Background/Objectives: Canine athletes have a higher energy requirement and are more susceptible to nutrient depletion, electrolyte imbalance, and metabolic stress than sedentary pets. The objective of this study was to characterize the plasma metabolome of American Foxhound dogs following a bout of unstructured exercise. Methods: Thirty-nine adult American Foxhound dogs (32 intact males, 7 spayed females; age: 6.2 ± 3.1 yr; BW: 36.3 ± 5.3 kg) were allotted to a standard performance diet (CTRL) or NUTRO® Natural Choice® Adult High Endurance Formula (TEST). After 80 d in the study, blood samples were collected prior to (0 h), and 3 h and 25 h post-exercise (average: 17.7 km run over 2–3 h). Plasma samples of the 10 top performers of each treatment group were analyzed for untargeted metabolite profiling. Results: Of the 566 named metabolites identified, >200 and >185 metabolites were impacted (p < 0.05) by exercise and diet, respectively. Principal component analysis indicated distinct clustering by diet. Random forest analysis highlighted several metabolites having a high degree of predictive accuracy based on diet and exercise, with most related to amino acid, lipid, xenobiotic, and cofactor and vitamin metabolism. Relating to exercise, glycolytic end-products and citric acid cycle intermediates were increased at 3 h post-exercise. Similarly, tocopherols and omega-3 polyunsaturated fatty acids were higher in dogs fed TEST than those fed CTRL during recovery, indicating a lower oxidative stress and anti-inflammatory response. Conclusions: Overall, the data suggest a protective effect (lower susceptibility to oxidative stress and muscle fatigue) of feeding a nutrient-fortified diet for dogs undergoing unstructured exercise.

The objectives of this study were to determine how diets distinctly processed from the same raw batch to mimic common pet food formats may affect apparent total tract macronutrient digestibility (ATTD), gastrointestinal transit time (GTT), and fecal characteristics, metabolites, and the microbiota of healthy dogs. Ten spayed female adult beagles (age: 6.10±1.20 yr; body weight: 8.63±0.77 kg) were used in a replicated 5x5 Latin square design to test the following diet formats: retorted (RT), mildly cooked [sous vide (SV), steamed (ST)], and raw [high-pressure processed (HPP), freeze-dried (FD)]. The study comprised five 28-d periods, including a 7-d diet transition, 14-d treatment, and 7-d collection phase. All feces excreted during the collection phase were pooled and analyzed for dry matter (DM), organic matter (OM), crude protein (CP), lipids, and gross energy. On the first day of fecal collections, one fresh fecal sample was collected to measure pH, DM, fermentative metabolite concentrations, and microbiota composition. Data were analyzed by Mixed Models using SAS 9.4, with P<0.05 being statistically significant. Dogs consuming the RT and FD diets had a higher (P<0.05) as-is fecal output to DM intake ratio than dogs consuming the ST and HPP diets. The HPP and ST diets had higher (P<0.05) DM and OM ATTD than the RT, FD, and SV (ST not different) diets. All diets had greater (P<0.05) CP ATTD than the RT diet and higher (P<0.05) fat ATTD than the FD diet. Energy ATTD was higher (P<0.05) in the ST, HPP, and SV diets than in the FD and RT (SV not different) diets. Fecal acetate and butyrate concentrations were higher (P<0.05) in dogs consuming the RT diet than the ST and SV (butyrate only) diets. Fecal isobutyrate, isovalerate, total branched-chain fatty acid, indole, and ammonia concentrations were higher (P<0.05) in dogs consuming the RT diet than all other diets (ST not different for indole and ammonia). Alpha and beta diversity measures were not impacted, but diet altered the relative abundances of 3 bacterial phyla and 19 genera (P<0.05). In summary, processing method influenced nutrient digestibility as well as the fecal metabolite concentrations and microbiota populations of dogs, but did not impact GTT, fecal score, pH, DM, and alpha and beta diversity measures. More research is needed to evaluate additional factors such as packaging size, ingredient inclusion levels, macronutrient concentrations, different processing parameters, and other formats.

