Total Short-chain Fatty Acid Concentration Research Articles

233 Inclusion of a multispecies fungal feed additive in forage-based diets fed to beef cattle: Effects on growth performance and ruminal fermentation

Abstract The objective was to evaluate the effect of adding a multispecies fungal feed additive (MFA; Aspergillus flavus, Aspergillus niger, Aspergillus oryzae) to forage-based diets fed to beef cattle on growth performance and ruminal fermentation. Experiment 1 evaluated the effect of supplementing Angus × SimAngus-crossbred steers [n = 80; initial body weight (BW) = 370 ± 44 kg] with varying doses of an MFA in a randomized complete block design. Steers were blocked by BW and housed in 8 feedlot pens (randomly assigned 2 pens per treatment) where a hay-based diet was fed for 122 d. The hay-based diet was offered with the inclusion of the MFA at 0.02, 0.04, and 0.08 % of the diet dry matter (DM), or without the inclusion of the MFA (CON). Steers were weighed at 28-d intervals. For experiment 2, ruminally cannulated Angus × SimAngus cows (n = 4; initial BW = 569 ± 21 kg) were used in a crossover design with two 21-d study periods to evaluate the effect of dietary inclusion of an MFA on in situ digestion and rumen metabolites. Treatments consisted of a forage-based diet with (WFA) or without (CON) the inclusion of the MFA. In situ digestion was evaluated on d 5, 10, and 20 throughout each period. In-situ bags were incubated in the rumen for 0 to 36 h, sampling every 4 h. On d 20, samples of ruminal fluid were collected to analyze short-chain fatty acids (SCFA) concentration. All data were analyzed using the PROC MIXED procedure of SAS. For experiment 1, a polynomial contrast was used. For experiment 2, the interaction between period and treatment was not significant (P > 0.45). In Experiment 1, the final BW, average daily gain (ADG), and gain to feed ratio (G:F) changed cubically (P ≤ 0.04; Table 1) as dietary inclusion of the MFA increased. Steers supplemented with the MFA at a rate of 0.02% of the diet DM were heavier at the end of the 122-d study period and had the greatest ADG and G:F among treatments. No differences between treatments (P ≥ 0.37) were observed for dry matter intake. In Experiment 2, no treatment × time interactions and treatment effects were detected (P ≥ 0.17; Table 2) for the in-situ disappearance rate and degradation kinetics of the diet DM, neutral detergent fiber, and acid detergent fiber. In addition, MFA supplementation did not affect (P ≥ 0.13; Table 3) the SCFA profile and the total SCFA content in the rumen fluid. Results from these studies indicate that dietary inclusion of an MFA might be an effective alternative to increase the feed efficiency of beef cattle-fed forage-based diets. However, the precise mode of action warrants further investigations.

Quantifying fecal and plasma short-chain fatty acids in healthy Thai individuals

Short-chain fatty acids (SCFAs) are involved in important physiological processes such as gut health and immune response, and changes in SCFA levels can be indicative of disease. Despite the importance of SCFAs in human health and disease, reference values for fecal and plasma SCFA concentrations in healthy individuals are scarce. To address this gap in current knowledge, we developed a simple and reliable derivatization-free GC-TOFMS method for quantifying fecal and plasma SCFAs in healthy individuals. We targeted six linear- and seven branched-SCFAs, obtaining method recoveries of 73-88% and 83-134% in fecal and plasma matrices, respectively. The developed methods are simpler, faster, and more sensitive than previously published methods and are well suited for large-scale studies. Analysis of samples from 157 medically confirmed healthy individuals showed that the total SCFAs in the feces and plasma were 34.1 ± 15.3 µmol/g and 60.0 ± 45.9µM, respectively. In fecal samples, acetic acid (Ace), propionic acid (Pro), and butanoic acid (But) were all significant, collectively accounting for 89% of the total SCFAs, whereas the only major SCFA in plasma samples was Ace, constituting of 93% of the total plasma SCFAs. There were no statistically significant differences in the total fecal and plasma SCFA concentrations between sexes or among age groups. The data revealed, however, a positive correlation for several nutrients, such as carbohydrate, fat, iron from vegetables, and water, to most of the targeted SCFAs. This is the first large-scale study to report SCFA reference intervals in the plasma and feces of healthy individuals, and thereby delivers valuable data for microbiome, metabolomics, and biomarker research.

In Vitro Fermentation Shows Polyphenol and Fiber Blends Have an Additive Beneficial Effect on Gut Microbiota States.

