Author: Sylvia Marinova, PhD student in in the "Genomic Stability" lab at BAS
Human health is strongly influenced by the trillions of bacteria that live in our digestive system bearing the common name intestinal microbiota. They are many species that coexist in a strictly defined balance. As amazing as it sounds to us, and even slightly frightening, we should be grateful to them because they perform a number of important functions for us.
Read more in the The Gut Microbiome and Our Health
For example, it is known these microorganisms modulate our immune system and any disturbance in their balance of communities increases the risk of developing various diseases. A link between many chronic diseases and the microflora has already been proven, such as inflammation, obesity and type 2 diabetes. There are studies in both model animals and humans that reveal differences between the microbiota of healthy organisms and those with type 2 diabetes [ref.1]. According to a new study from Oregon State University, four specific types of bacteria are particularly important in whether or not we develop type 2 diabetes [ref.2].
What is type 2 diabetes
Type 2 diabetes is the most common type of diabetes. It is a metabolic disease in which metabolism is impaired and blood glucose levels are increased due to decreased cell sensitivity to the hormone insulin. As a result, the body tries to increase insulin production, and over time this leads to a disturbance of the functions of the pancreas and the need to take insulin medicated.
Read more in All About Type 2 Diabetes.
The most significant risk factor for developing diabetes is obesity - which has also increased significantly in recentbdecades.The main reason for this is the change to a sedentary lifestyle, combined with the growing abundance of foods rich in saturated fatty acids and sugars - the so-called "Western diet"."t in turn leads to changes in the composition of intestinal communities, and hence follows one of the links of obesity with type 2 diabetes.
4 Types of Bacteria May Be Affecting Type 2 Diabetes
It is not entirely clear whether single bacterial species or complex changes in whole communities affect the development of type 2 diabetes, and there are studies to support both claims. The one that is the subject of this article falls into the first category.
With the help of a new methodology in systems biology, scientists at the State University of Oregon were able to predict the key species that they believe influenced the host's glucose and lipid metabolism. They analyzed a huge amount of data related to both the diversity of the microbiota and changes in metabolic parameters due to exposure to the "Western diet" in hosts, being able to predict 4 specific bacteria related to type 2 diabetes - Lactobacillus johnsonii, Lactobacillus gasseri, Romboutsia ilealis, and Ruminococcus gnavus.
Moreover, the method allows them to guess what effect they would have. Researchers believe that the first two species of the genus Lactobacillus have a positive influence in terms of glucose metabolism, and the second two - negative.
To confirm this hypothesis, the team conducted experiments on laboratory mice, which they put on a "Western diet". Model animals received a supplement containing bacteria from one of the two groups for eight weeks. The result confirms the assumption of the researchers. Mice supplemented with lactobacilli showed improved blood glucose tolerance. In contrast, mice supplemented with Romboutsia ilealis showed impaired glucose tolerance.
Sylvia Marinova has a BSc in Molecular biology (Sofia University, Bulgaria), and a MSc in structural biology (Grenoble, France). She is currently a doctoral student at the Laboratory of Genomic Stability at IMB, BAS. Her research interests are in the field of DNA repair, microscopy and biophysics. She loves photography, painting and sports.