Your next best diet may be based on the particular type of bacteria in your gut, and may help you lose weight and reduce the risk of disease.

Researchers at Sweden's Chalmers University of Technology have identified how some of the common bacteria found in our intestines interact during metabolism.

They have developed a mathematical formula that will predict how patients will respond to a particular diet based on the composition of their gut microbiome.

"This method allows us to begin identifying each individual bacteria type's metabolism and thus get a handle on the basic mechanisms in human metabolism," said Jens Nielsen, professor of systems biology at Chalmers and head of the research team.

The human digestive system can contain up to 1,000 different types of bacteria and other microorganisms, and there can be a wide difference in composition between individuals.
Recent research has found a connection between some diseases and the composition of the gut microbiome.

"This is clear as regards Type 2 diabetes, hardening of the arteries and obesity, for example," said Nielsen.

"There are also indications that the same might apply to depression and the body's ability to respond to various cancer treatments."

To discover how the microbiome operates, the gut microbiome was analyzed for a group of overweight patients.

All were put on a diet, and everyone lost weight.

However, in patients who had a gut microbiome low in diverse organisms, the researchers found substances that indicated health risks. The substances were also found in their blood and feces.

The diet didn't affect the health of patients who had greater biological diversity in their gut microbiome.

Using their modeling tools, the researchers were able to explain why both groups of patients reacted as they did to the diet.

"Amongst other things, we have been able to demonstrate that the intestines of the individuals with low-diversity gut microbiome produce fewer amino acids when they follow this diet," they wrote. "This is one explanation for the improved blood chemistry."

Nielsen believes the new findings will make it easier for physicians to identify overweight patients who are at higher risk of metabolic diseases, such as high blood pressure and diabetes, and who could benefit the most from dieting and losing weight.

"In the long term we might be able to add intestinal bacteria for patients whose metabolism does not function properly," says researcher Karine Clement.

Currently, probiotics, such as yogurt, are used to create a positive environment in the intestines.

"The next generation of probiotics will pertain more to adding bacteria that integrate directly with the existing gut microbiome and make a lasting change to the composition," Nielsen said.

The study was published in Cell Metabolism.