Concentrations Of Branched-chain Fatty Acids Research Articles

Markers of systemic exposures to products of intestinal bacteria in a dietary intervention study.

Systemic exposures to intestinal bacteria may play a role in the etiology of the chronic, low-grade inflammation that is associated with western diets. Production of lipopolysaccharide-binding protein (LBP) is one biomarker of increased exposures to intestinal bacteria. This study evaluated whether changes in diet quality could affect serum LBP. This was a randomized, controlled trial of Mediterranean and Healthy Eating diets over 6 months in 120 healthy subjects at increased risk of colon cancer. Blood samples obtained before and after intervention were analyzed for LBP, branched-chain fatty acids characteristic of intestinal bacteria, micronutrients and cytokines. Data were analyzed for changes in LBP over time and for predictors of LBP. Serum concentrations of branched-chain bacterial fatty acids declined significantly in both diet groups. However, there was no significant change in mean serum LBP concentrations with either diet intervention. In serum, LBP was positively associated with CRP and negatively associated with carotenoids both before and after intervention. After intervention, LBP was predicted positively by both CRP and bacterial fatty acid concentrations in serum, and negatively by serum carotenoids and the ω3/ω6 fatty acid ratio. This model accounted for 30 % of the inter-individual variation in serum LBP after intervention. These results indicate that dietary intervention over 6 months was insufficient to alter serum LBP. The relationships with inflammation-related markers, however, indicate that anti-inflammatory strategies other than changes in diet quality, such as weight loss or improved fitness, may have more potential for reducing systemic markers of LPS exposures in well-nourished populations.

Branch Chain Fatty Acids of Human Milk: Influenced by Maternal Diet?

Human milk (HM) fatty acid (FA) composition differs between mothers. The FA of HM include branched chain fatty acids (BCFA). HM BCFA may be influenced by maternal consumption of ruminant products; data are lacking. We examined BCFA concentrations in HM from 3 urban populations with differing diets: Cincinnati, Shanghai and Mexico City. Sample collection was standardized as part of the GEHM study. Enrollment was limited to healthy mothers of term, singleton infants. FA were extracted from milk using Bligh‐Dyer and analyzed by gas chromatography. Dietary analysis included three 24 hour dietary recalls, limited to Cincinnati mothers. Statistical analysis was done using ANOVA. Samples from ~115 women were analyzed per site at postpartum week 4. Cincinnati, Shanghai and Mexican mothers, respectively, had mean age in years of 32, 29, and 25; prepregnancy BMIs of 28, 21, and 24; and parity of 2, 1, and 2. The BCFA iso14:0, iso16:0, iso18:0, iso20:0, anteiso15:0, anteiso17:0 all differed in concentration (p<0.0001) among cohorts. With linear regression of BCFA, site differences persisted after controlling for delivery mode, maternal age and BMI. Intake of dairy was associated with iso14:0, anteiso15:0 and iso16:0 but not the longer BCFA. Beef intake was not associated with any BCFA. The BCFA intake of breastfed infants differs significantly worldwide; its significance requires investigation.

Arabinoxylan in Wheat Is More Responsible Than Cellulose for Promoting Intestinal Barrier Function in Weaned Male Piglets1–

Background: The effect of dietary fiber on intestinal function primarily has been ascribed to its interaction with intestinal bacteria in the hindgut, whereas changes in intestinal bacteria in the host have been considered to depend on fiber composition.Objectives: The objectives of this study were to determine the contribution of the major fiber components to the health-promoting effects of wheat bran on intestinal mucosal barrier function and to elucidate the involvement of microbiota changes in weaned piglets.Methods: Thirty freshly weaned male piglets were assigned to 5 dietary treatment groups (n = 6) according to litter and weight. The piglets consumed synthetic diets ad libitum for 30 d, including a basal control diet (CON) without fiber components, a wheat bran diet (WB) as reference diet (10% wheat bran), and 3 other diets containing amounts of fiber components equivalent to those in the WB, i.e., an arabinoxylan diet (AX), a cellulose diet (CEL), and a combined arabinoxylan and cellulose diet (CB).Results: The groups consuming diets containing arabinoxylans (i.e., the WB, AX, and CB groups) had increased intestinal secretory immunoglobulin A concentrations, goblet cell number and cecal short-chain fatty acid concentrations, and reduced branched-chain fatty acid concentrations and pH values compared with the CON group. In the WB group, the stimulated secretion of Cl− was suppressed (60.8% and 47.5% change in short-circuit current caused by theophylline and carbachol, respectively) in the distal small intestine compared with the CON group. The AX and CB groups also had increased intestinal alkaline phosphatase activities and reduced intestinal transcellular permeability (by 77.3% and 67.2%, respectively) compared with the CON group. Meanwhile, in the WB group, cecal Bacteroidetes and Enterobacteriaceae populations were lower, and the growth of Lactobacillus was higher in the AX and CB groups than in the CON group, whereas no positive effect on intestinal barrier function was observed in the CEL group.Conclusion: Arabinoxylan in wheat bran, and not cellulose, is mainly responsible for improving various functional components of the intestinal barrier function and the involvement of microbiota changes.

