We grow microbes and bacteria in glucose solutions.
Now in diabetes, the glucose uptake by cells decreases due to insulin resistance and this leads to accumulation of glucose in the tissues. The bacteria start growing and multiplying in the glucose rich tissue and produce various necrotic factors leading to the ulcer. The patient has neuropathy, that is he cannot feel pain. So these ulcers go unnoticed most of the time.
The ulcer heals all by itself if the glucose levels are maintained by appropriate treatment. The bright red granulation tissue at the base of the ulcer confirms that it is healing. The complications are -gangrene formation can occur. In this case, amputation of limb is the only way to prevent the gangrene from spreading.
So rather than losing a limb. It is better to take care of it right ?