Changes in gut microbiome burn fewer calories
Many anti-psychotic drugs induce weight gain. A new study conducted at the University of Iowa has concluded this may be due to alteration of the gut microbiome, changes in which have been associated with obesity. The researchers analysed the effects of the drug risperidone, an anti-psychotic drug that is commonly prescribed to adults and children as treatment for disorders including autism, bipolar, and schizophrenia. The researchers were building on previous knowledge that showed that risperidone increases weight in humans, however they did not know what the mechanism was, until now.
Using mouse models, they were able to measure changes in the gut microbiome that caused a reduction in resting metabolic rate. This shift eventually led to obesity in the risperidone mice, whereas the control mice had normal weight gain with age. The measurements were taken using a total calorimetry machine, which accurately measures energy intake, oxygen consumption, carbon dioxide output and heat production, that allowed the researchers to accurately determine the total energy changes of the mice and their metabolic rates. They were also able to repeat the results by faecal transplants from the risperidone mice to the control mice, proving that the weight changes were due to a microbiome change in the drug-using mice. The study as a whole suggests that manipulation of gut bacteria, and specifically the resting metabolic rate, may prove beneficial for patients undergoing risperidone treatment, but also for those suffering from obesity in general.