Researchers say diet plans should consider gut microbiome and lifestyle instead of just types of food.
It’s not what you eat but how your body reacts to it.
That’s the message from a group of researchers who looked at the best diets for glycemic response. The findings could be beneficial to people living with diabetes.
The Mayo Clinic scientists found that people can respond differently to similar foods due to their gut microbiome — the groups of bacteria that exist in the digestive system.
Being able to predict how a person’s blood sugar responds after eating based on these factors could be beneficial for those living with diabetes.
“Diabetes is a big problem worldwide, and it seems that it may get worse if efficient approaches aren’t created to better control blood sugar,” Helena Mendes-Soares, PhD, a research associate and assistant professor of surgery at the Mayo Clinic in Rochester, Minnesota, and lead author of the study, told Healthline. Some approaches exist, but they have variable efficacy.”
“A previous study used a model to predict the glycemic response of individuals to foods, but it was done in a group of Israeli participants, so it was unclear whether their initial findings could be applied to other populations with different genetic backgrounds and nutritional behaviors, for instance,” she said. “We show that the same approach can be applied to our cohort, which had some differences in relation to the Israeli cohort.”
In their research, Dr. Mendes-Soares and colleagues examined 327 people for 6 days.
Genetic sequencing of the gut microbiome of each participant was possible through stool samples. Those participating in the study ate bagels with cream cheese for breakfast, then ate what they liked for the rest of the day.
They were asked to keep a diary of how much food they ate and how much exercise they had. They also wore a monitor that tracked how their blood sugar varied in response to foods eaten.
The goal of the research was to develop a model that could accurately predict how a person’s blood sugar would respond to food. The researchers accounted for age, lifestyle, and unique microbiome.
The scientists found their model was able to accurately predict glycemic response to foods 62 percent of the time. Predictions based on just carbohydrate intake were by contrast 40 percent accurate, while predictions based on calories alone were 32 percent accurate.
Although the individuals studied didn’t have diabetes, the findings could be useful for people living with the disease.
“Our work shows that for people without diabetes, when you take into account several individual factors, including their gut microbiome, rather than just the nutritional content of the foods consumed, their glycemic response is predicted better than when you just look at the carbohydrates or calorie content of foods,” Mendes-Soares said. “The microbiome is a big part of who we are as individuals, and, specifically for food, our microbes can be our collaborators or competitors, so this view needs to be integrated in studies and approaches trying to understand how we respond to the foods we eat.”
Blood sugar (glucose), which comes from food, is what the body uses as an energy source.
If a person has diabetes, their body doesn’t properly handle blood sugar. Managing diabetes involves trying to keep blood sugar levels in a safe range through balancing food intake with activity, lifestyle, and medication.
But predicting glycemic responses to foods can be complicated and differ for each person.
“We have many variables that affect glycemic response. Some of these factors include gender, ethnicity, degree of insulin resistance, capacity, and pattern of insulin secretion by pancreas, mixed meals, especially in the presence of fiber that slows gastrointestinal transit, fat in the meal, and metabolic rate. That’s why it’s a big puzzle that’s not easily solved,” Dr. Osama Hamdy, director of the Inpatient Diabetes Program at the Joslin Diabetes Center in Massachusetts, told Healthline.
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Diet plays a crucial role in managing diabetes by controlling the type and amount of blood sugar and carbohydrates going into the body.
“Controlling carbohydrate portions, emphasizing complex carbohydrates, consuming soluble fiber, and pairing carbohydrates with protein are all techniques that have been shown to control blood sugar levels well,” Lauri Wright, PhD, assistant professor in public health at the University of South Florida, told Healthline.
Generally speaking, there are basic diet recommendations that are healthy for all people, including those with diabetes. But experts say individuals should work with a professional to determine the most appropriate diet for them.
“Recommendations, like eating small portions, fresh fruits and vegetables with every meal, balanced meals, and avoiding fried foods are good for everyone, but if you’re trying to find out what’s best for you and would like to create a personalized meal plan, it is best to seek professional help,” Sandra J. Arevalo, a registered dietician and spokesperson for the Academy of Nutrition and Dietetics, told Healthline.
Most foods we eat are broken down into sugars and released into the blood.
If a person’s blood sugar increases, the pancreas releases insulin, which allows the blood sugar to go into the cells of the body to be used as energy.
In a person with diabetes, the body is either not making enough insulin or isn’t using it properly. If cells stop responding to the insulin in the blood, or there isn’t enough insulin to begin with, blood sugar stays in the bloodstream and can lead to complications such as vision loss or kidney and heart disease.
Although managing food intake can be an effective means of controlling blood sugar levels, for many people it can also be challenging.
Sacha Uelmen, RDN, managing director of diabetes education and nutrition at the American Diabetes Association (ADA), says monitoring calorie and carbohydrate intake can be a burden at each meal for people living with the diabetes.
“Managing eating plans around carbohydrate intake, or volume of food, or calories can be effective for many people,” she told Healthline. “But for others, it may be a significant burden or task to manage with diabetes. A more effective approach would reduce the burden on the individual at each meal.”
Uelmen says an individualized approach to diet is appropriate when it comes to diabetes.
“Diabetes is a complex disease that affects each individual differently, from progression to symptoms to complications, and as such, the ADA’s recommendations are varied and should be tailored by a multidisciplinary healthcare team to meet each individual’s diabetes needs in tandem with all other health conditions they may have. There is no one-size-fits-all treatment or management plan for diabetes,” she said.
The Mayo Clinic researchers are just some of the many experts around the world examining the role gut microbiome may play in every aspect of health.
Mendes-Soares says understanding how the trillions of microbes in the digestive tract interact in the body will be an important factor in furthering our understanding of diseases such as diabetes.
However, experts say research into the microbiome is still evolving and people should be cautious of using any commercial microbiome products. Instead they should consult with their doctors.
“The use of microbiome analysis to guide diet is a potentially useful tool for researchers. At this time such a microbiome-based analysis is limited to research labs, and its benefits in research settings have been documented for only short-term use,” David Klonoff, MD, clinical professor of medicine at the University of California San Francisco and medical director of the Diabetes Research Institute at Mills-Peninsula Medical Center, told Healthline.
“For people who aren’t in a research study, using commercial microbiome products isn’t recommended at this point because much of the microbiome is poorly understood,” Dr. Klonoff said. “There’s great potential for wasting money on and being harmed by such products unless the product was scrupulously tested and reported in a peer review medical journal, and also approved for a specific indication by the U.S. Food and Drug Administration.”
In the future, Mendes-Soares is hopeful researchers can apply this type of model of predicting glycemic response in people with diabetes and prediabetes. She says being able to measure how clinical parameters change with personalized therapies for the condition would offer useful insights.
“I think in an era of personalized medicine, our work suggests that taking into consideration the features of individuals, including their microbiome profiles, can make a real difference in how successful an approach will be to prevent a disease like diabetes,” she said.