Isobutyric Acid Concentrations Research Articles

Phenotypic traits related to methane emissions from Holstein dairy cows challenged by low or high forage proportion

Limited literature is available identifying phenotypical traits related to enteric methane (CH4) production from dairy cows, despite its relevance in relation to breeding for animals with a low CH4 yield (g/kg DMI), and the derived consequences hereof. This study aimed to investigate the relationships between CH4 yield and different animal phenotypes when 16 2nd parity dairy cows, fitted with a ruminal cannula, were fed 2 diets differing in forage:concentrate ratio in a crossover design. The diets had either a low forage proportion (35% on DM basis, F35) or a high forage proportion (63% on DM basis, F63). Gas exchange was measured by means of indirect calorimetry. Spot samples of feces were collected, and indigestible NDF (INDF) was used as an internal marker to determine total-tract digestibility. In addition, ruminal evacuations, monitoring of chewing activity, determination of ruminal VFA concentration, analysis of relative abundance of methanogens, and measurement of liquid passage rate were performed. Statistical differences were analyzed by a linear mixed model with diet, days in milk, and period as fixed effects, and cow as random effect. The random cow estimates (RCE) were extracted from the model to get the Pearson correlations (r) between RCE of CH4 yield with RCE of all other variables measured, to identify possible phenotypes related to CH4 yield. Significant correlations were observed between RCE of CH4 yield and RCE of OM digestibility (r = 0.63) and ruminal concentration of valeric acid (r = -0.61), acetic acid (r = 0.54), ammonium (r = 0.55), and lactic acid (r = ‒0.53). Additionally, tendencies were observed for correlations between RCE of CH4 yield and RCE of H2 yield in g/kg DM (r = 0.47, P = 0.07), and ruminal isobutyric acid concentration (r = 0.43, P = 0.09). No correlations were observed between RCE of CH4 yield and RCE of ruminal pool sizes, milk data, urinary measurements, or chewing activity. Cows had a lower DMI and ECM, when they were fed F63 compared with F35. Cows fed F63 had higher NDF digestibility, CH4 emissions (g/d, g/kg of DMI, and g/kg of ECM), ruminal concentration of acetic acid, ruminal pH, degradation rate of digestible NDF (DNDF, %/h), and longer rumen retention time (h). Also, rumination and total chewing time (min/kg DMI) were higher for cows fed F63. The results in the present study emphasize the positive relation between cow's ability to digest OM and their CH4 emissions. The derived consequences of breeding for lower CH4 emission might be cows with lower ability to digest OM, but more studies are warranted for further documentation of this relationship.

Whole-plant silage maize to improve fiber digestive characteristics and intestinal microbiota of Hezuo pigs.

Utilizing roughage resources is an effective approach to alleviate the shortage of corn-soybean feed and reducing the costs in the swine industry. Hezuo pig is one group of plateau type local Tibetan pig with strong tolerance to crude feeding. Nevertheless, current research on the roughage tolerance in Hezuo pigs and the microbiological mechanisms behind it is still minimally.This study explored the impact of various ratios of whole-plant silage (WPS) maize on the pH, cellulase activity, short-chain fatty acids (SCFAs), and intestinal microbiota in Hezuo pigs. Thirty-two Hezuo pigs were randomly divided into four groups (n = 8). The control group received a basal diet, while experimental groups I, II, and III were given diets with incremental additions of 5%, 10%, and 15% air-dried WPS maize, respectively, for 120 days. The findings revealed that compared with the control group, in Group II, the pH of cecum and colon were notably decreased (p < 0.05), while acid detergent fiberdigestibility, the concentration of propionic and isobutyric acid in the cecum, and the concentration of isobutyric acid in the colon were significantly increased (p < 0.05). Also, carboxymethyl cellulase activity in the cecum in group II of Hezuo pigs was significantly higher than that in the other three groups (p < 0.05). Furthermore, the cecum microbiota showed a higher diversity in the group II of Hezuo pigs than that in the control group, as shown by the Simpson and Shannon indices. Specifically, 15 and 24 bacterial species showed a significant difference in relative abundance at the family and genus levels, respectively. Correlation analyses revealed significant associations between bacterial genera and SCFAs concentrations in the cecum. The abundance of Bacteroides and NK4A214_group was positively correlated with amounts of valeric and isovaleric acid but negatively with propionic acid (p < 0.05). The abundance of UCG-010 was positively linked with acetic acid and negatively correlated with butyric acid (p < 0.05). Actinobacillus abundance was positively associated with butyric acid levels (p < 0.05). In conclusion, a 10% WPS maize diet improved crude fiber digestibility by lowering cecal and colonic chyme pH, enhancing intestinal cellulase activity, improving SCFA production, and increasing intestinal microbiota diversity.

