Bacillus subtilis and Bacillus licheniformis reduce faecal protein catabolites concentration and odour in dogs

The Effects of Dietary Saccharomyces cerevisiae Supplementation on Gut Microbiota Composition and Gut Health in Aged Labrador Retrievers

The intestinal microbiome changes with age, influencing the host's health and immune status. Saccharomyces cerevisiae (S. cerevisiae) positively affects intestinal function in humans and animals, but its effects on gut health and the microbiota profile in aged dogs have not been thoroughly investigated. Twenty aged Labrador Retrievers were divided into two groups: a control group (CON) and a S. cerevisiae group (SC). The experiment lasted for 42 days, with assessments of their intestinal barrier function, inflammatory factors, antioxidant markers, and fecal microbiome composition. The results showed that dietary S. cerevisiae reduced the levels of TNF-α, IL-6, and IL-1β in the serum (p < 0.05). In the SC group, plasma superoxide dismutase and glutathione peroxidase activities increased, while the level of malondialdehyde significantly decreased (p < 0.05). Additionally, dietary S. cerevisiae lowered the serum zonulin and lipopolysaccharide (LPS) levels (p < 0.05) and inhibited fecal ammonia production (p < 0.05). Furthermore, the microbiota profile showed that dietary S. cerevisiae decreased the abundance of Firmicutes but increased the Chao index, the abundance of Bacteroidetes, and the proportion of Bacteroidetes to Firmicutes (p < 0.05). To conclude, dietary S. cerevisiae can regulate the gut's microbial structure and gut health, which may contribute to the overall health of companion animals as they age.

Effects of dietary fiber and biotic supplementation on apparent total tract macronutrient digestibility and the fecal characteristics, metabolites, and microbiota of healthy adult dogs

Dietary fibers and biotics have been shown to support gastrointestinal health in dogs, but are usually tested individually. There is value in testing fiber-biotic combinations that are commonly used commercially. Therefore, this study was conducted to determine the apparent total tract macronutrient digestibility (ATTD) of diets supplemented with fibers or biotics and to evaluate their effects on the fecal characteristics, metabolites, microbiota, and immunoglobulin A (IgA) concentrations of dogs. Twelve healthy adult female beagle dogs (age = 6.2 ± 1.6 yr; body weight = 9.5 ± 1.1 kg) were used in a replicated 3 × 3 Latin square design to test three treatments: 1) control diet based on rice, chicken meal, tapioca starch, and cellulose + a placebo treat (CT); 2) diet based on rice, chicken meal, garbanzo beans, and cellulose + a placebo treat (GB); 3) diet based on rice, chicken meal, garbanzo beans, and a functional fiber/prebiotic blend + a probiotic-containing treat (GBPP). In each 28-d period, a 22-d diet adaptation was followed by a 5-d fecal collection phase. Fasted blood samples were collected on day 28. Data were analyzed using the Mixed Models procedure of SAS 9.4, with P < 0.05 being significant and P < 0.10 being trends. ATTD of dry matter (DM), organic matter, and energy were lower (P < 0.001) and DM fecal output was higher (P < 0.01) in dogs fed GBPP than CT or GB, whereas ATTD of crude protein was higher (P < 0.001) in dogs fed CT and GBPP than GB. ATTD of fat was higher (P < 0.001) and wet fecal output was lower (P < 0.01) in dogs fed CT than GB or GBPP. Fecal DM% was higher (P < 0.001) in dogs fed CT than GBPP or GB, and higher in dogs fed GBPP than GB. Fecal short-chain fatty acid concentrations were higher (P < 0.001) in dogs fed GB than CT or GBPP, and higher in dogs fed GB than GBPP. Fecal IgA concentrations were higher (P < 0.01) in dogs fed GB than CT. Fecal microbiota populations were affected by diet, with alpha diversity being higher (P < 0.01) in dogs fed GB than CT, and beta diversity shifting following dietary fiber and biotic supplementation. The relative abundance of 24 bacterial genera was altered in dogs fed GB or GBPP than CT. Serum triglyceride concentrations were lower in dogs fed GB than GBPP or CT. Our results demonstrate that legume-based dietary fibers, with or without prebiotics and probiotics, reduce ATTD, increase stool output, beneficially shift fecal metabolites and microbiota, and reduce blood lipids in adult dogs.

