There are many odd things embedded in this paper. The first is that, despite enormous resources and an un-scoopable result, the treated sample size (N=6 biological reps) is incredibly small compared to the measured population.
It is unclear why, given access to almost 600 rodents and enough resources to measure their methylation profiles, only six biological replicates were included. Most scientists with this level of resources would seek to replicate such an amazing result, to exclude error or contamination. Given the rather huge claims made here, therefore, it seems highly unusual that only 18 rats in total were actually used for the experiment, and that the experiment was not replicated.
That is, given the researchers have access to a huge number of rats of known age, and are claiming to reverse aging, why would you fail to make absolutely sure of it by measuring more rats? It is not like they lack the resources, and the experimental intervention (injecting plasma into rats) is painfully simple.
Several obvious controls are also missing from the experimental design.
It is also striking that the PDF of this preprint has three times as many downloads as abstract views, and thirty times as many PDF downloads as HTML views. This pattern is completely unlike the organic download patterns of other preprints.
Given that any (non-automated, human) viewer has to view the abstract to reach and click the PDF download, this suggests somebody has written a bot-scraper to help their download count.
It could be suggested that this preprint is not targeted at sound, replicated science but rather represents a carefully calculated bid for good press for "Nugenics" and "Elixir" sales.