The objective of this study was to evaluate the sedative effects, propofol requirements, and cardiorespiratory effects following maropitant administration in healthy cats. Maropitant is a selective neurokinin-1 receptor antagonist licensed for use as an antiemetic in dogs and cats. Recent studies have highlighted the ability of maropitant to reduce inhalational anesthetic requirements during surgery from presumptive analgesic effects. Sedative properties of maropitant and its possible reduction of injectable anesthetic requirements have not yet been evaluated. Twenty adult purpose-bred domestic shorthair cats were randomized to receive maropitant (n = 10) or physiologic saline (n = 10) prior to anesthetic induction with propofol intravenously (IV). Cats were premedicated with butorphanol [0.4 mg/kg body weight (BW)] and alfaxalone [2 mg/kg BW intramuscularly (IM)]. Maropitant (1 mg/kg BW) or physiologic saline (0.1 mL/kg BW) was administered IV 10 min prior to anesthetic induction with propofol and subsequent orotracheal intubation. Sedation scores were recorded before premedication, after premedication, and 10 min after maropitant or saline administration. Propofol dose requirements to achieve orotracheal intubation were recorded. Heart rate (HR), respiratory rate (RR), and arterial blood pressures were measured before and after administration of maropitant or saline, after administration of propofol, and following intubation. Propofol dose requirements did not differ between groups, with mean ± standard deviation doses of 5.2 ± 2.1 mg/kg BW and 5.6 ± 1.3 mg/kg BW for maropitant and saline groups, respectively. Sedation scores and cardiorespiratory variables did not differ between groups at any timepoint. Maropitant administration prior to anesthetic induction with propofol did not affect sedation scores, propofol requirements, or cardiorespiratory variables.

Mushroom complex (MC) is a blend of mushroom water extracts including β-glucans and bovine colostrum that may provide benefits to cats. The objective of this study was to test the effects of MC supplementation on gut health and immune function outcomes of adult cats. Twenty healthy adult cats (7.40 ± 1.54 yr old; 4.25 ± 0.62 kg) were used in a randomized, blinded, placebo-controlled study using a completely randomized design. After a 3-wk wash-in phase, cats were assigned to one of two treatment groups (n = 10/group) and fed for 12 wk: placebo consisting of cellulose, rice bran, liver, and natural food coloring or MC consisting of mushroom (turkey tail mushroom, red reishi, and lion's mane) water extracts and bovine colostrum. Each treatment (900 mg/d) was top-dressed on the diet. Fecal samples [characteristics, metabolites, microbiota, immunoglobulin (Ig) A] and blood samples (serum chemistry, hematology, oxidative stress markers, immunoglobulins) were collected after the wash-in phase (wk 0) and after 6 and 12 wk. Data were analyzed using the GLIMMIX model of SAS, with P < 0.05 accepted as significant and P < 0.10 as trends. Fecal characteristics (pH, dry matter, scores, frequency) were not affected by treatment, but treatment-time interactions (P < 0.05) were observed for serum IgA and blood urea nitrogen (BUN). Serum IgA increased over time in controls but decreased over time in cats fed MC. Serum BUN tended to increase in all cats over time but to a higher level in cats fed MC. Serum triglycerides were lower (P < 0.05) in cats fed MC. Fecal ammonia, isovalerate, and total branched-chain fatty acids were greater (P < 0.05) in cats fed MC than controls. A treatment-time interaction (P < 0.05) was observed for alpha diversity measures (Fisher's Alpha, Shannon Diversity Index, and Observed Features), with all being reduced over time but to a lower extent in cats fed MC. The weighted PCoA plot for fecal beta diversity highlighted a significant treatment-time interaction, with some shifts in the microbiome being observed. The relative abundance of fecal Ruminococcus torques remained fairly stable over time in controls but increased in cats fed MC, while fecal Fusobacterium remained stable in cats fed MC but decreased in controls. Over 30 bacterial genera were affected by time. Our results suggest that without affecting fecal characteristics, MC supplementation slightly modified fecal microbiota and metabolite concentrations and reduced serum triglycerides in cats.

Thirty-two healthy adult dogs (16 males and 16 females) were fed control kibble diets for one month, followed by six months (Weeks 0 to 25) of diets containing either 0, 4, 6, or 8% cultured protein derived from Methylococcus capsulatus (FeedKind Pet®, FK), then they were fed control diets (0% FK) for a further two months (Weeks 25 to 34). The diets were isonitrogenous, isolipidic, and isocaloric and stage- and age-specific. The dogs were assessed for overall health, weight gain, and body condition score (BCS). Blood samples were collected 1 week prior to randomization, during acclimation, then in Weeks 5, 13, 25, 30, 32, and 34 for hematology, coagulation, and clinical chemistry; urine was collected according to the same time schedule for urinalysis. Feces were assessed for parasite load and presence of occult blood during Weeks 5, 9, 13, 17, 21, and 25. Fecal samples were collected during acclimation and Weeks 25 and 34 for fecal microbiome analysis and in Week 25 for apparent total gastrointestinal tract digestibility (ATTD). All dogs maintained a healthy weight and BCS throughout the study. Hematology parameters were within normal limits at the end of each phase of the study. With the exception of a decrease in serum phosphorus level and in urine pH in all groups at the end of the study, urine and serum chemistry results were within normal limits at the end of each phase. ATTD values for organic matter, protein, and energy exceeded 80%, whilst digestibility values for copper were around 20%. The fecal microbiome was dominated by Firmicutes. Alpha diversity increased during the safety phase before returning to baseline levels during the washout phase. The dominant genera in all groups were Megamonas, Peptoclostridium, Turicibacter, Catenibacterium, Fusobacterium, Romboutsia, and Blautia. The study has shown that the inclusion of cultured protein at up to 8% of the total diet of adult dogs can provide sufficient nutrition and is safe with no long-term effects on a range of health parameters.