Synbiotic Lactobacillus acidophilus NCFM and cellobiose does not affect human gut bacterial diversity but increases abundance of lactobacilli, bifidobacteria and branched-chain fatty acids: a randomized, double-blinded cross-over trial.

Probiotics, prebiotics, and combinations thereof, that is synbiotics, have been reported to modulate gut microbiota of humans. In this study, effects of a novel synbiotic on the composition and metabolic activity of human gut microbiota were investigated. Healthy volunteers (n = 18) were enrolled in a double-blinded, randomized, and placebo-controlled cross-over study and received synbiotic [Lactobacillus acidophilus NCFM (10(9) CFU) and cellobiose (5 g)] or placebo daily for 3 weeks. Fecal samples were collected and lactobacilli numbers were quantified by qPCR. Furthermore, 454 tag-encoded amplicon pyrosequencing was used to monitor the effect of synbiotic on the composition of the microbiota. The synbiotic increased levels of Lactobacillus spp. and relative abundances of the genera Bifidobacterium, Collinsella, and Eubacterium while the genus Dialister was decreased (P < 0.05). No other effects were found on microbiota composition. Remarkably, however, the synbiotic increased concentrations of branched-chain fatty acids, measured by gas chromatography, while short-chain fatty acids were not affected.

Spirulina (Spirulina platensis) algae supplementation increases microbial protein production and feed intake and decreases retention time of digesta in the rumen of cattle

Cattle consuming pastures low in protein have low liveweight gain due to low rumen degradable protein (RDP) supply and thus low microbial crude protein (MCP) production and efficiency of MCP production [EMCP, g MCP/kg digestible organic matter (DOM)]. Nitrogen supplements can increase MCP production and EMCP of cattle grazing low protein pastures. The objective of this study was to compare the effects of supplementation with a non-protein-N source (NPN), in this case urea and ammonium sulfate (US), with a single-cell algal protein source (Spirulina platensis), on intake, microbial protein supply and digestibility in cattle. Nine cannulated Bos indicus steers [initial liveweight 250.1 ± 10.86 (s.d.) kg] were fed Mitchell grass hay (Astrebla spp; 6.1 g N, 746 g NDF/kg DM) ad libitum and were supplied with increasing amounts of US (0, 6, 13, 19 and 33 g US DM/kg hay DM) or Spirulina 0, 0.5, 1.4, 2.5 and 6.1 g Spirulina DM/kg W.day in an incomplete Latin square design. The response of MCP production and EMCP to increasing amounts of the two supplements was different, with a greater response to Spirulina evident. The MCP production was predicted to peak at 140 and 568 g MCP/day (0.64 and 2.02 g MCP/kg W.day) for the US and Spirulina supplements, respectively. The highest measured EMCP were 92 and 166 g MCP/kg DOM for the US and Spirulina treatments at 170 and 290 g RDP/kg DOM, respectively, or a Spirulina intake of 5.7 g DM/kg W.day. Increasing RDP intake from US and Spirulina resulted in an increase in Mitchell grass hay intake and rumen NH3-N concentration and reduced the retention time of liquid and particulate markers and digesta DM, NDF and lignin in the rumen with greater changes due to Spirulina. Total DM intake peaked at a Spirulina supplement level of 4.6 g Spirulina DM/kg W.day with a 2.3-fold higher DOM intake than Control steers. Rumen NH3-N concentrations reached 128 and 264 mg NH3-N/L for the US and Spirulina treatments with a significant increase in the concentration of branched-chain fatty acids for the Spirulina treatment. The minimum retention time of liquid (Cr-EDTA; 23 and 13 h) and particulate (Yb; 34 and 22 h) markers in the rumen were significantly lower for Spirulina compared with US and lower than unsupplemented animals at 24 and 34 h for Cr-EDTA and Yb, respectively. Spirulina could be provided safely at much higher N intakes than NPN supplements. The results suggest that, at an equivalent RDP supply, Spirulina provided greater increases than US in MCP production, EMCP and feed intake of Bos indicus cattle consuming low protein forage and could also be fed safely at higher levels of N intake.

