Altered fecal microbiota, IgA, and fermentative end-products in adult dogs fed prebiotics and a nonviable Lactobacillus acidophilus

A study investigating the use of a nonviable Lactobacillus acidophilus (NVL: Culbac; TransAgra, Storm Lake, IA) and a mixed prebiotic (MP) blend (beet pulp, fructooligosaccharide (FOS), mannanoligosaccharide (MOS), inulin, and kelp) was done to evaluate changes in fecal microbiota, fermentative end products, and gut immune health in healthy female and male adult Beagle dogs (n = 24; 5.74 ± 2.18 yr; 9.30 ± 1.32 kg). The study protocol was first approved by the facility’s Institutional Animal Care and Use Committee (Summit Ridge Farms; Susquehanna, PA) and followed throughout. Each of four test diets (control, NVL, MP, and MP + NVL [formulated to crude protein 25%, crude fat 14%, crude fiber 10% as-fed]) was fed once daily to maintain body weight for 21 d in a randomized-crossover design (four treatment periods and four washout periods). Fecal samples were collected on days 0 and 21 only for immunoglobulin A (IgA) and microbiota evaluation (16S rRNA V4 region and qPCR for Escherichia coli and Bifidobacterium), and fecal fermentative end-products and fecal pH were assessed only on day 21. Over the test periods, apparent total tract nutrient digestibility and stool quality were assessed. Data were analyzed by ANOVA (SAS v9.4, Cary, NC) or Kruskal–Wallis for between-diet effects, and paired t-test or Wilcoxon for time effects. Statistical significance was set at P ≤ 0.05. Apparent total tract nutrient digestibility revealed feeding MP-containing diets resulted in lower (P < 0.05) crude protein and fat digestibility vs. control and NVL diets. When dogs were fed MP, they had lower (P < 0.05) fecal pH compared with control and NVL diets, whereas fecal pH was lower in (P < 0.05) MP + NVL- vs. NVL-fed dogs. Fecal E. coli was (P < 0.05) lower at day 21 vs. day 0 when dogs were fed MP. Fecal Fusobacterium spp. was lower (P < 0.05) in both MP diets vs. control. Fecal Lactobacillus spp. increased (P < 0.05) from baseline with MP. Both diets with MP elicited greater (P < 0.05) fecal acetate and propionate concentration vs. control diet. At day 21, fecal IgA was greater (P < 0.05) in MP and MP + NVL compared with NVL diet. Only when dogs were fed MP did they have increased (P < 0.05) fecal IgA from day 21 vs. day 0. The MP + NVL diet decreased (P < 0.05) fecal isovalerate, isobutyrate, phenol, and indole vs. control. Overall, the MP elicited the most changes on microbiota, fermentative end-products, and IgA. Further investigation into NVL’s gut health benefits is warranted.

A Comparative Study of Selected Gut Bacteria Abundance and Fecal pH in Bodybuilders Eating High-Protein Diet and More Sedentary Controls

Bodybuilders tend to overeat their daily protein needs. The purpose of a high-protein diet is to support post-workout recovery and skeletal muscle growth; however, its exact impact on gut microbiota still remains under investigation. The aim of this study was to assess the differences in selected gut bacteria (Faecalibacterium prausnitzii, Akkermansia muciniphila, Bifidobacterium spp., and Bacteroides spp.) abundance and fecal pH between the group of amateur bodybuilders and more sedentary control group. In total, 26 young healthy men took part in the study, and their daily nutrients intake was measured using a dietary interview. Real-time PCR was used to assess the stool bacteria abundance. Both groups reported fiber intake within the recommended range, but bodybuilders consumed significantly more protein (33.6% ± 6.5% vs. 22% ± 6.3%) and less fat (27.6% ± 18.9% vs. 36.4% ± 10%) than controls. Study results showed no significant differences in terms of selected intestinal bacteria colony forming unit counts. Significantly higher fecal pH in the bodybuilders’ fecal samples was observed in comparison to the control group 6.9 ± 0.7 vs. 6.2 ± 0.7. Gut microbiota composition similarities could be a result of appropriate fiber intake in both groups.