Gut Probiotics and Health of Dogs and Cats: Benefits, Applications, and Underlying Mechanisms

Pets (mostly domestic dogs and cats) play an important role in the daily lives of humans and their health has attracted growing attention from pet owners. The intestinal microbiota, a complex microbial community with barrier-protective, nutritional, metabolic, and immunological functions, is integral to host health. Dysbiosis has been related to a variety of diseases in humans and animals. Probiotics have been used in functional foods and dietary supplements to modulate intestinal microbiota and promote host health, which has been introduced in pet dogs and cats in recent years. Various canine- and feline-derived probiotic strains have been isolated and characterized. The administration of probiotics has shown positive effects on the gut health and can alleviate some intestinal diseases and disorders in dogs and cats, although the underlying mechanisms are largely unresolved. In this review, we summarize the current knowledge on the benefits of probiotics and discuss their possible mechanisms in dogs and cats in order to provide new insights for the further development and application of probiotics in pets.

Digestibility and Palatability of the Diet and Intestinal Functionality of Dogs Fed a Blend of Yeast Cell Wall and Oregano Essential Oil

Feed additives, such as prebiotics and essential oils, are used in pet foods and can affect digestibility, palatability, and intestinal functionality of dogs. The combined effects of yeast cell wall and oregano essential oil on apparent total tract digestibility (ATTD) and palatability of diet, intestinal fermentation products, and fecal microbiota in dogs were analyzed. Eighteen adult dogs were fed for 20 days with three dry extruded diets for adult dogs: control (without the additive), a diet containing 1.5 kg/ton of yeast cell wall and oregano essential oil (1.5YCO), and a diet containing 3.0 kg/ton of yeast cell wall and oregano essential oil (3.0YCO). The inclusion of both levels of YCO reduced the intake ratio. The addition of 3.0YCO reduced the ATTD of dry matter, compared to the control group (p < 0.05). There were greater putrescine and cadaverine concentrations and lower histamine and ammonia (p < 0.05) in the feces of dogs fed 3.0YCO. In addition, fecal odor of dogs fed YCO was less fetid than the control group (p < 0.05). There was greater fecal bacterial diversity in dogs fed with both dietary concentrations of YCO evaluated (p < 0.05). Dogs fed 1.5YCO and 3.0YCO showed higher relative abundance of Blautia and Faecalibacterium and lower abundance of Streptococcus (p < 0.05) in the feces, in comparison to the control group. Given the modulation of microorganisms considered beneficial and the lower fecal concentrations of histamine, phenols, and ammonia, the YCO blend resulted in indicators of improvement of intestinal functionality in dogs.

Diet supplemented with Saccharomyces cerevisiae from different fermentation media modulates the faecal microbiota and the intestinal fermentative products in dogs

This study aimed at evaluating the coefficients of total tract apparent digestibility (CTTAD) of nutrients, metabolisable energy (ME), diet palatability, faecal fermentative products and microbiota of dogs fed yeasts from different fermentation media and its fractions. Four diets were evaluated: control, without yeast (CO); diet with 10 g/kg brewer's yeast (BY); diet with 10 g/kg brewer's yeast + corn yeast (BCY); and diet with 10 g/kg BCY + cell wall fractions (BCYF). Twelve adult dogs were distributed in a randomized block design (periods). Each of the four diets was fed to a group of three dogs per period of 20 days, totalling two periods and six repetitions per treatment. Sixteen adult dogs were used for the palatability test, which compared the CO diet versus each one of the yeast diets. Data with normal distribution were subjected to analysis of variance (p < 0.05). Means were compared by orthogonal contrasts (p < 0.05): (A) CO diet versus BY, BCY and BCYF diets; (B) BY diet versus BCY and BCYF diets; (C) BCY diet versus BCYF diet. There was no difference in the CTTAD and ME of the diets (p > 0.05). Yeast diets reduced faecal odour and indole peak area (p < 0.05). Faecal short-chain fatty acids concentration was greater in dogs fed yeast diets compared to those fed the CO (p < 0.05). Yeast diets showed a higher intake ratio compared to the CO (p < 0.05). The BCY and BCYF diets resulted in a greater abundance of Bacteroides, Faecalibacterium, Coprococcus, and Phascolarctobacterium in relation to the CO (p < 0.05). Our results suggest that dietary yeast supplementation results in beneficial changes in intestinal functionality indicators, mainly with the combination of yeasts from brewers and corn fermentation media. In addition, yeast supplementation improves diet palatability without compromising nutrient digestibility.