Polyphenols and fermentable fibers have shown favorable effects on gut microbiota composition and metabolic function. However, few studies have investigated whether combining multiple fermentable fibers or polyphenols may have additive beneficial effects on gut microbial states. Here, an in vitro fermentation model, seeded with human stool combined from 30 healthy volunteers, was supplemented with blends of polyphenols (PP), dietary fibers (FB), or their combination (PPFB) to determine influence on gut bacteria growth dynamics and select metabolite changes. PP and FB blends independently led to significant increases in the absolute abundance of select beneficial taxa, namely Ruminococcus bromii, Bifidobacterium spp., Lactobacillus spp., and Dorea spp. Total short-chain fatty acid concentrations, relative to non-supplemented control (F), increased significantly with PPFB and FB supplementation but not PP. Indole and ammonia concentrations decreased with FB and PPFB supplementation but not PP alone while increased antioxidant capacity was only evident with both PP and PPFB supplementation. These findings demonstrated that, while the independent blends displayed selective positive impacts on gut states, the combination of both blends provided an additive effect. The work outlines the potential of mixed substrate blends to elicit a broader positive influence on gut microbial composition and function to build resiliency toward dysbiosis.

Effects of dietary energy levels on microorganisms and short-chain fatty acids of rumen and tight junction proteins in Honghe Yellow cattle.

This study was conducted to investigate the effects of dietary energy levels on microorganisms and short-chain fatty acids (SCFAs) of rumen and the expression of tight junction proteins in Honghe Yellow cattle. A total of fifteen male Honghe Yellow cattle were randomly divided into three treatments (five replicates per treatment), consisting of formulated energy concentrations of 5.90 MJ/kg (high-energy diet, group H), 5.60 MJ/kg (medium-energy diet, group M) and 5.30 MJ/kg (low-energy diet, group L). The results showed that compared with group H, the expression of Claudin-1 in rumen epithelium of groups M and L was increased, but the expression of ZO-1 was decreased (p < 0.05). Moreover, compared with group H, group M down-regulated the expression of Occludin and Claudin-1 in the brain (p < 0.05). For rumen bacteria, the dominant phyla included Bacteroidetes and Firmicutes, the abundance of Actinobacteriota in groups M and L was significantly increased compared with group H (p < 0.05). At the genus level, the relative abundance of Corynebacterium, Eubacterium_nodatum_group and Neisseraceae in groups M and L was significantly decreased compared with group H (p < 0.05). For rumen fungi, the dominant phyla included Basidiomycota, Ascomycota and Neocariastigomycota, the relative abundance of Ascomycetes was significantly higher than that of groups M and L compared with group H (p < 0.05). At the genus level, the relative abundance of Neocelimastigaceae and Myceliophthora in groups M and L was significantly reduced compared with group H (p < 0.05). Furthermore, the expression of Claudin-1 in rumen epithelium was significantly positively correlated with Actinobacteriota, Corynebacterium and Neisseriaceae. The expression of ZO-1 in the spinal cord was significantly positively correlated with Myceliophthora. The expression of Occludin in brain was positively correlated with valerate content (p < 0.05). In summary, dietary energy levels affected the rumen microbiota of Honghe Yellow cattle. The expression of Claudin-1 in rumen epithelium and the total SCFAs concentration were increased with decreasing dietary energy levels, but the expression of Claudin-1 in brain and ZO-1 in the spinal cord were reduced with decreasing dietary energy levels. Meanwhile, the rumen microbiota and SCFAs were significantly correlated with the expression of TJP.

Dietary crude protein and protein solubility manipulation enhances intestinal nitrogen absorption and mitigates reactive nitrogen emissions through gut microbiota and metabolome reprogramming in sheep

Dietary nutrient manipulation (e.g. protein fractions) could lower the environmental footprints of ruminants, especially reactive nitrogen (N). This study investigated the impacts of dietary soluble protein (SP) levels with decreased crude protein (CP) on intestinal N absorption, hindgut N metabolism, fecal microbiota and metabolites, and their linkage with N metabolism phenotype. Thirty-two male Hu sheep, with an age of six months and an initial BW of 40.37 ± 1.18 kg, were randomly assigned to four dietary groups. The control diet (CON), aligning with NRC standards, maintained a CP content of 16.7% on a dry matter basis. Conversely, the experimental diets (LPA, LPB, and LPC) featured a 10% reduction in CP compared with CON, accompanied by SP adjustments to 21.2%, 25.9%, and 29.4% of CP, respectively. Our results showed that low-protein diets led to significant reductions in the concentrations of plasma creatinine, ammonia, urea N, and fecal total short-chain fatty acids (SCFA) (P < 0.05). Notably, LPB and LPC exhibited increased total SCFA and propionate concentrations compared with LPA (P < 0.05). The enrichment of the Prevotella genus in fecal microbiota associated with energy metabolism and amino acid (AA) biosynthesis pathways was evident with SP levels in low-protein diets of approximately 25% to 30%. Moreover, LPB and LPC diets demonstrated a decrease in fecal NH4+-N and NO2--N contents as well as urease activity, compared with CON (P < 0.05). Concomitantly, reductions in fecal glutamic acid dehydrogenase gene (gdh), nitrite reductase gene (nirS), and nitric oxide reductase gene (norB) abundances were observed (P < 0.05), pointing towards a potential reduction in reactive N production at the source. Of significance, the up-regulation of mRNA abundance of AA and peptide transporters in the small intestine (duodenum, jejunum, and ileum) and the elevated concentration of plasma AA (e.g. arginine, methionine, aspartate, glutamate, etc.) underscored the enhancement of N absorption and N efficiency. In summary, a 10% reduction in CP, coupled with an SP level of approximately 25% to 30%, demonstrated the potential to curtail reactive N emissions through fecal Prevotella enrichment and improve intestinal energy and N utilization efficiency.

