Food poisoning is pretty common. The Centers for Disease Control and Prevention estimate that 48 million people are sickened from food-borne contaminants annually. The cases can be severe or even fatal; around 128,000 are hospitalized, and 3,000 die from their illnesses. One expert on food poisoning, Bill Marler, has decades of experience dealing with people who have gotten ill because of food, and he knows that some foods carry a much higher risk than others.
The latest health trend, raw water, is something Marler is definitely not interested in trying. Lots of uncooked foods are on his list, including raw oysters, sprouts, and uncooked flour. Although most people would think that eggs are the only danger from eating uncooked cookie dough (and they also pose a risk), around 50 people got sick from eating uncooked flour over the course of about a year.