Preprint links mTOR pathway to longevity via bile acid-like hormone signalling in C. elegans

The mechanistic target of rapamycin (mTOR) pathway is a central regulator of cell growth and metabolism whose inhibition is known to extend lifespan across diverse organisms, from yeast to mammals. How mTOR exerts this longevity effect at a systems level — particularly through cell non-autonomous signalling — has remained incompletely understood.

A bioRxiv preprint posted on 17 May 2026 describes work in the nematode *Caenorhabditis elegans* showing that deletion of *raga-1*, encoding the TORC1 regulatory subunit RRAGA, increases production of dafachronic acid (DA), a bile acid-like steroid hormone. The lifespan extension conferred by *raga-1* deletion was found to depend on DA biosynthetic genes and on DAF-12, the cognate nuclear hormone receptor — a homologue of the mammalian farnesoid X receptor (FXR). A functional genomic screen identified *dhs-26/DHRS1* as an additional component of this pathway.

The finding positions the mTOR–DA–DAF-12 axis as a hormonal mechanism linking nutrient sensing to organismal ageing, with potential relevance to understanding conserved longevity pathways in mammals given the evolutionary relationship between DAF-12 and FXR. The preprint has not yet been peer-reviewed. No mammalian or clinical data are reported; the work is at the model-organism mechanistic research stage. Readers should note that a cluster on the naked mole-rat longevity gene transfer into mice was published in Genetic Current on 16 May 2026; the present study is a distinct, complementary mechanistic finding in a different model system.