Comparative impact of bacitracin and select feed additives in the feeding program of Lohmann LSL-Lite pullets at the onset of lay through to 31 weeks of age

Abstract There are limited investigations on the role of feed additives in easing transition of pullets to egg production phase. We investigated the effects of supplementation of bacitracin methylene disalicylate (BMD) and select feed additives (myristic acid [MA], benzoic acid [BA], and Aspergillus niger probiotic [PRO]) in feeding program for pullets from the onset of lay through to 31 weeks of age (woa). Parameters measured included hen-day egg production (HDEP), feed intake (FI), feed conversion ratio (FCR), egg quality characteristics, ceca microbial activity, apparent retention of components, and plasma metabolites. A total of 1,200 Lohmann LSL Lite pullets were procured at 18 woa and placed in enriched cages (30 birds/cage) based on body weight (BW) and allocated to five diets. The diets were a basal diet formulated to meet specifications or basal mixed with either BMD, MA, BA, or PRO. Birds had free access to feed and water throughout the experiment. Between 18 and 20 woa, birds fed BMD ate a similar (P &amp;gt; 0.05) amount of feed to BA birds, but more (P = 0.0003) than birds fed basal, MA, or PRO diets. Basal birds had lower HDEP (P = 0.001) and lighter eggs (P &amp;lt; 0.0001) than birds fed any of the feed additives between 21 and 31 woa. The basal hens had a higher (P = 0.009) abundance of Escherichia coli than birds fed BMD, BA, and PRO diets. Consequently, BMD, BA, and PRO birds had a higher (P = 0.011) Lactobacilli: E. coli ratio (LER) than hens fed the basal diet. Specifically, relative to basal-fed hens, the LER of the BMD, MA, BA, and PRO hens was higher by 37%, 21%, 26%, and 45%, respectively. Moreover, birds fed PRO tended to have a higher concentration of ceca digesta acetic acid (P = 0.072) and a lower concentration of isobutyric acid (P = 0.096). In conclusion, supplementing pullet diets with broad-spectrum antibiotics or feed additives (MA, BA, and PRO) had a positive impact on FI, and egg production linked to modulation of indices of gut health. The results suggested supplementing feed additives in feeding programs for pullets at the onset of lay can bolster productivity outcomes.

Metabolomic analysis of serum short-chain fatty acid concentrations in a mouse of MPTP-induced Parkinson's disease after dietary supplementation with branched-chain amino acids.

The gut microbiota and microbial metabolites influence the enteric nervous system and the central nervous system via the microbial-gut-brain axis. Increasing body of evidence suggests that disturbances in the metabolism of peripheral branched-chain amino acids (BCAAs) can contribute to the development of neurodegenerative diseases through neuroinflammatory signaling. Preliminary research has shown that longitudinal changes in serum amino acid levels in mouse models of Parkinson's disease (PD) are negatively correlated with disease progression. Therefore, the aim of the present study was to determine the changes in serum levels of short-chain fatty acids (SCFAs) in a mouse model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD after dietary BCAA supplementation. In our research, gas chromatography-mass spectrometry was used to detect serum SCFA concentrations. The data were then analyzed with principal component analysis and orthogonal partial least squares discriminant analysis. Finally, the correlations of serum SCFA levels with gut and motor function in MPTP-induced PD mice were explored. Propionic acid, acetic acid, butyric acid, and isobutyric acid concentrations were elevated in MPTP + H-BCAA mice compared with MPTP mice. Propionic acid concentration was increased the most, while the isovaleric acid concentration was decreased. Propionic acid concentration was positively correlated with fecal weight and water content and negatively correlated with the pole-climbing duration. In conclusion, these results not only suggest that propionic acid may be a potential biomarker for PD, but also indicate the possibility that PD may be treated by altering circulating levels of SCFA.

Dietary NDF/Starch Ratio Modulates Colonic Microbiota and Metabolites in Lambs before and after Weaning

