Dietary Supplementation with Nervonic Acid Ameliorates Cerebral Ischemia-Reperfusion Injury by Modulating of Gut Microbiota Composition-Fecal Metabolites Interaction.

SCOPE: Cerebral ischemia-reperfusion (IR) injury stands as a prominent global contributor to disability and mortality. Nervonic acid (NA), a bioactive elongated monounsaturated fatty acid, holds pivotal significance in human physiological well-being. This research aims to explore the prophylactic effects and fundamental mechanisms of NA in a rat model of cerebral IR injury. METHODS AND RESULTS: Through the induction of middle cerebral artery occlusion, this study establishes a rat model of cerebral IR injury and comprehensively assesses the pharmacodynamic impacts of NA pretreatment. This evaluation involves behavioral analyses, histopathological examinations, and quantification of serum markers. Detailed mechanisms of nervonic acid's prophylactic effects are revealed through fecal metabolomics and 16S rRNA sequencing analyses. Our findings robustly support nervonic acid's capacity to ameliorate neurological impairments in rats afflicted with cerebral IR injury. Beyond its neurological benefits, NA demonstrates its potential by rectifying metabolic perturbations across diverse pathways, particularly those pertinent to unsaturated fatty acid metabolism. Additionally, NA emerges as a modulator of gut microbiota composition, notably by selectively enhancing vital genera like Lactobacillus. CONCLUSION: These comprehensive findings highlight the potential of incorporating NA as a functional component in dietary interventions aimed at targeting cerebral IR injury.

A complementary method with PFBBr-derivatization based on a GC-EI-MS platform for the simultaneous quantitation of short-, medium- and long-chain fatty acids in murine plasma and feces samples.

Fatty acids (FAs) are essential molecules in all organisms and are involved in various physiological and pathophysiological processes. Pentafluorobenzyl bromide (PFBBr) is commonly used for FA derivatization for gas chromatography-mass spectrometry (GC-MS) quantification by chemical ionization (CI). While CI is the conventional ionization mode for PFBBr derivatization, the electron ionization (EI) source has also demonstrated efficacy in achieving satisfactory analytical performance for the analysis of PFB esters. In this study, we present a novel approach utilizing PFBBr-derivatization on a GC-EI-MS platform to quantitatively analyze a comprehensive range of 44 fatty acids (FAs) spanning from C2 to C24. The method's sensitivity, precision, accuracy, linearity, recovery, and matrix effect were rigorously validated against predetermined acceptance criteria. In comparison to the conventional CI ionization mode, the utilization of PFBBr-derivatization in GC-EI-MS exhibits a wider range of applications and achieves comparable sensitivity levels to the conventional CI platform. By using this method, we successfully quantified 44 FAs in plasma and feces samples from the mice with deoxynivalenol (DON)-induced kidney injury. Among these, the levels of most FA species were increased in the DON-exposure group compared with the control group. The orthogonal partial least squares discriminant analysis (OPLS-DA) of all the tested FAs showed a visual separation of the two groups, indicating DON exposure resulted in a disturbance of the FA profile in mice. These results indicate that the established method by integration of GC-MS with PFBBr derivatization is an efficient approach to quantify the comprehensive FA profile, which includes short-, medium- and long-chain FAs. In addition, our study provides new insights into the mechanism underlying DON exposure-induced kidney injury.

In-depth investigation of the therapeutic effect of Tribulus terrestris L. on type 2 diabetes based on intestinal microbiota and feces metabolomics.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Tribulus terrestris L. (TT) is extensively documented in the Tibetan medical literature 'Si Bu Yi Dian', has been used to treat diabetes mellitus for more than a thousand years. However, the underlying mechanisms and comprehensive effects of TT on diabetes have yet to be investigated. AIM OF THE STUDY: The aim of the study was to systemically elucidate the potential mechanisms of TT in treating diabetes mellitus, and further investigate the therapeutic effects of the water extract, small molecular components and saccharides from TT. MATERIALS AND METHODS: Fecal metabolomics was employed to draw the metabolic profile based on UHPLC-Q-TOF-MS/MS. The V3-V4 hypervariable regions of the bacteria 16S rRNA gene were amplified to explore the structural changes of the intestinal microbiome after TT intervention and to analyze the differential microbiota. The microbial metabolites SCFAs were determined by GC-MS, and the BAs and tryptophan metabolites were quantified by UPLC-TQ-MS. Spearman correlation analysis was carried out to comprehensively investigate the relationship among the endogenous metabolites profile, intestinal microbiota and their metabolites. RESULTS: TT exhibited remarkably therapeutic effect on T2DM rats, as evidenced by improved glucolipid metabolism and intestinal barrier integrity, ameliorated inflammation and remission in insulin resistance. A total of 24 endogenous biomarkers were screened through fecal metabolomics studies, which were mainly related to tryptophan metabolism, fatty acid metabolism, bile acid metabolism, steroid hormone biosynthesis and arachidonic acid metabolism. Investigations on microbiomics revealed that TT significantly modulated 18 differential bacterial genera and reversed the disordered gut microbial in diabetes rats. Moreover, TT notably altered the content of gut microbiota metabolites, both in serum and fecal samples. Significant correlation among microbial community, metabolites and T2DM-related indicators was revealed. CONCLUSIONS: The multiple components of TT regulate the metabolic homeostasis of the organism and the balance of intestinal microbiota and its metabolites, which might mediate the anti-diabetic capacity of TT.

