Probiotics have grown increasingly pivotal for the health of pets, particularly dogs and cats. Emerging research demonstrates that probiotics exert a significant positive impact on gut health, including alleviating intestinal inflammation, regulating gut microbiota balance, and relieving diarrhea symptoms for pets. Regarding nutrient metabolism, probiotics aid in prevention and management of obesity and associated metabolic diseases, primarily by enhancing nutrient digestibility and regulating energy utilization and fat metabolism. Furthermore, probiotics exhibit positive effects, including antiviral activity, immune regulation, and antioxidation. Specific probiotic strains exert their functions via mechanisms such as increasing immunoglobulin levels, suppressing the expression of inflammatory factors, and boosting antioxidant enzyme activity. The underlying mechanisms primarily involve regulating metabolites (e.g., short-chain fatty acids, SCFAs), strengthening the intestinal barrier function, modulating immune responses, and optimizing the gut microbial composition. While existing studies highlight the broad potential of probiotics in preventing and managing various chronic diseases in dogs and cats, their utility in addressing acute illnesses and severe organ damage remains limited. Future research should prioritize investigating species-specific mechanisms of actions and extend to exploring potential applications in the neurological health and behavior of pets.

Background: To investigate the effects of probiotics and their postbiotics on mouse health, this study utilized healthy mice randomly assigned to a control group (CK, n = 6), a probiotic group (L, n = 6, oral gavage 200 μL Pediococcus lactis), and a postbiotic group (PL, n = 6, oral gavage 200 μL Pediococcus lactis postbiotic). Methods: Following 21 days of continuous intervention, changes in gut metabolic profiles, microbial community structure, tissue morphology, and tight junction protein expression were systematically analyzed using metabolomics, 16S rRNA sequencing, hematoxylin and eosin (HE) staining, and immunohistochemistry techniques. Results: The results revealed that screening for significantly altered endogenous metabolites identified core differences concentrated in metabolites related to intestinal barrier repair, anti-inflammation, and antioxidant activity (e.g., 3-indolepropionic acid, astaxanthin, hydroxybenzoic acid). 16S rRNA sequencing revealed that the overall community structure was relatively stable according to principal component analysis, although differences were detected in specific taxa. However, LEfSe analysis identified significantly enriched functional microbial groups at multiple taxonomic levels in the PL group: phylum: Actinomycetota; class: Coriobacteriia; order: Coriobacteriales, Erysipelotrichales; family: Erysipelotrichaceae, Eggerthellaceae; genus: norank_Erysipelotrichaceae, Intestinimonas. These results suggest that although the overall community structure remained relatively stable, specific taxa may have differed between groups. Hematoxylin and eosin staining revealed no pathological lesions in intestinal tissues from either group, with intact mucosal architecture. Immunohistochemistry demonstrated significantly elevated expression of intestinal tight junction proteins Claudin 1, MUC-2, Occludin, and ZO-1 in the PL group compared to the CK group (p < 0.001). Conclusions: In summary, this probiotic (Pediococcus lactis) and its postbiotic showed promising effects, which may be related to changes in specific microbiota taxa, intestinal metabolic profiles, and tight junction protein expression. Beyond maintaining gut microbiota and tissue homeostasis, it enhances intestinal barrier function, suppresses latent inflammation, and boosts antioxidant capacity. Postbiotics may exhibit superior efficacy compared to probiotics. This provides robust experimental evidence for its development and application in gut health products for healthy populations. However, these findings still require further validation in studies with longer intervention periods and in disease models.

Owing to their favorable stability and safety profile, postbiotics—defined as functional metabolites originating from probiotic microbes—have attracted growing interest in the field of companion animal health care. The present work sought to evaluate how postbiotics prepared from Lactiplantibacillus plantarum and Pediococcus lactis influence lipid metabolism, blood biochemistry, and the composition of fecal microbiota in felines. Eighteen clinically healthy adult cats were assigned at random to three equal-sized groups: a control treatment (n = 6, a basal diet), a L. plantarum postbiotic L-27-2 group (n = 6, a basal diet with 10⁹ CFU equivalent/kg/day), and a P. lactis L-14-1 postbiotic group (n = 6, a basal diet with 10⁹ CFU equivalent/kg/day). The supplementation lasted four weeks. Both postbiotics significantly lowered serum total cholesterol (TC) and triglycerides (TG) concentrations (p < 0.05), demonstrating a modulatory action on lipid metabolism in cats. The L-27-2 postbiotic selectively enriched beneficial taxa, notably Bifidobacterium (p < 0.05). Furthermore, fecal levels of malodorous compounds were significantly decreased by both treatments (p < 0.05). The results suggested both postbiotics have potential positive effects in cats. These findings are preliminary and hypothesis-generating.