Microbial Fermentation Patterns, Diarrhea Incidence, and Performance in Weaned Piglets Fed a Low Protein Diet Supplemented with Probiotics

To evaluate the effects of dietary protein levels and probiotic supplementation on microbial intestinal fermentation, diarrhea incidence, and performance in weaned piglets, 162 piglets were randomly assigned to three treatments: high-protein diet (20%), with antibiotics (HPa); high-protein diet (20%), without antibiotics (HP); and low-protein diet, without antibiotics but with probiotics (LPpb). Piglets and feed were weighed weekly to calculate the average daily gain (ADG), average daily feed intake (ADFI), and gain: feed ratio (G:F). Four piglets per treatment were killed on day 21 postweaning to collect ileal and colon digesta for measurement of short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs), lactic acid (LA), and ammonia (AM). In the digesta collected from the ileum and colon, piglets fed the HPa diet had the lowest concentration of volatile fatty acids. Additionally, the HP diet produced the highest concentration of BCFAs, while the LPpb diet produced moreacetic, propionic, and butyric acids than the HPa and HP diets. Piglets fed the HP diet had higher incidence and severity of diarrhea than piglets fed LPpb and HPa diets, and similar values were observed between these two groups. The second week postweaning was the most critical for diarrhea measurements; during the second week, animals had higher incidence and severity of diarrhea. Piglets fed the HPa and LPpb diets had similar ADGs, while those fed the HP diet had the poorest ADG. Similar results were observed with ADFI and G:F. A low-protein diet supplemented with probiotics changed the fermentation profile, reducing toxic metabolites, promoting gut health, decreasing the incidence and severity of postweaning diarrhea, and improving the performance of piglets.

Branched Chain Fatty Acids (BCFA) concentrations in US foods and estimated BCFA intake in the US population

IntroductionBranched chain fatty acids (BCFA) are a class of primarily saturated fatty acids (FA) with a methyl branch on the carbon chain. We recently showed that BCFA are constituents of the term newborn infant's gut, and feeding neonatal rats with a rat formula with BCFA of the type found in US food altered gut microbiota and reduced the incidence of Necrotizing Enterocolitis. Thus, BCFA may have beneficial effects on proper gut development and function.Our aim was to analyze the levels and distribution of BCFA in common foods consumed in the US, and to estimate the amount of BCFA intake from these foods. Because BCFA have been reported in cow's milk and are a major component of bacterial membranes, we were specifically interested in BCFA from dairy‐based and fermented foods.MethodsFood samples were purchased from local stores. FA analysis was carried out using routine methods.ResultsBCFA concentration in ruminant foods ranged from 1.4–2.7%w/w. Intake of BCFA per capita/d from foods was about 400mg/d. If Americans consumed the recommended amount of servings from the dairy food group, daily BCFA intake would increase.ConclusionsThis is the first report of BCFA concentrations in American foods. The consumption of BCFA per capita per day is higher than the consumption of bioactive n‐3 FA. The prominence of BCFA in the US food supply and their bioactivity strongly suggest that BCFA health effects should be studied.

Influence of dietary fiber type and amount on energy and nutrient digestibility, fecal characteristics, and fecal fermentative end-product concentrations in captive exotic felids fed a raw beef-based diet

Little nutritional or metabolic information has been collected from captive exotic cats fed raw diets. In particular, fiber types and concentrations for use in raw meat-based diets for captive exotic felids have not been well studied. Our objective was to evaluate the effects of fiber type and concentration on apparent total tract energy and macronutrient digestibility, fecal characteristics, and fecal fermentative end-products in captive exotic felids. Four animals of each captive exotic species (jaguar (Panthera onca), cheetah (Acinonyz jubatus), Malayan tiger (Panthera tigris corbetti), and Siberian tiger (Panthera tigris altaica) were randomized in four 4 × 4 Latin square designs (1 Latin square per species) to 1 of the 4 raw beef-based dietary treatments (94.7 to 96.7% beef trimmings): 2 or 4% cellulose or 2 or 4% beet pulp. Felid species, fiber type, and fiber concentration all impacted digestibility and fecal fermentative end-products. Inclusion of beet pulp increased (P ≤ 0.05) fecal short-chain fatty acids and fecal output in all cats. Inclusion of 2 and 4% cellulose, and 4% beet pulp increased (P ≤ 0.05) fecal bulk and diluted fecal branched-chain fatty acid concentrations compared with 2% beet pulp. Apparent total tract DM, OM, fat, and GE digestibility coefficients decreased (P ≤ 0.05) linearly with BW of cats. Additionally, fecal moisture, fecal score, and concentrations of fermentative end-products increased (P ≤ 0.05) with BW. Although the response of many outcomes was dependent on cat size, in general, beet pulp increased wet fecal weight, fecal scores, and fecal metabolites, and reduced fecal pH. Cellulose generally reduced DM and OM digestibility, but increased dry fecal weight and fecal percent DM. Although beet pulp and cellulose fibers were tested individually in this study, these data indicate that the optimum fiber type and concentration for inclusion in captive exotic felid diets is likely a combination of fermentable and nonfermentable fibers, with the optimal fiber blend being dependent on species. Smaller cats, such as cheetahs and jaguars, tolerated fermentable fibers, whereas larger cats, such as Malayan and Siberian tigers, appeared to require more insoluble fibers that limit fermentation and provide fecal bulk. Further research is required to test whether these trends hold true when fed in combination.