The neutral detergent fiber (NDF)/starch ratio is a key determinant of the carbohydrate composition in ruminant diets, which affects the development of the gastrointestinal tract and animal growth. In this study, we used a combination of 16S amplicon sequencing and metabolomics technologies to reveal changes in the microbiota and their metabolites associated with digestive matter in the colon of lambs between different starter NDF/starch ratios and before and after weaning. A total of 40 male lambs of Hu sheep with a newborn weight of 3.14 ± 0.05 kg were selected for the experiment and fed with breast milk until 10 days of age, and were randomly divided into 2 groups, which were fed ad libitum with a starter of NDF/starch of 0.5 (A) or 1.0 (B) for a period of 56 days, and then weaned off the milk powder at 35 days of age. Six lambs with weights close to the average weight of the group were selected for slaughter in each of the two groups before (35 days of age) and after weaning (56 days of age), and were accordingly named A35, A56, B35 and B56. The results showed that, before weaning, the concentrations of acetic acid, propionic acid, butyric acid and total volatile fatty acids (TVFA) in group B35 were significantly higher than those in group A35 (p &lt; 0.05), while the concentrations of isobutyric acid, valeric acid and isovaleric acid were significantly lower than those in group A35 (p &lt; 0.05). After weaning, the concentrations of all volatile acids and total acids in group B56 were significantly lower than those in group A56 (p &lt; 0.01). At the phylum level, the dominant phyla identified were Firmicutes and Bacteroidetes; the relative abundances of Firmicutes and Desulfobacterota were significantly higher and lower in group B35 than in group A35, respectively (p &lt; 0.05); the relative abundances of Euryarchaeota and Desulfobacterota were significantly higher and lower in group A56 than in group A35 (p &lt; 0.05); and, at the genus level, the relative abundance of Lachnospiraceae_FCS020_group and Eubacterium nodatum group had higher relative abundance in group B35 before weaning (p &lt; 0.05). Metabolomic results showed that feeding 1.0 NDF/starch ratio starter before weaning significantly up-regulated (p &lt; 0.05) the concentrations of several anti-inflammatory-related metabolites such as lithocholic acid, oleanolic acid and LysoP. After weaning, the number of differential microorganisms and anti-inflammatory-related metabolites decreased between the two ratios. In summary, feeding a 1.0 NDF/starch ratio starter may be more effective in regulating microbial fermentation, leading to an increase in beneficial microbiota and metabolites, thus improving colonic environmental homeostasis in lambs before and after weaning.

Effects of dietary rumen-protected choline supplementation to periparturient dairy cattle on inflammation and metabolism in mammary and liver tissue during an intramammary lipopolysaccharide challenge

The objective of this experiment was to examine the effects of supplementation and dose of rumen-protected choline (RPC) on markers of inflammation and metabolism in liver and mammary tissue during an intramammary lipopolysaccharide (LPS) challenge. Parous Holstein cows were blocked by calving month and randomly assigned within block to receive 45 g/d of RPC (20.4 g/d of choline ions; CHOL45), 30 g/d of RPC (13.6 g/d of choline ions; CHOL30), or no RPC (CON) as a top-dress starting 24 d before expected calving until 21 d postpartum. Cows were alternately assigned within treatment group to either receive an intramammary LPS challenge (200 μg in each rear quarter; Escherichia coli O111:B4) or not at 17 DIM (CHOL45, n = 9; CHOL45-LPS, n = 9; CHOL30, n = 11; CHOL30-LPS, n = 10; CON, n = 10; CON-LPS, n = 9). Hepatic and mammary tissues were collected from all cows on d 17 postpartum. Hepatic and mammary tissues were collected at ∼7.5 and 8 h, respectively, after the LPS challenge. An additional mammary biopsy was conducted on LPS-challenged cows (CHOL45-LPS, CHOL30-LPS, and CON-LPS) at 48 h postchallenge. Hepatic and mammary RNA copy numbers were quantified for genes involved in apoptosis, methylation, inflammation, oxidative stress, and mitochondrial function using NanoString technology. Targeted metabolomics was conducted only on mammary tissue samples (both 8 and 48 h biopsies) to quantify 143 metabolites including choline metabolites, amino acids, biogenic amines and derivatives, organic acids, carnitines, and glucose. Hepatic IFNG was greater in CHOL45 as compared with CON in unchallenged cows, suggesting an improvement in type 1 immune responses. Hepatic CASP3 was greater in CHOL45-LPS as compared with CON-LPS, suggesting greater apoptosis. Mammary IL6 was reduced in CHOL30-LPS cows as compared with CHOL45-LPS and CON-LPS (8 and 48 h). Mammary GPX4 and COX5A were reduced in CHOL30-LPS as compared with CON-LPS (8 h), and SDHA was reduced in CHOL30-LPS as compared with CON-LPS (8 and 48 h). Both CHOL30-LPS and CHOL45-LPS cows had lesser mammary ATP5J than CON-LPS, suggesting that dietary RPC supplementation altered mitochondrial function following LPS challenge. Treatment did not affect mammary concentrations of any metabolite in unchallenged cows, and only 4 metabolites were affected by dietary RPC supplementation in LPS-challenged cows. Mammary concentrations of isobutyric acid and 2 acyl-carnitines (C4:1 and C10:2) were reduced in CHOL45-LPS as compared with CHOL30-LPS and CON-LPS. Taken together, reductions in medium- and short-chain carnitines along with an increase in long-chain carnitines in mammary tissue from CHOL45-LPS cows suggests less fatty acid entry into the β oxidation pathway. Although the intramammary LPS challenge profoundly affected markers for inflammation and metabolism in liver and mammary tissue, dietary RPC supplementation had minimal effects on inflammatory markers and the mammary metabolome.