Bacillus amyloliquefaciens CU33 fermented feather meal-soybean meal product improves the intestinal morphology to promote the growth performance of broilers

This study is aimed to select optimum keratin degradation ability from Bacillus strains for feather meal-soybean meal fermentation, and favorably water content for the strain during fermentation of feather meal-soybean meal, and finally investigate the effects of the fermented feather meal-soybean meal product (FFSMP) on growth performance, carcass trait, clinical blood biochemistry, and intestinal morphology of broilers. Thirty-six bacteria strains from soil, sewage pool, and feather waste were screened and selected Bacillus subtilis var. natto N21 (N21), B. subtilis CU14 (CU14), and B. amyloliquefaciens CU33 (CU33) with better keratinase activity and feather-degrading rate. The result of trial 1 showed that the FFSMP produced by CU33 had the optimum physiochemical characterizations, amino acid composition and feeding performance for broilers. Hence the effects of water content (45, 50, 55, and 60%) on FFMSP fermentation of CU33 were investigated in trial 2. Result showed that pH value, counts of Bacillus-like bacteria, γ-PGA, viscosity, surfactin yield and odor all significantly increased according to the water content (P < 0.05). The protease activity reached significantly highest in the 55% and 60% water content groups (P < 0.01). The broilers performance of 55% and 60% water content group were significantly higher than control group (P < 0.05) in weight gain (WG), feed intake (b) at 0 to 21-d-old and the WG, feed conversion ratio (FCR), and production efficiency factor at 0 to 35-d-old, and could reach the similar growth performance as fish meal group (P > 0.05). The fermentation groups significantly decreased urea nitrogen (P < 0.05) and increased creatinine (P < 0.05) in the blood. The fermentation groups also significantly decreased the crypt depth in the duodenum (P < 0.05) and increased villus height to crypt depth ratio of the duodenum (P < 0.05). In conclusion, CU33 shows the best degradation rate for feather and keratinase activity, and the FFSMP with a water content of 50% to 60% during fermentation is suggested. Diets supplemented with 5% FFSMP can promote the growth of broilers by improving the morphology of the duodenum and achieve the feeding effect of high-quality fish meal.

Saccharomyces cerevisiae Dehydrated Culture Modulates Fecal Microbiota and Improves Innate Immunity of Adult Dogs

Saccharomyces cerevisiae yeast culture can be dehydrated, and it has a potential prebiotic effect. This study evaluated the effects of supplementing increasing levels of dehydrated yeast culture (DYC) of Saccharomyces cerevisiae (Original XPC™, Diamond V, Cedar Rapids, IA, USA) on fecal microbiota, nutrient digestibility, and fermentative and immunological parameters of healthy adult dogs. Eighteen adult male and female dogs with a mean body weight of 15.8 ± 7.37 kg were randomly assigned to three experimental treatments: CD (control diet), DYC 0.3 (control diet with 0.3% DYC) and DYC 0.6 (control diet with 0.6% DYC). After 21 days of acclimation, fecal samples were collected for analysis of nutrient digestibility, microbiota and fecal fermentation products. On the last day, the blood samples were collected for the analysis of immunological parameters. The microbiome profile was assessed by the Illumina sequencing method, which allowed identifying the population of each bacterial phylum and genus. The statistical analyses were performed using the SAS software and the Tukey test for multiple comparison (p < 0.05). Our results suggest that the addition of DYC increased the percentage of the phyla Actinobacteria and Firmicutes (p = 0.0048 and p < 0.0001, respectively) and reduced that of the phylum Fusobacteria (p = 0.0008). Regardless of the inclusion level, the yeast addition promoted reduction of the genera Allobaculum and Fusobacterium (p = 0.0265 and p = 0.0006, respectively) and increased (p = 0.0059) that of the genus Clostridium. At the highest prebiotic inclusion level (DYC 0.6), an increase (p = 0.0052) in the genus Collinsella and decrease (p = 0.0003) in Prevotella were observed. Besides that, the inclusion of the additive improved the apparent digestibility of the crude fiber and decreased the digestibility of crude protein, nitrogen-free extract and metabolizable energy (p < 0.05). There were no significant changes in the production of volatile organic compounds. However, an increase in propionate production was observed (p = 0.05). In addition, the inclusion of yeast resulted in an increased phagocytosis index in both treatments (p = 0.01). The addition of 0.3 and 0.6% DYC to the diet of dogs wase able to modulate the proportions of some phyla and genera in healthy dogs, in addition to yielding changes in nutrient digestibility, fermentative products and immunity in healthy adult dogs, indicating that this additive can modulate fecal microbiota and be included in dog nutrition.

