Diabetes is a disease that has been well-known since ancient times, described 1500 years before the birth of Christ in the Ebers Papyrus, an Egyptian medical text. Modern doctors thought they knew how it manifested itself: when the pancreas had trouble processing insulin and, as a result, blood glucose (or blood sugar) became too high.
But in recent years, scientists have begun to look at the gut microbiome—the menagerie of bacteria, fungi, viruses, and other microbes that live in our gut and impact our health—for clues about how diabetes develops. A recent study in the journal Nature Medicine reports that diabetes may be driven by changes in the microbiome, and that the changes a body goes through when it develops the disease may even start there.
As the rate of diabetes continues to rise in the United States, the medical world continues to search for effective treatments for this debilitating disease. Patients with type 2 diabetes, for example, experience symptoms such as fatigue, thirst, frequent urination, tingling sensations, and regular infections. If left untreated, patients with type 2 diabetes can suffer kidney damage, eye damage, heart attacks and strokes.
“We are convinced that the changes observed in the gut microbiome occur first and diabetes develops later, not the other way around.”
For decades, doctors have treated diseases like type 2 diabetes with drugs like metformin and SGLT2 inhibitors or with insulin injections.
What this surprising new research suggests is that diabetes treatment may extend beyond the blood or pancreas, focusing instead on the microorganisms that reside in our guts.
“Although our study is primarily hypothesis-generating and cannot be considered direct evidence for causal inference, our detailed analysis (including extensive sensitivity analyses) confirms that our findings on the microbial characteristics of diabetes are unlikely to be due to reverse causality, that is, pathological changes in diabetes cause microbial changes,” Dr. Daniel (Dong) Wang told Salon.
The study he co-authored includes the largest and most diverse analysis of gut microbiomes ever conducted for people with type 2 diabetes (T2D), prediabetes, and healthy glycemic status. In the process, researchers at Brigham and Women’s Hospital, the Broad Institute of MIT and Harvard, and the Harvard TH Chan School of Public Health discovered both specific viruses and genetic variants in specific bacteria that correspond to the risk of T2DM.
“Therefore, we are confident that the observed changes in the gut microbiome occur first and diabetes develops later, not the other way around,” Wang said. “However, future prospective or interventional studies are needed to firmly prove causality.”
That said, there are some things that researchers have determined for certain. First, there are 19 phylogenetically diverse species of microorganisms living in the human intestines and associated with T2D, including enriched microorganisms. Clostridium bolteae and exhausted Butyrivibrio crossotus. Furthermore, “our study identifies within-species phylogenetic diversity for strains of 27 species that explain inter-individual differences in type 2 diabetes risk, such as Rectal eubacteria“, explain the authors.
Perhaps the study’s most important contribution to understanding type 2 diabetes is that it clearly establishes that different species of microbes are linked to different levels of diabetes risk. Although scientists have yet to establish precisely Why These microbes are associated with diabetes, just knowing for sure that this is the case is an important first step. Think of it as a kind of police patrol: it will be easier to determine the causes of diabetes in the future if we know what potential “criminals” look like.
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“These results lay the foundation for future mechanistic studies. »
“Different microbial strains, even within the same microbial species, are associated with different diabetes risks,” Wang said. “Differences in the association can be explained by different genetic constitutions and, therefore, functions of the strains.”
When medical researchers apply the results of the latest study, Wang believes they can use microbial characteristics as biomarkers to help patients predict their risk of developing diabetes. That’s just the beginning.
“If future mechanistic studies can confirm that specific microbial strains are linked to diabetes risk, we could develop intervention measures, such as dietary supplements or pharmacological approaches targeting specific microbial strains to prevent and treat diabetes,” Wang said.
Recent years have seen an explosion of research into the human gut microbiome. Scientists have discovered the gut-brain axis, in which the gut biome helps control our cravings and may also be linked to neurological diseases. Technologies such as fecal transplants are being considered to treat diseases such as ulcerative colitis and, of course, diabetes. In addition to helping us fight disease and decide what we eat, the gut microbiota is also thought to play a vital role in helping humans digest foods that their digestive tract cannot digest on its own.
“Evidence suggests that gut microbes and their human host share much of the same metabolic machinery, with bacteria influencing the dietary components and the amount of energy their human host is able to extract from its diet,” the Institute of Medicine (US) Food Forum said in 2013. “What we eat and drink, in turn, influences the microbiome, with significant implications for disease risk. This growing understanding of the role of diet in microbiome-human interactions is driving interest and investment in probiotic and prebiotic food products as probiotic and prebiotic food products mean helping to build and maintain health.”
In this regard, Wang suggests that the new Nature Medicine study could truly pave the way for new ways of understanding the human gut microbiota.
“These results constitute the most comprehensive evidence to date of the involvement of the gut microbiome in the pathogenesis of type 2 diabetes, from a population study perspective,” Wang said. “These results lay the foundation for future mechanistic studies. Additionally, we provide a more nuanced understanding of the biology and pathogenicity of microorganisms by studying the genetic composition and characteristics of microbial strains, bringing us one step closer to causation. Our results provide evidence for the potential functional role of the gut microbiome in the pathogenesis of type 2 diabetes, and highlight the identification of taxonomic and functional biomarkers for future diagnostic applications. »
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