Effects of Bacillus licheniformis on the Growth Performance, Antioxidant Capacity, Ileal Morphology, Intestinal Short Chain Fatty Acids, and Colonic Microflora in Piglets Challenged with Lipopolysaccharide

The aim of the present study was to investigate the effects of Bacillus licheniformis (BL) on the growth performance, antioxidant capacity, ileal morphology, intestinal fecal short-chain fatty acids, and microflora of weaned piglets challenged with lipopolysaccharide (LPS). Piglets were assigned into three groups: basal diet (Con), a basal diet with added 109 CFU B. licheniformis/kg (BLl), and a basal diet with added 1010 CFU B. licheniformis/kg (BLh). On day 28, BLh piglets were intraperitoneally injected with LPS (CBL) and sterilized saline water (BL), Con piglets were injected with LPS (LPS) and sterilized saline water (Con), with the injections being administered for three consecutive days. The average daily gain significantly increased from day 1 to day 28 and the feed: gain ratio decreased with BL supplementation compared with the Con group. Supplementation with BLl and BLh reduced the diarrhea rate in piglets. Serum catalase activity increased and malondialdehyde concentration decreased in the CBL treatment group compared with the LPS treatment group. Both BL and CBL treatments increased the ileal villus length/crypt depth ratio compared with Con and LPS treatments. BL administration significantly increased colonic propionic and isobutyric acid concentrations compared with Con treatment. Both BL and CBL piglets had significantly increased fecal acetic, propionic, and butyric acid levels compared with LPS piglets. Analysis of the colonic microbial metagenome showed that Prevotella species were the predominant bacteria in piglets treated with BL and CBL. The CBL-treated piglets had higher scores for lysine biosynthesis, arginine biosynthesis, sulfur relay system, and histidine metabolism. BL-treated piglets had higher scores for glycosaminoglycan biosynthesis-keratan sulfate, oxidative phosphorylation, and pyruvate and carbon metabolism.

Effects of Ecologically Relevant Concentrations of Cadmium on the Microbiota, Short-Chain Fatty Acids, and FFAR2 Expression in Zebrafish.

Exposure to cadmium (Cd) can affect neurodevelopment and results in increased potential of developing neurodegenerative diseases during the early developmental stage of organisms, but the mechanisms through which exposure to environmentally relevant concentrations of Cd lead to developmental neurotoxicity remain unclear. Although we know that microbial community fixations overlap with the neurodevelopmental window during early development and that Cd-induced neurodevelopmental toxicity may be related to the disruption of microorganisms during early development, information on the effects of exposure to environmentally relevant Cd concentrations on gut microbiota disruption and neurodevelopment is scarce. Therefore, we established a model of zebrafish exposed to Cd (5 µg/L) to observe the changes in the gut microbiota, SCFAs, and free fatty acid receptor 2 (FFAR2) in zebrafish larvae exposed to Cd for 7 days. Our results indicated that there were significant changes in the gut microbial composition due to the exposure to Cd in zebrafish larvae. At the genus level, there were decreases in the relative abundances of Phascolarctobacterium, Candidatus Saccharimonas, and Blautia in the Cd group. Our analysis revealed that the acetic acid concentration was decreased (p > 0.05) while the isobutyric acid concentration was increased (p < 0.05). Further correlation analysis indicated a positive correlation between the content of acetic acid and the relative abundances of Phascolarctobacterium and Candidatus Saccharimonas (R = 0.842, p < 0.01; R = 0.767, p < 0.01), and a negative correlation between that of isobutyric acid and the relative abundance of Blautia glucerasea (R = -0.673, p < 0.05). FFAR2 needs to be activated by SCFAs to exert physiological effects, and acetic acid is its main ligand. The FFAR2 expression and the acetic acid concentration were decreased in the Cd group. We speculate that FFAR2 may be implicated in the regulatory mechanism of the gut-brain axis in Cd-induced neurodevelopmental toxicity.

Pueraria lobata polysaccharides alleviate neonatal calf diarrhea by modulating gut microbiota and metabolites.

Neonatal calf diarrhea (NCD) is still one of the most critical diseases in calf rearing. Studies have shown that Pueraria lobata polysaccharides (PLP) have intense antioxidant and immunomodulatory activity and modulate gut microbiota. This randomized clinical trial aimed to determine the effect of PLP on the neonatal calf with diarrhea. In this study, we recorded the fecal score of experimental calves, and calves with fecal scores ≥ 2 were determined as diarrhea and assessed their serum concentrations of inflammatory cytokines and oxidative damage-related indices. Fecal microbiota and metabolomics of diarrheal calves were further investigated. Results showed that treatment with PLP decreased the fecal score of diarrheal calves, serum concentrations of IL-1β, TNF-γ, and malondialdehyde, and also elevated the level of superoxide dismutase. In addition, PLP treatment altered the gut microbiota, significantly increased the relative abundances of beneficial bacteria, including the phyla Bacteroidetes and Actinobacteria, the genus Collinsella, Megamonas, and Bifidobacterium; decreased the relative abundances of pathogenetic or diarrhea related bacteria, such as Proteobacteria, Fusobacteria, Clostridium_sensu_stricto_1, and Escherichia_Shigella. Moreover, PLP can increase the fecal concentrations of isobutyric acid, propionic acid, and pantothenate; lower the levels of PC [18:0/18:1(9Z)], arachidonic acid, and docosahexaenoic acid. Thus, the results suggested that the PLP may perform the therapeutic activity via alleviating intestinal inflammation and regulating gut microbiota, avoiding further dysbiosis to restore the metabolism of gut microbiota, and finally promoting the recovery of diarrhea. The change further mitigated intestinal inflammation and oxidative damage in diarrheal calves. This indicated that PLP might be a promising treatment to attenuate diarrhea in neonatal calves.

