The authors of the reply in Nature Medicine respond to comments from Ludwig et al., Robinson & Forde, Wang & Peng on the original study. They confirm that their findings on ultra-processed foods and energy intake remain valid despite criticism. Short-term exposure of senescent muscle stem cells (MuSCs) to prostaglandin E2 (PGE2) has been reported to enhance their long-term regenerative capacity after transplantation. After PGE2 treatment, increased binding of transcription factors to sites with CRE and E-box motifs and decreased binding to sites with AP1 motifs are detected, overcoming the changes caused by aging. Injections of PGE2 after muscle damage by myotoxin or exercise overcome the aging niche, improving the regenerative function of endogenous resident MuSCs and increasing muscle strength. These effects have been observed in experiments on animal models.