A Low to Medium-Shear Extruded Kibble with Greater Resistant Starch Increased Fecal Oligosaccharides, Butyric Acid, and Other Saccharolytic Fermentation By-Products in Dogs

The objective of this study was to assess whether diets with increased resistant starch (RS) had a positive effect on markers of colonic health in dogs. Three identical diets were extruded with high, medium and low shear (HS, MS and LS) to incrementally increase RS, and fed to 24 dogs in a replicated 3 × 3 William’s Latin square design for 28-day periods. Fasting blood and fresh feces were collected on the last week of each period. Fecal quality was maintained among treatments. Gut integrity markers were measured by ELISA. Fecal short-chain fatty acids (SCFAs) were measured by LC MS/MS. In addition, the microbiota of dogs was determined from fresh feces by 16s rRNA high throughput sequencing. Untargeted metabolomics of both feces and serum were determined by UPLC. Data were analyzed using mixed models. There were no treatment effects on satiety hormones or gut integrity markers. Dogs fed LS or MS diets had marginal evidence (p < 0.10) for decreased fecal pH and for higher concentration (p < 0.05) of butyric acid and fecal oligosaccharides, succinate and lactate. Also, dogs fed the MS or LS diets had a shift towards more saccharolytic bacteria.

Clinical assessment and cytokines level in constipation-predominant irritable bowel syndrome participants treated with Lactobacillus-containing cultured milk drink

Gut dysbiosis is linked with the pathophysiology of irritable bowel syndrome (IBS). Manipulation of intestinal microbiota using cultured milk drinks may stimulate the immune system, hence providing beneficial support in IBS treatment. This study aimed to investigate the effects of cultured milk drink on clinical symptoms, intestinal transit time (ITT), fecal pH and cytokines in constipation- predominant IBS (IBS-C) as compared to non-IBS participants. Each recruited participant was given three bottles of 125 ml cultured milk drink containing 10 9 cfu Lactobacillus acidophilus LA-5 and Lactobacillus paracasei L. CASEI-01 consumed daily for 30 days. At pre- and post-30-day consumption, fecal pH, ITT, clinical symptoms, IL-6, IL-8 and TNF-α levels were assessed. Seventy- seven IBS-C and 88 non-IBS were enrolled. Post-consumption, 97.4% of IBS-C experienced improvements in constipation- related symptoms supported by the significant reduction of ITT and decreased fecal pH (p<0.05). All pro-inflammatory cytokines were significantly lower in post as compared to pre-consumption of cultured milk drinks in IBS-C (p<0.05). There was significant reduction in the IL-8 and TNF-α levels in post- as compared to pre-consumption for the non-IBS (p < 0.05). Cultured milk drink taken daily improved clinical symptoms and reduced cytokines, hence should be considered as an adjunctive treatment in IBS-C individuals.

Supplementing a Clay Mineral-Based Feed Additive Modulated Fecal Microbiota Composition, Liver Health, and Lipid Serum Metabolome in Dairy Cows Fed Starch-Rich Diets