Solid‐state fermentation pro‐enzymes supplementation benefits growth performance, health, and intestinal microbiota of broiler chickens fed wheat‐based diet

AbstractWheat as a kind of diet material can be used for broiler production. However, due to non‐starch polysaccharides in wheat, wheat may lead to lower growth performance and worth health. To reverse the negative effect, solid‐state fermentation pro‐enzymes were added. In this experiment, growth performance, intestinal health‐related genes, short chain fatty acids (SCFAs) and intestinal microbiota were detected to find the effects of wheat meal and combined with enzymes on broiler chickens from 15 to 42 days of age. A total of 432 1‐day‐old Arbor Acres broiler chickens were fed corn‐based diet (CD) for 14 days as the preparation stage of the experiment. Then, they were randomly divided into three groups and fed three different kinds of diets which were corn‐based diet (CD group), wheat‐based diet (WD group), and SFP enzymes supplementation in WD (Enzymes+Wheat‐based diet group). The results showed that compared with broilers in CD group, broilers in WD group had lower weight gain and higher Feed conversion ratio (p &lt; 0.05) during the whole experimental period especially from day 15 to day 21, but there was no significant effect on feed intake (p &gt; 0.05). Moreover, SFP enzymes decreased the spleen index (p &lt; 0.05). Wheat also had trends to decrease the expression of ZO‐1 (p = 0.096) and increase the concentrations of acetate (p &lt; 0.05), butyrate (p &lt; 0.05) and total SCFAs (p &lt; 0.05), in which SFP enzymes caused the opposite results except for butyrate, and SFP enzymes even increased the expression of ZO‐1 (p &lt; 0.001) and OCCLUDIN (p = 0.075) and decreased the expression of TNF‐α (p &lt; 0.01). Meanwhile, wheat enhanced the abundances of Barnesiella and Bifidobacterium (p &lt; 0.05) and inhibited the abundances of Flavonifractor, Sellimonas, Lachnospiraceae_NK4A136_group, Subdoligranulum, and Ruminococcus_gauvreauii_group (p &lt; 0.05), and SFP enzymes could reverse the negative effects, and the changes in microbiota could explain the other different parameters. Collectively, wheat results in inflammation and worse growth performance, but SFP enzymes supplementation in WD benefits chickens' growth performance by improving intestinal barrier function, decreasing inflammation, modulating cecal microbiota and SCFAs production.

Highly crystalline cellulose microparticles from dealginated seaweed waste ameliorate high fat-sugar diet-induced hyperlipidemia in mice by modulating gut microbiota

The effects of seaweed cellulose (SC) on high fat-sugar diet (HFSD)-induced glucolipid metabolism disorders in mice and potential mechanisms were investigated. SC was isolated from dealginated residues of giant kelp (Macrocystis pyrifera), with a crystallinity index of 85.51 % and an average particle size of 678.2 nm. Administering SC to C57BL/6 mice at 250 or 500 mg/kg BW/day via intragastric gavage for six weeks apparently inhibited the development of HFSD-induced obesity, dyslipidemia, insulin resistance, oxidative stress and liver damage. Notably, SC intervention partially restored the structure and composition of the gut microbiota altered by the HFSD, substantially lowering the Firmicutes to Bacteroidetes ratio, and greatly increasing the relative abundance of Lactobacillus, Bifidobacterium, Oscillospira, Bacteroides and Akkermansia, which contributed to improved short-chain fatty acid (SCFA) production. Supplementing with a higher dose of SC led to more significant increases in total SCFA (67.57 %), acetate (64.56 %), propionate (73.52 %) and butyrate (66.23 %) concentrations in the rectal contents of HFSD-fed mice. The results indicated that highly crystalline SC microparticles could modulate gut microbiota dysbiosis and ameliorate HFSD-induced obesity and related metabolic syndrome in mice. Furthermore, particle size might have crucial impact on the prebiotic effects of cellulose as insoluble dietary fiber.

Effects of fermented soymilk with Lacticaseibacillus paracasei YIT 9029 on gut microbiota and defecation habits: a randomised, double-blind, placebo-controlled study.