Effect of ginger supplementation on the fecal microbiome in subjects with prior colorectal adenoma.

Ginger has been associated with a decreased incidence of colorectal cancer (CRC) through reduction in inflammatory pathways and inhibition of tumor growth. Recent pre-clinical models have implicated changes in the gut microbiome as a possible mediator of the ginger effect on CRC. We hypothesized that, in adults previously diagnosed with a colorectal adenoma, ginger supplementation would alter the fecal microbiome in the direction consistent with its CRC-inhibitory effect. Sixty-eight adults were randomized to take either ginger or placebo daily for 6 weeks, with a 6-week washout and longitudinal stool collection throughout. We performed 16S rRNA sequencing and evaluated changes in overall microbial diversity and the relative abundances of pre-specified CRC-associated taxa using mixed-effects logistic regression. Ginger supplementation showed no significant effect on microbial community structure through alpha or beta diversity. Of 10 pre-specified CRC-associated taxa, there were significant decreases in the relative abundances of the genera Akkermansia (p < 0.001), Bacteroides (p = 0.018), and Ruminococcus (p = 0.013) after 6-week treatment with ginger compared to placebo. Ginger supplementation led to decreased abundances of Akkermansia and Bacteroides, which suggests that ginger may have an inhibitory effect on CRC-associated taxa. Overall, ginger supplementation appears to have a limited effect on gut microbiome in patients with colorectal adenomas.

Specific dietary fibers prevent heavy metal disruption of the human gut microbiota in vitro.

Heavy metal exposure is a growing concern due to its adverse effects on human health, including the disruption of gut microbiota composition and function. Dietary fibers have been shown to positively impact the gut microbiota and could mitigate some of the heavy metal negative effects. This study aimed to investigate the effects of different heavy metals (As, Cd and Hg in different concentrations) on gut microbiota in the presence and absence of different dietary fibers that included fructooligosaccharides, pectin, resistant starch, and wheat bran. We observed that whereas heavy metals impaired fiber fermentation outcomes for some fiber types, the presence of fibers generally protected gut microbial communities from heavy metal-induced changes, especially for As and Cd. Notably, the protective effects varied depending on fiber types, and heavy metal type and concentration and were overall stronger for wheat bran and pectin than other fiber types. Our findings suggest that dietary fibers play a role in mitigating the adverse effects of heavy metal exposure on gut microbiota health and may have implications for the development of dietary interventions to reduce dysbiosis associated with heavy metal exposure. Moreover, fiber-type specific outcomes highlight the importance of evidence-based selection of prebiotic dietary fibers to mitigate heavy metal toxicity to the gut microbiota.

Absorption, Distribution, Metabolism, and Excretion of [14C]BS1801, a Selenium-Containing Drug Candidate, in Rats.

BS1801 is a selenium-containing drug candidate with potential for treating liver and lung fibrosis. To fully elucidate the biotransformation of BS1801 in animals and provide sufficient preclinical drug metabolism data for human mass balance study, the metabolism of BS1801 in rats was investigated. We used radiolabeling techniques to investigate the mass balance, tissue distribution, and metabolite identification of BS1801 in Sprague-Dawley/Long-Evans rats after a single oral dose of 100 mg/kg (100 µCi/kg) [14C]BS1801: 1. The mean recovery of radioactive substances in urine and feces was 93.39% within 168 h postdose, and feces were the main excretion route. 2. Additionally, less than 1.00% of the dose was recovered from either urine or bile. 3. BS1801-related components were widely distributed throughout the body. 4. Fifteen metabolites were identified in rat plasma, urine, feces, and bile, and BS1801 was detected only in feces. 5. BS1801-M484, the methylation product obtained via a N-Se bond reduction in BS1801, was the most abundant drug-related component in plasma. The main metabolic pathways of BS1801 were reduction, amide hydrolysis, oxidation, and methylation. Overall, BS1801 was distributed throughout the body, and excreted mainly as an intact BS1801 form through feces. No differences were observed between male and female rats in distribution, metabolism, and excretion of BS1801.

