Cardio Metabolic Health Congress – Official Blog

The Influence of Gut Bacteria on Diabetes Drugs

Newly emerging research seeks to investigate the effect of gut microbiota on the efficacy of type 2 diabetes drugs, suggesting that the composition of gut bacteria may illuminate why certain diabetes medications work for some people—and not others.

Estimates indicate that over 415 million people across the globe have type 2 diabetes, a statistic leading some scientists to refer to the condition as a “global pandemic.” While there is no current cure for diabetes, treatments and lifestyle changes can help those living with the disease. Yet pharmaceutical drugs for diabetes have varying rates of success, contingent on the form of administration, and results often vary from person to person.

The research, led by Hariom Yadav, PhD, an assistant professor of molecular medicine at the Wake Forest Baptist Medical Center in Winston-Salem, investigates one of the possible causes behind such varying success rates: the gut bacteria. Previous studies cited in the paper published by Yadav and colleagues demonstrate that the gut bacteria can “instigate” obesity and type 2 diabetes, and that people living with diabetes have an overall imbalance in the composition of their gut bacteria.

Moreover, as Yadav explains, there are some drugs for diabetes that are only effective when given intravenously, but not when delivered orally: leading him to believe that gut bacteria are critical in regulating how a person metabolizes drugs. “For example, certain drugs work fine when given intravenously and go directly to the circulation, but when they are taken orally and pass through the gut, they don’t work. Conversely, metformin, a commonly used anti-diabetes drug, works best when given orally but does not work when given through an IV.”

Based on these observations, the researchers sought to understand whether or not the composition of gut bacteria directly influences the efficacy of certain diabetes medications. Yadav and colleagues reviewed over 100 studies of rodents and humans, and published their findings in the journal EBioMedicine.

How the microbiome can influence drugs

The research focused on the ways in which the microbiome either enhanced or reduced the drugs’ effectiveness, finding that regulating the gut microbiome with drugs could help alter, enhance, or even reverse the success of drugs for type 2 diabetes. Yadav summarized the findings by stating: “We believe that differences in an individual’s microbiome help explain why drugs will show a 90 or 50 percent optimum efficacy, but never 100 percent…our review showed that the metabolic capacity of a patient’s microbiome could influence the absorption and function of these drugs by making them pharmacologically active, inactive, or even toxic.”

Nevertheless, researchers must conduct additional studies to “continue to decipher the interactions between the gut bacteria and diabetes drugs” in clinical practice and further applications. Yadav adds, “This field is only a decade old, and the possibility of developing treatments derived from bacteria related to or involved in specific diseases is tantalizing.”

The latest report from the Centers for Disease Control and Prevention (CDC) indicates that over 100 million adults in the United States are currently living with diabetes or prediabetes.

The Link Between Stress & Strokes

Clinical data has established a connection between stress and cardiovascular disease, identifying chronic stress as a risk factor for acute cardiovascular syndromes, which could potentially be included in risk assessments of cardiovascular disease in daily clinical practice: particularly given the increasing number of individuals with chronic stress.

An important study utilizing brain scans previously demonstrated the link between stress and heart attacks or strokes, confirming that people who have increased activity in their amygdala—often termed the ‘fear center’ of the brain—are at higher risks for cardiovascular disease. While stress can activate the amygdala, leading to extra immune cell production by the bone marrow, the arteries may become inflamed, leading to cardiovascular disease.

The study tracked the health of 293 adults for two to five years, during which 22 patients experienced a cardiovascular disease event, such as a stroke, heart attack, or coronary heart failure. Researchers found that those people with more active amygdalas were more likely to have a critically serious heart event over the next few years; additionally, they had more inflammation in their arteries, which ultimately leads to heart disease, and bone marrow activity that may be linked with blood clots. 

The link was strong, even when taking into account additional factors like smoking, lipids, diabetes, and hypertension. The subjects with higher activity in the amygdala developed heart attacks and strokes sooner than those who showed lower activity. The sub-study from Mount Sinai demonstrated that the subjects’ psychosocial stress level – assessed using a stress questionnaire – went hand-in-hand with amygdalar activity: measured with imaging.

The leader of the team, Dr. Ahmed Tawakol of Massachusetts General Hospital and Harvard Medical School, expressed that chronic stress could eventually be treated as an important risk factor for cardiovascular disease. The study also provides new insights into how to reduce stress-related cardiovascular diseases, which involve the heart or blood vessels, and are the leading cause of death and women around the world—according to the World Health Organization.

In the United States, more than one in three adults has at least one type of cardiovascular disease, and heart disease has been confirmed as the leading cause of death in the country. While smaller stress reduction studies have been promising, large trials are still needed to confirm that treating stress actually reduces heart attacks. In the meantime, it is reasonable to recommend stress reduction techniques to patients with higher stress levels, and an increased risk of heart disease. Controlling stress should be part of the dialogue between patient and physician, in addition to diet and exercise: when discussing strategies to combat cardiovascular disease.