Previous studies have demonstrated that soymilk and Lacticaseibacillus paracasei YIT 9029 (strain Shirota: LcS) each beneficially affect the gut microbiota and defecation habits. To investigate the effects of daily consumption of fermented soymilk containing LcS (FSM), we conducted a randomised, double-blind, placebo-controlled study of 112 healthy Japanese adults with a low faecal Bifidobacterium count. They consumed 100ml FSM or placebo (unfermented soymilk base) once daily for 4 weeks. Their gut microbiota was analysed by 16S rRNA gene amplicon sequencing and quantitative reverse transcription-polymerase chain reaction (PCR), and faecal short-chain fatty acids (SCFAs) and urinary putrefactive products were assessed during the pre- and post-consumption periods. Defecation habits were examined weekly using a subjective questionnaire. In the post-consumption period, living LcS were not detected in two subjects in the FSM group (n= 57) but were detected in one subject in the SM group (n= 55). The FSM group had a significantly higher number and relative abundance of faecal lactobacilli compared with the placebo group. The relative abundance of Bifidobacterium, alpha-diversity of microbiota, and concentrations of acetate and total SCFAs in faeces were significantly increased in the FSM group, although no significant differences were detected between the groups. The number of defecations and defecation days per week significantly increased in both groups. Subgroup analysis of 109 subjects, excluding 3 with inconsistent LcS detection (2 and 1 subjects in the FSM and SM groups, respectively), revealed that the FSM group (n= 55) had significantly greater increases in faecal acetate concentration compared with the SM group (n= 54) and significant upregulation of pathways related to energy production or glucose metabolism in the gut microbiota. These findings suggest that daily FSM consumption improves the gut microbiota and intestinal environment in healthy adults and may help to maintain health and prevent diseases. Registered at the University Hospital Medical Information Network (UMIN) clinical trials registry under: UMIN 000035612.

Comparison of prebiotic candidates in ulcerative colitis using an in vitro fermentation model.

This study explored the effect of three different prebiotics, the human milk oligosaccharide 2'-fucosyllactose (2'-FL), an oligofructose-enriched inulin (fructo-oligosaccharide, or FOS), and a galacto-oligosaccaride (GOS) mixture, on the faecal microbiota from patients with ulcerative colitis (UC) using in vitro batch culture fermentation models. Changes in bacterial groups and short-chain fatty acid (SCFA) production were compared. In vitro pH controlled batch culture fermentation was carried out over 48 h on samples from three healthy controls and three patients with active UC. Four vessels were run, one negative control and one for each of the prebiotic substrates. Bacterial enumeration was carried out using fluorescence in situ hybridization with flow cytometry. SCFA quantification was performed using gas chromatography mass spectrometry. All substrates had a positive effect on the gut microbiota and led to significant increases in total SCFA and propionate concentrations at 48 h. 2'-FL was the only substrate to significantly increase acetate and led to the greatest increase in total SCFA concentration at 48 h. 2'-FL best suppressed Desulfovibrio spp., a pathogen associated with UC. 2'FL, FOS, and GOS all significantly improved the gut microbiota in this in vitro study and also led to increased SCFA.

The Potential Role of SCFAs in Modulating Cardiometabolic Risk by Interacting with Adiposity Parameters and Diet.

The main objective of this cross-sectional study was to analyze the influence of lifestyle factors (diet, physical activity, sleep) that can affect the concentration of fecal short-chain fatty acids (SCFAs) and SCFAs' potential role in modulating cardiometabolic disease risk by interacting with biochemical and body composition parameters. The study comprised 77 healthy, non-obese individuals aged 30-45 years who were assessed for the concentration of SCFAs in stool, diet, physical activity level, and sleep duration. Moreover, body composition measurement and patients' biochemical parameters were included in the analysis. We have indicated a significant negative correlation between several SCFAs (especially acetic acid (AA), isobutyric acid (IBA), butyric acid (BA), propionic acid (PA), isovaleric acid (IVA) and valeric acid (VA)) with BMI, VAT/SAT ratio (visceral to subcutaneous fat ratio), and percentage of fat mass in a group of females enrolled in the study as well as with waist circumference (WC) in case of both sexes included in the study. Moreover, the results of our study acknowledged the importance of a diet in shaping the SCFA profile-we noticed significant negative associations between energy and fat intake and some SCFAs in males (IBA, IVA, VA, isocaproic acid (ICA)). Further, we indicated that a high intake of fiber (insoluble and soluble) in both males and females results in an elevated concentration of the vast majority of SCFAs and the amount of SCFAs in total. This effect was particularly noticeable in the case of the soluble fraction of fiber. These correlations reflect the fact that diet shapes the composition of the gut microbiota and SCFAs (main microbial metabolites) are synthesized from dietary fiber. In addition, we noticed that in a group of women, the concentration of AA, PA, and ICA as well as the total concentration of SCFAs showed a significant positive association with their sleep duration. We concluded that SCFAs can have a potential role in modulating cardiometabolic disease risk by interacting with adiposity parameters and diet. In addition, this potential direct link between diet and SCFAs may at least partly contribute to sleep improvement.

Cultivar and Harvest Time of Almonds Affect Their Antioxidant and Nutritional Profile through Gut Microbiota Modifications.

