Grim study suggests popular bedroom item has more bacteria than a toilet seat

An analysis that determined the cleanliness of bedding determined the dirtiest item in your bedroom are the pillowcases, with a whopping 3 million bacteria per square inch - that's 17,000 more than your toilet seat.

Researchers spent years looking at data for cleanliness data for mattresses, linens and pillowcases and managed to create a breakdown of exactly what kind of bacteria is lurking in beds.

According to the New York Post, "Allergens, fungi and dead skin are among the unsettling particles you wouldn’t want to cozy up with at night — and they can attract dust mites, microscopic critters that feast on sloughed skin cells."

Your pillowcases likely need to be changed more often than you think, as a new study shows just how much bacteria is on them (Getty Images)

So how often should you change your bedding?

The experts at Amerisleep said you should ideally be changing your sheets once a week, and your pillowcases every few days, as both harbor an extreme amount of bacteria that can actually make you sick.

"In our study, there were four main strains of bacteria that love to make sheets their new home. The most common kind (at over 41 percent) was gram-negative rods. These bacteria commonly cause pneumonia and other kinds of infections. Also, the majority of gram-negative rods are dangerous and can lead to antibiotic resistance, according to the CDC," write the study's authors.

"We looked into how the bacteria was distributed in bed sheets and pillowcases. Sheets had the most gram-negative rods (about 42 per cent) and gram-positive rods (almost 27 per cent). Pillowcases won first place for both bacilli (almost 25 per cent) and gram-positive cocci (almost 12 per cent). These infectious bacteria are the stuff of nightmares," the study continues.

Mattresses were also included in the study. It was determined that after 7 years of owning a mattress, it has more than 16 million CFU (colony-forming units) - compared to just 3 million when it's new.

If that's too much for you, be aware that you can disinfect your mattress regularly, which is highly reccomended by experts.

“When you get into bed, you contaminate your bed linens with dead skin cells (about 50 million per day), sweat, makeup, lotions, hair, and anything else you’ve picked up during the day, from pollen and pet dander to fungal mold and dirt particles to bacteria and viral particles as well,” Dr. Hadley King told Well+Good.

“Dead skin cells and sweat provide food for dust mites, attracting them to your bed and helping them multiply," Hadley continued.