Scientists have discovered a natural compound called indole, produced by healthy gut bacteria, that dramatically reduces fatty liver disease. Research in mice has shown that indole protects the livers of the offspring of mothers who ate a diet high in fat and sugar during pregnancy. The compound improves blood sugar levels and curbs weight gain. Indole also permanently reshapes the composition of the gut microbiome. The results indicate that a mother's diet during pregnancy can have a long-term effect on her baby's liver health. But new research offers a way to improve liver health by supporting healthy gut bacteria and their products.