When we are hungry and see and smell food, our body immediately starts to prepare for food intake. A team of researchers at the Max Planck Institute for Metabolism Research conducted a study on mice and found that adaptations in the liver mitochondria occur within a few minutes of seeing and smelling food. The mitochondria in the liver cells change, preparing the liver for the adaptation of sugar metabolism. These findings, published in the journal Science, could have implications for the treatment of type 2 diabetes.
The researchers fed hungry mice that could only see and smell the food without actually eating it. After just a few minutes, they analyzed the mitochondria in the liver and observed that processes typically stimulated by food intake were activated. The studies demonstrated that the sight and smell of food for just a few minutes can influence the mitochondria in liver cells through the phosphorylation of a mitochondrial protein, affecting the sensitivity of the liver to insulin. This discovery has revealed a new signaling pathway that regulates insulin sensitivity in the body.
The effect on the liver mitochondria is mediated by a group of nerve cells in the hypothalamus known as POMC neurons. Upon perceiving food, these neurons are rapidly activated, signaling the liver to prepare for the incoming nutrients. Remarkably, the researchers found that the activation of POMC neurons alone is sufficient to induce changes in the liver mitochondria, even in the absence of actual food consumption. This research sheds light on the close relationship between sensory perception of food, adaptive processes in the mitochondria, and insulin sensitivity, which is crucial given the impaired insulin sensitivity in type 2 diabetes mellitus.
The lead author of the study, Sinika Henschke, highlights the speed at which the adaptation of mitochondria in liver cells occurs when exposed to the sensory perception of food. These organelles are essential for metabolism and energy production in the body. Jens Brüning, the head of the study and director at the Max Planck Institute for Metabolism Research, emphasizes the importance of understanding these mechanisms, especially in the context of type 2 diabetes mellitus. Brüning is also a research group leader at the CECAD Cluster of Excellence in Ageing Research at the University of Cologne and the Director of the Department of Endocrinology, Diabetology, and Preventive Medicine at Cologne University Hospital. This research reveals the intricate interplay between sensory perception, mitochondrial adaptation, and insulin sensitivity in response to food cues.
