A new study reports that trimethylamine N-oxide, or TMAO, is not only tied to the well-known gut microbiota-liver pathway. The researchers found that pancreatic beta-cells can also make TMAO locally through the enzyme FMO3, pointing to a previously underappreciated source of this molecule inside the pancreas.
According to the study, this beta-cell FMO3-TMAO axis appears to play a protective role during ageing and under diabetic conditions. Rather than promoting damage in this setting, the locally produced TMAO was linked to lower levels of NF-κB-mediated cellular senescence and inflammation in beta-cells.
That finding is notable because beta-cells are responsible for producing insulin, and their decline is a major feature of both ageing-related metabolic dysfunction and diabetes. By dampening inflammatory and senescence-related pathways, the local FMO3-TMAO mechanism may help preserve beta-cell health when these cells are under stress.
The work adds a new layer to how researchers think about TMAO biology. Instead of viewing it only as a metabolite generated through the gut-liver axis, the study suggests that tissue-specific production inside pancreatic beta-cells could have a distinct and potentially beneficial role in maintaining islet function during ageing and diabetes.