Growth performance, bile acid profile, fecal microbiome and serum metabolomics of growing-finishing pigs fed diets with bile acids supplementation.

The present experiment was conducted to determine the effect of bile acids (BAs) supplementation on growth performance, BAs profile, fecal microbiome, and serum metabolomics in growing-finishing pigs. A total of 60 pigs [Duroc × (Landrace × Yorkshire)] with an average body weight of 27.0 ±â€…1.5 kg were selected and allotted into one of 2 groups (castrated male to female ratio = 1:1), with 10 replicates per treatment and 3 pigs per replicate. The 2 treatments were the control group (control) and a porcine bile extract-supplemented group dosed at 0.5 g/kg feed (BA). After a 16-wk treatment, growth performance, BAs profiles in serum and feces, and fecal microbial composition were determined. An untargeted metabolomics approach using gas chromatography with a time-of-flight mass spectrometer was conducted to identify the metabolic pathways and associated metabolites in the serum of pigs. We found that BAs supplementation had no effect on the growth performance of the growing-finishing pig. However, it tended to increase the gain-to-feed ratio for the whole period (P = 0.07). BAs supplementation resulted in elevated serum concentrations of secondary bile acids, including hyodeoxycholic acid (HDCA), glycoursodeoxycholic acid, and tauro-hyodeoxycholic acid, as well as fecal concentration of HDCA (P < 0.05). Fecal microbiota analysis revealed no differences in alpha and beta diversity indices or the relative abundance of operational taxonomic units (OTUs) at both phylum and genus levels between groups. Metabolic pathway analysis revealed that the differential metabolites between control and BA groups are mainly involved in purine metabolism, ether lipid metabolism, glycerophospholipid metabolism, and amino sugar and nucleotide sugar metabolism, as well as primary bile acid biosynthesis. Our findings indicate that BAs supplementation tended to improve the feed efficiency, and significantly altered the BA profile in the serum and feces of growing-finished pigs, regardless of any changes in the gut microbial composition. The altered metabolic pathways could potentially play a vital role in improving the feed efficiency of growing-finished pigs with BAs supplementation.

Bile acids (BAs), known to exhibit a key role in emulsification and absorption of dietary fat in the intestinal lumen, have also become appreciated as important regulators of intestinal function, lipid and energy metabolism in humans and animals. This study investigated the effect of BAs supplementation on growth performance, BAs profile, fecal microbiome, and serum metabolomics in growing-finishing pigs. The results showed that BAs supplementation had few effects on pig growth performance and fecal microbiota, but modified serum and fecal BAs profile and serum metabolomics profile. The altered metabolic pathways could potentially play a vital role in improving the feed efficiency of growing-finished pigs with BAs supplementation.

Metabolic profiling of Qi-Yu-San-Long decoction in rat feces by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry combined with a post-targeted screening strategy.

Research into traditional Chinese medicine metabolism in feces is one of the key avenues to understanding the fate of traditional Chinese medicines in vivo. In this study, we used ultraperformance liquid chromatography-quadrupole time-of-flight MS in combination with a post-targeted screening strategy to identify the prototype components and metabolites in rat feces after oral administration. Based on our group's previous research, the component database of Qi-Yu-San-Long decoction (QYSLD) was established. Prototype components were screened from the fecal samples based on summarized chromatographic and MS behaviors. According to the chemical structure characteristics of related compounds, the possible metabolic pathways were inferred, and the metabolites related to QYSLD were predicted. We extracted ion chromatograms by predicting the m/z values of metabolite excimer ions and identified related metabolites based on their retention time and fragmentation behavior. A total of 93 QYSLD-related xenobiotics were confirmed or tentatively identified in rat fecal samples, and the results indicated that the main metabolic pathways of QYSLD were hydrolysis, deglycosylation, oxidation, reduction, decarboxylation, methylation and acetylation. This study presents a rapid method for identifying the prototype components and metabolites, and offers valuable insights into the biotransformation profiling of QYSLD in rat feces.

Microbial-Transferred Metabolites of Black Tea Theaflavins by Human Gut Microbiota and Their Impact on Antioxidant Capacity.

Theaflavins (TFs), the primary bioactive components in black tea, are poorly absorbed in the small intestine. However, the biological activity of TFs does not match their low bioavailability, which suggests that the gut microbiota plays a crucial role in their biotransformation and activities. In this study, we aimed to investigate the biotransferred metabolites of TFs produced by the human gut microbiota and these metabolites' function. We profiled the microbial metabolites of TFs by in vitro anaerobic human gut microbiota fermentation using liquid chromatography tandem mass spectrometry (LC-MS/MS) methods. A total of 17 microbial metabolites were identified, and their corresponding metabolic pathways were proposed. Moreover, full-length 16S rRNA gene sequence analysis revealed that the TFs altered the gut microbiota diversity and increased the relative abundance of specific members of the microbiota involved in the catabolism of the TFs, including Flavonifractor_plautii, Bacteroides_uniformis, Eubacterium_ramulus, etc. Notably, the antioxidant capacity of the TF sample increased after fermentation compared to the initial sample. In conclusion, the results contribute to a more comprehensive understanding of the microbial metabolites and antioxidant capacity of TFs.

