Increasingly in recent years, gut bacteria have been implicated in metabolic health. Emerging evidence indicates that the composition and function of our gut microbiome are very important to the development of type 2 diabetes (T2D). This article explains the latest scientific evidence linking gut bacteria to risk for T2D and answers some commonly asked questions regarding this association.
There are trillions of bacteria, viruses, fungi, and archaea within the human gut. These microbes play a crucial role in digestion, metabolism, immune function, and even mental states. Thus, a balanced gut microbiome is instrumental to our health; however, an imbalance in the microbial community, known as dysbiosis, has been linked to most metabolic disorders including type 2 diabetes.
This research has demonstrated that the gut microbiome pattern in a patient suffering from type 2 diabetes differs from that of a non-diabetic patient. A meta-analysis in Diabetes Care (2022) came to the conclusion that in the majority of diabetic patients, there is lesser microbial diversity, with an abundance of pro-inflammatory bacteria and lowered beneficial strains. Such an imbalance can cause impaired glucose metabolism and insulin sensitivity.
Gut microbes ferment dietary fibers into short-chain fatty acids, including acetate, propionate, and butyrate. SCFAs have been shown to have anti-inflammatory actions and to enhance sensitivity to insulin. Researchers in a study published recently in Nature Metabolism (2023) indicate that individuals with the highest concentrations of SCFAs in their blood tend to show a reduced risk of type 2 diabetes. The authors conclude that a healthy microbiome that favors the production of SCFAs might therefore be a protective factor.
Chronic low-grade inflammation is a hallmark of type 2 diabetes. Research over the past few years has shed light on the role of gut bacteria in modulating the inflammatory process. Recently published in Cell Host & Microbe (2023), there are some gut bacteria that actually modulate the immune response to either up- or down-regulate inflammation. Thus, dysbiosis might be one of the causes for the inflammation seen in T2D.
Diet has a significant role in shaping the gut microbiome. According to a report published in The Lancet (2022), diet high in fiber and low in processed sugars positively contributes to beneficial gut bacteria. Conversely, a diet high in fat and sugar can contribute to dysbiosis and an associated increase in risk for T2D. Thus, dietary choices are critical factors in the maintenance of a healthy gut and preventing metabolic disorders.
Fecal Microbiota Transplantation (FMT) is an experimental therapy involving the intestinal microbiota of a healthy donor transplanted into a recipient. Initial studies have shown that FMT from lean, healthy persons improves insulin sensitivity and metabolic health in obese subjects. A study published in Nature in 2023 demonstrated that FMT could reverse some metabolic abnormalities in at-risk T2D subjects, yielding some therapeutic potential for gut microbiota manipulation.
Really, it is very complex and fast-evolving between gut bacteria and type 2 diabetes. The more research done, the clearer it becomes that a better-balanced gut microbiome is necessary for fighting chronic diseases such as T2D. By having healthy diets and lifestyles, each person can certainly do some positive steps towards having better gut health to reduce the risk of developing type 2 diabetes.
How would you contribute to the onset of type 2 diabetes in relation to gut bacteria?
The gut bacteria influence T2D through a variety of mechanisms, such as the production of metabolites that affects insulin sensitivity, modulations of inflammation, and impact on the gut barrier function. Dysbiosis leads to increased inflammation and impaired glucose metabolism, thereby contributing to the risk of T2D.
Can I manipulate my gut bacteria to reduce my type 2 diabetes risk?
Most importantly, nutritional and lifestyle changes can help to improve your gut microbiota. The diet includes high amounts of fiber, many fermented foods, low processed sugars, and regular exercise for a healthy balance in the gut.
Do probiotics have any kind of role to play in preventing type 2 diabetes?
Whereas a number of limited evidence indicate some probiotic strains could hold potential for optimizing metabolic health and improving certain elements of insulin sensitivity, research on the topic is still very much in its formative stages. Probiotics may not benefit everyone, and it is especially crucial to choose strains that have been researched for effects on metabolic health.
What can I do to determine whether my gut microbiome is healthy?
At present, there is no test which can predict the well-being status of gut microbiome, but symptomatology like bloating and irritable bowel movement, perhaps interlinked with chronic inflammation, may be indicative. However, proper consultation with a healthcare provider is essential in this regard as everyone has varied health situations.
Is there a genetic factor to the association between the gut microbiota and type 2 diabetes?
Yes, genetics could have been influencing the way people react to the presence of certain bacteria in the gut and, therefore the risk for developing diabetes and, thereby, be considered a predisposing factor. Genetic predisposition can influence the nature of the gut microbiome and some metabolic responses hence leading to the conclusion that personalized prevention and treatment approaches are called for.
Do drugs affect gut bacteria and susceptibility to diabetes?
Certain drugs, like antibiotics, can alter the gut microbiome and affect metabolic health. Some diabetes medications-including metformin-are thought to positively change the way the gut microbiota is composed. Talk with your healthcare professional about any concerns regarding prescription medications.