Effects of diets supplemented with bioactive peptides on nutrient digestibility, immune cell responsiveness, and fecal characteristics, microbiota, and metabolites of adult cats.

Bioactive peptides (BP) are recognized for their ability to function as antioxidants and maintain lipid stability. They may have positive health effects, including antihypertensive, anti-inflammatory, antimicrobial, osteoprotective, gut health, and immunomodulatory properties, but are poorly tested in cats. Our primary objective was to determine the apparent total tract digestibility (ATTD) of BP-containing kibble diets and assess how the fecal characteristics, metabolites, and microbiota were affected in adult cats. Our secondary objective was to test whether BP could impact blood oxidative stress markers and cytokine concentrations following transport stress. Twelve adult cats (4.83 ± 0.37 yr; 4.76 ± 0.14 kg) were used in a replicated 4 × 4 Latin square design to test four extruded kibble diets: Control (no BP), Chicken (4% chicken BP), Marine1 (2% marine BP), and Marine2 (4% marine BP). Each experimental period lasted 28 d, with a 20-d adaptation phase, 5 d for fecal collection, 2 d for blood collection, and 1 d for transport stress testing (driven in vehicle in individual carriers for 45 min). Salivary cortisol and blood oxidative stress markers and cytokines were measured after transport. Fecal microbiota data were evaluated using 16S rRNA gene amplicon sequencing and QIIME2. All other data were analyzed using the Mixed Models procedure of SAS, with P < 0.05 being considered significant and P < 0.10 considered trends. No differences were observed in animal health outcomes, with all cats remaining healthy and serum metabolites remaining within reference ranges. Cats fed the Marine2 diet had higher (P < 0.05) ATTD of dry matter (84.5% vs. 80.9%) and organic matter (88.3% vs. 85.8%) than those fed the control diet. The ATTD of protein and energy tended to be higher (P < 0.10) for cats fed the Marine2 diet. Fecal characteristics, metabolites, and bacterial alpha and beta diversity measures were not affected by treatment. However, the relative abundances of six bacterial genera were different (P < 0.05) and two bacterial genera tended to be different (P < 0.10) across treatments. Treatment did not alter salivary cortisol, blood oxidative stress markers, or blood cytokines after transport stress. Our data suggest that BP inclusion may increase nutrient digestibility and modify fecal microbiota and immune measures. More testing is required, however, to determine whether BP may provide additional benefits to cats.

Dietary bioactive peptides (BP) may have positive health effects, but are poorly tested in cats. Our primary objective was to determine the apparent total tract digestibility of BP-containing kibble diets and assess how fecal characteristics, metabolites, and microbiota were affected in adult cats. Our secondary objective was to test whether BP could impact blood oxidative stress markers and cytokines following transport stress. Adult cats were used in a replicated 4 × 4 Latin square design to test four extruded kibble diets containing different BP concentrations. After diet adaptation, fecal and blood samples were collected and transport stress testing was done in each experimental period. All cats remained healthy and serum metabolites remained within reference ranges. Cats fed one of the BP diets had higher dry matter and organic matter digestibilities and tended to have higher protein and energy digestibilities. Fecal characteristics, metabolites, and microbiota diversity measures were not different, but the relative abundances of eight bacterial genera differed or tended to differ across treatments. Treatments did not alter oxidative stress markers after transport stress. Our data suggest that BP inclusion may increase nutrient digestibility and modify fecal microbiota. Further testing is required to determine whether BP provides additional benefits to cats.

Effects of weight loss and feeding specially formulated diets on the body composition, blood metabolite profiles, voluntary physical activity, and fecal metabolites and microbiota of overweight cats.

Feline obesity is a common and preventable disease, posing a myriad of health risks and detriments. Specially formulated diets and restricted feeding may serve as an intervention strategy to promote weight loss and improve feline health. In this study, our objective was to determine the effects of restricted feeding and weight loss on body composition, voluntary physical activity, blood hormones and metabolites, and fecal microbiota of overweight cats. Twenty-two overweight adult spayed female and neutered male cats [body weight (BW) = 5.70 ± 1.0 kg; body condition score (BCS) = 7.68 ± 0.6; age = 4 ± 0.4 yr] were used in a weight loss study. A control diet (OR) was fed during a 4-wk baseline to identify intake needed to maintain BW. After baseline (week 0), cats were allotted to OR or a test diet (FT) and fed to lose ~1.0% BW/wk for 24 wk. At baseline and 6, 12, 18, and 24 wk after weight loss, dual-energy x-ray absorptiometry scans were performed and blood samples were collected. Voluntary physical activity was measured at weeks 0, 8, 16, and 24. Fecal samples were collected at weeks 0, 4, 8, 12, 16, 20, and 24. Change from baseline data were analyzed statistically using the Mixed Models procedure of SAS, with P < 0.05 considered significant. Restricted feeding of both diets led to weight and fat mass loss, lower BCS, and lower blood triglyceride and leptin concentrations. Cats fed the FT diet had a greater reduction in blood triglycerides and cholesterol than cats fed the OR diet. Restricted feeding and weight loss reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations. Fecal valerate concentrations were affected by diet, with cats fed the OR diet having a greater reduction than those fed the FT diet. Fecal bacterial alpha diversity was not affected, but fecal bacterial beta diversity analysis showed clustering by diet. Restricted feeding and weight loss affected relative abundances of 7 fecal bacterial genera, while dietary intervention affected change from baseline relative abundances of 2 fecal bacterial phyla and 20 fecal bacterial genera. Our data demonstrate that restricted feeding promoted controlled and safe weight and fat loss, reduced blood lipids and leptin concentrations, and shifted fecal metabolites and microbiota. Some changes were also impacted by diet, highlighting the importance of ingredient and nutrient composition in weight loss diets.