Fast profiling of primary, secondary, conjugated, and sulfated bile acids in human urine and murine feces samples.

Bile acids (BAs) are a complex class of metabolites that have been described as specific biomarkers of gut microbiota activity. The development of analytical methods allowing the quantification of an ample spectrum of BAs in different biological matrices is needed to enable a wider implementation of BAs as complementary measures in studies investigating the functional role of the gut microbiota. This work presents results from the validation of a targeted ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of 28 BAs and six sulfated BAs, covering primary, secondary, and conjugated BAs. The analysis of 73 urine and 20 feces samples was used to test the applicability of the method. Concentrations of BAs in human urine and murine feces were reported, ranging from 0.5 to 50 nmol/g creatinine and from 0.012 to 332 nmol/g, respectively. Seventy-nine percent of BAs present in human urine samples corresponded to secondary conjugated BAs, while 69% of BAs present in murine feces corresponded to primary conjugated BAs. Glycocholic acid sulfate (GCA-S) was the most abundant BA in human urine samples, while taurolithocholic acid was the lowest concentrated compound detected. In murine feces, the most abundant BAs were α-murocholic, deoxycholic, dehydrocholic, and ß-murocholic acids, while GCA-S was the lowest concentrated BA. The presented method is a non-invasive approach for the simultaneous assessment of BAs and sulfated BAs in urine and feces samples, and the results will serve as a knowledge base for future translational studies focusing on the role of the microbiota in health.

Chemotherapy-induced weight gain in early-stage breast cancer: a prospective matched cohort study reveals associations with inflammation and gut dysbiosis.

BACKGROUND: Early-stage breast cancer patients treated with chemotherapy risk the development of metabolic disease and weight gain, which can result in increased morbidity and reduced quality of life in survivorship. We aimed to analyze changes within the gastrointestinal microbiome of early-stage breast cancer patients treated with and without chemotherapy to investigate a potential relationship between dysbiosis, a systemic inflammatory response, and resultant anthropomorphic changes. METHODS: We undertook an a priori analysis of serially collected stool and plasma samples from 40 patients with early-stage breast cancer who underwent adjuvant endocrine therapy only, adjuvant chemotherapy only, or both. Gut microbiota were assessed by metagenomic comparison of stool samples following deep sequencing. Inflammatory biomarkers were evaluated by proteomic analysis of plasma and measurement of fecal calprotectin. Body composition was investigated by dual-energy X-ray absorptiometry to determine biomass indices. RESULTS: As opposed to treatment with endocrine therapy only, chemotherapy resulted in statistically and clinically significant weight gain and an increase in the android to gynoid ratio of fat distribution. Patients treated with chemotherapy gained an average of 0.15% total mass per month, as opposed to a significantly different loss of 0.19% in those patients who received endocrine-only therapy. Concurrently, a twofold increase in fecal calprotectin occurred after chemotherapy that is indicative of interferon-dependent inflammation and evidence of colonic inflammation. These anthropomorphic and inflammatory changes occurred in concert with a chemotherapy-dependent effect on the gut microbiome as evidenced by a reduction in both the abundance and variety of microbial species. CONCLUSIONS: We confirm the association of chemotherapy treatment with weight gain and potential deleterious anthropometric changes and suggest that alterations of bacterial flora may contribute to these phenomena through the induction of systemic inflammation. Consequently, the gut microbiome may be a future target for intervention in preventing chemotherapy-dependent anthropometric changes.

Use of near-infrared reflectance spectroscopy on feces to estimate digestibility and dry matter intake of dietary nutritional characteristics under grazing conditions in Colombian creole steers.

