Sounds promising but the study is behind a paywall. What are the 12 indole molecules?
"The team grew a big batch of P. sanguinis for three days and then extracted the mixture of metabolites the microbes produced. A combination of analytical methods, including spectrometry, isotope labeling and computational analysis, enabled the team to tease out the chemical structure of 12 individual indole metabolites from this mix, including six that had never been identified.
Next, Kim, Lee and colleagues investigated whether these indole metabolites could mitigate harmful processes that are also associated with aging in human skin. They applied liquid solutions containing each indole to wells with cultured human skin cells. Prior to the experiment, the cells were treated to induce elevated levels of reactive oxygen species, compounds responsible for inflammation and collagen damage.
Of the 12 indoles the researchers investigated, three, including two newly identified ones, lowered the amounts of harmful reactive oxygen species in the stressed human skin cells compared to untreated cells. The three metabolites also reduced the levels of two inflammatory proteins and a collagen-damaging protein.
As a result of these initial findings, the researchers say the new indole metabolites are promising candidates for future treatments to counteract skin aging."