THE MICROBIOME AND RISK OF DIABETES

There is increasing interest in the role that the microbiome may play in our health. One area that is the subject of much recent research is the impact of our gut bacteria on glucose metabolism and risk of type 2 diabetes.

Many studies have shown differences in the gut microbiome between people with and without type 2 diabetes. A 2020 review found that the majority reported an association between particular groups of microbes and risk of type 2 diabetes, although the findings of which bacterial species were associated with diabetes risk varied between the studies.

There is also some evidence of an association between different microbial metabolites (substances produced when bacteria in the gut break down food) and type 2 diabetes risk. For example, an observational study of close to 5,200 Finnish men published in Diabetes Care, found that certain microbial metabolites were associated with an increased risk of type 2 diabetes and decreased insulin secretion and insulin sensitivity.

Exactly how and why gut bacteria play a role is still unclear but research suggests they may alter inflammation, gut permeability, insulin resistance, glucose metabolism, fatty acid oxidation and/or energy expenditure.
The association between our gut microbiome and diabetes risk is supported by a few intervention studies showing that dietary changes, taking certain probiotics and faecal microbiota transplant (FMT for short and otherwise known as a poo transplant) can lead to beneficial changes in glucose metabolism. However, much more research is needed before these become part of the recommended treatment for type 2 diabetes, particularly because the response to different interventions varies between individuals and FMT has several risks alongside potential benefits.

Another interesting area is the interaction between the gut microbiome and diabetes medications. Several animal studies have found that the combination of different diabetes medications and certain prebiotics or probiotics is more effective than taking the medication alone.

At the moment we don’t have enough evidence to be able to prescribe particular prebiotics or probiotics to prevent or manage diabetes, but this may be something we will see in the future. Indeed, several researchers have suggested that the future of treatment for type 2 diabetes will be personalised medicine based on an individual’s gut microbiome. In the meantime, there is evidence that you can build a healthy gut microbiome by eating a wide variety of plant foods including fruits, vegetables, legumes, wholegrains, nuts and seeds, and avoiding highly processed foods – changes we already know will benefit overall health, diabetes management and chronic disease risk.

Read more:

• Gurung and colleagues. Role of gut microbiota in type 2 diabetes pathophysiology. EBioMedicine. 2020
• Zhu and Goodarzi. Metabolites Linking the Gut Microbiome with Risk for Type 2 Diabetes. Curr Nutr Rep. 2020
• Vangipurapu and colleagues. Microbiota-Related Metabolites and the Risk of Type 2 Diabetes. Diabetes Care. 2020

Dr Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).

Contact: Via her website www.drkatemarsh.com.au