Dietary silymarin ameliorating reproductive and lactation performance of sows via regulating body antioxidant and metabolism

ObjectiveThe experiment was conducted to explore the effects of silymarin on reproductive and lactation performance, serum antioxidants, and body metabolism of sows. MethodsSixty pregnant sows (85 d, Large × Landrace) with similar genetic background, body condition, and parity were randomly divided into three groups, and each group has 20 individually housed sows. The sows in the control group (CG) were fed with basal diet, and those in the experimental group A (EGA) and B (EGB) were fed with basal diet containing 250 and 500 mg/kg silymarin, respectively. The experiment lasted 46 days from day 85 of gestation to the end of lactation (weaning on day 17 ).The milk composition and serum biochemical parameters were determined by a milk composition analyzer and a blood biochemical analyzer, respectively. Serum antioxidant indexes and plasma hormone levels were measured using the biochemical kits. The gas chromatograph was applied to detect the fecal short chain fatty acids. ResultsCompared with the CG, the total feed intake (TFI) and average daily feed intake (ADFI) were significantly increased (P < 0.01), and the urea content in regular milk tended to increase (P = 0.095) in the EG. The serum malondialdehyde (MDA) contents were decreased on day 90 of gestation and the day of farrowing (P < 0.01), and the serum contents of total antioxidant capacity (T-AOC) tended to increase on day 17 of lactation (P = 0.099) compared with the CG. Compared with the CG, the serum triglyceride (TG) concentrations in the EG tended to increase on day 90 of gestation (P = 0.062), and the content of serum total protein (TP) and albumin (ALB) reduced on day 17 of lactation (P < 0.01). Compared with the CG, plasm D-lactic acid content was decreased (P < 0.05), and the plasma prostaglandin (PG) level tended to increase (P = 0.088) in the EG on the day of farrowing and day 17 of lactation. Compared with the CG, fecal isobutyric acid concentration in the EG significantly decreased on the day of farrowing ( P < 0.05). ConclusionAdding 250 – 500 mg/kg silymarin to diets from the late gestation to the end of lactation could improve reproductive and lactation performance of sows via the regulation of nutrient metabolism and serum antioxidant.

Effects of compound of hawthorn (Crataegus pinnatifida) and Chinese yam (Dioscorea opposita Thunb.) extracts on growth performance, intestinal health, and immune function in weaned pigs.

Plant extracts were considered as natural resources to alleviate weaning stress in pig production. A 28-day study (Phase 1: d 0-14 and Phase 2: d 15-28) was conducted to investigate the effects of compound of hawthorn and yam extracts on growth performance, intestinal health, and immune function in weaned pigs. A total of 144 weaned pigs with average body weight (BW) of 7.89 ± 1.09 kg were assigned to three treatments with six replicates pens by BW and sex. Dietary treatments included negative control (NC), corn-soybean meal basal diet; positive control (PC), NC + 0.08% enzyme preparations and 0.3% acidifiers; and CHY, NC + 0.3% compound of hawthorn and yam extracts. Compared with NC-fed pigs, pigs fed CHY had greater (p < 0.05) growth performance in Phase 1. The CHY-fed pigs had greater (p < 0.05) activities of duodenal lipase, trypsin, and greater (p < 0.05) serum concentrations of total antioxidant capacity and glutathione peroxidase. The CHY-fed pigs had improved (p < 0.05) jejunal morphology and greater (p < 0.05) ileac valeric acid and colonic propionic acid, isobutyric acid concentrations than NC- and PC-fed pigs. In conclusion, CHY can improve growth performance and is a promising additive in weaned pig diets.