Almonds are a rich source of beneficial compounds for human health. In this work, we assessed the influence of almond cultivars and harvest time on their morphological (length, width and thickness) and nutritional (ash, moisture, proteins) profiles. We also evaluated the impact of an in vitro digestion and fermentation process on almonds' antioxidant and phenolic content, as well as their support of gut microbiota community and functionality, including the production of short-chain fatty acids (SCFAs), lactic and succinic acids. The length, width, and thickness of almonds varied significantly among cultivars, with the latter two parameters also exhibiting significant changes over time. Moisture content decreased with maturity, while protein and ash increased significantly. Total antioxidant capacity released by almonds after digestion and fermentation had different trends depending on the antioxidant capacity method used. The fermentation step contributed more to the antioxidant capacity than the digestion step. Both cultivar and harvest time exerted a significant influence on the concentration of certain phenolic compounds, although the total content remained unaffected. Similarly, fecal microbiota modulation depended on the cultivar and maturity stage, with the Guara cultivar and late maturity showing the largest effects. Cultivar type also exerted a significant impact on the concentration of SCFAs, with the Guara cultivar displaying the highest total SCFAs concentration. Thus, we conclude that cultivar and harvest time are key factors in shaping the morphological and nutritional composition of almonds. In addition, taking into account all the results obtained, the Guara variety has the best nutritional profile.

The Impact of Fiber Source on Digestive Function, Fecal Microbiota, and Immune Response in Adult Dogs.

This study evaluated the impact of different fiber sources on intestinal function, fecal microbiota, and overall health in dogs. Twelve dogs were used in a crossover design, involving three periods of 6 weeks and three diets: a low-fiber diet (CTR), a cereal-fiber and beet-pulp-supplemented diet (BRA), and a fruit-fiber-supplemented diet (FRU). Each period included a digestibility trial and fecal and blood sampling in the last week. Short-chain fatty acids (SCFAs) and microbiota taxonomy (16S rRNA Illumina-MiSeq) and functionality (Shotgun-NovaSeq 6000) were determined in the feces. General biochemistry, complete blood cells, and lymphocyte subsets were also analyzed. The fiber-supplemented diets showed lower digestibility without significant changes in the fecal consistency. The BRA diet showed higher total SCFA concentrations (p = 0.056), with increases in alpha diversity and particular beneficial genera, such as Lachnospira, Bifidobacterium, and Faecalibacterium. The BRA microbiota was also associated with an overabundance of genes related to carbohydrate and amino acid metabolism. The FRU diet had a distinct impact on the microbiota composition and functionality, leading to higher levels of CD8 lymphocytes. These findings emphasize the importance of selecting the right fiber source when formulating dog diets, as it can have a differential impact on gut microbiota and animal health.

Dose-Dependent Effects of Supplementing a Two-Strain Bacillus subtilis Probiotic on Growth Performance, Blood Parameters, Fecal Metabolites, and Microbiome in Nursery Pigs.

This experiment was conducted to evaluate the effects of dietary supplementation level of a two-strain Bacillus subtilis probiotic on growth performance, blood parameters, fecal metabolites, and microbiome in nursery pigs. A total of 54 weaned piglets were allotted to three treatments in three replicate pens with six pigs/pen for a 28 d feeding trial. The treatments were as follows: control: no probiotic supplementation; Pro1x: B. subtilis supplementation at 1.875 × 105 CFU/g diet; and Pro10x: B. subtilis supplementation at 1.875 × 106 CFU/g diet. Body weight at d 14 postweaning (p = 0.06) and average daily gain for d 0 to 14 postweaning (p < 0.05) were greater in the Pro1x treatment than in the other treatments. Blood glucose levels were greater in both probiotic treatments than in the control treatment at d 14 postweaning (p < 0.05). In the fecal short-chain fatty acid (SCFA) concentrations, the butyrate concentrations were greater in the Pro1x treatment than in the other treatments (p < 0.05), and the acetate, propionate, and total SCFA concentrations were greater in the Pro1x treatment than in the Pro10x treatment (p < 0.05). The beta diversity of fecal microbiome composition at d 14 postweaning based on Unweighted Unifrac analysis was dissimilar between the Pro1x and Pro10x treatments (p < 0.05). In conclusion, dietary B. subtilis supplementation of two strains selected to reduce effects of pathogenic Escherichia coli to nursery diets at 1.875 × 105 CFU/g diet improved the growth rate in the early postweaning period, increased fecal SCFA concentrations and altered the fecal microbial community composition. A higher dose of B. subtilis did not improve the performance parameters over those of the control piglets.

Dietary crude protein time-dependently modulates the bacterial community and metabolites and changes dietary nutrient efficiency in growing pigs