Starch-rich diets are a commonly adopted strategy in order to sustain high milk yields in dairy cows. However, these diets are known to increase the risk of gut dysbiosis and related systemic health disorders. This study aimed to evaluate the effects of supplementing a clay mineral-based feed additive (CM; Mycofix® Plus, BIOMIN) on fecal microbiota structure, fecal short-chain fatty acid (SCFA) fermentation, serum metabolome, and liver health in primiparous (PP, n = 8) and multiparous (MP, n = 16) early-lactation Simmental cows (737 ± 90 kg of live body weight). Cows were randomly assigned to either a control or CM group (55 g per cow and day) and transitioned from a diet moderate in starch (26.3 ± 1.0%) to a high starch diet (32.0 ± 0.8%). Supplementation of CM reversed the decrease in bacterial diversity, richness, and evenness (p &lt; 0.05) during high-starch diet, demonstrating that CM supplementation efficiently eased hindgut dysbiosis. The CM treatment reduced levels of Lactobacillus in PP cows during starch-rich feeding and elevated fecal pH, indicating a healthier hindgut milieu compared with that in control. Butyrate and propionate levels were modulated by CM supplementation, with butyrate being lower in CM-treated MP cows, whereas propionate was lower in MP but higher in PP cows. Supplementing CM during high-starch feeding increased the concentrations of the main primary bile salts and secondary bile acids in the serum and improved liver function in cows as indicated by reduced levels of glutamate dehydrogenase and γ-glutamyl-transferase, as well as higher serum albumin and triglyceride concentrations. These changes and those related to lipid serum metabolome were more pronounced in PP cows as also corroborated by relevance network analysis.

108 Evaluation of Graded Levels of Grain Distillers Dried Yeast (GDDY) on Apparent Nutrient Digestibility and Stool Quality in Healthy Adult Dogs

Yeast and distillers’ grains from ethanol products have been included in pet food for many years. However, their combination has not been evaluated in pet food. Grain distillers dried yeast (GDDY) is a combination of fermented grains which is rich in yeast. The objectives of this study were to determine the effects of increasing levels of GDDY on apparent total tract digestibility (ATTD) and stool quality in adult dogs. Four extruded diets were fed to twelve adult Beagle dogs in a replicated 4 x 4 Latin Square design. The control diet contained 15% soybean meal (15S) and GDDY was exchanged for soybean meal at either 5%, 10%, or 15% (5G, 10G, 15G). Dogs were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1–5 scale, with 1 representing liquid diarrhea. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and dog and period as random effects. No differences (P &gt; 0.05) were observed in wet fecal output or fecal pH (average; 112.74g/d and 5.77). Fecal DM and defecations per day were greater (P &lt; 0.05) at elevated levels of GDDY. Stool scores were higher (P &lt; 0.05) when dogs consumed diets containing GDDY versus 15S (average; 3.85 vs 3.67). Organic matter ATTD was the greatest (P &lt; 0.05) for dogs fed 15S compared to GDDY treatments (average; 87.64% vs 86.67%). Dogs fed 10G had the lowest (P &lt; 0.05) ATTD for crude protein compared to all others (average; 87.92% vs 88.78%). These results suggest that levels of GDDY between 5 and 15% are comparable to soybean meal when fed to adult dogs.

Buffering capacity and fecal pH in healthy horses submitted to experimental enteral nutrition

This study set out to determine the impacts of a commercial equine enteral nutrition product on fecal pH, buffering capacity (BC) and physical examination variables. Eight healthy horses were randomly allocated to one of two simultaneous experimental groups in a 4×4 Latin square design. Horses were submitted to 12 hours of solid fasting, then fed increasing doses of the test product via nasogastric tube, as follows: 0% (pure water), 50%, 75% and 100% of the daily recommended dose. Test product doses were diluted in water (1:3) and delivered by bolus feeding. Fecal samples were taken directly from the rectal ampulla prior to (T0) and within 3, 6, 12, 24, 36 and 48 hours of product administration (T3, T6, T12, T24, T36 and T48 respectively). Within 24 to 36 hours of product administration, fecal pH was near 6 (p = 0.01). However, dose variation had no effect on pH. Product dose and sample collection time had a significant impact (p = 0.00) on buffering capacity at pH 6. The more dramatic drop in pH occurred within 24 to 36 hours of product administration, except in horses receiving the 0% dose (water). At pH 5, buffering capacity was affected by dose but not by sample collection time. Soft fecal consistency, increased intestinal motility and fat droplets in fecal samples were noted in most horses. Fecal pH and buffering capacity assessment are indirect tests. Still, results obtained from these tests were deemed useful for detection of intestinal changes, particularly when combined with physical examination. The product had an impact on faecal pH, buffering capacity and intestinal motility, therefore, it is recommended that the formulation be revised.

