Topical cream containing live lactobacilli decreases malodor-producing bacteria and downregulates genes encoding PLP-dependent enzymes on the axillary skin microbiome of healthy adult Nigerians.

Background: Clinical data exist that support the utility of topical probiotics for certain dermatological diseases such as atopic dermatitis, acne, and psoriasis. However, there is paucity of data on the use of live lactobacilli to control axillary malodor. The objective of this study was to determine whether application of topical oil-based cream containing live Lactobacilli could decrease malodor-producing bacteria in the axilla of healthy subjects.

Aims: To determine the effects of topical cream with live lactobacilli on malodor-producing bacteria in the axilla of healthy subjects.

Patients/methods: Twenty-five adult volunteers comprising 12 males and 13 females provided informed consent. Axillary skin swabs were collected before and after 14 days application of topical cream containing live Lactobacillus pentosus KCA1. Bacterial DNA was extracted, and V4 region of the 16S rRNA was amplified and sequenced in a pair-end configuration on the Illumina MiSeq platform rendering 2 × 150 bp sequences. Microbial taxonomy to species level was generated using the Greengenes database. Linear discriminant analysis (LDA) effect size (LEfSe) was used to identify biologically and statistically significant differences in relative abundance.

Results: Actinobacteria decreased from 70% to 24%, and Firmicutes increased from 26.6% to 73.9% among the female participants. In males, Actinobacteria decreased from 65% to 38%, while Firmicutes increased from 24% to 57%. Corynebacterium decreased from 62.91% to 36.63%, while Lactobacillus increased from 0.06% to 23.11%. In males, unliked females, there were reduction of Staphylococcus species associated with malodor, notably Staphylococcus hominis, Staphylococcus hemolyticus, and Staphylococcus lugdunensis. Bacterial functional gene- Pyridoxal protein dependent enzymes involved in biotransformation of malodor precursor to volatile thioalcohols were down-regulated.

Conclusions: Application of Lactobacillus pentosus KCA1 cream led to a significant decrease in the relative abundance of odor-producing Corynebacterium species in both female and male subjects. Some species associated with malodor especially Corynebacterium striatum, Corynebacterium jeikeium, Corynebacterium tuberculostearicum, and Staphylococcus hominis decreased by 96%, 73%, 7%, and 20.8%, respectively, in males.