The reduced nutrient digestibility of low-protein (LP) diets has been shown to be caused by the weakened fermentative capacity of the post-gut flora. The dynamic regulation of dietary protein contents on post-gut microbial population and fermentative metabolism is unclear. Twelve growing barrows (19.9 ± 0.8 kg) fitted with a T-cannula at the blind end of the cecum were randomly administered a high-protein (HP, 21.5% crude protein [CP]) diet or an LP (15.5% CP) diet for 28 d. The cecal content and feces were collected at d 1, 14, and 28 of the experiment for microflora structures and metabolite concentrations analysis. The nutrient digestibility coefficient and plasma biochemical parameters were also determined. Compared with the HP treatment, the LP treatment showed decreased plasma urea nitrogen concentration and apparent total tract digestibility of dry matter, gross energy, and CP (P < 0.01). In addition, urinary nitrogen losses, total nitrogen losses, and daily nitrogen retention in the LP treatment were lower than those in the HP treatment (P < 0.01), and the nitrogen retention-to-nitrogen intake ratio in the LP treatment was increased (P < 0.01). The HP group showed increased cecal total short-chain fatty acids (SCFA) concentration and fecal propionate, butyrate, and total SCFA concentrations (P < 0.05) on d 14 and 28, which may be mainly related to the elevated abundance of SCFA-producing bacteria, such as Ruminococcus, Lactobacillus, and Prevotella (P < 0.05). Probiotics, such as Bifidobacterium, Bacteroidales S24-7, and Rikenella, enriched in the LP treatment possibly contributed to reduced plasma endotoxin content. The differences in the abundances of almost all the above-mentioned flora appeared on d 28 but not d 14. Likewise, differences in the Simpson and Shannon indices and clustering patterns of the microbiota between treatments were also only observed on d 28. To sum up, in a time-dependent manner, the LP diet increased probiotics with gut-improving functions and decreased SCFA-producing bacteria, which may cause enhanced intestine health and reduced nutrient digestibility.

Chitosan associated with technical cashew nut shell liquid in supplements for grazing beef steers: nitrogen balance and rumen metabolism

ABSTRACT The aim of this study was to evaluate the inclusion of the chitosan (CHI) and technical cashew nutshell liquid (CNSLT) on nitrogen metabolism and ruminal fermentation on pasture system. Five steers (5 × 5 Latin square); kept of Marandu grass and supplemented daily by up to 0.4% BW. The experimental diets were: CON (mineral supplement); PRO (protein supplement); CHI supplementation; CNSLT supplementation and CC (CHI + CNSLT supplementation). Animals supplemented with CNSLT showed a reduction of pasture intake. The combination CC increased the intake of supplement. Steers supplemented with the combination of CNSLT, and CHI showed a higher supplement intake. The ruminal pH for the animals that received the combination of CNSLT and CHI, showed the lowest values. CHI decreased rumen acetate concentration, and increased propionate. Animals fed CC had a higher concentration of short-chain fatty acids (SCFA) and a reduced value for purines. CNSLT increased the excretion of total purines, microbial nitrogen synthesis and crude protein. Animals that received CC showed higher urinary excretion of N compared to the other treatments. The CHI + CNSLT proved to be favourable, with a higher total concentration of SCFA and positive effect on nitrogen balance.

The Progressive Utilization of Ponkan Peel Residue for Regulating Human Gut Microbiota through Sequential Extraction and Modification of Its Dietary Fibers.

As a by-product of citrus processing, ponkan (Citrus reticulata Blanco, cv. Ponkan) peel residue is a source of high quality dietary fiber (DF). To make a full utilization of this resource and give a better understanding on the probiotic function of its DF, soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were extracted from ponkan peel residue (after flavonoids were extracted) using an alkaline method, followed by modifications using a composite physical-enzymatic treatment. The in vitro fermentation properties of the modified SDF and IDF (namely, MSDF and MIDF) and their effects on short-chain fatty acids (SCFA) production and changes in the composition of human gut microbiota were investigated. Results showed that MSDF and MIDF both significantly lowered the pH value and enhanced total SCFA content in the broths after fermented for 24 h by fecal inocula (p < 0.05) with better effects found in MSDF. Both MSDF and MIDF significantly reduced the diversity, with more in the latter than the former, and influenced the composition of human gut microbiota, especially increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes to Bacteroidetes (F/B) value. The more influential microbiota by MSDF were g-Collinsella, p-Actinobacteria and g-Dialister, while those by MIDF were f-Veillonellaceae, c-Negativicutes and f-Prevotellacese. These results suggested that the modified ponkan peel residue DF can be utilized by specific bacteria in the human gut as a good source of fermentable fiber, providing a basis for the exploitation of the citrus by-product.

PSVIII-A-7 Effects of New Forage Barley and Oat Varieties on Silage Fermentation Characteristics, and Feed Intake, Milk Production and Composition, and N Balance in Dairy Cows

