Effects of probiotics, prebiotics and dietary fibers on the gastrointestinal health and immune indices of adult dogs and cats

Lee, Anne Heejai

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https://hdl.handle.net/2142/115690 Copy

Description

Title

Effects of probiotics, prebiotics and dietary fibers on the gastrointestinal health and immune indices of adult dogs and cats

Author(s)

Lee, Anne Heejai

Issue Date

2022-04-18

Director of Research (if dissertation) or Advisor (if thesis)

Swanson, Kelly S

Doctoral Committee Chair(s)

Swanson, Kelly S

Committee Member(s)

• Fahey, Jr., George C
• de Godoy, Maria R.C.
• Holscher, Hannah D
• Steelman, Andrew J

Department of Study

Animal Sciences

Discipline

Animal Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Functional ingredients
• gut health
• immune health
• companion animal
• nutrition
• canine
• feline
• dietary fiber
• probiotics
• prebiotics
• milk oligosaccharides
• gut microbiome

Abstract

Functional ingredients are those that provide health benefits beyond that of basic nutrients, and their inclusion in pet foods has become a popular practice in the industry. This is largely due to the increased owner awareness pertaining to pet health and well-being. A variety of functional ingredients, including fibers, prebiotics, probiotics, postbiotics, and milk oligosaccharides have been considered and added to pet foods to support gastrointestinal and immune health. While many of these ingredients have been tested individually, others have yet to be tested. Moreover, commercial foods often include ingredient blends that also require testing. Therefore, the goal of this dissertation was to investigate the effects of individual or blends of functional ingredients on the gastrointestinal health and immune responses of healthy adult dogs and cats. The aim of the first study was to evaluate the effects of diets containing blends of fibers, ‘biotics’, and/or spray-dried plasma on apparent total tract digestibility (ATTD), stool quality, fecal microbiota and metabolites, and immune health outcomes of adult dogs. Twelve healthy adult intact English pointer dogs (6 M; 6 F; age = 6.4 ± 2.0 yr; BW = 25.8 ± 2.6 kg) were used in a replicated 3x3 Latin square design to test diets formulated to: 1) contain a low concentration of fermentative substances (control diet; CT); 2) be enriched with a fiber-prebiotic-probiotic blend (FPPB); and 3) be enriched with a fiber-prebiotic-probiotic blend + immune-modulating ingredients (iFFPB). In each 28-d period, 22 d of diet adaptation was followed by a 5-d fecal collection phase and 1 d for blood sample collection. Dogs fed FPPB or iFPPB had decreased (P<0.01) dry matter (DM), organic matter, fat, fiber, and energy ATTD, improved (P<0.01) fecal scores and higher (P<0.01) fecal DM% than CT. Serum triglyceride and cholesterol concentrations were lower (P<0.01) in dogs fed FPPB or iFPPB than those fed CT. Fecal protein catabolite (isobutyrate, isovalerate, indole, ammonia) and butyrate concentrations were lower (P<0.05), while fecal immunoglobulin A (IgA) concentration was higher (P<0.01) in dogs fed FPPB and iFPPB than those fed CT. Fecal microbial alpha diversity was lower (P<0.05) in dogs fed iFPPB and the relative abundance of 20 bacterial genera were altered in dogs fed FPPB or iFPPB compared to those fed CT. The circulating helper T cell:cytotoxic T cell ratio was higher (P<0.05) in dogs fed iFPPB than those fed CT. Circulating B cell numbers were lower (P<0.05) in dogs fed FPPB than those fed iFPPB, and lower (P<0.05) in dogs fed iFPPB than those fed CT. The aim of the second study was to evaluate the ATTD, stool quality, fecal microbiota and metabolites, and immune health outcomes of dogs fed a novel milk oligosaccharide (MO) biosimilar (GNU 100). 32 adult dogs were used in a completely randomized design study. Following a 2-wk baseline, dogs were assigned to one of four treatments and fed for 26 wk: 0%, 0.5%, 1% and 1.5% GNU100. On wk 2, 4 and 26, fresh fecal samples were collected to measure stool quality, IgA concentration, and calprotectin concentration, and blood samples were collected to measure serum chemistry and inflammatory markers and hematology. On wk 2 and 4, fresh fecal samples were collected to measure metabolites and microbiota. On wk 4, total feces were collected to assess ATTD. All dogs were healthy and had no signs of GI intolerance or illness. All diets were well-accepted and food intake, fecal characteristics and metabolite concentrations and macronutrient digestibilities were not altered. GNU100 modulated fecal microbiota, increasing evenness and Catenibacterium, Megamonas, and Prevotella (SCFA producers) and reducing Collinsella. Overall, results suggest that GNU100 is palatable and well-tolerated, causes no genotoxicity or adverse effects on health, and beneficially shifts the fecal microbiota, supporting the safety of GNU100 for inclusion in canine diets. The aim of the third study was to evaluate the effects of diets enriched in resistant starch or fibers on the fecal characteristics, microbiome, and metabolite profiles of cats. Twelve healthy adult domestic shorthair cats (age = 9.6±4.0 yr; body weight = 3.9±1.0 kg) were used in a replicated 3x3 Latin square design to test diets that were enriched with: 1) resistant starch (ERS), 2) a fiber-prebiotic-probiotic blend (FPPB), or 3) a fiber-prebiotic-probiotic blend + immune-modulating ingredients (iFPPB). In each 28-d period, 22d of diet adaptation was followed by fecal and blood sample collection. Fecal microbiota was assessed with shotgun and 16S sequencing. In addition, fecal and blood metabolite measurements and white blood cell stimulation was performed to assess immune function. A total of 1,690 bacterial species were identified via shotgun sequencing, with 259 species differing between fiber-rich and ERS treatments. Fiber-rich treatments increased diversity and promoted Firmicutes and Bacteroidetes populations, while resistant starch reduced (P<0.01) microbial diversity and fecal pH, led to a bloom in Actinobacteria, and modified KO terms (KEGG Orthology; KEGG: Kyoto Encyclopedia of Genes and Genomes) pertaining to starch and sucrose metabolism, fatty acid biosynthesis and metabolism, epithelial cell signaling, among others. Resistant starch increased (P<0.01) butyrate concentrations; decreased (P<0.01) propionate and protein catabolite (branched-chain fatty acids; phenols and indoles; ammonia) concentrations and reduced (P<0.05) blood cholesterol, which correlated strongly with microbial taxa and KO terms, and allowed for a high predictive efficiency of diet groups by random forest analysis. Our results indicate that supplementation of a fiber-prebiotic-probiotic blend may have positive impacts on stool quality, fecal metabolites, fecal microbiota and immune function in dogs. Different effects were observed in cats fed a fiber-prebiotic-probiotic blend, however, likely being impacted by the ERS diet they were compared with. Our results indicate that the feline microbiome and metabolite profiles were highly responsive to resistant starch intake. In addition, the MO biosimilar tested did not produce a beneficial health effect, though no adverse effects were observed. The utilization of these fiber-prebiotic-probiotic + immune modulating ingredient blends and MO on geriatric or obese dog and cat populations that are more susceptible to inflammation and gut microbial dysbiosis may also be of interest in future studies.

Graduation Semester

2022-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Anne Lee

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