Effect of replacing soybean meal protein with protein from upland cottonseed, Pima cottonseed, or extruded Pima cottonseed on production of lactating dairy cows

Pima cotton production is increasing in the United States, but Pima cottonseed generally contains higher concentrations of the antinutritive pigment gossypol than conventional upland cottonseed. Heating promotes the reaction of gossypol with protein, reducing gossypol absorption and toxicity. The objective of this study was to assess the nutritional value for dairy cattle of Pima cottonseed cake (PCSC) that was heated and oil largely removed by an experimental extrusion process, compared with upland cottonseed (UCS) and Pima cottonseed (PCS). The PCS had greater crude protein (CP) and ether extract, less neutral detergent fiber (NDF) and acid detergent fiber (ADF), similar total gossypol, but higher (−)-gossypol isomer compared with UCS. Extrusion reduced lipid content by 73%, increased concentrations of CP, NDF, and ADF, and reduced total gossypol, (+)-gossypol, and (−)-gossypol in PCSC versus PCS. Forty lactating Holsteins (8 with ruminal cannulas) were blocked by days in milk into 5 squares in a replicated, incomplete 8 × 8 Latin square, and were fed diets containing, on a dry matter (DM) basis, 30% alfalfa silage, 31% corn silage, 21 to 25% high-moisture corn, and about 15% CP. Diets were fed as total mixed rations for ad libitum intake. Supplemental CP was from (1) solvent soybean meal (SSBM) only or 50% from SSBM plus 50% from (2) UCS, (3) PCS, (4) PCSC, (5) UCS plus PCS, and (6) UCS plus PCSC, or (7) 50% from expeller soybean meal (ESBM) plus 50% from PCS, and (8) 50% from ESBM plus 50% from PCSC. Periods were 4 wk long (total of 16 wk); production data were collected over the last 2 wk and blood and ruminal samples were taken on d 28 of each period. Data were analyzed using Proc Mixed of SAS (SAS Institute Inc., Cary, NC). Diet affected dry matter intake, with greatest intake on diet 6 and lowest intake on diets 1 and 3. The highest milk fat content was observed on diet 5 and the greatest fat yield on diet 7; fat content and yield were lowest on diet 1 (soybean meal control). Milk fat secretion was proportional to dietary fat content, indicating that cottonseed oil was used effectively for milk fat synthesis. We observed a trend for an effect on milk protein yield with the greatest protein secretion occurring on diet 7. Milk urea was lowest on diets 3, 7, and 8. Ruminal concentrations of branched-chain volatile fatty acids were lower, or tended to be lower, when PCSC replaced either UCS or PCS in the diet, suggesting reduced degradation and increased escape of PCSC protein. Among cottonseed-containing diets, total gossypol intake was lowest on PCSC, intermediate on PCS, and highest on UCS. Total gossypol and both (+)- and (−)-isomers of gossypol were higher in blood plasma on PCS and lower on PCSC than on the corresponding diets containing UCS, indicating that the extrusion process reduced gossypol absorption. In this trial, production on diets supplemented with UCS, PCS, or PCSC was comparable to that on diets containing soybean meal.

Soluble Fiber Dextrin and Soluble Corn Fiber Supplementation Modify Indices of Health in Cecum and Colon of Sprague-Dawley Rats

The objective of this study was to evaluate health outcomes resulting from dietary supplementation of novel, low-digestible carbohydrates in the cecum and colon of Sprague-Dawley rats randomly assigned to one of four treatment groups for 21 days: 5% cellulose (Control), Pectin, soluble fiber dextrin (SFD), or soluble corn fiber (SCF). Rats fed Pectin had a higher average daily food intake, but no differences in final body weights or rates of weight gain among treatments were observed. No differences were observed in total short-chain fatty acid (SCFA) or branched-chain fatty acid (BCFA) concentrations in the cecum and colon of rats fed either SFD or SCF. The SFD and SCF treatments increased cecal propionate and decreased butyrate concentrations compared to Control or Pectin. Pectin resulted in increased BCFA in the cecum and colon. Supplementation of SFD and SCF had no effect on cecal microbial populations compared to Control. Consumption of SFD and SCF increased total and empty cecal weight but not colon weight. Gut histomorphology was positively affected by SFD and SCF. Increased crypt depth, goblet cell numbers, and acidic mucin were observed in both the cecum and colon of rats supplemented with SFD, SCF, and Pectin. These novel, low-digestible carbohydrates appear to be beneficial in modulating indices of hindgut morphology when supplemented in the diet of the rat.

