Changes in the gut microbiome increase the risk of diabetes

Diabetes mellitus 2, the most common type of diabetes, It is related to a history of insulin resistance or “prediabetes”, in addition to poor dietary habits and a sedentary lifestyle, as well as hereditary factors. It is estimated that 12.3% of the Chilean population suffers from this disease.

But many People do not know they have it because they do not present clear symptoms as it is a disease that is generally asymptomatic. AND Since they do not show symptoms, patients do not go to the doctor.

However, some of the early symptoms are:

• Very thirsty.
• Urinating very frequently, even at night.
• Lose weight.
• Being very hungry, since at that late stage diabetes is already unbalanced.

But doctors and scientists are still not quite sure when exactly the disease begins. However, researchers have found that Specific species and strains of bacteria were linked to changes in gut microbiome function and a person’s risk of developing diabetes.

This is the largest and most comprehensive ethnic and geographic study to date on the gut microbiome of people with type 2 diabetes, prediabetes, and healthy glucose status.

The research, conducted by Brigham and Women’s Hospital, the Broad Institute of MIT and the Harvard T.H. Chan School of Public Health, found that Some specific viruses and genetic variants within bacteria generate changes in the function of the intestinal microbiome increasing the risk of developing the disease. The results of the study are published in Nature Medicine.

“The microbiome is highly variable across different geographic locations and racial and ethnic groups. If you only study a small, homogenous population, you’re likely to miss something,” study co-author Daniel Wang said in a statement. “Our study is by far the largest and most diverse of its kind.”

“The relationship between the intestinal microbiome and complex, chronic and heterogeneous diseases such as diabetes is quite subtle”said study co-author Curtis Huttenhower, a Ph.D., of Harvard Chan School of Health and Broad University. “Just as studies of large human populations have been crucial to understanding human genetic variation, so too are large, diverse populations necessary (and increasingly feasible) for detailed studies of microbiome variation.”

Diabetes affects approximately 537 million people worldwide. In illness, the body gradually loses its ability to effectively regulate blood sugar. Research over the past decade has linked changes in the gut microbiome (the collection of bacteria, fungi and viruses that inhabit our intestines) to the development of the disease.

However, previous studies on the gut microbiome and its role in diabetes have been too small and varied in study design to draw meaningful conclusions.

The study analyzed data from the newly formed U.S. Microbiome and Cardiometabolic Disease Consortium (MicroCardio) and included newly generated data and those originally captured during several other experiments, whichwhich cover a total of 8,117 metagenomes of the intestinal microbiome of ethnically and geographically diverse participants.

People included in the study had type 2 diabetes, prediabetes or no change in their blood sugar levels and came from USA, Israel, Sweden, Finland, Denmark, Germany, France and China.

“With this large-scale study, we asked two questions. One is: ‘What are the roles of the species and strains that make up the intestinal microbiome in type 2 diabetes? The other question is: ‘What are these microbes doing?“When we analyzed this data, we found a relatively consistent set of microbial species linked to disease in our study populations. Many of those species had never been reported before.”

To understand the role of these microbes in the gut, The team analyzed the functional capabilities of the species. Different strains of a microbial species can have varied functions, such as the ability to produce a specific amino acid. The team found that Certain strains had functions that may be linked to varying risk of developing diabetes.

One important functional difference they observed was that one strain of Prevotella copious (a common gut microbe that has the ability to produce large amounts of branched-chain amino acids, BCAAs) was more frequently observed in the gut microbiomes of diabetes patients. Previous studies have shown that people with chronically high blood levels of BCAAs are at increased risk for obesity and type 2 diabetes.

The researchers also found evidence suggesting that bacteriophages (viruses that infect bacteria) could be driving some of the changes they detected within certain strains of gut bacteria.

“Our findings related to bacteriophages were very surprising”“This could mean that the virus infects bacteria and modifies their function in ways that increase or decrease the risk of diabetes, but more research is needed to understand this connection,” Wang said.

In another analysis, the team studied a small subset of samples from newly diagnosed diabetes patients to assess microbiomes that were less likely to have been affected by medication use or a long-term high glucose state. Their results were similar to those of their broader findings.according to Wang.

“We believe that the changes in the gut microbiome cause diabetes″“Changes in the microbiome may occur first and diabetes develops later, not the other way around, although future prospective or interventional studies are needed to demonstrate this relationship firmly,” Wang said.

“If these microbial features are causal, we may be able to find a way to change the microbiome and reduce the risk of type 2 diabetes,” he added. “The microbiome is amenable to intervention, meaning it can be changed, for example, with changes in diet, probiotics or fecal transplants.”

One of the main limitations of the study is that, for the most part, it focused on patients’ microbiomes at a single point in time. Changes in the gut microbiome or disease status over time were not analyzed. Future studies that build on this work include studying this link over a longer period and examining strain-specific functions to better understand how they lead to diabetes.

“A benefit and a challenge of the human microbiome is that it is highly personalized”Huttenhower said. “The fact that each of us has very distinct microbial communities and microbial genetics means that very large population studies are needed to find consistent patterns. But once we do, “Individual microbiomes have the potential to be reshaped to help reduce disease risk.”

In our country, a survey established that 57% of patients were diagnosed late, That is, when they presented symptoms that the disease had already developed. This percentage It rises to 73% in the case of people between 18 and 29 years old.

An interesting fact that the survey revealed is that 43% did not know the exam or did not remember their results. Patients with diabetes generally know glycated hemoglobin as “the little accuser” because it shows how their glucose has been on average over the last three months and more accurately reflects the stability of the diabetes disease.

The measurement of the hemoglucotest (capillary blood glucose test), “Measuring the fingers is generally known but is associated with people who have already been diagnosed with the disease,” explains Sapiro.

The measurement of glycosylated hemoglobin in capillary blood is more recent and the general population is not yet aware of its usefulness.

Any patient with risk factors for type 2 diabetes mellitus, such as overweight, obesity, sedentary lifestyle, family history of the illness, You should go for preventive tests.

“Based on the results of these tests, the diagnosis, the treatment and the patient’s comorbidities, the patient will be scheduled for evaluation and follow-up at a specific time,” says Dr. Pinto.

Nowadays There are three ways to make the diagnosis:

1. Through the oral glucose tolerance test, in which a fasting blood glucose test is taken first and then an oral glucose load with 75g of glucose is taken, and another blood glucose test is taken 2 hours later.
2. Glycated hemoglobin, But for this we must have it certified for diagnosis, which is a huge gap, given that there are very few centers that have the necessary certification for this. And this is an area where we have to work to improve.
3. Through a random venous blood glucose exceeding 200 mg/dL in a patient with symptoms. “But in this way we are already arriving late to the diagnosis and a lot of damage has already been done, which is why active search in asymptomatic patients is so important,” says Sanhueza.

“If a person’s blood sugar is found to be 100 or higher, they should go to the health team to have these measurements taken and make a diagnosis,” explains the UT specialist.