Abstract Forages are the foundation of dairy cow diets and typically comprise 50% of the dietary dry matter and ≥40% of the total NEL intake. New forage barley (CDC Renegade; designated RENE) and forage oat (CDC Arborg; ARBO) varieties are available for feeding dairy cows in western Canada. The objectives were to determine the ensiling characteristics of RENE and ARBO and to compare the effects of feeding them as the major forage source on feed intake, milk yield and composition, ruminal pH, and nitrogen (N) balance in dairy cows. Eight multiparous Holstein cows (82 ± 12 days-in-milk at the beginning of the study) were used in a 4 × 4 Latin square design study with 14 d of dietary adaptation and 7 d of data and sample collection. Cows in one Latin square were ruminally cannulated to determine dietary effects on ruminal pH and N balance. The four diets tested contained RENE, ARBO, Conlon (CONL), and Rosser (ROSS) silages as the major source of forage, with ROSS and CONL being included for comparison as they are commonly used barley varieties in western Canada. Silage fermentation characteristics were largely similar for the four forages, except for total short-chain fatty acid concentrations which tended (P = 0.08) to be greater for RENE and ROSS when compared with CONL and ARBO. Silage starch contents were greater (P &amp;lt; 0.01) for CONL and ROSS when compared with RENE and ARBO, which were similar. Silage aNDFom contents were greater (P &amp;lt; 0.01) for RENE and ARBO when compared with CONL and ROSS, which were similar. Dry matter intake (mean = 34.3 kg/d) and milk yield (mean = 48.6 kg/d) were unaffected by treatment (P ≥ 0.42). Milk fat content was greater (P = 0.03) for cows fed RENE compared with those fed CONL, with that of cows fed ROSS and ARBO being intermediate and not different to RENE and CONL. Milk fat yield was greater (P = 0.02) for cows fed RENE compared with those fed ROSS, with that of cows fed CONL and ARBO being intermediate and not different to RENE and ROSS. Intake of N, urinary and fecal excretion of N, total N excretion, milk N, and apparent N balance were unaffected by diet (P ≥ 0.21). Mean ruminal pH was greater (P = 0.02) in cows fed ARBO compared with those fed ROSS, with that of cows fed CONL and RENE being intermediate and not different to CONL and RENE. Our results show that the new forage varieties, RENE and ARBO, can support similar levels of milk yield compared with forage varieties such as CONL and ROSS.

PSIX-4 A Veterinary Gastrointestinal Diet Affects Fecal Characteristics, Metabolites, Bile Acids, and Microbiota Concentrations of Antibiotic-Treated Cats

Abstract Antibiotics are often used to treat animals with gastrointestinal diseases or infections, but their use is known to have negative effects on the intestinal microbiota community. Identifying dietary strategies that may aid in the recovery from antibiotic use is of interest. The objective of this study was to determine how a veterinary gastrointestinal diet affected the fecal characteristics and metabolite, bile acid (BA), and microbiota concentrations of cats recovering from metronidazole administration. Twenty-four healthy adult cats were used in an 8-wk completely randomized design study. The study began with a 2-wk baseline phase where all cats consumed a leading grocery brand dry diet (GBD; wk 0 to wk 2). Over the next 2 wk, cats continued to consume GBD and received metronidazole (20 mg/kg BW; wk 2 to wk 4). At wk 4, cats were randomly allotted to one of two treatments [GBD; Blue Buffalo Gastrointestinal Support (BB)] for the remaining 4 wk (wk 5 to wk 8). 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, and metabolite and BA concentrations. Fecal microbiota were analyzed by 16S rRNA sequencing and qPCR, which was used to calculate dysbiosis index. All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, with treatment treated as a fixed effect, cat as a random effect, and significance set at P&amp;lt; 0.05 and trends at P &amp;lt; 0.10. Metronidazole administration had dramatic effects on the outcomes measured, including increased fecal scores (looser stools), reduced fecal pH and dry matter %, reduced fecal short-chain fatty acid (SCFA), branched-chain fatty acid, ammonia, phenol, and indole concentrations, and altered fecal BA concentrations (increased primary BA; reduced secondary BA). Furthermore, fecal bacterial alpha diversity was reduced, dysbiosis index was increased, and the abundance of several individual bacterial taxa were altered. Fecal outcome variables partially recovered over the next 4 wk, with some being impacted by diet. The change in fecal acetate concentrations were greater and the change in total SCFA concentrations tended to be greater in cats fed BB. Dysbiosis index and alpha diversity measures slowly recovered over 4 wk, without differences due to diet. Recovery of about 20 bacterial genera were impacted by diet. Primary and secondary BA concentrations and ratios demonstrated a prolonged impairment of primary to secondary BA conversion. Most of these changes were an effect of time, but the change of fecal cholic acid concentrations were less in cats fed BB. In conclusion, our data demonstrate that metronidazole is a powerful antibiotic that has long-lasting effects on the fecal microbiota and metabolites of cats. The veterinary gastrointestinal diet tested aided in the recovery of some variables measured.

211 Evaluating the Influence of Soybean Meal and its Bioactive Compounds on Nutrient Utilization, Fermentation, and Gastrointestinal Metabolites of Nursery Pigs