There is great interest in studying the canine gastrointestinal microbiome. In healthy dogs versus those with acute and chronic enteropathies, specific bacterial taxa have been identified that are consistently associated with shifts in the microbiome. A qPCR-based dysbiosis index (DI) that assesses microbiome shifts was developed based on a subset of these taxa. Because most dogs consume kibble diets, published data on core bacteria and the DI were largely derived from dogs consuming that diet form. Because dietary composition impacts the microbiome, it was unknown whether data from dogs consuming other diet types would adhere to reported core taxa abundance and DI guidelines. The study's aim was to determine the fecal abundance of core bacteria and DI of dogs fed commercially available kibble vs. mildly-cooked human-grade (fresh) diets. Fecal samples collected from adult dogs across four experiments were used (4 kibble diets, n = 10-12/treatment; 4 fresh diets, n = 10-24/treatment). Moderate correlations were observed between total dietary fiber (TDF) and Fusobacterium (positive correlation), Lactobacillus (negative), and DI (negative). Dietary protein was correlated with fecal Ruminococcus gnavus (negative), while dietary fat was correlated with fecal Bacteroides and C. perfringens abundance (both positive). Dogs fed fresh diets exhibited higher (p < 0.01) abundances of Streptococcus, Escherichia coli, and Clostridium perfringens, while those fed kibble diets had higher (p < 0.05) abundances of Fusobacterium, Clostridium hiranonis, and Bacteroides. Dogs fed fresh diets had a greater (p < 0.0001) DI, but the majority of scores remained within the normal range. Dogs fed animal protein-based kibble diets had higher (p < 0.05) fecal Faecalibacterium and Fusobacterium, while dogs fed animal protein-based fresh diets had higher (p < 0.05) Streptococcus, E. coli, and C. perfringens. Bifidobacterium and Bacteroides were more abundant (p < 0.01) in dogs fed animal protein-based kibble and plant protein-based fresh diets. Dogs fed animal protein-based fresh diets had a greater (p < 0.0001) DI. Even though microbiota populations were statistically different among diets, all mean DI were <0, with only a few individual dogs consuming fresh diets having DI >0 (5 dogs >0; 1 dog >2). Overall, these data demonstrate the utility of the DI across different diet types in healthy dogs.

Acacia fiber is a soluble fiber often used as a processing aid in pet foods. The objective of this experiment was to evaluate the fermentation characteristics of acacia fiber, inulin, pectin (positive control), and cellulose (negative control) using an in vitro fermentation system and feline fecal inoculum. Triplicate samples of each fiber were fermented for 0, 6, 12, and 18 h, with short-chain fatty acids (SCFA), pH, and microbiota measured at each time point. Blank-corrected data were analyzed using PROC GLIMMIX of SAS, with significance set at P ≤ 0.05. Significant (P < 0.01) fiber × time interactions were observed for pH change, gas and SCFA production, and microbiota populations. Pectin and inulin had greater (P < 0.01) gas production than acacia fiber and cellulose. Inulin had the greatest pH reduction, followed by pectin, both of which had greater pH reductions (P < 0.01) than acacia fiber and cellulose. Acacia fiber had a small reduction in pH, being lower than cellulose after 12 h. Total SCFA production, including acetate, propionate, and butyrate, was higher (P < 0.01) in pectin and inulin than acacia fiber and cellulose. However, acacia fiber had greater (P < 0.01) total SCFA, acetate, and propionate production than cellulose after 12 h. Bacterial alpha diversity metrics increased (P < 0.01) during acacia fiber fermentation and decreased (P < 0.01) during inulin and pectin fermentation. Bacterial beta diversity shifted over time and showed separate clustering of bacterial communities among the different fiber substrates evaluated. The relative abundances of predominant (% sequences > 1%) bacterial genera were affected by significant fiber × time interactions. Specifically, acacia fiber had a greater (P < 0.01) increase in Bacteroides, Blautia, and Faecalibacterium than other fibers. Inulin had a greater (P < 0.01) increase in Collinsella, Prevotella, Megamonas, Holdemanella, Blautia, and Faecalibacterium, whereas pectin had a greater (P < 0.01) increase in Bifidobacterium, Lactobacillus, Phascolarctobacterium, and Succinivibrio. These results suggest that acacia fiber is moderately fermentable, resulting in low gas and SCFA production, greater bacterial diversity, and microbiota shifts. Although positive responses were observed in vitro, research in live animals is necessary to confirm potential benefits in felines.