Digestibility and intake are parameters difficult and expensive to estimate under grazing conditions; therefore, the aim of this study was to develop near-infrared reflectance spectroscopy (NIRS) calibrations applied to feces (F-NIRS) and evaluate their accuracy to predict dry matter digestibility (DMD) and dry matter intake (DMI) of Colombian creole cattle. Five digestibility trials using creole steers were conducted; indigestible neutral detergent fiber (iNDF) was used as internal marker and Cr2O3 and TiO2 as external markers. A total of 249 forage and 396 fecal samples from individual animals were collected, dried, and grinded for conventional chemical analysis. For spectral analysis, fecal samples were pooled across collection periods (77 samples). Chemometric analysis was performed using WinISI V4.10 software applying the modified partial least squares method. Cross-validation was performed to avoid overfitting the models. The goodness-of-fit statistics considered were the coefficient of determination in cross-validation and prediction sets (R2cv and r2, respectively) and the ratio performance deviation (RPD). Fecal NIRS calibrations developed for forage and supplement DMD showed a satisfactory fit (R2cv =0.87 and RPD=2.77 and R2cv=0.92 and RPD=3.50, respectively). The accuracy of fecal output equations using chromium (Cr) and titanium (Ti) was similar in terms of R2cv (0.92) and RPD (3.63 vs. 3.57). Total DMI equations using Ti performed better compared to Cr (R2cv = 0.82 vs. 0.78; RPD=2.41 vs. 2.17, respectively). The F-NIRS models were validated using a completely independent set of fecal samples showing a moderate fit (r2>0.8 and RPD>2.0). This study showed that F-NIRS is a feasible tool to predict DMD and DMI of creole steers under grazing conditions. However, previous to socialization, this requires an improvement in accuracy of the calibrated equations related to grazing animals in different production contexts.

Fibre fermentation and pig faecal microbiota composition are affected by the interaction between sugarcane fibre and (poly)phenols in vitro.

We investigated the effects of (poly)phenol-rich sugarcane extract (PRSE), sugarcane fibre (SCFiber), and the combination of them (PRSE + SCFiber) on the gut microbiota and short-chain fatty acids (SCFA) production using in vitro digestion and pig faecal fermentation. Measuring total phenolic content and antioxidant activity through the in vitro digestion stages showed that PRSE + SCFiber increased the delivery of (poly)phenols to the in vitro colonic fermentation stage compared to PRSE alone. The PRSE + SCFiber modulated the faecal microbiota profile by enhancing the relative abundances of Prevotella, Lactobacillus, and Blautia, and reducing the relative abundance of Streptococcus. PRSE + SCFiber also mitigated the inhibitory effects of PRSE on SCFA production. These results suggest that the inclusion of sugarcane fibre with PRSE could increase the availability of phenolic compounds in the colon and modulate the gut microbiota towards a more favourable profile.

Substrate degradation and postbiotic analysis of alternative fiber ingredients fermented using an in vitro canine fecal inoculum model.

Many fiber ingredients are used by the pet food industry; however, little data are available regarding the fermentation characteristics of alternative fibers currently being used. The objectives of this study were to determine organic matter disappearance (OMD) and postbiotic production from various fruit and vegetable fiber sources using an in vitro dog fecal inoculum model. Apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), tomato pomace (TP), and pea fiber (PF) were used as experimental treatments. Inoculum was prepared using freshly voided feces under anaerobic conditions. Predigested fibers were inoculated and incubated for 1, 3, 6, and 12 h at 39 °C. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), total volatile fatty acids (VFA), and OMD were determined for each fiber source and time point in triplicate. After 12 h of incubation, OMD was similar (P > 0.05; average of 18.5%) among treatments. Proportionally, acetate was greater for BP and AP (P < 0.05; average of 80.1%) than for the other treatments (68.3% to 71.2%). Molar proportions of propionate was greatest (P < 0.05) for CP (26.8%) compared to the remaining treatments (13.6 to 20.7%). Butyrate was proportionally greater for PF (7.7%; P < 0.05) than for BP and CP (average of 4.8%) and was lowest for AP (3.8%); however, TP was not different from PF (P > 0.05; average of 7.25%). Total VFA concentration was highest for AP (P < 0.05) followed by TP (1.17 and 0.75 mmol*g-1 of substrate, respectively). Both BP and PF were similar (average of 0.48 mmol*g-1 of substrate) and lower than for TP, with CP having the lowest VFA concentration (0.21 mmol*g-1 of substrate) among all treatments. Additionally, when comparing molar concentrations, AP and TP (average of 0.0476 mmol*g-1 of substrate) had greater butyrate concentrations than did PF (0.0344 mmol*g-1 of substrate). The AP, BP, and TP treatments had both linear and quadratic relationships (Table 7; P < 0.05) for acetate, propionate, and butyrate concentrations across time. CP only demonstrated a linear relationship for propionate (P < 0.05), whereas acetate and butyrate had quadratic relationships with time. PF only demonstrated quadratic relationships between acetate, propionate, and butyrate concentrations and time (P < 0.05). Overall, the fiber substrates evaluated were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Fibers fermented in the gut result in the production of short-chain fatty acids (SCFA) acetate, propionate, and butyrate. These postbiotic compounds, particularly butyrate, play an important role in colonic and host health. Fibers not degraded by the microbiota aid in stool formation and promote laxation. Many fiber ingredients are used in pet diets; however, data regarding the fermentation characteristics of alternative fiber ingredients are scarce. In this work, substrate degradation and postbiotic analysis were evaluated for apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), pea fiber (PF), and tomato pomace (TP) incubated for 1, 3, 6, and 12 h at 39 °C using canine fecal inoculum. After 12 h, substrate degradation was not different among treatments due to high variability. AP had the highest concentration of total SCFA, followed by TP, BP, PF, and CP. The molar proportion of acetate was greatest for AP and BP. CP had the highest molar proportion of propionate. PF had greater molar proportions of butyrate than did AP, BP, and CP, but had similar molar proportions as TP. Additionally, the molar concentrations of butyrate were greatest for AP and TP. Overall, fiber substrates were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Effects of forage phosphorous content on faecal phosphorous excretion and possible markers of low phosphorous intake in foals fed forage-only diets.