Effects of Biofloc Reduction on Microbial Dynamics in Minimal‐exchange, Superintensive Shrimp, Litopenaeus vannamei, Culture Systems

The microbial community in minimal‐exchange, superintensive culture systems should be managed to cycle nutrients and enhance production. This paper explores the effects of biofloc concentration reduction and a fish‐free diet on several microbial community characteristics. In 16, 3.5‐m diameter, 71‐cm deep outdoor tanks, shrimp were stocked at 460/m3. Eight of the tanks received a fish‐free, plant‐based feed and eight received a conventional feed containing fishmeal and fish oil. Within each diet type, biofloc concentration was reduced in four of the tanks and was not reduced in the other four tanks. Photosynthetically active radiation (PAR) extinction coefficients, photosynthetic oxygen production, chlorophyll‐a (chl‐a) concentrations, pheophytin‐a (pheo‐a) concentrations, and the sum of odd and branched chain fatty acid concentrations as a bacterial abundance indicator (BAI) were measured. Biofloc reduction significantly (P≤ 0.003) decreased PAR extinction coefficients, chl‐a concentration, pheo‐a concentration, and BAI concentration, while significantly increasing photosynthetic oxygen production. Diet did not significantly affect (P &gt; 0.05) any of these measured parameters. The observed changes in microbial community characteristics corresponded with, and may help to explain, significantly improved shrimp feed conversion ratios, growth rate, final weight, and biomass yield in the tanks with biofloc reduction.

Effects of oligosaccharides in a soybean meal-based diet on fermentative and immune responses in broiler chicks challenged with Eimeria acervulina

Fermentable oligosaccharides, particularly those found in soybean meal (SBM), may modulate fermentation in the ceca, thus affecting intestinal immune responses to intestinal pathogens. We hypothesized that fermentable oligosaccharides found in SBM would positively affect cecal fermentation and intestinal immune status in chicks challenged with an acute coccidiosis (Eimeria acervulina) infection and fed either a SBM-based diet or a semi-purified soy protein isolate- (SPI) based diet. Using a completely randomized design, 1-d-old broiler chicks (n = 200; 5 replications/treatment; 5 chicks/replication) were assigned to 1 of 4 SBM- or SPI-based diets containing either dietary cellulose (4%) or a fermentable carbohydrate, galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex (4%). On d 9 posthatch, an equal number of chicks on each diet were inoculated with either distilled water (sham control) or E. acervulina (1 × 106 oocysts) and then euthanized on d 7 postinoculation. Overall, body weight gain and feed intake were greater (P < 0.01) for SBM-fed chicks, regardless of infection status. Gain:feed ratio was greater (P ≤ 0.05) for SPI-fed chicks except during d 3–7 postinoculation. Infection status, but not fiber source, affected propionate, isobutyrate, isovalerate, and total branched-chain fatty acid concentrations (P ≤ 0.02). Soybean meal-based diets resulted in greater (P ≤ 0.04) short-chain fatty acid and branched-chain fatty acid concentrations than SPI-based diets. Messenger RNA fold changes relative to uninfected SBM-cellulose-fed chicks of all duodenal cytokines were greater (P ≤ 0.01) for infected chicks, and SBM-fed chicks had greater (P < 0.01) interferon-γ and interleukin-12β expression compared with SPI-fed chicks. Cecal tonsil cytokine expression was also affected (P ≤ 0.02) by infection; however, protein source only affected (P < 0.01) interleukin-1β expression in this tissue. Overall, a SBM-based diet, compared with a semi-purified SPI-based diet with a different ingredient composition, resulted in greater weight gain, feed intake, and short-chain fatty acid production regardless of infection status, and also greater duodenal cytokine expression in E. acervulina- infected chicks, which is hypothesized to be related to the nutrients and oligosaccharides found in SBM.

