Candida is a natural part of every human's internal ecosystem. Candida is a backup system against high blood sugar. When your normal insulin process is unable to lower Sugar from your blood, Candida picks up the slack. Candida only becomes a problem when it blooms to larger populations than it's supposed to stay at in our bodies, that's when it's referred to as Candidiasis.
That article is just trying to scare people so they can sell you their supplements:
"Candida is like a seven-headed dragon – nearly impossible to kill.
Q: Are there any “miracle cures” for Candida?
A: I came across something that actually does work with any kind of chronic Candida infection.
We sell it here.
One rare symptom of Candida albicans is Candida of the nails:
We sell a natural antifungal against nail fungus."
Excess Sugar may be the direct cause of Candidiasis, but it is not the root cause.
The root cause of Candidiasis is EXCESSFATS.
When foods are converted into glucose (sugar), it travels through the bloodstream to the cells. Insulin is then needed to allow the glucose to be absorbed into the cells. Insulin is like the key to open the cell's doors to allow glucose in.
When you eat too much fat, the fat starts coating all the cells and their receptor sites in your body which makes it harder for the insulin to do its job and any of the glucose that can't get into the cells remains in the bloodstream. High Sugar in your blood is dangerous, so your backup system (Candida) begins to eat all the excess sugar in the bloodstream. A side-effect of this is that the Candida population starts to grow in size, but soon returns back to healthy levels once all the excess sugar is gone.
The problem arises when people continually eat too much fat, that indirectly causes a constant supply of excess sugar in the bloodstream which keeps feeding the Candida, causing the population to bloom out of control and that is why Candida is "nearly impossible to kill," because even if you did start killing off the excess Candida population, a person's high fat diet will just keep indirectly fueling it.
It also doesn't help much when articles like that promote a high-fat diet that will keep indirectly fueling Candida:
"Managing chronic Candida
The Atkins diet is your friend in this case. I would recommend going easy on the butter and fat meat, and eat nuts, fatty fish and organic eggs instead."
Resources explaining why fat is what really causes illness like Candidiasis and Type II diabetes: