In the 1980 sci-fi thriller "Altered States," Harvard Medical School professor Eddie Jessup (William Hurt) claims he entered an alternate physical and mental state by using drugs and an isolation chamber. Recently, researchers at Johns Hopkins University claimed that people altered the physical state of their intestinal biome, where trillions of bacteria live, by taking too many antibiotics during childhood.

When this antibiotic altered state happens, one result is excess weight gain. Here's how that works.

If your child has a bacterial infection (say, an ear infection) and takes an antibiotic to appropriately kill harmful, spreading microbes, there's collateral damage to good gut bacteria. And their loss can affect the way a person's whole biome breaks down food — a basic function of gut bacteria — and that can lead to weight gain. Young kids are the most susceptible.

After reviewing health data on over 163,000 children 3 to 18 years old, researchers found that kids' body mass index increased throughout teen years as their use of antibiotics increased. To be specific, the more antibiotics taken during childhood, the greater the teenage weight gain.

What should parents of a sick child do? First, don't insist that your doctor provide antibiotics when they're not appropriate — say, for a viral infection or a bacterial infection that will resolve on its own.

And if the doctor does prescribe antibiotics, make sure they're completely necessary. Then ask about taking an appropriate probiotic during and after that antibiotic use. That will help correct your child's altered state and restore biome balance.