A peer-reviewed study connects skin bacteria with differences in mosquito attraction and tests two Bacillus species in macaques. Applying the bacteria changed skin chemistry and reduced mosquito attraction in a small experiment. Separate mouse tests examined candidate repellent compounds. The human component was observational, so the findings establish no protective treatment for people.
In one peer-reviewed study, 37 volunteers aged 22–32 underwent mosquito-attraction tests and skin-microbe sampling. People attracting fewer Aedes aegypti, the mosquito species used in the experiments, carried more Bacillus bacteria. The human comparison was observational. It linked microbial differences with attraction but did not test whether applying those bacteria protects people from bites.[1]
Researchers next tested two purchased bacterial strains on the skin of three male cynomolgus macaques, a nonhuman primate. The strains were Bacillus licheniformis and Bacillus paralicheniformis. Treatment continued for three days. Follow-up measurements were taken after application on day two, then on days five and eight. Mosquito attraction was lower at each check. Skin chemistry also changed, with increases in compounds including p-cresol and decanoic acid. Commercial strains may differ from bacteria naturally present on the volunteers.[1]
Mouse experiments tested four candidate compounds individually. The compounds deterred mosquitoes from the mice, with the extent of deterrence depending on dose. Comparing skin measurements with bacteria cultured alone indicated that interactions on the skin mattered to the chemical changes. The study used one mosquito species and only three macaques. Human safety, persistence on human skin and comparative performance against established repellents remain undetermined; no human clinical efficacy trial was conducted.[1]
