudin 5 and ZO-1, which was confirmed by low concentrations of LPS-SIgA and DAO in serum. Multi omics and spearman correlation analysis indicated that SHTB regulated the abundance of Escherichia-Shigella and Lactobacillus to increase Acetic acid, Propionic acid, and Butyric acid to induce the expression of PPARγ, thereby regulating fatty acid metabolism and degradation, improving lipid metabolism disorders, downregulating lipid oxidative stress, inhibiting ferroptosis, and alleviating brain injury. ConclusionThis study confirmed that SHTB improved the disturbance of fatty acid metabolism in brain tissue by regulating gut microbiota and the production of fecal SCFAs to inhibit ferroptosis caused by lipid oxidative stress and prevent CIS injury, which provided a potential candidate drug for the prevention of CIS.

Effects of a Veterinary Gastrointestinal Low-Fat Diet on Fecal Characteristics, Metabolites, and Microbiota Concentrations of Adult Dogs Treated with Metronidazole.

Antibiotics are known to cause loose stools, disrupt the fecal microbiota, and alter fecal bile acid (BA) profiles of dogs. Recovery may be aided by diet, but little research has been conducted. The objective of this study was to determine how a veterinary low-fat diet affected the fecal characteristics, metabolites, BA, and microbiota of dogs receiving antibiotics. Twenty-four healthy adult dogs [7.38 ± 1.95 yr; 7.67 ± 0.76kg body weight (BW)] were used in an 8-wk completely randomized design study. During a 2-wk baseline, all dogs were fed a leading grocery brand dry kibble diet (GBD). Over the next 2wk, dogs were fed GBD and received metronidazole orally (20mg/kg BW twice daily). At wk 4, dogs were randomly allotted to one of two treatments [GBD or Blue Buffalo Natural Veterinary Diet GI Gastrointestinal Support Low-Fat (BB)] and fed for 4wk. Fecal scores were recorded daily and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter content, and metabolite and BA concentrations. Fecal microbiota populations were analyzed by 16S rRNA gene amplicon sequencing and qPCR-based dysbiosis index (DI). All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of treatment, time, and treatment*time and significance set at P<0.05. Metronidazole increased (P<0.0001) fecal scores (looser stools), reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations, increased primary BA concentrations, and decreased secondary BA concentrations. Metronidazole also reduced fecal bacterial alpha diversity, altered the abundance of 58 bacterial genera, and increased DI. During antibiotic recovery, change in fecal pH, dry matter percentage, and metabolite and immunoglobulin A concentrations were altered (P<0.05) by diet. Fecal BA concentrations recovered quickly for all dogs. Change in lithocholic acid was affected (P<0.0001) by diet, but other BA were not. Recovery of over 25 bacterial genera was impacted by diet (P<0.05). While many bacterial taxa returned to baseline levels after 4wk, others did not fully recover. DI and bacterial alpha diversity measures recovered quickly for all dogs, but were not impacted by diet. In conclusion, metronidazole drastically altered the fecal microbiota and metabolites of dogs. While most variables returned to baseline by wk 8, diet may be used to aid in recovery.

Altered gut microbial profile accompanied by abnormal short chain fatty acid metabolism exacerbates nonalcoholic fatty liver disease progression

Dysregulation of the gut microbiome has associated with the occurrence and progression of non-alcoholic fatty liver disease (NAFLD). To determine the diagnostic capacity of this association, we compared fecal microbiomes across 104 participants including non-NAFLD controls and NAFLD subtypes patients that were distinguished by magnetic resonance imaging. We measured their blood biochemical parameters, 16 S rRNA-based gut microbiota and fecal short-chain fatty acids (SCFAs). Multi-omic analyses revealed that NAFLD patients exhibited specific changes in gut microbiota and fecal SCFAs as compared to non-NAFLD subjects. Four bacterial genera (Faecalibacterium, Subdoligranulum, Haemophilus, and Roseburia) and two fecal SCFAs profiles (acetic acid, and butyric acid) were closely related to NAFLD phenotypes and could accurately distinguish NAFLD patients from healthy non-NAFLD subjects. Twelve genera belonging to Faecalibacterium, Subdoligranulum, Haemophilus, Intestinibacter, Agathobacter, Lachnospiraceae_UCG-004, Roseburia, Butyricicoccus, Actinomycetales_unclassified, [Eubacterium]_ventriosum_group, Rothia, and Rhodococcus were effective to distinguish NAFLD subtypes. Of them, combination of five genera can distinguish effectively mild NAFLD from non-NAFLD with an area under curve (AUC) of 0.84. Seven genera distinguish moderate NAFLD with an AUC of 0.83. Eight genera distinguish severe NAFLD with an AUC of 0.90. In our study, butyric acid distinguished mild-NAFLD from non-NAFLD with AUC value of 0.83. And acetic acid distinguished moderate-NAFLD and severe-NAFLD from non-NAFLD with AUC value of 0.84 and 0.70. In summary, our study and further analysis showed that gut microbiota and fecal SCFAs maybe a method with convenient detection advantages and invasive manner that are not only a good prediction model for early warning of NAFLD occurrence, but also have a strong ability to distinguish NAFLD subtypes.

Chondroitin Sulfate from Halaelurus burgeri Skin Inhibits Hepatic Endoplasmic Reticulum Stress and Inflammation, and Regulates Gut Microbiota.

Previous study has demonstrated the chemical structure of chondroitin sulfate (CHS) from Halaelurus burgeri skin and its effects on insulin resistance. However, the precise impact of this phenomenon on endoplasmic reticulum (ER) stress and inflammation, which contribute to insulin resistance, remains unclear. This study is to investigate the impact of CHS on ER stress, inflammatory response and signaling, and gut microbiota in high-fat diet (HFD)-fed mice. HFD-fed C57BL/6J mice receive dietary gavage intervention of CHS for 18 weeks. Blood, liver tissue, and feces are harvested for further investigation. Results show that CHS inhibits ER stress, accompanied by lowered blood glucose, nitric oxide (NO), reactive oxygen (ROS), and free fatty acids (FFA) levels, and increases hepatic glycogen accumulation. Moreover, hepatic inflammation is improved by CHS treatment via inactivation of Toll-like receptor 4 (TLR4) signaling and its downstream c-jun N-terminal kinase (JNK) and nuclear factor kappa B (NFκB) pathways. Additionally, CHS regulates gut microbiota, particularly the decline in the Firmicutes to Bacteroidetes ratio. CHS also lowers fecal lipopolysaccharide and elevates several fecal short chain fatty acids. These findings suggest that CHS from H. burgeri skin may be an alternative functional food supplement for anti-ER stress, anti-inflammtion, and regulation of gut microbiota.