How our children’s guts can affect their adult health


baby’s gut bacteria shape her health, and may partly explain rising rates of asthma, allergies and obesity.

It’s a modern medical mystery: Across the Western world, a growing number of people—especially children—are suffering from asthma, and nobody can really say why. In barely one generation, “we’ve seen rates triple or quadruple,” says Dr. Stuart Turvey, a professor of pediatrics at the University of British Columbia and B.C. Children’s Hospital. About one in five kids has asthma today. “It’s the No. 1 reason they’ll come to a children’s hospital, or miss school. It’s the No. 1 cause of physician billing for children in Canada.” Genes must predispose some people to this chronic lung disease, but Turvey’s research, published in the journal Science Translational Medicine, suggests that a baby’s gut bacteria play a critical role. Infants who acquire four specific types of bacteria by three months of age, he and his co-authors found, are actually protected from getting the disease. As the latest science shows, a baby’s gut bacteria will shape her health well into adulthood. Changes in the gut partly explain why conditions such as asthma, allergies and even obesity are seeing a staggering rise in the West.

As long as humans have existed, bacteria have lived in, on, and around us. Each of us is home and host to our own microbiome, a community of bacteria, unique as a fingerprint, which begins to establish itself from the moment we’re born, if not before. Babies acquire a big dose of bacteria as they pass through the birth canal, and fill out their microbiome during the first year of life or longer. (Some say colonization begins before birth: In 2014, U.S. scientists reported the discovery of a unique microbiome in the human placenta.) Gut bacteria provide nutrients and vitamins for growing babies by synthesizing vitamins or amino acids. And they help “train the immune system,” says Anita Kozyrskyj, professor of pediatrics at the University of Alberta, especially in crucial early months when immune cells are developing. But when something throws the microbiome’s development off course, the immune system can go haywire. A huge number of women receive antibiotics during or after childbirth, and they’re the most common drug prescribed to children. While many of these drugs are certainly necessary, they seem to be having unintended consequences. . .  reader_3