Gut microbiota Alterations Associated with 1-kestose Supplementation and Owner-reported Aggression-related Behaviors in Dogs
Tadashi Fujii *
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan, Department of Medical Research on Prebiotics and Probiotics, Fujita Health University, Toyoake, Aichi, Japan and BIOSIS Lab. Co., Ltd., Toyoake, Aichi, Japan.
Saki Yamakawa
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan, Department of Medical Research on Prebiotics and Probiotics, Fujita Health University, Toyoake, Aichi, Japan and WELLNEO SUGAR Co., Ltd., Tokyo, Japan.
Nobuhiro Kondo
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan, Department of Medical Research on Prebiotics and Probiotics, Fujita Health University, Toyoake, Aichi, Japan and WELLNEO SUGAR Co., Ltd., Tokyo, Japan.
Takayuki Asahina
Minori Inc., Haga, Okayama, Japan.
Kohei Funasaka
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
Eizaburo Ohno
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
Yoshiki Hirooka
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan, Department of Medical Research on Prebiotics and Probiotics, Fujita Health University, Toyoake, Aichi, Japan and BIOSIS Lab. Co., Ltd., Toyoake, Aichi, Japan.
Takumi Tochio
Department of Gastroenterology and Hepatology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan, Department of Medical Research on Prebiotics and Probiotics, Fujita Health University, Toyoake, Aichi, Japan and BIOSIS Lab. Co., Ltd., Toyoake, Aichi, Japan.
Chie Mogi
Department of Animal Health Technology, Yamazaki University of Animal Health Technology, Hachioji, Tokyo, Japan.
*Author to whom correspondence should be addressed.
Abstract
Aims: To characterize fecal gut microbiota features associated with a history of aggression in dogs and to explore whether supplementation with the prebiotic fructooligosaccharide 1-kestose is associated with alterations in gut microbiota composition and owner-reported aggression-related behaviors.
Study Design: An exploratory, non-randomized field study comparing aggressive and non-aggressive client-owned dogs, followed by a single-arm pre–post supplementation study in aggressive dogs with owner-reported behavioral outcomes.
Place and Duration of Study: The study was conducted in Japan between 2021 and 2023, with a 60-day 1-kestose supplementation period for the intervention group.
Methodology: Fecal samples from aggressive toy poodles (Agg; n = 10) and non-aggressive controls (N-Agg; n = 6) were analyzed using 16S rRNA gene sequencing. Dogs in the Agg group received 1-kestose (400 mg/day) for 60 days. Behavioral outcomes were assessed before and after supplementation using the shortened, owner-reported Canine Behavioral Assessment and Research Questionnaire (C-BARQ). Genome analysis of Blautia caecimuris was conducted to identify glycoside hydrolase family 32 (GH32) enzymes, and a recombinant GH32 enzyme was functionally characterized for fructooligosaccharide hydrolysis.
Results: At baseline, Agg dogs differed in gut microbial β-diversity from N-Agg dogs and showed higher relative abundances of Mediterraneibacter gnavus, the Segatella copri group, and the Phocaeicola vulgatus group. Following 1-kestose supplementation, M. gnavus was lower, the B. caecimuris group was higher, and the β-diversity difference between groups diminished. In parallel, owner-reported aggression-related C-BARQ items—particularly responses to unfamiliar dogs and strangers near the home—were lower after supplementation. The characterized GH32 enzyme from B. caecimuris hydrolyzed 1-kestose and nystose.
Conclusion: These findings indicate that 1-kestose supplementation is associated with concurrent alterations in the canine gut microbiota and owner-reported aggression-related behavioral scores. While causality cannot be established, the results support further investigation of microbiota–behavior associations using larger, well-controlled study designs incorporating objective physiological and microbial measurements.
Keywords: Dog, aggression, 1-kestose, gut microbiota, Mediterraneibacter gnavus, Blautia caecimuris