Antibiotics may be used for gastrointestinal enteropathies but research has demonstrated significant microbiota dysmetabolism, fermentation pattern alterations, and prolonged dysbiosis following treatment. The objective of this study was to determine how dietary fiber or fecal microbial transplant (FMT) treatments impacted the fecal characteristics, metabolite concentrations, and microbiota populations of cats treated with metronidazole. Twenty-five healthy adult cats (6.75 ± 1.20 yr) were fed a commercial kibble diet for 2 wk, administered metronidazole (20 mg/kg BW BID) for 2 wk, then monitored for 4 wk. Cats were allotted to one of three interventions (diet, diet + beet pulp, diet + FMT) for 1 wk, interventions ceased, then recovery was monitored for 4 wk. Fresh fecal samples were collected at the end of each phase and at the mid-points of recovery. As anticipated, metronidazole increased fecal scores and moisture (p < 0.05), reduced fecal bacterial alpha diversity (p < 0.0001), and reduced fecal metabolite concentrations. Few treatment effects were detected, with antibiotic recovery contributing to many of the results observed. Dysbiosis was persistent throughout the study, with 4/25 cats still demonstrating mild dysbiosis after 9 wk. Overall, dietary or FMT treatments may aid in accelerated antibiotic recovery in cats but further research is needed to refine treatments for greater efficacy.

Soybean meals, soy protein isolates, and other forms of soy have served as protein sources in pet foods for many years. The amino acid (AA) content and protein quality of soybean-based ingredients vary depending on their composition and processing, however, so the testing of new ingredients is required. Our objective was to measure the AA composition, AA digestibility, and protein quality of fermented soybean-based ingredients using the precision-fed cecectomized rooster assay. Cecectomized roosters were randomly allotted to one of five test ingredients (n = 6/ingredient): 1) autoclaved soybeans (ASB); 2) fermented soybeans (FSB); 3) fermented soybeans + Lactococcus lactis subsp. lactis ATCC 11454 (FSBP); 4) fermented soybean meal (FSBM); and 5) fermented soybean meal + L. lactis (FSBMP). After 26 h of feed withdrawal, roosters were tube-fed test ingredients. Following crop intubation, excreta samples were collected for 48 h. Endogenous losses were accounted for by using 5 additional fasted cecectomized roosters. In addition to calculating AA digestibility, digestible indispensable AA score (DIAAS)-like values were determined and first limiting AA were identified based on dog and cat nutrient requirements or recommendations from the National Research Council (NRC). All data were analyzed by the Mixed Models procedure in SAS version 9.4. All ingredients had acceptable AA digestibilities, with all indispensable AA digestibilities being >80%, with the exception of histidine (79.3%), lysine (73.5%), and valine (79.0%) for ASB. All AA digestibility values were different (P < 0.05) among ingredients, with FSBP usually being the most digestible and ASB usually being the least digestible. The DIAAS-like values were highest for FSBP. The criteria for a high-quality protein source for adult cats was met by FSB, FSBP, FSBM, and FSBMP, with ASB meeting the criteria for a good-quality protein. The DIAAS-like values based on NRC recommendations for adult dogs, growing puppies, and growing kittens were lower. For adult dogs, growing dogs, and growing kittens, methionine + cystine was the first limiting AA. For adult cats, phenylalanine + tyrosine was first limiting. Differences existed, but our results show that fermented soybean-based ingredients have moderately high AA digestibilities and may serve as adequate proteins in pet foods.

Metronidazole is a potent antibiotic often prescribed to treat gastrointestinal enteropathies, but is known to induce loose stools, negatively alter the fecal microbiome, and affect fecal metabolites. Dietary intervention may aid in the recovery following antibiotic cessation, but little research has been conducted regarding the potential of fiber utilization for microbial recovery in canines. Using an in vitro fermentation assay, the objective of this study was to investigate the fermentation characteristics of dietary fibers using fecal inocula from dogs treated with metronidazole. Four healthy male beagles were fed a commercial kibble diet for 2 weeks, then administered metronidazole (20 mg/kg body weight twice a day) for 2 weeks. Fresh fecal samples were collected at weeks 2 and 4, stabilized in a 20

