Microbiome Bites May 2nd: Your Gut Microbiome Affects What You Eat and Can Protect Against Diabetes
1. The Gut Microbiome Protects Against Diabetes
Diabetes is a widespread and growing problem. It doubles a person’s risk of early death and is attributable to 1.5-5 million deaths per year.
It is well known that genetics, lifestyle and diet play a significant role in the development of type 2 diabetes. However, it is less clear what happens at the molecular level to link these factors to disease.
A new study published in the journal Scientific Reports, suggests that the gut microbiome may protect against the development of type 2 diabetes.
Scientists at the University of Eastern Finland have identified a bacterium living in the intestine that produces a metabolite called indolepropionic acid, which protects against type 2 diabete
In the study, researchers found that overweight participants that did not go on to develop diabetes had higher concentrations of indolepropionic acid in their blood than overweight individuals who did develop diabetes.
Indolepropionic acid promotes the secretion of insulin from pancreatic beta cells, which most likely explains the protective effect.
Additional research revealed that whole grain and dietary fiber-rich diets increased the indolepropionic acid concentration by encouraging the growth of certain types of bacteria in the gut microbiome.
Ultimately, the research suggests that to lower the risk of developing type 2 diabetes people should: lose weight, exercise more and adjust diet to include more whole grains, fruits and vegetables and cut back sugar and saturated fatty acids.
This is the first randomized, controlled study that shows type 2 diabetes can be prevented by lifestyle changes and reveals the mechanisms that form the basis of that protection.
2. How Your Gut Bacteria Tell You What to Eat
Scientists have known for some time that what we eat can change the balance of microbes in our digestive tracts. As the relative numbers of different bacteria change, they secrete different substances, activate different genes and absorb different nutrients.
However, those food choices are probably not your decision alone. You gut bacteria (gut microbiome) have been shown to influence diet, behavior, depression, anxiety, hypertension and a variety of other conditions.
Now neuroscientists at the Champalimaud Center for the Unknown in Lisbon have identified specific types of gut bacteria that help the host detect which nutrients are missing in food and then fine-tune how much of those nutrients the host needs to eat.
The research, published in the journal PLoS Biology, shows that after being fed a diet lacking an essential amino acid for three days, fruit flies will preferentially chose a food source that contains the missing amino acid.
When the researchers increased five different types of bacteria commonly found in the flies’ digestive tracts, they completely lost the urge to eat the food containing he missing amino acid
Surprisingly, the scientists found that the flies were still deficient for the amino acid – so the bacteria weren’t making it. Instead, the bacteria were transforming the food they received into new chemicals that tell the host (fly) that it can carry on without the amino acid. This chemical trick could overcome problems the amino acid deficiency would normally induce, such as inability to reproduce.
This effect only occurred with amino acids normally acquired through diet.
Although the study was conducted in insects, the researchers believe that this type of gut-brain communication could be a great way to develop new treatments for humans as a way to improve diet-related behaviors.