100 million microbes live in our gut, affecting our metabolism, immune system, and even our mental health.
Molecular biologist and geneticist Dr. Francine marques has a special interest in whether intestinal bacteria can also affect hypertension. She is now conducting clinical trials to see if a high fiber diet can keep blood pressure within a healthy range.
Her research in mice has shown that dietary fiber, especially prebiotic fiber, "can prevent hypertension.".
Prebiotic fiber resists digestion until it reaches the large intestine, where it feeds bacteria "thought to be good for health," Dr. marques explained.
Microbial fermentation in the gut releases metabolites, small molecules called short chain fatty acids. Her research showed that if mice were fed these short chain fatty acids directly, their blood pressure would be lowered and their cardiovascular health would be improved.
The experiment was to test whether humans would respond in the same way.
"We provide people with a high fiber diet," she said. "But food also contains this fiber, which is rich in these metabolites. Participants will also receive a placebo because it is the gold standard design for clinical trials. "
For three weeks, twice a day, all participants were given food, including muffins, Felicitas and aloncini balls, developed by research chefs. These foods were tested to eliminate taste differences between foods rich in metabolites and those that were not.
"If the results are positive, we can try to reduce hypertension in a more natural way. "
The food was prepared by research chefs and volunteers in the Monash University kitchen. Dr. marques said they decided to add metabolites to the food instead of having participants swallow a powder, hoping it would encourage them to comply. Twelve untreated men and women with hypertension have participated in a three week trial. She hopes to recruit a total of 30 people.
"We do everything we can to make sure the food is delicious, delicious and of good quality," she said. Research chefs do very well. "
With funding from the heart foundation, preliminary research is possible. If the results are good, she hopes to have a larger trial.
"We know from epidemiological studies and a large meta-analysis that integrates a large number of small clinical trials, that fiber intake is usually associated with lower blood pressure," she said. "
In 2017, marques published a study suggesting that the type of fiber in the gut and its interaction with microorganisms may be responsible.
"If the results are positive, we can try to reduce hypertension in a more natural way," she said.
The trial was conducted on people aged 18 to 70 with a body mass index below 30. It does not include patients with intestinal diseases such as irritable bowel syndrome or abdominal disease, nor does it include vegetarians, because meat is included in the diet provided.
Participants "are hard to find because either people don't know they have high blood pressure or they are taking drugs," she said. Some volunteers are keen to avoid drugs because they can have side effects.
About 1/3 of Australians aged 18 or above are suffering from hypertension, and the incidence rate of hypertension increases with age. More than two-thirds of them do not take drugs. One reason is that they don't know they have this situation, which in most cases is asymptomatic, which is the so-called "silent killer".
Another reason is that diagnosis can be difficult - up to a quarter of patients have "white coat syndrome," in which their blood pressure readings suddenly rise in the doctor's office but stabilize in a more familiar environment. The other 20% are the opposite. They have "masked high blood pressure," and their readings are artificially lowered in a clinical setting.
If not treated in time, high blood pressure can lead to stroke, myocardial infarction, atherosclerosis of arteries and heart muscles, as well as kidney sclerosis, thereby reducing its function. It is the most common risk factor for cardiovascular disease.
After she was diagnosed with stage 3 ovarian cancer, Dr. marques said her research methodology changed - her condition had improved for four years.
"I'm a molecular geneticist, so my research is mostly in the laboratory," she said. "Cancer has changed the way I look at life. I hope my research can have more practical application and help people more directly. "
