Eating a powdered food supplement based on a molecule produced by bacteria in the gut reduces cravings for high-calorie foods such as chocolate, cake and pizza and thus helps avoid weight gain, a new study has found.

Previous studies have shown bacteria in the gut release a compound called propionate when they digest the fibre inulin, which can signal to the brain to reduce appetite. 

However the inulin-propionate ester supplement releases much more propionate in the intestines than inulin alone. 
 

After drinking the milkshakes, the participants in the current study underwent a magnetic resonance imaging (MRI) scan, where they were shown pictures of various low or high calorie foods such as salad, fish and vegetables or chocolate, cake and pizza. 

Those who drank the milkshake containing inulin-propionate ester had less activity in areas of their brain linked to reward - but only when looking at the high calorie foods. 

These areas, called the caudate and the nucleus accumbens, found in the centre of the brain, have previously been linked to food cravings and the motivation to want a food. 

The volunteers also had to rate how appealing they found the foods. The results showed when they drank the milkshake with the inulin-propionate ester supplement they rated the high calorie foods as less appealing. 

In a second study, volunteers were given a bowl of pasta with tomato sauce, and asked to eat as much as they like. 

When participants drank the inulin-propionate ester, they ate 10 per cent less pasta than when they drank the milkshake that contained inulin alone. After drinking the milkshakes, the participants in the current study underwent a magnetic resonance imaging (MRI) scan, where they were shown pictures of various low or high calorie foods such as salad, fish and vegetables or chocolate, cake and pizza. 

Those who drank the milkshake containing inulin-propionate ester had less activity in areas of their brain linked to reward - but only when looking at the high calorie foods. 

These areas, called the caudate and the nucleus accumbens, found in the centre of the brain, have previously been linked to food cravings and the motivation to want a food. 

The volunteers also had to rate how appealing they found the foods. The results showed when they drank the milkshake with the inulin-propionate ester supplement they rated the high calorie foods as less appealing. 

In a second study, volunteers were given a bowl of pasta with tomato sauce, and asked to eat as much as they like.