Polyphenol‐rich Dietary Fiber Sources Increased Antioxidant & Anti‐inflammatory Polyphenols in the Lower Gastrointestinal Tracts of Healthy Adult Cats While Maintaining Fecal Characteristics Similar to Control

Abstract

Plant fibers may benefit feline gastrointestinal (GI) health. Healthy adult cats (n=46) were fed control food (CF) for 4 wks, randomized to either Hill’s® Prescription Diet® Gastrointestinal Biome Feline (GB) or Royal Canin Feline Gastrointestinal Fiber Response™ (FR) for 8 wks, CF for 4 wks & the opposite test food for 8 wks (CF: 4129 kcal/kg, 1.6 g total dietary fiber, TDF; 0.7 g soluble fiber, SF; & 0.9 g insoluble fiber, INSF, per 100 kcal; GB: 4010 kcal/kg, 3.2 g TDF, 0.3 g SF, 2.9 g INSF per 100 kcal; FR: 3890 kcal/kg, 2.8 g TDF, 0.8 g SF, 2.0 g INSF per 100 kcal). All foods were complete & balanced dry foods (2017 AAFCO Cat Food Nutrient profiles for adult cats). CF fiber sources included cracked pearled barley, corn, dried beet pulp, fructooligosaccharides (FOS) & psyllium seed husk; GB: corn, ground pecan shells, cracked pearled barley, whole grain oats, dried beet pulp, pea fiber, flaxseed, dried citrus pulp, pumpkin, cranberry pomace, FOS & psyllium seed husk; FR: corn, psyllium seed husk, chicory & FOS. Feces were collected every 4 wks & scored on a 6‐point scale (1=watery to 6=very hard), cleaned, weighed, photographed, & scored for blood, mucus, segmentation, casing, odor & unusual texture; feces were scored for color & size vs. photos from same cat on CF. Feces were homogenized & frozen within 1 hr of defecation. A commercial lab analyzed untargeted metabolomics. Fecal short chain fatty acids were analyzed by liquid‐liquid extraction & gas chromatography with flame ionization detection. Statistical analysis was performed using a linear mixed‐model (PROC GLIMMIX). Stool characteristics were analyzed with Fisher’s exact test. All analyses used SAS® v. 9.4. This study was reviewed & approved by the IACUC, Hill’s Pet Nutrition, Inc. Cats had free access to water & were housed with daylight & enrichment. By 4 wks, GB increased fecal butyric acid (unadj. p=0.012; adj. p=0.083) vs. FR; this difference was not significant at 8 wks. Both foods yielded acceptable stool scores though cats fed FR had larger feces by weight vs. cats fed GB at 4 & 8 wks (adj. p <.0001). Feces from cats fed FR more often had mucus, casing, unusual texture, unusually light color, & unusually large size at wks 4 & 8 (all p<0.01); feces from cats fed GB were more similar in size, weight, color & characteristics to feces from the same cat fed CF. Feces from cats fed GB had increased fecal saccharolytic products ribulose/xylulose, maltose, arabinose & fecal anti‐inflammatory & antioxidant plant compounds & postbiotics naringenin, eriodictyol, limonin, ponciretin, poncirin, secoisolariciresinol & secoisolariciresinol diglucoside, hesperidin & hesperetin at wks 4 & 8 (all adj. p<0.0001) vs. feces from cats fed FR. Hill’s® Prescription Diet® Gastrointestinal Biome Feline with specialized polyphenol‐rich fiber sources delivered anti‐inflammatory & antioxidant plant‐derived polyphenols & postbiotics to the lower GI tract of healthy adult cats, & produced fecal characteristics more similar to control vs. a competitor product.Support or Funding InformationThis study was funded by Hill’s Pet Nutrition, Inc.