This is issue that was addressed in, “Starvation-Induced Stress Response Is Critically Impacted by Ceramide Levels in Caenorhabditis elegans”
I’ve pasted an extract below. You can retrieve other relevant papers by searching “ceramide” at http://www.textpresso.org/cgi-bin/wb/tfw.cgi
Switch on Advanced Search Options and restrict to “materials”. I hope this helps.
Short fatty acyl chain ceramides (C6 and C8) are soluble in DMSO, but are toxic to animals in high concentrations, and may not be physiologically relevant. The long-acyl chain ceramides (C16–25) are insoluble in either DMSO or aqueous solution, rendering dietary supplement analysis difficult. Indeed, we failed to rescue the L1 starvation survival of either sptl-2(lf) or CerS(rf) mutants with dietary supplementation of ceramides containing various lengths of fatty acyl chains. In contrast, the sphingoid bases (sphinganine), which are ceramide precursors and downstream products of the serine palmitoyltransferase, have better solubility in DMSO and aqueous solution. In C. elegans, the majority of sphingoid bases are derived from monomethyl branched-chain fatty acids (C15ISO and C17ISO) (Zhu et al. 2013). We then examined dietary supplementation with a custom synthesized d17iso-SPA (sphinganine), and found it was able to partially rescue the L1 starvation survival of sptl-2(lf) (Figure 2, B and C). This result may also suggest that intestinal ceramides play prominent roles in promoting starvation survival.