Research Note: Integrated gut microbiome and short-chain fatty acids responds to dominance hierarchy in roosters

The dominant chickens have priority over the use of resources, such as resting places and the announcement of dawn. While cooperation from the subdominant animal is of great help to reduce conflict and maintain the sustainability of a group. However, whether the dominance hierarchy is associated with individuals’ health is not yet known. In this study, we first determined the dominance hierarchy within a group of roosters, to figure out its effects on individuals’ health status by the determination of microbial composition and short-chain fatty acids (SCFAs). Sixteen Weining roosters were kept in a group in order to fix and determine the ranking of dominance hierarchy, as R1 (the highest-ranking rooster), R2, R3, and R4. Results show that the R1 roosters had the highest aggression behavior followed by R2, R3 and R4 (P < 0.05). The alpha diversity of R1, R2, and R4 was higher than R3 roosters (P < 0.05). There were several top 10 phylum and genus microbes among the different ranking roosters (P < 0.05). The acetic acid, propionic acid, butyric acid, and valerate acid concentrations were higher, while isobutyric acid concentration was lower in the higher rank roosters (R1 and R2) than the lower rank roosters, respectively (R3 and R4) (P < 0.05). Our results show that the variation of dominance hierarchy contributes to changes of microbial composition, diversity and metabolites. Dominant roosters seem to benefit from SCFAs activities while subdominant roosters profit from microbial functions.

The effect of dietary supplementation with silkworm pupae meal on gastrointestinal function, nitrogen retention and blood biochemical parameters in rabbits

BackgroundThe aim of this study was to determine the effect of dietary inclusion of silkworm pupae meal (SPM) on nutrient digestibility, nitrogen utilization, gastrointestinal physiology and blood biochemical parameters in rabbits. Thirty Termond White rabbits were divided into three groups: SBM – fed a diet containing 10% soybean meal (SBM), SPM5 – fed a diet containing 5% SBM and 5% SPM, and SPM10 – fed a diet containing 10% SPM.ResultsNutrient digestibility and nitrogen retention decreased with increasing SPM inclusion levels in rabbit diets. The dietary inclusion of SPM caused a significant increase in the stomach pH. Group SPM10 rabbits were characterized by the highest cecal tissue and digesta weights. The lowest cecal pH was noted in group SPM5. The relative weights of colonic tissue and digesta tended to increase with increasing levels of SPM. The total and intracellular activity of bacterial α-galactosidase decreased significantly in both SPM groups. The replacement of SBM with SPM led to a decrease in the activity of bacterial β-glucuronidase in the cecal digesta. The intracellular activity of bacterial α-arabinofuranosidase increased, and its release rate decreased in the cecum of rabbits in SPM groups. The extracellular activity of bacterial β-xylosidase in the cecal digesta tended to decrease in group SPM10. The highest extracellular and intracellular activity of bacterial β-cellobiosidase in the cecal digesta was noted in the SPM5 treatment. The lowest and the highest activity of bacterial N-acetyl-β-D-glucosaminidase (NAGase) was observed in groups SBM and SPM10. The SPM10 treatment contributed to a decrease in the cecal concentrations of butyric, iso-valeric and valeric acids. The lowest total concentration of putrefactive short-chain fatty acids (PSCFAs) was observed in group SPM10. The cecal concentration of propionic acid tended to increase in group SPM5, whereas the cecal concentration of iso-butyric acid tended to decrease in group SPM10. The colonic concentration of iso-valeric acid was lowest in group SPM5. SPM treatments resulted in a significant increase in plasma albumin concentration. Plasma urea concentration was significantly higher in group SPM10 than in SBM and SPM5.ConclusionsThe results of this study suggest that rabbit diets can be supplemented with SPM at up to 5%.

The metabolic effect of fructose on normal rats in a mild dose with glucose and saccharose as control.

AimsTo study the metabolic effects of fructose, glucose and saccharose in a moderate dose by analyzing changes of blood indicators, pancreas inflammation, liver fat accumulation and intestinal microbiota in normal Sprague-Dawley (SD) rats.Subjects and methodsSix-week-old rats were assigned to four groups (n = 10), which were gavaged with normalsaline (Con), glucose dissolved in normal saline (Glu), saccharose-glucose dissolved in normal saline (Sac), and fructose dissolved in normal saline (Fru) for 20 weeks.ResultsNo significant differences in body weight and blood parameters including total cholesterol (TC), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), lipase (LPS) and free fatty acid (FFA) among the Con, Glu, Sac and the Fru group. The fructose can significantly (P < 0.05) decrease fasting and postprandial blood glucose increase compared to glucose, and the risk of pancreas inflammation and liver fat accumulation induced by fructose is lower than glucose in rats. We found there were no significant differences in intestinal microbial diversity. At the family level, rats in the Glu group had a relatively higher abundance of Peptostreptococcaceae and rats in the Fru group had a relatively higher abundance of Bacteroidaceae. Moreover, the proportions of Peptostreptococcaceae romboutsia and Staphylococcus lentus in the Glu group were significantly higher than in the Fru group, while the proportions of Lachnospira; Lachnospiraceae blautia, Bacteroides and Cellulosilyticus in the Fru group were significantly higher than in the Glu group. The concentration of isobutyric acid was relatively lower in all the sugar treated groups than in the Con. A significant decrease in isobutyric acid was found on comparing the Fru group to the Con group (P < 0.05).ConclusionFructose, glucose and sucrose made no significant changes on rats in body weight, blood indicators, organ index and bacterial diversity. Moreover, fructose can potentially attenuate fasting and postprandial blood-glucose increase, pancreas inflammation and liver-fat accumulation when compared to glucose in mild doses. The relative abundance of six kinds of bacterial genera was found significantly different between rats fed on fructose and glucose.

