Obesity, often caused by eating a lot of fat and sugar with little physical activity, is known to be a major factor in the development of type 2 diabetes. However, some obese people do develop the disease, which affects millions of people worldwide. It turns out that gut bacteria play a role.
Andrey Morgon and Natalia Chulzenko of Oregon State University and Giorgio Trencheri of the National Cancer Institute have developed a new analytical technique, Multi-Organ Tissue Analysis, to explore the mechanisms underlying early-stage systemic insulin resistance.
The results, published in the Journal of Experimental Medicine, show that certain types of gut microbes give rise to white adipose tissue containing macrophages, large cells that are part of the immune system, linked to insulin resistance.
In the human body, white adipose tissue is the main type of fat.
Morgon, assistant professor of pharmaceutical sciences at Cairo University, said: “Our experiments and analyzes predict that a high-fat/sugar diet acts primarily on white adipose tissue by inducing microbial-associated damage in energy synthesis, leading to systemic insulin resistance”. OSU Faculty of Pharmacy.
“Therapies that modify the patient’s microbiota by targeting insulin resistance in adipose tissue macrophages could be a new treatment strategy for type 2 diabetes,” he added.
The human gut microbiome contains more than 10 trillion microbial cells from nearly 1,000 different bacterial species.
“The so-called Western diet, which is rich in saturated fat and refined sugars, is a key factor. But gut bacteria have an important role in mediating the effects of the diet,” Shulzenko said.
Experiments in mice, looking at gut, liver, muscle and white adipose tissue, found that “adipose tissue has a dominant role in systemic insulin resistance.”
Furthermore, they found that serotonin, enriched in Western foods, caused an increase in macrophages in insulin-resistant adipose tissue.
However, the researchers add, Oscillibacter is likely not the only microbial regulator of the expression of the key gene they identified, Mmp12, and that the Mmp12 pathway, while clearly functional, may not be the only pathway of interest, depending on the gut microbiome. Present.
Previous studies have shown that another bacterial species “Romboutsia ilealis worsens glucose tolerance by suppressing insulin levels, which may be relevant to advanced stages of type 2 diabetes,” Chulzenko said.
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