This pilot study aimed to investigate the effects of gallic acid-containing mouth spray on oral microbiota in healthy cat subjects. Forty healthy cats were recruited and randomly allocated to the control (G1; n = 20) and treatment groups (G2; n = 20). The cats were treated with mouth spray twice daily for 42 days. The changes in the gingival index (GI) and plaque index (PI) were measured at baseline (day 0) and end of the study (42nd day). The changes in the oral microbial composition of representative animals (control, n = 9; and treatment, n = 8) were also evaluated at baseline and end of the study. Oral microbial composition was assessed by amplifying the V1–V3 region of the 16S rRNA gene from supragingival dental plaque DNA extracts. The sequences were annotated using the QIIME 2.0. The GI and PI were significantly reduced after 42 days of treatment. The deep sequencing revealed that mouth spray influenced the cats’ oral microbiome and was significantly diverse. About 20 phyla and 59 species were observed after 42 days of mouth spray usage in cats’ oral microbiota. The number of operational taxonomic units (OTUs) of post-treatment samples (PoTS) of G2 was greatly reduced compared to other samples. Further analysis revealed that mouth spray acts substantially against Desulfomicrobium orale, one of the known pathogens in periodontal disease. The mouth spray efficiently reduced the growth of 22 species and uprooted 17 species. Moreover, the mouth spray supported the growth of normal oral microbiota, including Moraxella and Neisseria species. The preliminary study suggested that the gallic acids-containing mouth spray could be an essential oral product to improve the oral hygiene of the cats. Moreover, further studies are needed to confirm the beneficial effect of mouth spray on cats.

The skin is a physical barrier to protect the human body and is rich in microbial niches. Skin is damaged due to several factors, including poor nutrition and exposure to harsh environments resulting in dryness, acidic skin, and infections. Studies have shown that probiotics and their derivatives could protect the skin. Skin care products with probiotic components are the latest approach to developing cosmetic products with health benefits. The current study aimed to examine the moisturizing effect of paraprobiotics (moist heat-inactivated Bifidobacterium lactis (B. lactis), Lactobacillus plantarum (L. plantarum))-containing moisturizer (APM) and its influences on the skin microbiome of healthy subjects. Fifty healthy subjects were randomly divided into treatment (n = 25) and control (n = 25) groups. The APM or placebo (without paraprobiotics; PM) was applied on the skin of the right forehand of subjects, and the changes in transepidermal water loss (TEWL) and stratum corneum moisture (SCM) levels every 1 h for 4 h and after 4 weeks of treatment were observed. Skin swab samples were collected before and after the treatments (4 weeks) and subjected to microbiome analysis through next-generation sequencing technology. The results indicated that the APM treatment significantly reduced the TEWL and increased the SCM values compared to the respective baseline values and controls. The sequencing study showed significant changes in Cutibacterium (p = 0.0431), Corynebacterium (p = 0.0431), and Acinetobacter (p = 0.0431) in the treatment group. The changes in phylum were not statistically significant. Still, based on the relative frequency, the abundance of phylum Proteobacteria and Firmicutes and Cyanobacterial was decreased, and the abundance of Planctomycetes, Chloroflexi, Verrucomicrobia, and Gemmatimonadetes was increased after treatment. Additionally, the APM treatment suppressed C. tuberculostearicum in healthy subjects. The results suggested that APM could improve skin hydration and skin-beneficial microbial composition. The study has limitations such as a small sample size and treatment period, so further extensive studies are required to confirm the findings of the current study, which could aid in developing paraprobiotics-based skin care formulations.