Producing enough protein continues to be a challenge, but alternatives may provide economic and ecological relief. Sufficient testing is necessary to confirm safety and evaluate nutritional value. Our objective was to evaluate the safety, efficacy, gastrointestinal tolerance, and apparent total tract digestibility (ATTD) of brewed chicken protein (BCP; Saccharomyces cerevisiae expressing a chicken protein). Thirty-two healthy adult dogs (BW = 9.68 ± 1.18 kg; age = 4.16 ± 1.85 yr) were used in a completely randomized design (n = 8/treatment). After a 2-wk acclimation phase, baseline measurements were collected and dogs were allotted to the following treatments and fed for 26 wk: control diet (0% BCP; Control), 15% BCP (Low), 30% BCP (Medium), or 40% BCP (High). Palatability was assessed by comparing dry diets coated with 0% (control) vs. 1% BCP in 20 adult dogs. Data were analyzed using the Mixed Models procedure of SAS 9.4, with p < 0.05 being significant and trends accepted at p < 0.10. Consumption of BCP did not affect food intake, BW, physical parameters, serum chemistry, hematology, and urinalysis. The dry matter, organic matter, and crude protein ATTD were greater (p < 0.05) for High, while the fat ATTD was greater (p < 0.05) for Control. Fecal output was lower (p < 0.0001) and fecal dry matter was lower (p < 0.001) for dogs fed High. Fecal acetate concentrations were lower (p < 0.05) and propionate concentrations tended to be higher (p = 0.06) in dogs fed BCP. Fecal isobutyrate, isovalerate, indole, total phenol and indole, and ammonia concentrations were lower (p < 0.001) and fecal valerate concentrations were higher (p < 0.0001) in dogs fed BCP. Fecal bacterial alpha diversity was lower (p < 0.05) in dogs fed BCP. For beta diversity, dogs fed Control were different than those fed BCP. Over 20 fecal bacterial genera were affected by BCP consumption. Palatability of BCP was high (p < 0.05; 2.93:1 consumption ratio). These results indicate that the BCP ingredient tested is an effective source of protein that is safe for use in adult dog foods at an inclusion level of up to 40%. No detrimental effects were observed, and notable changes to nutrient digestibility and fecal characteristics, metabolites, and microbiota populations suggest potential benefits on gastrointestinal health.

This study investigated the effects of up to 45% inclusion of whole pulse ingredients in grain-free (GF) diets on the excretion of bile acids (BAs) and other fecal metabolites in healthy large-breed dogs. Twenty-eight adult Siberian Huskies were fed 1 of 4 experimental diets formulated to meet the same macronutrient profiles for 20 wk: 1) grain-inclusive diet with 45% corn (Ctl), 2) GF diet with 15% pulses (Pulse15), 3) GF diet with 30% pulses (Pulse30), 4) GF diet with 45% pulses (Pulse45). All diets included chicken meal and pea starch. Fecal samples were collected on weeks 2 and 19. Bile acids were analyzed using ultra-performance liquid chromatography-MRM/MS technology, while fecal metabolites were analyzed using Agilent HP1000 high-performance liquid chromatography. Bile acids and fecal metabolite data were analyzed using the PROC GLIMMIX procedure in SAS studios (SAS version 9.4, SAS Inst., Inc., Cary, NC). All means were separated using the Tukey-Kramer adjustment (significant when P < 0.05). After 20 wk of feeding, concentrations of lithocholic acid were greater in Pulse15 and Pulse30 than Ctl (P = 0.001), but all were similar to Pulse45. Concentrations of deoxycholic (P = 0.054), lithocholic (P = 0.001), total secondary (P = 0.022), and total BA (P = 0.045) tended to be linearly associated with dietary pulse inclusion. Dogs consuming Pulse30 had greater fecal propionic acid concentrations than Ctl (P = 0.017), but both were similar to Pulse15 and Pulse45. Total branched-chain fatty acids (P = 0.001) and iso-butyric acid (P < 0.0001) were greater in Ctl than in all pulse groups. Inversely, arabinose concentrations were greater in all pulse groups compared to Ctl (P = 0.001). In summary, diets with up to 45% inclusion of whole pulse ingredients do not increase total BA excretion but may contribute to greater short-chain fatty acids production.