Evaluation of four raw meat diets using domestic cats, captive exotic felids, and cecectomized roosters

Our objective was to evaluate raw meat diets for captive exotic and domestic carnivores containing traditional and alternative raw meat sources, specifically, beef trimmings, bison trimmings, elk muscle meat, and horse trimmings. We aimed to examine diet composition and protein quality; apparent total tract energy and macronutrient digestibility in domestic cats, African wildcats, jaguars, and Malayan tigers; and ME and fecal fermentative end-products in domestic cats. Because of variation in the meat sources, dietary proximate, AA, and long-chain fatty acid composition were variable. Our analyses indicated that all diets had essential fatty acid deficiencies, and the elk diet (i.e., trimmed muscle meat) was deficient in total fat. Standardized AA digestibilities measured using the cecectomized rooster assay were high (>87%). Using the NRC minimum requirements for the growth of kittens, the first limiting AA of all diets was the combined requirement of Met and Cys (AA score: 81 to 95; protein digestibility corrected AA score: 75 to 90). All diets were highly digestible (88 to 89% OM digestibility). There was no effect of diet or felid species on DM (85 to 87%), OM, and GE (90 to 91%) digestibilities. Apparent CP digestibility was greater (P≤0.05) in cats fed elk (97%) compared with those fed bison (96%), and greater (P≤0.05) in wildcats (97%) and domestic cats (97%) compared with tigers (95%). The diet and species interaction (P≤0.05) was observed for apparent fat digestibility. In domestic cats, the fresh fecal pH and proportions of acetate and butyrate were altered (P≤0.05) due to diet. Diet also affected (P≤0.05) fresh fecal concentrations of total branched-chain fatty acids, valerate, and Lactobacillus genus. In conclusion, although the raw meat diets were highly digestible, because of variation in raw meat sources the nutrient composition of the diets was variable. Thus, compositional analysis of raw meat sources is necessary for proper diet formulation. The types of meat commonly used in raw meat diets may be deficient in total fat (trimmed muscle meat) and essential fatty acids (trimmings and muscle meats). Additionally, differences in raw meat source nutrient composition and digestibility affect the beneficial and putrefactive fermentative end-products found in feces.

Prediction of ruminal volatile fatty acid proportions of lactating dairy cows based on milk odd- and branched-chain fatty acid profiles: New models, better predictions

The volatile fatty acids (VFA) produced in the rumen and the proportions in which they are produced are important determinants of a ruminant's metabolism, but their monitoring requires rumen-fistulated animals, which is not feasible under practical conditions or in experimental setups at herd level. An alternative approach was suggested earlier, consisting of predicting the VFA proportions from measured odd- and branched-chain fatty acid concentrations in the milk with a linear model. Here, we have improved this strategy through the development and application of 2 new model structures: the quadratic model, containing quadratic terms and interactions, and the rational model, consisting of a ratio of linear expressions. Both were found to improve prediction accuracy significantly compared with the linear model. Although the quadratic model achieved the best prediction accuracy, the rational model has the interesting property that it takes the dependence of the 3 predicted VFA into account and guarantees that the 3 proportions add up to 1. Adding a study effect to correct for a possible study bias in the multi-study data improved prediction substantially for all 3 methods. Our results demonstrate the potential of using milk odd- and branched-chain fatty acid concentrations to predict rumen VFA proportions.

Influence of dietary protein content and source on colonic fermentative activity in dogs differing in body size and digestive tolerance1

Low-consistency, high-moisture feces have been observed in large dogs (Canis lupus familiaris), compared with small dogs, and particularly in sensitive breeds (e.g., German Shepherd dogs). The aim of this work was to determine if greater colonic protein fermentation is responsible for poorer fecal quality in large sensitive dogs. Twenty-seven bitches were allotted to 4 groups based on size and digestive sensitivity: small, medium, large tolerant, and large sensitive. Five experimental diets varying in protein source [highly digestible wheat gluten (WG) vs. medium digestible poultry meal (PM), and protein concentration from 21.4 to 21.6 (LP) to 38.2 to 39.2% CP (HP)] were tested. Diets were fed for 14 d and followed by a 12-d transition period. Digestive fermentation by-products were investigated in fresh stools [ammonia, phenol, indole, and short chain fatty acids including acetate, propionate, and butyrate (C2 to C4 SCFA), branched-chain fatty acids (BCFA), and valerate] and in urine (phenol and indole). Bacterial populations in feces were identified. The PM diets resulted in greater fecal concentrations of ammonia, BCFA, valerate, indole, and C2 to C4 SCFA than WG diets (P = 0.002, P < 0.001, P = 0.039, P = 0.003, and P = 0.012, respectively). Greater concentrations of ammonia, BCFA, and valerate were found in the feces of dogs fed HP compared with LP diets (P < 0.001, P < 0.001, and P = 0.012, respectively). The concentrations of ammonia, valerate, phenol, and indole in feces of large sensitive dogs were greater (P < 0.001, P < 0.001, P = 0.002, and P = 0.019, respectively) compared with the other groups. The Enterococcus populations were greater in feces of dogs fed with PMHP rather than WGLP diets (P = 0.006). Urinary phenol and indole excretion was greater when dogs were fed PM than WG diets (P < 0.001 and P = 0.038, respectively) and HP than LP diets (P = 0.001 and P = 0.087, respectively). Large sensitive dogs were prone to excrete a greater quantity of phenol in urine (P < 0.001). A diet formulated with highly digestible protein, such as WG, led to reduced concentrations of protein-based fermentation products in feces together with improved fecal quality in dogs, especially in large sensitive ones. Poor fecal quality in large sensitive dogs could be partly related to the pattern of protein fermentation in the hindgut.

Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets

The objectives of this study were to determine differences in apparent total tract energy and macronutrient digestibility, fecal and urine characteristics, and serum chemistry of domestic cats fed raw and cooked meat-based diets and extruded diet. Nine adult female domestic shorthair cats were utilized in a replicated 3 × 3 Latin square design. Dietary treatments included a high-protein extruded diet (EX; 57% CP), a raw beef-based diet (RB; 53% CP), and a cooked beef-based diet (CB; 52% CP). Cats were housed individually in metabolic cages and fed to maintain BW. The study consisted of three 21-d periods. Each period included diet adaptation during d 0 to 16; fecal and urine sample collections during d 17 to 20; and blood sample collection at d 21. Food intake was measured daily. Total feces and urine were collected for determination of nutrient digestibility. In addition, a fresh urine sample was collected from each cat for urinalysis, and a fresh fecal sample was collected from each cat for determination of DM percentage and ammonia, short-chain fatty acid (SCFA), and branched-chain fatty acid (BCFA) concentrations. All feces were scored after collection using a scale ranging from 1 (hard, dry pellets) to 5 (watery, liquid that can be poured). Blood was analyzed for serum metabolites. Apparent total tract DM, OM, CP, fat, and GE digestibilities were greater (P ≤ 0.05) in cats fed RB and CB than those fed EX. Total fecal SCFA concentrations did not differ among dietary treatments; however, molar ratios of SCFA were modified by diet, with cats fed RB and CB having an increased (P ≤ 0.05) proportion of fecal propionate and decreased (P ≤ 0.05) proportion of fecal butyrate compared with cats fed EX. Fecal concentrations of ammonia, isobutyrate, valerate, isovalerate, and total BCFA were greater (P ≤ 0.05) in cats fed EX compared with cats fed RB and CB. Our results indicated that cooking a raw meat diet does not alter apparent total tract energy and macronutrient digestibility and may also minimize risk of microbial contamination. Given the increasing popularity of feeding raw diets and the metabolic differences noted in this experiment, further research focused on the adequacy and safety of raw beef-based diets in domestic cats is justified.

Digestive physiological outcomes related to polydextrose and soluble maize fibre consumption by healthy adult men

The objective of the present study was to evaluate digestive physiological outcomes elicited by functional fibres fed to healthy adult men. A total of twenty-one healthy adult men were utilised in a cross-over design. Each subject received polydextrose (PDX) or soluble maize fibre (SCF) (21g/d) or no supplemental fibre (no fibre control; NFC) in a snack bar. Periods were 21d and faeces were collected during the last 5d of each period. Food intake, including fibre intake, did not differ among treatments. Flatulence (P=0·001) and distention (P=0·07) were greatest when subjects consumed PDX or SCF. Reflux was greater (P=0·04) when subjects consumed SCF compared with NFC. All tolerance scores were low (<2·5), indicating only slight discomfort. Faecal ammonia, 4-methylphenol, indole and branched-chain fatty acid concentrations were decreased (P<0·01) when subjects consumed the functional fibre sources compared with NFC. Faecal acetate, propionate and butyrate concentrations were lower (P<0·05) when subjects consumed PDX compared with SCF and NFC. Faecal pH was lower (P=0·01) when subjects consumed SCF compared with NFC, while PDX was intermediate. Faecal wet weight was greatest (P=0·03) when subjects consumed SCF compared with NFC. Faecal dry weight tended to be greater (P=0·07) when subjects consumed PDX compared with NFC. The functional fibres led to 1·4 and 0·9g (PDX and SCF, respectively) increases in faecal dry mass per g supplemental fibre intake. Bifidobacterium spp. concentrations were greater (P<0·05) when subjects consumed SCF compared with NFC. These functional fibres appear to be beneficial to gut health while leading to minimal gastrointestinal upset.

