The impact of gastrointestinal surgery on the brain

Chih Kun Huang, MD

Since the time of Pavlov, the brain-body connection has been recognized in appetite stimulation and the physiology of eating. During the meal, constant interplay continues between the visceral organs and the central regulatory centers of the brain, and the simple activity of eating has been shown to activate complex neural networks and stimulate reward centers of the brain. In this century, obesity, has become “Health Bomb”, which attacks every city in the world, and Asia is not put as exception. And bariatric surgery has been proved to be clinically the most effective and economically viable for obese people compared to non-surgical interventions. Bariatric surgery not only proves its efficacy in marked long-term weight loss, also aids in achieving substantial improvement or remission of co-morbidities, attributed to metabolic derangement, including type 2 diabetes mellitus (T2DM), hypertension, hyperlipidemia, and obstructive sleep apnea. At present, most popular techniques of bariatric surgeries include Roux-en-Y gastric bypass, sleeve gastrectomy, and bilopancreatic diversion, which involving reconstruction of gastrointestinal tract. Recent studies showed that bariatric surgery can alter the patterns of neural activation in the mesolimbic reward centers in response to food. These changes were associated with a reduction in subjective appetite, and this highlights the importance of deciphering how bariatric surgery alters the communication pathways of the enteroencephalic endocrine axis. This axis is believed to be at the core of the physiologic regulation of human appetite, the process of nutrient intake, energy homeostasis, and human metabolism. A group of hormonal peptides facilitate the functions of this axis, and the following is a review of the key components of the enteroencephalic axis.

Here in this speech we will review the current evidence and mechanism how gastrointestinal surgery impact on the brain, in hormones, neural signals and receptors.