The application of heat in dietary processing is known to influence nutrient digestibility. Novel pet food formats with differing processing methods are gaining popularity, but few studies have examined their digestibility. Most research evaluating dietary processing type on nutrient digestibility has tested commercial foods that were vastly different regarding ingredient inclusion and macronutrient content, making it difficult to determine the processing influences. To address this research question, the current study aimed to determine amino acid (AA) digestibility and nitrogen-corrected true metabolizable energy (TMEn) of diets having the same ingredient formulations and nutrient concentrations but manufactured using different processing methods. Five diets were manufactured using the following processing methods: retort (RT), mildly cooked [sous vide (SV) and steamed (ST)], and raw [high-pressure processing (HPP) and freeze-drying (FD)]. Those diets were compared against the raw ingredient batch (RAW) that served as a control. Two precision-fed rooster assays utilizing Single Comb White Leghorn (1.5 to 2.5 y old, 2.5 to 3 kg body weight) were conducted to determine the standardized AA digestibility (30 cecectomized roosters; n = 5) and TMEn content (30 conventional roosters; n = 5) of the 6 pet foods. Prior to feeding, wet diets (RT, SV, ST, HPP, and RAW) were freeze-dried, and all diets were ground. Following crop intubation, excreta were collected for 48 h and analyzed, and then AA digestibility and TMEn calculations were performed. Data were analyzed using the Mixed Models procedure of SAS with P < 0.05 accepted as statistically significant and P < 0.10 a trend. The digestibility of 6 indispensable AA were affected by processing. The SV and ST diets had greater (P < 0.05) histidine digestibilities than all other diets. For valine, methionine, leucine, phenylalanine, and isoleucine, the RAW diet tended to have greater (P < 0.10) digestibility than the RT diet. The RT diet had lower (P < 0.05) aspartic acid digestibility than ST, HPP, FD, and RAW diets. Dietary TMEn was higher (P < 0.05) for the SV and ST diets than the RT, HPP, and FD diets, suggesting that those cooking methods are less damaging to macronutrients. Overall, the RT diet had lower indispensable digestible AA concentrations than RAW, likely due to the high heat of processing. Future research should test differences in these diet types in the target species (i.e., dog) to evaluate how they perform.

Probiotics, prebiotics, and other biotic substances are not only effective ways to promote a healthy gastrointestinal tract, an effective immune system, and the overall health of humans, but also in agricultural and companion animals. Because key differences exist in regard to gastrointestinal tract anatomy and physiology, dietary management and feeding strategy, and disease susceptibility, however, biotic types and amounts often differ according to host species and life stage. Despite these differences, the literature demonstrates the value of biotics in agricultural and companion animal species. While high variability in responsiveness and efficacy has been reported, biotic substances may be effectively used to improve digestion, reduce morbidity, increase growth rate and/or efficiency in agricultural animals and promote gastrointestinal health and immune response in companion animals. As the oversight of antibiotic use intensifies, the population density of animals and humans increases, and production strategies of agricultural animals are more heavily scrutinized, the importance of biotics and other health promotors will continue to increase in the future. To date, the effects of animal biotic use have focused primarily on the farm, home, or veterinary clinic. In the future, their impact must be viewed on a larger scale. As global "One Health" approaches seek to reduce antimicrobial use and resistance and there are increasing demands for sustainable and safe food production, biotics will continue to be an important part of the solution. As knowledge of gastrointestinal microbiomes grows and the biotic field develops, more targeted and effective strategies for health promotion in these species are expected. At the 2023 International Scientific Association for Probiotics and Prebiotics meeting, experts were invited to participate in a discussion group focused on "The Use of Probiotics and Prebiotics in Agricultural and Companion Animals". This review reports the outcomes of that discussion, including the documented use of probiotics, prebiotics, and other biotic substances to promote health or treat disease in agricultural and companion animals, provide implications of animal biotic use on human health, and provide perspective on how scientific advances may impact the development and improvement of biotics in the future.

Black soldier fly larvae (BSFL) is a recently approved alternative protein source for dog and cat foods and treats in the United States, but research in cats remains limited. The objective of this study was to determine the effects of BSFL on the serum chemistry, hematology, skin and coat health markers, fecal characteristics, immune function, and oral health measures of healthy adult cats. Twenty-five adult cats (17 females and 8 males; 6.28 ± 0.27 yr; 4.50 ± 0.18 kg) were used in a completely randomized design. The study was composed of a 21-d baseline period and a 70-d experimental period. During the baseline period, all cats were fed a chicken meal-based control diet (35% of diet). After baseline, cats were assigned to 1 of 2 experimental diets: control diet (n = 12) or a BSFL-containing diet (20% whole BSFL meal and 24% chicken meal; n = 13). At baseline, teeth were cleaned by a veterinarian. Breath samples were analyzed for odor components, salivary pH was measured, and blood samples were collected after baseline cleaning, day 35, and day 70. Feces were scored, fecal samples were collected, skin was assessed, and hair was collected at baseline and day 70. Oral health indicators were assessed by a board-certified veterinarian at day 70. Data were analyzed using the mixed models procedure of SAS, testing for effects of diet (oral microbiota) or diet, time, and diet*time (variables measured over time), with P < 0.05 being significant. Diet*time interactions (P < 0.05) were noted for blood calcium, cholesterol, and triglyceride concentrations and fecal characteristics, metabolite concentrations, and microbiota populations. Some hematologic measures were affected by time, but none were impacted by diet. Cats fed BSFL had lower (P < 0.05) fecal pH, dry matter, and phenol, indole, and branched-chain fatty acid concentrations, and greater (P < 0.05) fecal scores and short-chain fatty acid concentrations. Fecal microbiota populations were affected by BSFL, with alpha diversity, beta diversity, and >20 bacterial genera being different between groups. Immune markers, skin and hair measures, salivary pH, breath odor, and oral microbiota and health measures were unaffected by the diet. In conclusion, a 20% dietary BSFL inclusion had clear effects on the fecal characteristics, metabolites, and microbiota of healthy adult cats, shifting most outcomes in a positive direction. Inclusion of BSFL had mild effects on serum metabolites and did not significantly affect the other variables measured.

