LONDON — The human microbiome contains trillions of microorganisms, which makes it difficult to study, said Tracy Shafizadeh, PhD, director of scientific communications for Evolve BioSystems, Davis, Calif.

The microbiomes of infants are not as complicated.

“Infants are actually born with an essentially sterile gut,” she said in an Oct. 1 presentation at the Future Food-Tech Summit, a virtual event. “They don’t have a microbiome to speak of yet.”

Evolve BioSystems researches the microbiome of infants, who for a short time have a food source of human milk or formula and nothing else. Evolve BioSystems offers Evivo (activated B. infantis EVCOO1-ActiBif), a probiotic powder clinically proven to restore the infant gut microbiome to its original, natural state, according to the company.

Many more variables come into play with the adult diet, but Evolve BioSystems’ research on infants could lead to knowledge on how to study the adult microbiome, including how humans metabolize food and how their immune systems work. About 70% of the immune system is in the gut, Dr. Shafizadeh said.

The pace of research on the human microbiome has accelerated, but much is still unknown.

“There have been so many publications over the last five years with the results kind of all over the place in terms of whether or not you can affect colonization of certain bacteria in the microbiome, whether those bacteria stick around for any length of time, whether they elicit beneficial effects in all of the subjects,” Dr. Shafizadeh said.

Formulating foods that benefit the microbiome requires correct timing, she said.

“You have to know the right bug (probiotic), and you have to get it the right food (prebiotic), and you have to administer it at the right time in the life cycle,” Dr. Shafizadeh said. “If you get those three things right, then the chances are you’ll be able to find a benefit for the microbiome.”

The right time refers to the correct time in the life cycle of the probiotic and not the time of day.

Dr. Shafizadeh said the microbiome was like an organ such as the kidney or the liver, but much less is known about the microbiome.

“If you had an organ in your body that was not functioning properly — like if your kidney or your liver or your heart were not functioning properly — you would have major health effects,” she said. “You would have major deleterious effects. It’s the same with our microbiome. We just don’t understand the microbial organ the same way that we understand the other organs in our body.”