Miscanthus Grass as a Novel Functional Fiber Source in Extruded Feline Diets

Although dietary fiber is not considered an essential nutrient in a complete and balanced diet for felines, it provides a substrate for fermentation by gut microbiota, thus promoting gastrointestinal health through the production of fermentative metabolites, as well as improving laxation. The aim of this research was to evaluate the novel fiber source, Miscanthus grass (Miscanthus giganteus), in comparison with traditional fiber sources and their effects on fecal quality, apparent total tract digestibility (ATTD), fecal fermentative end products, and microbiota of healthy adult cats. Four dietary treatments were evaluated, differing in dietary fiber source. The diets were formulated to meet or exceed the AAFCO (2018) nutritional profile for adult cats and contained either cellulose (CO), Miscanthus grass fiber (MF), a blend of Miscanthus fiber and tomato pomace (MF + TP), or beet pulp (BP). The study was conducted using a completely randomized design with 28 neutered adult, domesticated shorthair cats (19 females and 9 males, mean age 2.2 ± 0.03 years; mean body weight 4.6 ± 0.7 kg, mean body condition score 5.6 ± 0.6). The experimental period comprised 21 days, and a fresh fecal and a total fecal collection were performed during the last 4 days of the trial period. Daily food intake (DM basis) was similar across all groups (P &gt; 0.05). Additionally, treatment did not affect fecal output (as-is or DM basis), fecal score, or fecal pH (P &gt; 0.05). Cats fed BP had significantly higher total dietary fiber ATTD than all the other treatments (P &lt; 0.05) and the highest concentrations of total short-chain fatty acid, acetate, and propionate (P &lt; 0.05), while butyrate concentrations were similar for all treatments (P &gt; 0.05). Inclusion of dietary fibers was effective in modulating gut microbiota. Cats fed diets containing Miscanthus grass had greater α-diversity than cats fed BP. As no adverse effects on health, fecal quality, or ATTD of macronutrients were observed with the inclusion of 9% Miscanthus grass fiber or fiber blend, the data suggest that Miscanthus grass fiber and fiber blends are viable alternatives to the traditional dietary fiber sources used in commercial extruded feline diets, being most comparable to cellulose.

Short- and Branched-Chain Fatty Acids as Fecal Markers for Microbiota Activity in Vegans and Omnivores

A vegan diet could impact microbiota composition and bacterial metabolites like short-chain (SCFA) and branched-chain fatty acids (BCFA). The aim of this study was to compare the concentrations of SCFA, BCFA, ammonia, and fecal pH between vegans and omnivores. In this cross-sectional study (vegans n = 36; omnivores n = 36), microbiota composition, fecal SCFA, BCFA, and ammonia concentrations and pH were analyzed in complete stool samples. A random forest regression (RFR) was used to identify bacteria predicting SCFA/BCFA concentrations in vegans and omnivores. No significant differences in SCFA and BCFA concentrations were observed between vegans and omnivores. Fecal pH (p = 0.005) and ammonia concentration (p = 0.01) were significantly lower in vegans than in omnivores, while fiber intake was higher (p < 0.0001). Shannon diversity was higher in omnivores compared to vegans on species level (p = 0.04) only. In vegans, a cluster of Faecalibacterium prausnitzii, Prevotella copri, Dialister spp., and Eubacterium spp. was predictive for SCFA and BCFA concentrations. In omnivores, Bacteroides spp., Clostridium spp., Ruminococcus spp., and Prevotella copri were predictive. Though SCFA and BCFA did not differ between vegans and omnivores, the results of the RFR suggest that bacterial functionality may be adapted to varying nutrient availability in these diets.