Excess body fat leads to an overabundance of adipose tissue macrophages (AT MΦs) with altered phenotypes that play pathogenic roles in obesity comorbidities including diabetes and cancer. Peroxisome proliferator-activated receptors (PPARs) are leading targets to modulate AT MΦ phenotype. Here, we developed a dextran-based nanomedicine that delivers PPARα/γ agonists to AT MΦs and improves obesity and diabetic phenotypes in vivo. Within 1 week of treatment, AT MΦs decreased and became lipid laden, while extracellular vesicles secreted from AT decreased and reduced in lipid content. Within 2 weeks, glucose tolerance returned to levels of lean controls, followed by weight loss and reduced food intake. After 4 weeks, AT browning and amelioration of hepatic steatosis were evident. The physiological shifts were reproducible in three rodent models of obesity, spanning sexes and gonadal status. Effects were enhanced for the targeted nanomedicine compared with free drugs at equivalent doses, supporting the hypothesis that targeted PPAR activation in AT MΦs benefits systemic metabolism.

Background: Abrupt dietary changes may disrupt gut microbiota populations and lead to gastrointestinal issues. This study aimed to determine the effects of live Bacillus pumilus SG154 or Lacticaseibacillus paracasei 327 postbiotic on fecal characteristics and microbiota populations of dogs following an abrupt diet change. Methods: Twelve healthy adult English pointer dogs (6.38 ± 2.75 yr) were used in a replicated 3 × 3 Latin square design to test the following treatments: (1) placebo (control; 250 mg maltodextrin/d); (2) live B. pumilus [5 × 109 colony-forming units (CFU)/d]; and (3) L. paracasei postbiotic (100 mg; derived from 2 × 109 CFU/d). Each period lasted 42 days, with the diet change occurring on day 28. Fecal samples were scored and analyzed for pH, dry matter content, and microbiota before and 2, 6, 10, and 14 days after the diet change. Results: The abrupt diet change increased (p < 0.01) fecal pH, increased (p < 0.01) the dysbiosis index, decreased (p < 0.0001) fecal dry matter, and led to a large shift in the fecal microbiota community. Fecal scores were lower (p < 0.05) in the B. pumilus group. B. pumilus reduced (p < 0.05) the relative abundance of fecal Prevotella and Muribaculaceae, while both treatments (B. pumilus; L. paracasei) increased (p < 0.05) the relative abundance of fecal Holdemanella. Conclusions: These results suggest that an abrupt diet change leads to large shifts in fecal microbiota and modified fecal characteristics. The supplementation with a B. pumilus probiotic and a L. paracasei postbiotic slightly altered the relative abundance of a few microbial taxa but was unable to attenuate most responses.

Gastrointestinal and stool quality issues are common in companion animals. In addition to dietary fibers and prebiotics, the consumption of live microorganisms may be used to support the gastrointestinal health of pets. Spore-forming Bacillus species are gaining interest due to their viability during processing, storage, and within the gastrointestinal tract. The objective of the current study was to determine the effects of B. subtilis ATCC PTA-122264 supplementation on dietary apparent total tract macronutrient digestibility and the fecal characteristics, metabolites, and microbiota of healthy adult dogs. Twelve healthy adult beagle dogs (6 ± 1.14 yr; 8.71 ± 0.91 kg body weight) were used in a replicated 3 × 3 Latin square design. Dogs were fed to maintain body weight and allotted to 1 of the 3 treatments each experimental period (n = 12/treatment): Control [kibble diet + placebo (1.25 g of maltodextrin)], Low [kibble diet + 1 × 109 colony-forming units (CFU)/d of B. subtilis], and High (kibble diet + 5 × 109 CFU/d of B. subtilis). Each experimental period was composed of a 22-d adaptation phase, 5-d fecal collection phase, and 1 d for blood collection. Fecal microbiota data were evaluated using QIIME2. All other data were analyzed using the Mixed Models procedure of SAS, with P < 0.05 being considered significant. B. subtilis supplementation tended to decrease (P < 0.10) apparent total tract dry matter, organic matter, and energy digestibilities but did not influence food or energy intake, fecal output, and apparent total tract protein or fat digestibilities. Most serum metabolites, hematology, fecal characteristics, and fecal bacterial alpha and beta diversity indices were not affected. Fecal dysbiosis index tended to be affected and fecal Streptococcus, Escherichia coli, and Blautia abundances were lower (P < 0.05) in dogs allotted to the Low treatment. These data suggest that daily supplementation of up to 5 × 109 CFU/d of B. subtilis ATCC PTA-122264 is safe and does not affect markers of general health and fecal characteristics of healthy dogs, warranting further exploration.

