Assessing the Impact of Prebiotics on Gut Health in Canine Patients with Gastrointestinal Disorders

Thesis Abstract

Gastrointestinal (GI) disorders are among the most prevalent health concerns in canine patients, often resulting in compromised nutrient absorption, altered gut microbiota, and reduced quality of life. Despite the widespread use of probiotics and dietary modifications, the role of prebiotics—non-digestible dietary fibers that selectively stimulate beneficial gut bacteria—remains underexplored within veterinary clinical practice. This study aims to empirically evaluate the impact of prebiotic supplementation on gut health parameters in dogs diagnosed with gastrointestinal disorders, specifically focusing on microbial diversity, fecal characteristics, and clinical symptom resolution. The primary objectives include assessing changes in fecal microbiota composition following prebiotic treatment, evaluating improvements in clinical GI scores, and establishing correlations between microbiota modifications and health outcomes. The study adopts a quantitative, controlled experimental design rooted in a positivist paradigm. The target population comprises domestic dogs diagnosed with chronic gastrointestinal disorders, recruited from veterinary clinics in the metropolitan region. A total sample size of 60 dogs will be randomly assigned into two groups an intervention group receiving a standardized dose of inulin-based prebiotics (10 grams daily) and a control group receiving a placebo, over a period of eight weeks. Sample size calculations are based on previous studies aiming for a power of 0.8 at a significance level of 0.05 to detect a minimum effect size of 0.5 in microbiota diversity indices. Data collection will involve analyzing fecal samples at baseline, mid-point (four weeks), and study-end (eight weeks) using 16S rRNA gene sequencing to quantify bacterial taxa and assess diversity indices. Clinical parameters, including stool consistency, frequency, and presence of vomiting or diarrhea, will be recorded weekly through owner-maintained logs and veterinarian assessments. Validated clinical scoring systems, such as the Canine Inflammatory Bowel Disease Activity Index, will be employed to quantify symptomatic severity. The reliability and validity of the molecular assays will be ensured through calibration with known microbial standards and replicate analyses. Data will be analyzed using SPSS and R statistical software, employing repeated measures ANOVA to identify differences over time, and multivariate regression models to examine associations between microbiota changes and clinical outcomes. It is anticipated that prebiotic supplementation will significantly enhance microbial diversity, particularly increasing populations of beneficial bacteria such as Bifidobacterium and Lachnospiraceae, compared to controls. Correspondingly, dogs in the intervention group are expected to demonstrate marked improvements in stool quality, reduced clinical scores, and fewer episodes of diarrhea and vomiting. The findings are expected to fill existing gaps concerning the efficacy of specific prebiotics in canine GI health management, providing tangible evidence supporting their integration into routine clinical care. The study contributes theoretically by validating the applicability of the prebiotic concept within veterinary science, grounded in the conceptual framework of the microbiota-gut-brain axis and using the Theory of Gut Microbiome Modulation. The main conclusion underscores the therapeutic potential of prebiotics as a non-invasive, adjunctive treatment for canine GI disorders, promoting microbial balance and clinical recovery. It is recommended that veterinary practitioners incorporate tailored prebiotic regimens into treatment protocols for chronic GI conditions and consider larger-scale longitudinal studies to explore long-term benefits. Future research should also evaluate the comparative effectiveness of different types of prebiotics and investigate their mechanistic pathways in gut microbiota modulation. Overall, this study affirms the pivotal role of diet-derived immunomodulators in advancing veterinary gastroenterology and improving canine health outcomes.