Earlier diagnosis of gestational diabetes thanks to microbiota
Changes associated with gestational diabetes are present in the microbiota of pregnant women from the first trimester of pregnancy. This may lead to earlier detection and better care for mothers and their babies. 1
About this article
It is a long-lasting misconception that gestational diabète mellitus (GDM) is triggered in the second or third trimester of pregnancy. A recent study published in the journal Gut says otherwise. Changes in the gut microbiota linked to this sugar metabolism disorder may clearly appear as early as the first trimester, potentially opening the door to new predictive tools.
Nearly 400 pregnant women followed over several weeks
Researchers from Bar-Ilan University in Safed, Israel, recruited 394 women aged between 18 and 40 who were less than 3 months pregnant. The researchers collected stool samples to analyze their microbiota and blood samples to measure inflammation levels and various other parameters. The participants were then followed over several weeks. During this follow-up, 44 women developed GDM (11%).
Diabetes driven by microbiota-induced inflammation
By comparing their blood results to those of unaffected women, the researchers found that, as early as the first trimester, women with GDM had glucose regulation problems and higher levels of inflammatory messengers, particularly interleukin-6 (IL-6). Several studies have shown that, by promoting inflammation, IL-6 is involved in various forms of diabetes, including GDM.
In addition, a microbiota analysis showed alterations ( (sidenote: Dysbiosis Generally defined as an alteration in the composition and function of the microbiota caused by a combination of environmental and individual-specific factors. Levy M, Kolodziejczyk AA, Thaiss CA, et al. Dysbiosis and the immune system. Nat Rev Immunol. 2017;17(4):219-232. ) ) in some bacterial communities in women with GDM. There were also fewer short-chain fatty acids ( (sidenote: Short chain fatty acids (SCFA) Short chain fatty acids (SCFA) are a source of energy (fuel) for an individual’s cells. They interact with the immune system and are involved in communication between the intestine and the brain. Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). 2020;11:25. ) ) compounds produced by bacteria that lower inflammation and improve sensitivity to insulin (and thus blood sugar management).
By transferring the microbiota of women with GDM into mice with no microbiota, the researchers reproduced the symptoms of GDM, including the inflammation associated with increased IL-6, demonstrating that dysbiosis is indeed at play in the development of GDM.
A step towards more efficient predictive tools that detect GDM earlier?
Lastly, the researchers used a prediction model to find out which parameters were the most relevant for predicting GDM accurately and early. While data from the patient’s medical record (weight, height, history, blood sugar levels, etc.) gave the most accurate predictions, data from the microbiota strongly improved predictive accuracy.
Despite certain limitations, this study is a further step towards understanding GDM. It also opens the door to high-precision detection methods allowing better management of GDM and a reduction in the associated risks.
Excellent news given the increasing prevalence of the disease worldwide due to the surge in cases of excess weight and obesity.