If you can't remember the last time you changed your sheets, drop everything and strip your bed.A new study is suggesting that if you aren't washing your sheets at least once a month (ideally once a fortnight), you could be sleeping alongside bacteria linked to a host of diseases such as pneumonia, gonorrhoea, and Lemierre's syndrome.The study byTime4Sleepsaw a member of the public sleep in the same bed sheets for a whole month, with researchers swabbing parts of the bed at the end of each week.Each swab was then sent to the Biology Development Centre at the University of Seville laboratory and tested.When they tracked the bacteria that was found back to the original source, they discovered it came from - warning gross - human skin, the oral cavity, and human stool.Jonathan Warren, CEO at Time4Sleep, said we should be changing out sheets at least every fortnight."Despite the accepted habit that you should change your clothes every day, there is significantly less attention paid to how often you should look to change your bed sheets," she said. "Given almost a quarter wait as long as a month, we decided to find out what meant for the hygiene of your bed."The results highlight how important bed hygiene is to us all. Look to change your bedding at least every fortnight. If you don't, you're likely sleeping in worse condition than a chimpanzee."The research comes in light of arecent surveythat discovered almost a quarter (24 per cent) of people in the UK only change their bedsheets every "three or four weeks."Microbiologist Philip Tierno has said previously that when you are sleeping, gravity draws everything from sweat, dribble, hair and skin cells into the sheets."The environment in that mattress becomes akin to a botanical park," Tierno told the New York Post, after asurvey revealed the average person changes their sheets once every 24 days."And what happens is, you kick up that material when you toss and turn in bed and you breathe in that material for eight hours or so at night and then you wake up with a stuffy nose or other issues."Excuse us while we go change our sheets and burn the old ones.Got a story tip? Send it to ant more lifestyle and celebrity news? Follow Yahoo Lifestyle on Facebook,Twitter and Instagram.Or sign up to our daily newsletter here.