The rapid increase in cases of people with Type 2 Diabetes Mellitus (T2DM) has made it a widespread metabolic condition. It is well known that diabetes is influenced by genetic makeup and lifestyle. However, the new kid on the block, otherwise known as the microbiome, may also act as a potential and very important, modifiable risk factor. Genes in the human microbiome produce multitudes of compounds that can influence diabetes, including molecules of inflammation, hormones and neurotransmitters. Studies have shown associations both between the development of T2DM and its complications.
Gut microbiota associated with developing T2DM
The association between gut bacteria and obesity has been well established. The microbiota influences the calories that the body absorbs, and the bacterial group that generates more energy, known as Firmicutes, is found in high populations in obese individuals. Given the strong association T2DM has with obesity, it is not surprising that the microbiome also affects this disorder. T2DM is a condition very closely linked with abnormal energy metabolism and inflammation in fat tissues. These two factors have been found to be related to the presence of certain gut bacteria.
Furthermore, In T2DM, people are unable to process insulin properly, otherwise known as insulin resistance. Majority of the gut microflora are one of two types: Bacteroidetes and Firmicutes. In the case of T2DM, high ratios of the bacteria Firmicutes to Bacteroidetes have been found, compared to healthy people. These microbiota influence carbohydrate metabolism, and affect the production of short-chain fatty acids. Specifically, the production of short chain fatty acid, acetate is increased while butyrate is decreased. Low levels of this fatty acid may encourage low-grade inflammation and induce insulin resistance. In contrast, a recent study has found that increased acetate levels can also increase insulin resistance and appetite through the production of a the hormone, ghrelin. In people with T2DM, it has also been found that there is reduced gene diversity.
Why is gut inflammation a problem?
Gut inflammation can weaken epithelial tight junctions in the gut mucosa which helps the entry of bacterial endotoxins into the blood. This leads to increased activity of the immune system which can lead to insulin resistance and weight gain, and eventually T2DM. Accumulation of inflammatory molecules derived from gut-bacteria may intensify the inflammation in T2DM. This can result in a vicious cycle, where more inflammation causes more insulin resistance and vice versa.
Can food and nutrition help?
A recent study by De Filippo et al., compared the fecal microbiota of rural African children and European children. The diet of the rural African children mainly comprised of cereals, legumes and vegetables, while the European children mainly consumed animal protein, sugars, starch, fat and not a large amount of fiber. Essentially, the study compared a modern Western diet to a high-fiber, rural diet. Significant differences were found between the gut microbiota of the two groups. The rural diet showed large amounts of Bacteroidetes and less Firmicutes (remember these were the bacteria that shows up in high amounts in people with T2DM), in addition to large amounts of bacteria known as Prevotella and Xylanibacter, which didn’t exist in the children consuming a Western diet. Furthermore, the African children had a lot less short-chain fatty acids (which were shown in large amounts in people with T2DM). The study hypothesized that the gut bacteria in the fiber-rich diet, maximized energy intake from fibers and protects them from inflammations and disease.
Another study reviewed probiotics in the management of type 2 diabetes and found significant reductions in fasting blood glucose levels.
At DayTwo our goal is help individuals achieve balanced glucose levels through personalized nutrition recommendations based your individual health parameters and gut microbiome. We know that the composition of an individual’s microbiota plays a significant role in patients with T2DM. However, the jury is still out whether or not intestinal bacteria play a causal role in the development of T2DM or whether they are only associated with the disease.