January 5, 2015

expert reaction to new study investigating pill given daily to obese mice that then stopped gaining weight

Researchers publishing in the journal Nature Medicine have reported that in mice, the activation of a receptor in certain cells improved a number of different metabolic outcomes such as weight. They suggest that this mechanism may be used for treatment of metabolic disorders and obesity.

Prof. Nick Finer, Honorary Professor, UCL Institute of Cardiovascular Science, said:

“There has been a huge increase in our understanding over the past years of how the gut is involved in regulating body weight.  We know that hormones are released in response to food that both stimulate insulin release and produce satiety. Changes in the bacteria that live in the gut have been linked to weight gain. The role of bile acids, synthesised in the liver and secreted into the gut to aid digestion, have become a focus for research in part because it seems that the efficacy of weight  loss surgery in part depends upon changes in bile acid metabolism and circulation.

“The researchers at the Salk Institute have shown that a chemical fexaramine that mimics how bile acids interact with gut receptors in mice,  reduced diet-induced weight gain, body-wide inflammation and liver  glucose production (important for controlling diabetes). The chemical also increased energy expenditure by converting ordinary white fat to brown fat – a tissue that can generate heat.  These findings are potentially of great importance to our basic understanding of how energy intake is balanced by energy expenditure, and  potentially as to why this system is mismatched in those who gain (or lose) excessive weight. In the long-term it also offers a new approach to potential treatment of human obesity. Mice however are not human and much work is still needed to see if the effects of fexaramine are the same in humans and to establish its safety.”

‘Intestinal FXR agonism promotes adipose tissue browning and reduces obesity and insulin resistance’ by Sungsoon Fang et al. published in Nature Medicine on Monday 5 January 2015.

Declared interests

None declared