The TESSA study aims to understand how a pomegranate extract can change the production of compounds associated with increased heart disease risk.

The TESSA study team is looking for 40 people whose diets include meat to take part in the research study.

The compound of interest in the TESSA study is called trimethylamine N-oxide (TMAO), which is produced naturally in some people who eat meat.

Previous studies have linked a high production of TMAO with increasing a person’s risk of heart disease, but more research is needed to understand this link.

TMAO is formed in the gut from nutrients such as L-carnitine and choline, found in meat, fish, dairy, and eggs. During digestion, some of these nutrients make their way to the gut where gut microbes break them down. Some people produce high levels of TMAO, depending on the makeup of their gut microbiome.

At the Quadram Institute we have shown that naturally occurring compounds in pomegranate fruit, called ellagitannins, can reduce the production of TMAO precursors by the gut microbes.

In the TESSA study, researchers will look more closely at the difference between people’s gut microbes and the impact of pomegranate extract on how much TMAO they produce.

Participants in the study will be asked to follow meal plans and take capsules containing L-carnitine together with either a placebo or a pomegranate extract. This will allow scientists to compare the impact of a pomegranate extract on the gut microbiome and TMAO production.

To be eligible to take part in the study, volunteers must regularly eat four potions of meat per week at least two months before starting the study. They must also live within 40 miles of Norwich and have a body mass index (BMI) between 18.5 to 30 kg/m2.

Taking part in the study involves up to eight appointments at the Quadram Institute’s Clinical Research Facility. Blood, urine, and stool samples are taken during the study visits to allow researchers to learn how the body responds to L-carnitine and pomegranate extract, including the impact of these compounds on the gut microbiome.

The study is split into two phases and selected participants will be asked to complete the second phase. Participants will receive an inconvenience payment of £30 for completion of Phase I and an additional £320 upon completion of Phase II. During Phase II participants will also get meals provided by the study team.

Chief Investigator on the study Dr Paul Kroon from the Quadram Institute said: “In the lab we discovered that a pomegranate extract rich in ellagitannins can significantly reduce precursors of TMAO. Following these observations, we propose this human trial to find out if we can see the same effect in healthy humans.”

Principal Investigator Julia Haarhuis adds, “I am very excited to see how our observations from the laboratory can be translated into an intervention that may improve people’s health. If we indeed find that a pomegranate extract reduces TMAO levels in humans, this could potentially reduce the risk of heart disease.”

The study has been approved by the relevant Research Ethics Committee and will be carried out using the NIHR Norfolk Clinical Research Facility in the Quadram Institute, which is managed by the Norfolk and Norwich University Hospital.

The TESSA study is funded by the Wellcome Trust through the EDESIA Plants, Food and Health PhD programme.

Anyone interested in taking part in the study can find out more on our TESSA study webpage