Think of it: We are each a megalopolis – a dwelling place for trillions of microorganisms whose number, diversity and health have an enormous impact on our own. Our 10 trillion human cells actually depend upon the 100 trillion microbes colonizing our guts to extract energy from the food we eat, build our immune system, and defend us from foreign invader microbes.

Now scientists are researching the possibility that the right amount of the right microorganisms might also help prevent allergies in infants, improve metabolism in overweight people, reduce anxiety and depression, heal skin disorders, etc. However, research is in its early stages in all of these areas and scientists don’t yet understand how it all works or which species of ‘bugs’ in what numbers are necessary to produce the desired effects.

This hasn’t stopped business in probiotics from booming. They’re being added to all sorts of foods that don’t naturally contain them – so there’s no telling whether the micro-bugs advertised in your breakfast cereal are alive or dead upon delivery. “At some level, there’s more hype about probiotics than there should be," Dr. Patricia Hibberd, a professor of pediatrics and chief of global health at MassGeneral Hospital for Children in Boston told LiveScience. "The enthusiasm has gotten ahead of the science."

Nevertheless, the consensus remains that probiotics in the billions are good for your digestion. However, as always, the principle of ‘caveat emptor’ – buyer beware – is always in effect. Fortunately, there’s plenty of information available on the Internet to equip consumers with the knowledge they need to make wise choices for themselves and their families when it comes to buying or cultivating and ingesting these expensive and industrious little super-bugs.