Diet modulates gut microbiome composition and function. However, determining causal links between diet-gut microbiome interactions and human health is complicated by inconsistencies in the evidence, arising partially from variability in research methods and reporting. Widespread adoption of standardized best practices would advance the field but require those practices to be identified, consolidated, and discussed. This umbrella review aimed to identify recommended best practices, define existing gaps, and collate considerations for conducting research on diet-gut microbiome interactions and their impact on human health outcomes. Reviews meeting inclusion criteria and published after 2013 were identified using a systematic search. Recommendations, considerations, and gaps relating to the best practices associated with study design, participant selection, dietary intervention/assessment, biological sample collection, and data analysis and reporting were extracted and consolidated. Eight narrative reviews were included. Several general points of agreement were identified, and a recurring theme was that best practices are dependent upon the research aims, outcomes, and feasibility. Multiple gaps were also identified. Some, such as suboptimal diet assessment methods and lack of validated dietary intake biomarkers, are particularly relevant to nutrition science. Others, including defining a "healthy" gut microbiome and the absence of standardized sample and data collection/analysis protocols, were relevant specifically to gut microbiome research. Gaps specific to diet-gut microbiome research include the underrepresentation of microbiome-modulating dietary components in food databases, lack of knowledge regarding interventions eliciting changes in the gut microbiome to confer health benefits, lack of in situ measurement methods, and the need to further develop and refine statistical approaches for integrating diet and gut microbiome data. Future research and cross-disciplinary exchange will address these gaps and evolve the best practices. In the interim, the best practices and considerations discussed herein, and the publications from which that information was extracted provide a roadmap for conducting diet-gut microbiome research. This trial was registered at PROSPERO as CRD42023437645.

Yellow mealworms (Tenebrio molitor) serve as an alternative for traditional protein sources (e.g., chicken, beef, pork). Because the amino acid (AA) concentrations, AA digestibility, and protein quality of ingredients vary depending on husbandry, harvest and processing procedures, and other factors, each should be evaluated separately. The objective of this study was to measure the AA composition, AA digestibility, and protein quality of yellow mealworm-based ingredients using the precision-fed cecectomized rooster assay. Eighteen cecectomized roosters were randomly allotted to one of three test ingredients (n = 6/group): 1) defatted yellow mealworm flour without cuticles (TM); 2) defatted yellow mealworm flour with cuticles (TMc); and 3) whole yellow mealworm pulp (TMp). After 26 h of feed withdrawal, roosters were tube-fed test ingredients (15 g ingredient + 15 g corn). Following crop intubation, excreta was collected for 48 h. Endogenous loss corrections for AA were made using five additional cecectomized roosters. In addition to calculating AA digestibility, digestible indispensable AA score (DIAAS)-like values were determined and limiting AA were identified based on dog and cat nutrient requirements or recommendations from the Association of American Feed Control Officials (AAFCO), European Pet Food Industry Federation (FEDIAF), and National Research Council (NRC). All data were analyzed by the Mixed Models procedure in SAS version 9.4. All ingredients were highly digestible, with all indispensable AA digestibilities being > 90%, with the exception of histidine (89.55%) and valine (89.36%) for TMc. Histidine digestibility was higher (P < 0.05) for TM and TMp than for TMc. Isoleucine, leucine, lysine, and valine digestibilities were higher (P < 0.05) for TMp than TMc. The DIAAS-like values were highest for TM, which scored high enough to be considered a high-quality protein source for most guidelines and life stages, with DIAAS-like values for TMc and TMp being slightly lower. For dogs and growing puppies, methionine or threonine were the limiting AA depending on reference guideline and life stage. For cats and growing kittens, arginine or methionine were the limiting AA. Even though there were slight differences among ingredients differing in composition (with or without cuticles; whole or defatted), our results demonstrate that yellow mealworm-based proteins have high AA digestibilities and protein quality, making them suitable proteins for pet foods.