A diet high in fiber may provide relief for people suffering from type 2 diabetes, researchers have found. Promoting the growth of certain kinds of gut bacteria improved blood glucose control in people with the disease. It also led to weight loss and improved lipid levels, reported researchers at Rutgers University-New Brunswick. The study is the product of a six-year study, which has been reported in Science.
The connection between human health and the community of microbes that resides in our gastrointestinal tract is well-established at this point, but many of the details and physiological mechanisms underlying that relationship are unknown. This study helps reveal more about the impact of a specific bacterium on one disease and reinforces the importance of the relationship.
"Our study lays the foundation and opens the possibility that fibers targeting this group of gut bacteria could eventually become a major part of your diet and your treatment," said the lead author of the work, Liping Zhao, a professor in the Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences at Rutgers University-New Brunswick.
Type 2 diabetes is a common disease that affects people all over the world. It happens when the body, or specifically, the pancreas, can’t make enough insulin or doesn’t use it normally, and the regulation of glucose levels in the blood is disrupted.
Short-chain fatty acids are produced when carbohydrates get broken down by bacteria that live in our gastrointestinal tracts. Those fatty acids can help control appetite, reduce inflammation and nourish the cells that line the gut; low levels have been linked to disease, including type 2 diabetes. While clinical studies have connected fiber and type 2 diabetes, there is not a comprehensive understanding of the how the relationship works, and therefore, it can be difficult to maximize the benefits to every patient.
This project aimed to fill in some of the blanks in our knowledge; it followed type 2 diabetes patients in China that were given a drug, acarbose, to control blood glucose, as well as patient information. But one group also increased their dietary fiber intake, including whole grains, prebiotics, and traditional Chinese foods that were rich in fiber. After twelve weeks, the group given a lot of fiber showed an improved reduction in glucose levels in the blood, and they had lost more weight.
The research team found that of 141 strains of bacteria that produce short-chain fatty acids, only fifteen are driven to multiply by increased fiber consumption, leading the researchers to conclude that they are most relevant to the health improvements. They also became dominant in the guts of study participants, with a resulting increase in levels of butyrate and acetate, short-chain fatty acids. A mildly acidic environment was created in the gut by those acids, lowering levels of detrimental bacteria as well as increasing the production of insulin, leading to better control of blood glucose.