Bacteroides ovatus Influences the Levels of Intestinal Neurotransmitters in a Gnotobiotic Model

Background Microbial metabolites and colonization have been associated with the levels and turn-over of a wide range of host neurotransmitters. Although animal models have been paramount in linking microbes to fundamental gastrointestinal and neural processes, the majority of current work has focused on complete microbial communities. The complex nature of these communities’ obscures which species drive neurotransmitter changes and makes it challenging to identify specific gut-brain-axis pathways. Previous studies have identified that Bacteroides, a dominant member of the human gut microbiome, can influence the gut-brain-axis; although the exact pathways of communication remain unclear. We hypothesized that Bacteroides species could influence gut neurotransmitter levels, initiating communication between distant organs. Methods & Result We grew B. ovatus, a representative human gut commensal, in a fully defined bacteria media, ZMBI, and examined short chain fatty acids and neurotransmitters by targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS). We found that B. ovatus generates high levels of acetic acid and propionic acid, and relatively low concentrations of isobutyric acid and isovaleric acid. Pathway analysis revealed that B. ovatus consumed tryptophan and glutamate, and synthesized glutamine and GABA, potent neurotransmitters. We did not observe serotonin, 5-HIAA, melatonin, 5-hydroxytryptophan, dopamine, norepinephrine, or epinephrine in any of the samples. To determine how B. ovatus secreted products influenced neurotransmitter release from the intestinal epithelium, we microinjected intestinal organoids with B. ovatus supernatant. B. ovatus injected organoids were also found to have increased concentrations of tyrosine and tyramine compared to media control. Interestingly, B. ovatus was not found to stimulate host serotonin, melatonin, 5-HIAA or 5-hydroxytryptophan. Finally, we mono-associated germ-free adult C57BL/6J mice with the commensal B. ovatus for 17 days and examined colonic short chain fatty acids and neurotransmitters levels. Similar to B. ovatus supernatant, we observed acetic acid, propionic acid, isobutyric acid and isovaleric acid in gnotobiotic intestines. Complementing our organoid experiments, the concentrations of serotonin, melatonin, 5-HIAA and 5-hydroxytryptophan were not changed in B. ovatus mono-associated mice. However, B. ovatus mono-associated mice did increase intestinal tyrosine, glutamate, glutamine and GABA concentrations compared to germ-free controls. Conclusions These results highlight novel connections between microbial colonization and neurotransmitters. Our data indicates that B. ovatus selectively influences intestinal neurotransmitters levels, particular those of the GABA/Glu/Gln pathway, which likely has far reaching implications on human health.

PSX-7 Effect of varying levels of hempseed meal supplementation on animal performance, rumen fermentation, and blood metabolites of growing meat goats

Abstract Hempseed meal (HSM) is a byproduct of hemp oil production and is high in crude protein, fiber, and fat, making it a potential feedstuff for ruminants. The objective of this study was to evaluate the effect of HSM supplementation on growth performance, rumen fermentation and blood chemistry profile of growing meat goats. Forty castrated, Boer cross goats were randomly assigned to one of the four treatments (n = 10): control, 10%, 20%, and 30% HSM supplementation. Data collected over a period of a 60-day feeding trial were analyzed utilizing the mixed model analysis function of SYSTAT, version 13. The result revealed total live weight gain decreased with the increasing levels of HSM supplementation 10.75, 9.53, 8.48, and 7.80 kg, for 0, 10, 20, and 30%, respectively. Average daily gain followed the same trend 0.179, 0.159, 0.141, and 0.13 kg, with a significant difference (P &amp;lt; 0.05) observed between the control and 30 % supplementation. Conversely, feed to gain ratio increased with the increasing levels of supplementation 9.0, 10.2, 11.9, 12.2, likewise a significant difference was observed (P &amp;lt; 0.05) between the control and 30% supplementation. Acetic, propionic, butyric, valeric, iso-valeric, and iso-butyric acid concentrations as well as the total VFA concentration decreased significantly (P &amp;lt; 0.05) with the increasing level of supplementation. Acetic to propionic acid ratios increased with increasing level of supplementation 3.43, 4.36, 4.52, and 4.59, significant differences (P &amp;lt; 0.05) were observed between control-20% and 30% HSM group. Serum glucose concentration decreased with an increasing rate of HSM supplementation while BUN concentration increased with no significant differences. These findings provide new insights into the feeding value of HSM for meat goats; however, further research needs to be conducted to determine the optimal level of supplementation.

