Several iterations of Cheerios will go gluten-free, General Mills said Wednesday.

Gluten-free foods have become all the rage in recent years. You may ask, however, aren't Cheerios made of oats, which are naturally gluten-free?

Well, there's a small amount of wheat, rye and barley in the oats supplied to General Mills, gluten-bearing grains inadvertently introduced at the farm or in transit to the mill, the company says.

Golden Valley-based Mills says it has developed a way – "years in the making" – to sort the errant grains from the oats.

The five types of Cheerios that will be gluten-free beginning in July are: Honey Nut, Multi-Grain, Apple Cinnamon, Frosted and the original yellow-box version. Only Multi-Grain Cheerios will be reformulated, with wheat and barley replaced by sorghum and millet.

General Mills markets its Chex cereals -- sans Wheat Chex – as gluten-free, turning Chex into one of its best-selling cereals in recent years.

People who suffer from celiac disease can't eat gluten, while others with celiac-like digestive symptoms also stay away from it. Together, they make up less than 10 percent of the populace.

But gluten-free diets have also become popular with people who believe they they'll lose weight or be healthier.

Proof is short for that contention. Still, food companies have gone to great links promoting gluten-free foods, to the point of trumpeting a lack of gluten in products even when they lacked gluten from the get-go.

Mills' move to gluten-free Cheerios is reminiscent of its decision early last year to make Cheerios without genetically-modified (GM) ingredients and label it as such.

Oats aren't grown from seeds that are genetically modified in the first place. But General Mills switched out the type of sugar and cornstarch in Cheerios, which were made from GM ingredients.

Some consumers online had been clamoring for GMO-free Cheerios before General Mills made the switch.