Liming Pei, a research associate at the Salk Institute for Biological Studies, who coauthored an editorial on the paper in Cell Metabolism, cautions that applying this specific approach to humans is many steps away. But the study is important in terms of finding new strategies to target obesity. Previous approaches, Pei says, “focused on stimulating existing natural pathways” for burning fat. The idea of introducing a strategy from another organism that is not present in the body is a novel one.
“This opens up an opportunity for understanding metabolism and finding new therapeutic applications,” Liao says. Someday, it may be possible to actually introduce these bacterial genes or proteins into humans, although Pei points out that such a feat poses many challenges, including a potential immune response to foreign genes. Another possibility would be to search for drugs that could mimic the effects of these enzymes. Furthermore, earlier studies reported glyoxylate shunt activity in chickens and rats, suggesting that higher organisms might retain the genes for this pathway but don’t use them; it might be possible to activate dormant genes.
Liao says that the study borrows strategies from synthetic biology, a field that has for the most part focused on engineering new functions into bacteria and other lower organisms. The study suggests that the same concepts could be applied to mammals: just as we create bacteria that produce biofuels, we could introduce new abilities into the bodies of humans and other animals.
“What I found fascinating is that it shows how you could use synthetic biology for human therapies in a highly novel way,” says James Collins, a synthetic biologist at Boston University. Current strategies for gene and protein therapy largely focus on single molecules–replacing a missing substance like insulin or inhibiting a harmful protein in cancer. Instead, Collins says, scientists might consider introducing an engineered pathway that allows the body to do something that it couldn’t before.