Risperidone affects gut biome, spurs obesity

A drug that helps your mind may turn your gut microbes—and waistline—against you.

In a series of experiments in mice, researchers found that a common drug used to treat psychiatric illnesses, including autism and bipolar disorder, alters the gut microbial community. Those changes caused the mice to burn fewer calories while resting and gain weight, researchers report in EBioMedicine. The finding, which lines up with weight gain seen in patients, suggests that drugs other than antibiotics can easily mess with a person’s microbes, which in turn profoundly influence metabolism, weight, and overall health.

In the study, researchers led by microbiologist John Kirby of the University of Iowa gave mice water laced with the psychiatric drug risperidone. This drug is well-known to cause significant weight-gain, insulin resistance, and metabolic problems in people. Kirby and colleagues had a hunch that the hefty side-effects were linked to changes in the gut microbiome, but they were unsure of the exact mechanism.

In the study, the risperidone-drinking mice also gained weight—an average of 10 percent of their normal body mass in just two months. And when researchers sequenced the microbes in the mice’s poop, they found that the microbial communities in the animals’ intestinal tracts were dramatically altered.

By measuring energy intake, oxygen consumptions, carbon dioxide release, and heat production, the team found that the drug-dosed mice were burning fewer calories while resting and sleeping compared to normal mice. In fact, the drug-dosed mice were burning about 16 percent fewer calories. That would be equivalent to a person on a standard 2,000 calorie-a-day diet eating a McDonald’s cheeseburger everyday in addition to their normal diet, which would lead to about a 29-pound weight gain over a year, the authors note.

Interesting. I have been on risperdal injections for 6 years and my weight ballooned by over 4 stone(had put on 6 stone over 10 years- four of those taking zyprexa albeit erratically).
In July I went on a diet and was successful initially going from 239.6 to 230.8 in about 8 weeks. Then the weight crept up again and for the most part has hovered between 233-237 for most of the last 3 months(dropped to 232 on a couple of occasions).
Despite not going back up to my start weight I’ve managed to lose 6.5 lbs in 5 months based on today’s weighing.
Admittedly I have slacked off a little out of frustration but even when I was being conscientious the weight was not shifting after the initial success.
This would certainly explain why my attempts to lose weight have proved relatively fruitless.


I wonder about Latuda… Ive gained weight but on vacation and now i eat normal calories. I will watch out the next month January

This makes sense I put on allot of weight fast when put on meds.

I wonder if risperidone alter gut serotonin? That Gut Feeling With a sophisticated neural network transmitting messages from trillions of bacteria, the brain in your gut exerts a powerful influence over the one in your head, new research suggests.

1 Like