The study presents exciting evidence of how Trp and its metabolite ILA contribute to skin rejuvenation via AhR activation. One question I had was whether the study examined direct interactions between AhR and downstream genes in keratinocytes, such as those regulating tight junction proteins or collagen synthesis. Could additional experiments, like chromatin immunoprecipitation (ChIP) assays, further verify these interactions?
Furthermore, while antibiotics were used to prepare the aged mice for FMT, how might their use have influenced the skin phenotype independently of the young microbiota? Including a control group with antibiotics but no FMT could provide deeper insights into this interaction.
Finally, given the promising metabolomics data, are there plans to validate these findings in larger models or through clinical studies?