Effect of Dietary Composite Probiotic Supplementation on the Microbiota of Different Oral Sites in Cats.

Probiotics demonstrated effectiveness in modulating oral microbiota and improving oral health in humans and rodents. However, its effects and applications on the oral microbiota of cats remain underexplored. Twelve healthy cats were randomly assigned to a control group (CON) and a composite probiotic group (CPG) for a 42-day trial. The CPG diet included additional supplementation of subsp. HN019, NCFM, and LC-11, each at approximately 1 × 10 CFU/kg. On days 0 and 42, microbial samples were collected from the gingiva, tooth surfaces, and tongue of all cats for 16S rRNA gene sequencing. Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla across all oral sites. The CPG treatment enriched seven genera, such as , , and in the gingiva. Meanwhile, and were enriched on the tooth surfaces, while , , and were enriched on the tongue. Furthermore, the composite probiotic effectively suppressed eight genera, such as , , and in the gingiva of CPG cats, as well as and on tooth surfaces, and and on the tongue. These findings suggest that the composite probiotic used in this study modulates the feline oral microbiota by supporting beneficial or commensal bacteria and inhibiting oral pathogens, demonstrating potential to improve oral health in cats.