satiety tagged posts

Scientists have discovered a new role for bile acids: they curb appetite by entering the brain. Their findings provide new insights into the signals and mechanisms by which satiety is controlled and may have implications for treating obesity.

Our brain is usually well protected from uncontrolled influx of molecules from the periphery thanks to the blood-brain barrier, a physical seal of cells lining the blood vessel walls. The hypothalamus, however, is a notable exception to this rule. Characterized by “leaky” blood vessels, this region, located at the base of the brain, is exposed to a variety of circulating bioactive molecules. This anatomical feature also determines its function as a rheostat involved in the coordination of energy sensing and feeding behavior.

Several hormone...

Multiple sensors and multiple downstream effectors of gut sensory systems, using the L cell as an example

A team of scientists from King’s College London and Imperial College London tested a high-fat diet, containing a fermentable carbohydrate, and a control diet on mice and looked at the effect on food intake of those with and without the FFAR2 receptor.

The results showed that mice fed the diet containing fermentable carbohydrate were protected against obesity. This protection was lost however, when the FFAR2 receptor was not present. Indeed, those with the receptor showed an increase of 130% in the satiety inducing gut hormone peptide YY, as well as an increased density of cells containing PYY, leading to an increased feeling of fullness.

Lead author of the study, Gavin Bewick from King...

These are neurons (c-fos, green) in the rat central amygdala activated by E. coli proteins in stationary phase and surrounded by nerve terminals (calcitonin gene-related peptide, red) originating from anorexigenic brainstem projections. Credit: J. Breton, N. Lucas & D. Schapman.

Don’t have room for dessert? The bacteria in your gut may be telling you something. 20 min after a meal, gut microbes produce proteins that can suppress food intake in animals, reports a study. The researchers also show how these proteins injected into mice and rats act on the brain reducing appetite, suggesting that gut bacteria may help control when and how much we eat.

The new evidence coexists with current models of appetite control, which involve hormones from the gut signalling to brain circuits when we’re hu...