Abstract Recently soybean meal (SBM) has garnered more attention due to its increased feeding value during periods of stress and improved bioavailable energy. However, the influence of the innate bioactive compounds in SBM on the microbiome and fermentation products have not been fully elucidated. Thus, the experimental objective was to investigate the mechanism of action of SBM and its bioactive compounds in the gastrointestinal tract of nursery pigs. Two replications of 18 barrows (8.12 ± 0.80 kg BW; PIC800 × Camborough; n = 36), were randomly assigned to a dietary treatment of either a high SBM positive control (SBMC; 28.6%), a negative control void of SBM (SP), but included soy protein isolate and concentrate to provide amino acids from soy protein the same as SBM in SBMC; SP formulated to the same contribution and composition of isoflavones as SBMC (SP+ISO; 528 mg/kg of soy-isoflavones); SP diet fortified with soybean functional lipids of lecithin and phytosterols at similar concentration in SBMC (SP+LIP; 2.85 g/kg of functional lipids); SP formulated to the same contribution and ratio of insoluble to soluble fiber as SBM in SBMC (SP+FIB; 30 g/kg of soy fiber); or SP diet fortified with lunasin peptide at 3.81 g/kg (SP+LUN). Pigs were individually housed, and limit fed 2.5 times maintenance for a metabolism study consisting of a 6-d adaptation period, followed by 72-h of urine and fecal collections. On d 12, pigs were necropsied, and ileal, cecal, and colonic digesta were collected for immediate short-chain fatty acid (SCFA) analysis. The pH of ileal and cecal digesta were also collected. Data were analyzed as a linear mixed model with treatment as a fixed effect, replicate as a random effect, and initial BW as a covariate where appropriate using PROC MIXED in SAS 9.4. The pH of both ileal (P = 0.478) and cecal (P = 0.874) digesta did not differ among treatments. Relative to SP, pigs fed SP+FIB and SBM had a 97.8% and 63.4% increase in acetate production, respectively (P = 0.012). Similarly, pigs fed SP+FIB and SBM had increased total SCFA concentration in the ileum (P = 0.016), but there was no difference among treatments for propionate or butyrate production (P &amp;gt; 0.05). The molar proportion of butyrate was increased in the cecum in pigs fed SBMC and SP+FIB (P &amp;lt; 0.01), which increased the total concentration (mM/g) of SCFA in the cecal digesta (P &amp;lt; 0.05). The SP+FIB treatment had increased concentration (mM/g) and molar proportion of butyrate produced in the colon (P &amp;lt; 0.01). While pigs fed SBMC and SP had increased molar proportion of propionate in the colon (P &amp;lt; 0.05), total colonic SCFA concentration did not differ (P &amp;gt; 0.05). Collectively, SBM and its fiber can modulate SCFA composition and production in nursery pigs, and this may be related to an increase in fermentable substrates available to the microbiome.

32 Effect of Probiotics Supplementation Level on Growth Performance, Blood Parameters and Fecal Metabolites in Nursery Pigs

Abstract This experiment was conducted to evaluate the effects of dietary supplementation level of probiotics on growth performance, blood variables, and fecal metabolites in nursery pigs. Certain strains of Bacillus subtilis have been shown to reduce the incidence and severity of diarrhea and therefore improve growth performance of nursery pigs. A total of 54 newly weaned piglets were allotted to 3 treatments in 3 replicates with 6 pigs per pen based on body weight, gender, and breed for a 28-d feeding trial. Treatments were: 1) Control: no probiotics supplementation, 2) CERTILLUS 1x: probiotics supplementation at the recommended level, and 3) CERTILLUS 10x: probiotics supplementation at 10 times the recommended level. The CERTILLUS products consisted of two strains of Bacillus subtilis at a low and a high dose of 3.75 × 108 CFU/g and 3.75 × 109 CFU/g supplemented at 0.05% resulting in 1.875 × 105 CFU/g diet and 1.875 × 106 CFU/g diet for the 1x and 10x treatments, respectively. Corn-soybean meal-based diets were used for d 0-14 (Phase 1) and d 14-28 (Phase 2) postweaning. Body weight, blood glucose and creatinine, fecal short chain fatty acid (SCFA) and bile acid concentrations were measured at d 14 and 28 postweaning. Body weight at d 14 postweaning (P = 0.06; 11.98, 12.73, and 12.21 kg for the control, 1x, and 10x treatments, respectively) and average daily gain for d 0 to 14 postweaning (P &amp;lt; 0.05; 0.206, 0.259, and 0.222 kg/d, respectively) were greater in the 1x treatment than the control and 10x treatments although there was no significant difference in growth performance at d 28 postweaning. Blood glucose concentrations were greater in both probiotic treatments than the control treatment at d 14 postweaning (P &amp;lt; 0.05; 95.2, 111.7 and 114.3 mg/dL for the control, 1x, and 10x treatments, respectively). In the fecal SCFA concentrations, the butyrate concentrations were greater in the 1x treatment than the control and 10x treatments (P &amp;lt; 0.05; 36.17, 47.57, and 33.23 µmol/g feces for the control, 1x, and 10x treatments, respectively) and the acetate (120.02, 141.87, and 101.17 µmol/g feces, respectively), propionate (62.95, 71.42 and 55.27 µmol/g feces, respectively), and total SCFA (236.72, 282.23, and 205.80 µmol/g feces, respectively) concentrations were greater in the 1x treatment than the 10x treatment with the intermediate value in the control treatment (P &amp;lt; 0.05). There were no significant differences in fecal bile acid concentrations and blood creatinine concentrations at both d 14 and 28 postweaning. In conclusion, dietary probiotics supplementation to nursery diets at the recommended level could improve growth rate in the early postweaning period and increase fecal SCFA concentrations but not at a high level of supplementation.