The objective of this study was to determine the effects of diet, restricted feeding and weight loss on body composition, voluntary physical activity, blood hormones and metabolites, and fecal metabolites and microbiota of overweight cats. Overweight cats were allotted to a control diet (OR) or weight loss diet (FT) and fed to lose ~1.0% body weight/week for 24 wk. Body weight, body composition, and voluntary physical activity were measured, while fecal and blood samples were collected over time. Restricted feeding led to weight and fat mass loss, and lower blood triglyceride and leptin concentrations. Cats fed FT had a greater reduction in blood triglycerides and cholesterol than cats fed OR. Restricted feeding reduced fecal metabolite concentrations and affected relative abundances of 7 fecal bacterial genera. Fecal bacterial beta diversity analysis showed clustering by diet. Dietary intervention affected change from baseline relative abundances of 2 fecal bacterial phyla and 20 fecal bacterial genera. Our data demonstrate that restricted feeding promoted controlled and safe weight and fat loss, reduced blood lipids and leptin concentrations, and shifted fecal metabolites and microbiota. Some dietary differences were noted, highlighting the importance of ingredient and nutrient composition in weight loss diets.

Effects of weight loss and feeding specially formulated diets on the body composition, blood metabolite profiles, voluntary physical activity, and fecal metabolites and microbiota of obese dogs.

Canine obesity negatively influences health and well-being, but can be managed by altering diet composition and caloric intake. Restricted feeding, dietary intervention, and consequent weight loss may be used to improve health and modify gastrointestinal microbiota. In this study, we aimed to determine the effects of restricted feeding of specially formulated foods on weight loss, body composition, voluntary physical activity, serum hormones and oxidative stress markers, and fecal metabolites and microbiota populations of obese dogs. Twenty-four obese dogs [body weight (BW) = 15.2 ±â€…1.7 kg; body condition score (BCS) = 8.7 ±â€…0.4; muscle condition score (MCS) = 3.5 ±â€…0.3; age = 7.2 ±â€…1.6 yr] were used in a 24-wk study. A control (OR) food was fed during a 4-wk baseline to identify intake needed to maintain BW. After baseline, dogs were allotted to one of two diets: OR or test (FT), and then fed to lose 1.5% BW/wk. Food intake, BW, BCS, and MCS were measured, blood and fecal samples were collected, DEXA scans were performed, and voluntary physical activity was measured over time. Microbiota data were evaluated using QIIME2 and change from baseline data from other measures were evaluated using the Mixed Models procedure of SAS, with P < 0.05 being significant. Restricted feeding led to reduced BW, BCS, fat mass, and blood cholesterol, triglyceride, glucose, and leptin concentrations, and increased MCS and lean body mass percentage. Blood cholesterol reduction was greater in dogs fed FT vs. OR. Fecal metabolites and bacterial alpha-diversity were affected by diet and weight loss. Dogs fed FT had greater reductions in fecal short-chain fatty acid, branched-chain fatty acid, and ammonia concentrations than those fed OR. Dogs fed OR had a higher alpha-diversity than those fed FT. Weight loss increased alpha-diversity (weeks 16, 20, and 24 > weeks 0 and 4). Beta-diversity showed separation between dietary groups and between week 0 and all other time points after week 8. Weight loss increased fecal Allobaculum and Ruminococcus torques. Weight loss also increased fecal Bifidobacterium, Faecalibaculum, and Parasutterella, but were greater in dogs fed OR. Weight loss decreased fecal Collinsella, Turicibacter, Blautia, Ruminococcus gnavus, Faecalibacterium, and Peptoclostridium, but were greater in dogs fed OR. In summary, restricted feeding promoted safe weight and fat loss, reduced blood lipid and leptin concentrations, and altered fecal microbiota of obese dogs.

In this study, we aimed to determine the effects of restricted feeding of specially formulated foods on weight loss, body composition, voluntary physical activity, serum hormones and oxidative stress markers, and fecal metabolites and microbiota populations of obese dogs. A control (OR) food was fed during a 4-wk baseline to identify intake needed to maintain the body weight (BW). After baseline, dogs were allotted to one of two diets: OR or test (FT) and then fed to lose 1.5% BW per week for 24 wk. Restricted feeding and weight loss led to reduced BW, body condition score, fat mass, and blood cholesterol, triglyceride, glucose and leptin concentrations and increased muscle condition score and lean body mass percentage. The reduction in blood cholesterol was greater in dogs fed FT vs. OR. Fecal metabolites and bacterial alpha-diversity were affected by diet and weight loss, with dogs fed with OR having a higher alpha-diversity than those fed with FT. Restricted feeding and weight loss increased alpha-diversity, affected beta-diversity, and impacted the relative abundances of nearly 20 bacterial genera. In summary, restricted feeding with high-protein, low-starch kibble diets promoted safe weight and fat loss, reduced blood lipid and leptin concentrations, and altered fecal microbiota of obese dogs.