The role of short chain fatty acids in appetite regulation and energy homeostasis

Over the last 20 years there has been an increasing interest in the influence of the gastrointestinal tract on appetite regulation. Much of the focus has been on the neuronal and hormonal relationship between the gastrointestinal tract and the brain. There is now mounting evidence that the colonic microbiota and their metabolic activity play a significant role in energy homeostasis. The supply of substrate to the colonic microbiota has a major impact on the microbial population and the metabolites they produce, particularly short chain fatty acids (SCFAs). SCFAs are produced when non-digestible carbohydrates, namely dietary fibres and resistant starch, undergo fermentation by the colonic microbiota. Both the consumption of fermentable carbohydrates and the administration of SCFAs have been reported to result in a wide range of health benefits including improvements in body composition, glucose homeostasis, blood lipid profiles, and reduced body weight and colon cancer risk. However, published studies tend to report the effects that fermentable carbohydrates and SCFAs have on specific tissues and metabolic processes, and fail to explain how these local effects translate into systemic effects and the mitigation of disease risk. Moreover, studies have tended to investigate SCFAs collectively and neglect to report the effects associated with individual SCFAs. Here, we bring together the recent evidence and suggest an overarching model for the effects of SCFAs on one of their beneficial aspects: appetite regulation and energy homeostasis

The Parallel Power System as an Alternative to Revolution and Passivity

The idea of the parallel power system within the Shi’ite political thinking emerged during the 16th century. It was when worldly rulers offered the Shi’ite legal scholars influence in the judiciary, education and social care. In exchange they wanted religious legetimacy for their worldly power. The parallell power system was a compromise in Shi’ite political thinking. It was a third option between political passivity, quietism, and revolutionary ideas based on judicial and theological arguments. It was a compromise that found a model for cooperation with worldly power. This was a power distribution system that lasted in four hundred years, but was abandouned during the interwar period in early twentinth century. The abandounment of this compromise was one of the main reasons to the revolution in Iran in 1979.    The purpose of this chapter is to show how this compromise was formed, what theological and judicial arguments the Shi’ite legal scholars used to legimate their cooperation with worldy rulers who did not fullfil their ideal of worldly rulers, and how its abandounment led to the revolution in Iran. This chapter conclude with an overview of the religious criticism directed at the revolutionary model that replaced the parallel power system