Dietary Lycium barbarum Polysaccharide Supplementation Modulates Serum Metabolomic Profiles and Gut Microbiota in...

Functional pet foods are increasingly being developed to support host metabolism and intestinal health. Lycium barbarum polysaccharide (LBP), a major bioactive component of goji berries, has been reported to possess antioxidant, anti-inflammatory, immunomodulatory, and gut microbiota-regulatory activities; however, its effects in domestic cats remain unclear. This study investigated the effects of dietary LBP supplementation on serum metabolomic profiles and gut microbiota in adult cats. Twenty-four healthy adult Chinese domestic cats (1.50 ± 0.50 years old; 3.70 ± 0.80 kg) were allocated to four groups using a body-weight-balanced procedure (n = 6 per group): a basal diet group (C) and basal diet supplemented with 0.2% (L), 0.3% (M), or 0.4% (H) LBP. After a 1-week adaptation period, the formal feeding trial lasted 8 weeks. Growth-related indices, health scores, hematological and serum biochemical parameters, untargeted serum metabolomics, and fecal 16S rRNA sequencing were evaluated. LBP supplementation did not significantly affect body weight, average daily feed intake, body condition score, fecal score, coat score, hematological indices, or serum biochemical parameters. Metabolomic analysis showed that LBP mainly affected lipid metabolism, unsaturated fatty acid biosynthesis, branched-chain amino acid metabolism, lysine degradation, and protein digestion and absorption-related pathways. Microbiota analysis showed changes in alpha diversity, community structure, and the relative abundance of taxa such as Olsenella, Bifidobacterium, Catenibacterium, Peptoclostridium, Collinsella, and Clostridium. Correlation analysis suggested potential associations between key bacterial genera and serum metabolites related to fatty acid and amino acid metabolism. Overall, dietary LBP altered serum metabolic signatures and gut microbial composition without causing adverse effects in adult cats, These exploratory findings require confirmation in larger feline studies and do not establish an optimal supplementation level.