Digestive physiological outcomes related to polydextrose and soluble corn fiber consumption by healthy adult men

The objective of this study was to evaluate fermentation characteristics of novel fibers by healthy adults. Twenty‐one healthy adult males were utilized in a crossover design. Each subject received each treatment of 21 g of polydextrose (PDX) or soluble corn fiber (SCF), or a no‐fiber control (NFC) in a snack bar. Each period lasted 21 d and feces were collected during the last 5 d of each period. Food intake, including fiber intake (average 14.7 g/d) did not differ among treatments. Cramping, flatulence, and distention were greatest (P&lt;0.01) when subjects consumed PDX. Reflux, flatulence, and distension were greater (P&lt;0.01) when subjects consumed SCF compared to NFC. All tolerance scores were very low (&lt;2) indicating only small decreases in comfort. Fecal ammonia, 4‐methylphenol, indole, and branched‐chain fatty acid concentrations were decreased (P&lt;0.01) when subjects consumed the novel fiber sources compared to NFC. Fecal acetate, propionate, and butyrate concentrations were lowest (P&lt;0.05) when subjects consumed PDX compared to SCF and NFC. Fecal pH was lower (P=0.01) when subjects consumed SCF compared to NFC, while PDX was intermediate. Fecal wet weight was greatest (P=0.03) when subjects consumed SCF compared to NFC. Fecal dry weight tended to be greater (P=0.07) when subjects consumed PDX compared to NFC. The novel fibers led to 1.4 and 0.9 (PDX and SCF, respectively) gram increases in fecal dry mass per gram of supplemental fiber intake. These novel fibers appear to be beneficial to gut health while leading to minimal gastrointestinal upset in healthy adult males.

Branched Chain Fatty Acid Content of United States Retail Cow's Milk and Implications for Dietary Intake

Branched chain fatty acids (BCFA) have recently been shown to be a major component of the normal human newborn gastrointestinal tract and have long been known to be a component of human milk. Ruminant food products are major sources of fat in the American diet, but there are no studies of milkfat BCFA content in retail milk. We report here the profile and concentrations of BCFA in a representative sampling of retail milk in the 48 contiguous United States (US), and their estimated intake in the American diet. Conventionally produced whole fluid milk samples were obtained from 56 processing plants across the contiguous 48 states. Retail milk samples contain exclusively iso- and anteiso-BCFA with 14-18 carbons. BCFA were 2.05±0.14%, w/w of milkfat fatty acids (mean±SD), and anteiso-BCFA comprised more than half this total. Based on these data and USDA food availability data, the average per capita BCFA intake of Americans is estimated to be about 220mg/d from dairy; if current dietary recommendations were followed, BCFA intake would be about 400mg/d. Adding intake from beef consumption, these estimates rise to approximately 400 and 575mg/d, respectively. These results indicate that BCFA intake is a substantial fraction of daily fat intake, in amounts exceeding those of many bioactive fatty acids.

Effects of short-chain fructooligosaccharides and galactooligosaccharides, individually and in combination, on nutrient digestibility, fecal fermentative metabolite concentrations, and large bowel microbial ecology of healthy adults cats

Short-chain fructooligosaccharides (scFOS) and galactooligosaccharides (GOS) are nondigestible oligosaccharides that result in a prebiotic effect in some animal species; however, the cat has not been well studied in this regard. This experiment evaluated scFOS and GOS supplementation on nutrient digestibility, fermentative end product production, and fecal microbial ecology of cats. Eight healthy adult cats were fed diets containing no prebiotic, 0.5% scFOS, 0.5% GOS, or 0.5% scFOS + 0.5% GOS (scFOS + GOS) in a replicated 4 × 4 Latin square design. Apparent total tract CP digestibility was decreased (P < 0.05) when cats were fed a diet containing scFOS + GOS compared with the other treatments. Dry matter, OM, acid hydrolyzed fat, and GE digestibilities were not different (P > 0.05) among treatments. Cats fed scFOS-, GOS-, and scFOS + GOS-supplemented diets had greater (P < 0.05) fecal Bifidobacterium spp. populations compared with cats fed the control diet. Fecal pH was less (P < 0.05) for cats fed the scFOS + GOS-supplemented diet compared with the control. Butyrate (P = 0.05) and valerate (P < 0.05) concentrations were greater when cats consumed the scFOS + GOS diet. Acetate tended (P = 0.10) to be greater when cats were fed the scFOS + GOS diet. Total short-chain fatty acid (P = 0.06) and total branched-chain fatty acid (P = 0.06) concentrations also tended to be greater when cats consumed the scFOS + GOS treatment. Fecal protein catabolites, including ammonia, 4-methylphenol, indole, and biogenic amines, blood lymphocytes, neutrophils, total white blood cell counts, or fecal DM concentration and output did not differ (P > 0.05) among treatments. Low level supplementation of scFOS, GOS, and their combination exert positive effects on select indices of gut health in cats.