Knowledge of endogenous nutrient losses is important when estimating the nutrient requirements of animals. It has been suggested that faecal endogenous phosphorus (P) losses differ between growing and adult horses, but studies on foals are scarce. In addition, studies on foals on forage-only diets with different P contents are lacking. Thus this study: (1) assessed faecal endogenous P losses in foals fed a grass haylage-only diet close to or below estimated P requirements; (2) evaluated use of serum cross-linked carboxyterminal telopeptides of type-I collagen (CTx) as a marker of bone resorption secondary to low-P intake; and (3) examined whether analysis of faecal P concentration on a dry matter (DM) basis could be used as an indicator of P intake. Six foals were fed three grass haylages (fertilised to contain different amounts of P: 1.9, 2.1, 3.0 g/kg DM) for 17-day periods in a Latin square design. Total collection of feaces was performed by the end of each period. Faecal endogenous P losses were estimated using linear regression analysis. There was no difference in the concentration of CTx in plasma between diets in samples collected on the last day of each period. A correlation was found (y = 0.64x - 1.51; r2 = 0.75, p < 0.0001) between P intake and faecal P content, but regression analysis indicated that underestimation as well as overestimation of intake is likely if faecal P content is used to assess intake. It was concluded that faecal endogenous P losses in foals are low, probably no higher than in adult horses. It was also concluded that plasma CTx cannot be used to assess short-term low-P intake in foals and that faecal P content cannot be used to assess differences in P intake, at least not when P intake is close to or below estimated P requirements.

In-depth investigation of the mechanisms of Schisandra chinensis polysaccharide mitigating Alzheimer's disease rat via gut microbiota and feces metabolomics.

Schisandra chinensis (S. chinensis) is an herbal medicine used for the treatment of Alzheimer's disease (AD). The purified polysaccharide fraction, namely SCP2, was previously isolated from S. chinensis crude polysaccharide (SCP) and its structure and in vitro activity were investigated. However, the in vivo activity of SCP2 and its potential mechanism for the treatment of AD have yet to be determined. This study used a combination of microbiomics and metabolomics to comprehensively explore the microbiota and metabolic changes in AD rats under SCP2 intervention, with the aim of elucidating the potential mechanisms of SCP2 in the treatment of AD. SCP2 showed significant therapeutic effects in AD rats, as evidenced by improved learning and memory capacity, reduced neuroinflammation, and restoration of the integrity of the intestinal barrier. Fecal metabolomic and microbiomic analyses revealed that SCP2 significantly modulated 19 endogenous metabolites and reversed gut microbiota disorders in AD rats. Moreover, SCP2 significantly increased the content of short-chain fatty acid (SCFAs) in the AD rats. Correlation analysis showed a significant correlation between gut microbes, metabolites and the content of SCFAs. Collectively, these findings will provide the basis for further development of SCP2.

Evaluation of high-protein diets differing in protein source in healthy adult dogs.