Influence of Probiotic Supplementation on Health Status of the Dogs: A Review

Most commonly, pet dogs suffer from gastrointestinal (GI) diseases due to careless eating behaviors, such as eating food other than dog food; excess or insufficient nutrient intake of food leading to malnutrition, which could be harmful to dogs; a lack of digestive enzymes; food intolerance or allergies; infections; and/or breed-related hypersensitivities. Probiotics are live microorganisms that deliver health benefits to the host when administrated in an adequate amount. The possible mechanism behind probiotics’ beneficial effects could be their positive regulation of the host’s intestinal microbiota. Probiotics are reported to have therapeutic properties against canine GI and other diseases. The most suitable dosages and applications of probiotics have not been evaluated extensively. The present review summarizes current knowledge regarding the benefits of probiotics and the changes in canine microbiota during probiotic interventions. This literature review provides clinical evidence for probiotics’ beneficial effects in preventing or treating canine ill-health conditions. Based on current knowledge, subsequent researchers could develop or improve probiotics-based canine pharmacological products.

In vitro assessment of probiotic potential of selected bacteria isolated from pig faeces with potential application of odour reduction

To evaluate the odour reduction potential of four different bacterial species such as Enterococcus faecium, Enterococcus faecalis, Acetobacter tropicalis, and Bacillus subtilis subsp. subtilis that were isolated from fresh faeces of pigs and identified based on16S rDNA gene sequence analyses. Faecal slurry in anaerobic salt medium with 1% soluble starch (which was served as control group) and the addition of four different isolated bacterial cultures (1.0 × 10⁷CFU/mL), designated as M1, M2, M3, and M4, respectively, were incubated anaerobically for 12 and 24 h. Total gas production was increased with the incubation period (p < 0.05). M1 and M4 had decreased pattern (p < 0.05) of ammonia and hydrogen sulphide gas from 12 to 24 h. The lowest total volatile fatty acids (p < 0.05), highest lactate, and moderate butyrate concentration was observed in the M1 group at 24 h of incubation. Likewise, M1 group had the lowest total biogenic amine, histamine, ethylamine, putrescine, methylamine, and cadaverine compared to the other groups (p < 0.05) at 24 h of incubation. Overall results suggest that E. faecium can be used as a potent odour reducer in pigs production.

Evaluation of graded levels of Bacillus coagulans GBI-30, 6086 on apparent nutrient digestibility, stool quality, and intestinal health indicators in healthy adult dogs

Bacillus coagulans GBI-30, 6086 is a commercially available spore-forming non-toxigenic microorganism approved for use in dog foods with high resiliency to stresses associated with commercial manufacturing. The objectives of this research were to examine the effect of B. coagulans on stool quality, nutrient digestibility, and intestinal health markers in healthy adult dogs. Extruded diets containing graded levels of B. coagulans applied either to the base ration before extrusion or to the exterior of the kibble as a topical coating after extrusion were randomly assigned to 10 individually housed adult beagle dogs (7 castrated males and 3 spayed females) of similar age (5.75 ± 0.23 yr) and body weight (12.3 ± 1.5 kg). The study was designed as a 5 × 5 replicated Latin square with 16-d adaptation followed by 5-d total fecal collection for each period. Five dietary treatments were formulated to deliver a dose of 0-, 6-, 7-, 8-, and 9-log10 colony-forming units (CFU) per dog per day for the control (CON), extruded B. coagulans (PEX), and low, moderate, and high B. coagulans coating levels (PCL, PCM, and PCH), respectively. Food-grade TiO2 was added to all diets at a level of 0.4% to serve as an indigestible dietary marker for digestibility calculations. Data were analyzed using a mixed model through SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and room (i.e., replicate), period, and dog(room) as random effects. Apparent total tract digestibility of organic matter, crude protein, crude fat, and gross energy calculated by the marker method were numerically greatest for dogs fed the 9-log10 dose treatment with increases (P < 0.05) observed in gross energy and organic matter digestibility compared with the negative control. No significant differences were observed in food intake, stool quality, fecal pH, fecal ammonia, fecal short-chain fatty acids, or branched-chain fatty acids for the extruded B. coagulans treatment (PEX) or the coated B. coagulans treatments (PCL, PCM, and PCH) compared with CON. These results suggest that B. coagulans has a favorable impact on nutrient digestibility and no apparent adverse effects when added to extruded diets at a daily intake level of up to 9-log10 CFU in healthy adult dogs.