Stool Short-Chain Fatty Acids in Critically Ill Patients with Sepsis

Objective: To determine the concentration of stool short-chain fatty acids (SCFAs) in critically ill patients with sepsis and to compare the results between the critically ill patient and the control group.Methods: This descriptive, multicenter, observational study was conducted in five health institutions. Over a 6-month study period, critically ill patients with sepsis who were admitted to the intensive care unit (ICU) and met the inclusion criteria were enrolled, and a control, paired by age and sex, was recruited for each patient. A spontaneous stool sample was collected from each participant and a gas chromatograph coupled to a mass spectrometer (Agilent 7890/MSD 5975 C) was used to measure the concentrations SCFAs.Results: The final sample included 44 patients and 45 controls. There were no differences in the age and sex distributions between the groups (p > 0.05). According to body mass index (BMI), undernutrition was more prevalent among critically ill patients, and BMI in control subjects was most frequently classified as overweight (p = 0.024). Propionic acid, acetic acid, butyric acid, and isobutyric acid concentrations were significantly lower in the critically ill patient group than in the control group (p = 0.000). No association with outcome variables (complications, ICU stay, and discharge condition) was found in the patients, and patients diagnosed with infection on ICU admission showed significant decreases in butyric and isobutyric acid concentrations with respect to other diagnostic criteria (p < 0.05).Conclusions: The results confirm significantly lower concentrations of stool SCFAs in critically ill patients with sepsis than in control subjects. Due to its role in intestinal integrity, barrier function, and anti-inflammatory effect, maintaining the concentration of SCFAs may be important in the ICU care protocols of the critical patient.

Different dietary lipid consumption affects the serum lipid profiles, colonic short chain fatty acid composition and the gut health of Sprague Dawley rats

Palm oil (PO), leaf lard oil (LO), rapeseed oil (RO), sunflower oil (SO), and linseed oil (LINO) are the five of the most typical dietary lipids, while few studies have explored and compared their influences on the serum lipid profiles, colonic short chain fatty acids (SCFAs) composition and colon health of Sprague Dawley (SD) rats. Results from the present work showed that PO and LO groups showed significantly higher serum TG and TC level compared with Ctrl group, whereas, the LDL-C/HDL-C and TC/HDL-C ratio were significantly lower in the RO, SO and LINO groups. Different dietary lipid consumption (15% of the normal diet) decreased the colonic SCFAs concentration. The saturated fatty acid (SFA) was negatively correlated, while unsaturated fatty acid (UFA)/SFA ratio was positively correlated, with colonic isobutyric acid concentration. The C18:2ω6 and ω3 fatty acids were positively correlated with colonic butyric acid and isovaleric acid concentration, respectively. Results also demonstrated that PO and LO could decrease the colon villus length and crypt depth, and led to colon injury, which might be due to their high SFAs content. Moreover, results suggested that PO and LO could specifically up-regulate the colon inflammation related gene expression levels and down-regulate the Muc2 expression levels, thus, imposing negative impact on the mucus layers. The present study could provide some information for nutritional evaluation about these dietary lipids.

Effects of PM2.5 exposure during gestation on maternal gut microbiota and pregnancy outcomes

A number of studies have reported that fine particulate matter (PM2.5) exposure is associated with adverse pregnancy outcomes. Moreover, PM2.5 exposure contributes to changes of gut microbiota. However, influences of PM2.5 exposure during gestation on maternal gut microbiota and pregnancy outcomes were not well understood. Here we performed a study using mice models. Dams were exposed to PM2.5 suspension by intratracheal instillation on gestational day (GD) 3, 6, 9, 12 and 15. Pregnancy outcomes, maternal gut microbiota and short chain fatty acids on GD 18 were all measured. The fetal body weight of PM2.5 group was significantly lower than that of control group (p < 0.05). Meanwhile, the fetal body length of PM2.5 group was significantly shorter than that of control group (p < 0.05). The Shannon or Simpson index of PM2.5 group were higher than that of control group (p < 0.05). At the phyla level, compared to dams in control group, mice in the PM2.5 group had higher ratio of phyla Proteobacteria, Candidatus Saccharibacteria and Fusobacteria and lower ratio of phyla Acidobacteria, Gemmatimonadetes and Deferribacteres in the gut. Compared with control group, the concentration of isobutyric acid was higher in PM2.5 group, but butyric acid concentration was lower in PM2.5 group (p < 0.05). These findings suggested that prenatal exposure to PM2.5 had an effect on birth weight of fetus. Meanwhile, PM2.5 tracheal exposure during gestation caused changes in the distribution and structure of gut microbiota of dams.

Distinct alterations of gut morphology and microbiota characterize accelerated diabetes onset in nonobese diabetic mice

Distinct alterations of gut morphology and microbiota characterize accelerated diabetes onset in nonobese diabetic mice