Given the dynamic market for protein-based ingredients in the pet food industry, demand continues to increase for both plant- and animal-based options. Protein sources contain different amino acid (AA) profiles and vary in digestibility, affecting protein quality. The objective of this study was to evaluate the apparent total tract digestibility (ATTD) of canine diets differing in protein source and test their effects on serum metabolites and fecal characteristics, metabolites, and microbiota of healthy adult dogs consuming them. Four extruded diets were formulated to be isonitrogenous and meet the nutrient needs for adult dogs at maintenance, with the primary difference being protein source: 1) fresh deboned, dried, and spray-dried chicken (DC), 2) chicken by-product meal (CBPM), 3) wheat gluten meal (WGM), and 4) corn gluten meal (CGM). Twelve adult spayed female beagles (body weight [BW] = 9.9 ± 1.0 kg; age = 6.3 ± 1.1 yr) were used in a replicated 4 × 4 Latin square design (n = 12/treatment). Each period consisted of a 22-d adaptation phase, 5 d for fecal collection, and 1 d for blood collection. Fecal microbiota data were analyzed using QIIME 2.2020.8. All other data were analyzed using the Mixed Models procedure of SAS version 9.4. Fecal scores were higher (P < 0.05; looser stools) in dogs fed DC or CBPM than those fed WGM or CGM, but all remained within an appropriate range. Dry matter ATTD was lower (P < 0.05) in dogs fed CBPM or CGM than those fed DC or WGM. Crude protein ATTD was lower (P < 0.05) in dogs fed DC or CGM than those fed WGM. Dogs fed CBPM had lower (P < 0.05) organic matter, crude protein, and energy ATTD than those fed the other diets. Fecal indole was higher (P < 0.05) in dogs fed CBPM than those fed WGM. Fecal short-chain fatty acids were higher (P < 0.05) in dogs fed DC than those fed CGM. Fecal branched-chain fatty acids were higher (P < 0.05) in dogs fed DC or CBPM than those fed WGM. Fecal ammonia was higher (P < 0.05) in dogs fed DC or CBPM than those fed WGM or CGM. The relative abundances of three bacterial phyla and nine bacterial genera were shifted among treatment groups (P < 0.05). Considering AA profiles and digestibility data, the DC diet protein sources provided the highest quality protein without additional AA supplementation, but the animal-based protein diets resulted in higher fecal proteolytic metabolites. Further studies evaluating moderate dietary protein concentrations are needed to better compare plant- and animal-based protein sources.

Pet food trends are constantly changing. Because consumers are often focused on dietary proteins, with ingredient sources, dietary inclusion levels, and processing methods being important, they are a popular research topic. Protein sources contain different amino acid (AA) profiles and vary in digestibility, affecting protein quality. Our objective was to evaluate the apparent total tract digestibility of canine diets differing in protein source and test their effects on serum metabolites and fecal characteristics, metabolites, and microbiota of healthy adult dogs. Test diets were formulated to be similar nutritionally, but differed in protein source: fresh deboned, dried, and spray-dried chicken (DC), chicken by-product meal (CBPM), wheat gluten meal (WGM), and corn gluten meal (CGM). Fecal scores were higher in dogs fed chicken-based diets, but remained within an appropriate range. Dogs fed CBPM had lower nutrient and energy digestibilities than those fed the other diets, with protein digestibility also being lower in dogs fed DC or CGM than those fed WGM. Fecal metabolites and microbiota were shifted among diets, with animal-based protein diets increasing fecal protein metabolites. All diets were complete and balanced and performed well. When considering AA profiles and digestibility, however, the DC diet provided the highest protein quality.

Fecal microbiota transplantation and short-chain fatty acids protected against cognitive dysfunction in a rat model of chronic cerebral hypoperfusion.

AIMS: Clear roles and mechanisms in explaining gut microbial dysbiosis and microbial metabolites short-chain fatty acids (SCFAs) alterations in chronic cerebral ischemic pathogenesis have yet to be explored. In this study, we investigated chronic cerebral hypoperfusion (CCH)-induced gut microbiota and metabolic profiles of SCFAs as well as the effects and mechanisms of fecal microbiota transplantation (FMT) and SCFAs treatment on CCH-induced hippocampal neuronal injury. METHODS: Bilateral common carotid artery occlusion (BCCAo) was used to establish the CCH model. Gut microbiota and SCFAs profiles in feces and hippocampus were evaluated by 16S ribosomal RNA sequencing and gas chromatography-mass spectrometry. RNA sequencing analysis was performed in hippocampal tissues. The potential molecular pathways and differential genes were verified through western blot, immunoprecipitation, immunofluorescence, and ELISA. Cognitive function was assessed via the Morris water maze test. Ultrastructures of mitochondria and synapses were tested through a transmission electron microscope. RESULTS: Chronic cerebral hypoperfusion induced decreased fecal acetic and propionic acid and reduced hippocampal acetic acid, which were reversed after FMT and SCFAs administration by changing fecal microbial community structure and compositions. Furthermore, in the hippocampus, FMT and SCFAs replenishment exerted anti-neuroinflammatory effects through inhibiting microglial and astrocytic activation as well as switching microglial phenotype from M1 toward M2. Moreover, FMT and SCFAs treatment alleviated neuronal loss and microglia-mediated synaptic loss and maintained the normal process of synaptic vesicle fusion and release, resulting in the improvement of synaptic plasticity. In addition, FMT and SCFAs supplement prevented oxidative phosphorylation dysfunction via mitochondrial metabolic reprogramming. The above effects of FMT and SCFAs treatment led to the inhibition of CCH-induced cognitive impairment. CONCLUSION: Our findings highlight FMT and SCFAs replenishment would be the feasible gut microbiota-based strategy to mitigate chronic cerebral ischemia-induced neuronal injury.

Effects of a milk oligosaccharide biosimilar on fecal characteristics, microbiota, and bile acid, calprotectin, and immunoglobulin concentrations of healthy adult dogs treated with metronidazole.

