Greetings

I've been making sourdough bread and pizza several times during the last 2 weeks to my 8y and 11y old kids. The 8y complained from diarhea several times, then recently started vomiting repeatedly till he started to faint. I had to take him to hospital. He still suffer from diarhea, and his brother (11y) started suffering from stomach pain and diarhea too.

I make my bread and pizzas from a sourdough starter that I made myself at home. Could that starter be the reason for this? I'm thinking, maybe, during the first stages of catching the wild yeast, some bad bacteria could have infected the culture and developed in the starter too?

Is wild yeast too strong or bad for kids, specially when it has that strong sour taste?

Personally, when I eat too much from my sourdough bakes, I kind of feel like vomiting, as a result of that sour taste left in my throat, specially in the morning after a late dinners.

Should I avoid baking with my sourdough starter? How can you tell if wild yeat is the only living thing in your starter?