The leading cause of blindness in American adults is diabetic retinopathy, progressive damage to blood vessels in the light-sensitive tissue at the back of the eye. Yet the source of this damage appears to lie in the belly — mainly a leaky small intestine that weakens the barrier between gut bacteria and the blood system, according to a study from the University of Alabama at Birmingham.
Blood from human subjects with Type 1 diabetes and a mouse model of Type 1 diabetes were used to explore mechanisms underlying diabetic retinopathy. The results show a way to possibly prevent, or even reverse, the eye damage.
Using the Akita mouse-Type 1 diabetes model, researchers gave the ACE2-producing Lactobacillus paracasei to the mice orally beginning at the onset of diabetes. This probiotic treatment prevented the loss of gut epithelial ACE2 typically seen in Akita mice, and importantly, it prevented intestinal epithelial and endothelial barrier damage. It also reduced the high blood sugar levels known as hyperglycemia.
The researchers also found evidence for several mechanisms that contributed to the ACE2-reduced gut barrier damage and ACE2-lowering of blood sugar.