DOES THE MICROBIOME AFFECT THE RISK OF DEVELOPING TYPE 1 DIABETES?
The
number of people developing type 1 diabetes has increased significantly
all around the world since World War II, but incidence rates (number of
new cases in a year) vary amongst regions. It is most common in
Northern Europe, with Finland having the highest rate in the world, with
more than 60 new cases per 100,000 people per year. Surprisingly, there
is a 5- to 6-fold higher incidence of type 1 diabetes in Finnish
Karelia compared to Russian Karelia. Karelia is a region in Finland that
crosses into Russia. The border between Finnish and Russian Karelia
marks one of the sharpest boundaries in the standard of living and
health in the world.
The risk factors for type 1 diabetes are still not fully known or
understood and are the subject of ongoing scientific research.
Environmental factors (e.g., sunlight and vitamin D production) and
exposure to certain infectious diseases have been linked to the risk of
developing type 1 diabetes, but the research is not conclusive. There is
emerging evidence that the microbiome can affect the risk of developing
type 1 diabetes in genetically susceptible individuals.
Recently,
148 infants who were at risk of developing type 1 diabetes and living
in Finland and Russia were followed from birth to 3 years of age. Each
month, stool samples and laboratory assays were collected, and
questionnaires regarding breastfeeding, diet, allergies, infections,
family history, use of medications, and clinical examinations were
conducted. It was found that Finnish infants had a greater proportion of
Bacteroides species, whereas the Russians had more Bifidobacterium in
their stools. The nature and composition of different
lipopolysaccharides derived from the respective microbiomes determined
the level of immune activation in the infants. It is interesting to note
that it has also been found that the injection of an immunogenic
subtype of lipopolysaccharides from E. coli in to mice can decrease the
incidence of diabetes. More research is needed to determine if changing
the microbiome can decrease the risk of developing type 1 diabetes in
susceptible humans.
The gut microbiome composition within the first year of an
infant’s life is largely shaped by milk, the sole nutrient source
available to infants, whether from breast- or bottle-feeding. After
that, foods and drinks consumed have an increasingly large impact.
Traditional Russian Karelian cuisine has been developing for centuries
and incorporates a variety of local foods including fish (lake), wild
mushrooms, berries and honey. Milk and dairy foods are popular, along
with bread made from barley, rye or oat flour. Meat is traditionally a
winter dish and is not eaten every day. Drinks include bread and turnip
“kvas” (In Russian “kvas” means mildly alcoholic drink made from
fermented rye bread, yeast or berries) and teas from wild raspberries
and currants.
While we are unable to prevent type 1
diabetes at this point in time, research into our microbiome may help
certain at-risk individuals prevent it in the future. Stay tuned.
Read more:
- The emerging global epidemic of type 1 diabetes.
- Hunt for the origin of allergy - comparing the Finnish and Russian Karelia.
- Environmental risk factors for type 1 diabetes.
- The Role of the Intestinal Microbiome in Type 1 Diabetes Pathogenesis.
- The Karelia study of type 1 diabetes.
- Russian Karelian cuisine.
Alan Barclay, PhD is a consultant dietitian and chef (Cert III). He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of more than 30 scientific publications, and author/co-author of The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).
Contact: You can follow him on Twitter or check out his website.
