We and other scientists discovered that gut bacteria contribute to the development of type 1 diabetes. The varieties of gut bacteria in diabetic children and those at high risk of developing diabetes are very different from those of healthy individuals. Using an animal model of type 1 diabetes, we recently found that some of the gut bacteria share similar molecular markers with insulin-producing beta cells in pancreas. The presence of these bacteria can stimulate the autoreactive T cells to mistakenly attack insulin-producing beta cells. One group of these diabetes-inducing bacteria is called Fusobacteria. We found more Fusobacteria in diabetic mice and the number of Fusobacteria increased as mice approached onset of diabetes. We hypothesize that Fusobacteria are associated with human type 1 diabetes. If our hypothesis is correct, we may be able to use the quantity of Fusobacteria present in the gut to predict and monitor the time of diabetes development in individuals who are prone to the disease.

1. A Bacteria in the Gut may Predict Type
1 Diabetes
Ningwen Tai, Associate Research Scientist
Yale Diabetes Center

2. Heart and blood vessel
disease
Nerve damage
Kidney damage
Eye damage
Foot damage
Pregnancy problem
Diabetes complications
Type 1 diabetes (T1D)
Healthy
Insulin
Glucose
Diabetic
Immune cells
Pancreas
islet
XX
X

3. 5 million Americans are
expected to have type 1
diabetes by 2050, including
nearly 600,000 youth.
Prevalence of type 1 diabetes
The percentage of newly diagnosed cases
of T1D rose 21.2% from 2001-2009
American Diabetes Association 2016

4. Less than 50% of identical twins
develop type 1 diabetes
One twin develops diabetes while the
other does not.

5. HealthyDiabetic
Different gut bacteria composition between
diabetic patients and healthy controls
Gut bacteria

6. NOD - mouse model of human T1D
GUT
BACTERIA
TYPE 1
DIABETES

7. Type 1
diabetes
Autoimmune
response
Environment
(bacteria,
virus)
Genetics
(Genes)
Genetic and environmental factors
contribute to T1D development

8. Less Fusobacteria
Mimic peptide
Mimic peptide
Immune cells
Preliminary study: mouse
Lower diabetes
incidence
Higher diabetes
incidence
More Fusobacteria

9. Research plans -
1. Collection of human oral and fecal samples
from diabetic, high-risk and healthy individuals
2. Measurement of Fusobacteria in the collected
samples by two different methods - sequencing
and qPCR
3. Data analysis and evaluation

10. Research goal
To prove the increase of Fusobacteria is associated
with human diabetes development and provide a
better knowledge for early disease intervention.
1. Prevention: to find specific treatment for
eliminating diabetes inducing bacteria in order to
better prevent from diabetes development in high-
risk individuals
2. Cure: to modify diabetes inducing bacteria and
replace with “good” bacteria to treat diabetic
patients
Future applications