Scientists were looking at the interaction between gut microbiota and diet on glucose metabolism.
Previous studies at the Sahlgrenska Academy and University of Gothenburg have shown microbiota is altered in type 2 diabetes and associated with obesity and cardiovascular disease.
In this latest paper 39 subjects ate barley kernel bread for three days followed by three days of white flour bread as a control.
Those who had a beneficial glucose response to the barley kernel bread had dominance of the bacteria Prevotella copri (P.copri) and more positive interactions between other microbial species in the gut.
By transferring the gut microbiota of these individuals to mice, they found P.copri had no effect on glucose tolerance in mice on a high-fat, low-fibre diet.
This suggests dietary fibres are important for P.copri colonisation and beneficial glucose metabolism.
“Our results also show that control of blood sugar is improved in mice supplemented with Prevotella if they are given a high-fibre diet. Our findings could lead to a combination product with Prevotella and fibre from grains,” Fredrik Bäckhed, professor and principle investigator at the Sahlgrenska Academy, said in a press release.
Asked about the importance of a fibre-rich diet, Bäckhed told NutraIngredients: “Fiber increases Prevotella in responders, but not non-responders. So yes, supplementing fiber-rich diet with Prevotella may do the trick for non-responders.”
Bäckhed also said other grains may be beneficial for glucose metabolism but may be mediated by other bacteria.
Bread with different fibres has attracted considerable interest and is a focus area at the Antidiabetic Food Center at Lund University which participated in the study.
Commenting in a press release, Professor Inger Björk from the university said: “It is incredibly exciting to see the link between the gut microbiota and various dietary fibers, which can help us develop more individualised dietary guidelines.”
The researchers are now planning further studies and hope to confirm if the gut microbiota can identify which individuals will respond to a specific diet.
Bäckhed told us: “This is an interesting and growing field that is still relatively young. However, by learning more about how the gut microbiota relates to dietary components will be essential for increasing our understanding on how the gut microbiota affects host metabolism.
"Such knowledge may pave the way for personalised therapeutic and preventative strategies to tackle diseases in humans.”
Source: Cell Metabolism
Published online ahead of print doi:10.1016/j.cmet.2015.10.001
“Dietary fiber-induced improvement in glucose metabolism is associated with increased abundance of Prevotella"
Authors: P. Kovatcheva-Datchary et al.