In recent dog and cat experiments, a novel milk oligosaccharide biosimilar (GNU100) positively modulated fecal microbiota and metabolite profiles, suggesting benefits to gastrointestinal health. The objective of this study was to investigate the effects of GNU100 on the fecal characteristics, microbiota, and bile acid (BA) concentrations of healthy adult dogs treated with antibiotics. Twelve healthy adult female dogs (mean age: 3.74 ± 2.4 yr) were used in an 8-wk crossover design study (dogs underwent both treatments). All dogs were fed a control diet during a 2-wk baseline, then randomly allotted to 1 of 2 treatments (diet only or diet + 1% GNU100) for another 6 wk. From weeks 2 to 4, dogs were orally administered metronidazole (20 mg/kg BW) twice daily. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, and 8 for measurement of pH, dry matter, microbiota populations, and BA, immunoglobulin A, and calprotectin concentrations. On weeks 0, 4, and 8, blood samples were collected for serum chemistry and hematology analysis. All data were analyzed as repeated measures using the Mixed Models procedure of SAS version 9.4, with significance considered P < 0.05. Metronidazole increased (P < 0.0001) fecal scores (looser stools) and modified (P < 0.05) fecal microbiota and BA profiles. Using qPCR, metronidazole reduced fecal Blautia, Fusobacterium, Turicibacter, Clostridium hiranonis, and Faecalibacterium abundances, and increased fecal Streptococcus and Escherichia coli abundances. DNA sequencing analysis demonstrated that metronidazole reduced microbial alpha diversity and influenced the relative abundance of 20 bacterial genera and families. Metronidazole also increased primary BA and reduced secondary BA concentrations. Most antibiotic-induced changes returned to baseline by week 8. Fecal scores were more stable (P = 0.01) in GNU100-fed dogs than controls after antibiotic administration. GNU100 also influenced fecal microbiota and BA profiles, reducing (P < 0.05) the influence of metronidazole on microbial alpha diversity and returning some fecal microbiota and secondary BA to baseline levels at a quicker (P < 0.05) rate than controls. In conclusion, our results suggest that GNU100 supplementation provides benefits to dogs treated with antibiotics, providing more stable fecal scores, maintaining microbial diversity, and allowing for quicker recovery of microbiota and secondary BA profiles which play an essential role in gut health.

Our objective was to test the effects of a novel milk oligosaccharide biosimilar (GNU100) on the fecal characteristics, microbiota, and bile acid (BA) concentrations of healthy adult dogs treated with antibiotics. Dogs were fed a control diet during a 2-wk baseline, then randomly allotted to 1 of 2 treatments (diet only or diet + 1% GNU100) for another 6 wk. From weeks 2 to 4, dogs were given an oral antibiotic. Fecal scores were recorded and fresh fecal samples were collected over time to assess fecal characteristics, microbiota populations, and BA concentrations. The antibiotic was shown to increase fecal scores (looser stools) and modify fecal microbiota populations (altered diversity and ~20 bacterial genera and families) and BA profiles (increased primary and reduced secondary BA). Most antibiotic-induced changes returned to baseline by week 8. In dogs fed GNU100, fecal scores were more stable and changes to microbial diversity were lower than controls after antibiotic administration. Fecal microbiota and secondary BA of GNU100-fed dogs also returned to baseline levels at a quicker rate than controls. These results suggest that GNU100 provides benefits to dogs given antibiotics, providing more stable fecal scores, maintaining microbial diversity, and allowing for quicker recovery of microbiota and BA profiles.

Metabolite Identification of Huangqi Jianzhong Tang in Rat Urine and Feces after Oral Administration Based on UHPLC-Q-Exactive-MS.

Huangqi Jianzhong Tang (HQJZ), a famous traditional Chinese medicine formula, is widely used in the treatment of gastrointestinal diseases in China. In this study, an ultra-high-performance liquid chromatography coupled with quadrupole-Exactive mass spectrometry was used to identify the metabolites in rat urine and feces after oral administration of HQJZ coupled with Compound Discover 3.0 software. The possible metabolic pathways were calculated and deduced based on 71 previous detected prototype compounds. As results, 88 compounds were identified in urine and feces, respectively. In urine sample, we identified 20 prototype compounds and 68 related metabolites. Meanwhile, a total of 21 prototype compounds and 67 related metabolites were identified in feces. Among them, flavonoids and saponins were the main ingredients in vivo. Further, we also speculated that HQJZ experienced oxidation, reduction, acetylation, methylation and glucuronic acid reaction in urine and feces. This study established a reliable method for the detection of prototype components and metabolites of traditional Chinese medicines, which would provide helpful information for further research into the active substances of HQJZ.