Adding probiotics -- good bacteria -- to an infant's feedings in the first month of life may reduce the risk of type 1 diabetes for those genetically predisposed to getting the disease, new research suggests.
Supplementing with probiotics later in infancy didn't seem to confer the same benefit, the researchers noted.
"Early probiotic exposure during the first 27 days is associated with a decreased risk of type 1 diabetes among those who have the highest genetic risk of type 1 diabetes," said lead researcher Ulla Uusitalo, an associate professor in the department of pediatric epidemiology at the University of South Florida in Tampa.
However, Uusitalo noted that because of the study's design, the researchers "cannot make a conclusion about causality." But she stressed that the association was so strong, these findings warrant further study.
The study was published in the Nov. 9 issue of JAMA Pediatrics.
Type 1 diabetes is an autoimmune disease. It develops when the body's immune system mistakenly destroys the insulin-producing cells in the pancreas, according to JDRF (formerly the Juvenile Diabetes Research Foundation). This leaves people without enough insulin to meet the body's needs. Insulin is a hormone that helps cells use sugar from foods as fuel.
What triggers type 1 diabetes is unclear. A number of genes are suspect, but experts believe an environmental trigger also plays a role. One possible trigger is an imbalance in the bacteria in the gut (the microbiome) may help fuel the autoimmune attack, the researchers said.
To explore this idea further, the researchers looked at an ongoing prospective study from six medical centers -- three in the United States and three in Europe. The final study sample included nearly 7,500 children between 4 and 10 years old.
Blood samples were taken every three months from age 3 months to 48 months to detect signs of type 1 diabetes. Samples were taken every six months after that.
Parents completed questionnaires and food diaries to detail infant feeding and probiotic supplement use from birth to 3 months. Mothers provided information on their diets during pregnancy as well.
Probiotics are live bacteria thought to help maintain a healthy digestive system. In Europe, probiotic use is more common than in the United States, the study indicates. Babies received probiotics through infant formula or through a liquid dietary supplement, Uusitalo said.
"In general, probiotics are considered safe," Uusitalo said. "There are no reports that among healthy children there would be any adverse outcomes from probiotics."
The researchers found that probiotic use in the first 27 days is linked to reduced odds of type 1 diabetes by 60 percent for children with the highest risk of developing the disease. These children have the genotype called DR3/4, the study said.
Children without that genetic makeup didn't benefit from the early probiotics. And no one seemed to benefit from later probiotic use, the researchers said.
George Weinstock, from the Jackson Laboratory for Genomic Medicine in Farmington, Conn., said, "It was striking that the benefit was only seen when probiotics were administered in the first 27 days of life." He's the author of an accompanying journal editorial.
"This may be a safe and affordable treatment for babies at risk for type 1 diabetes. It requires confirmation and further study, but is encouraging at this point," he said.
Weinstock suggested that given early enough, the probiotics might help set up a healthy microbiome.
"One imagines that there is a window early in life when external microbes are entering the body and colonizing, and during this period, it may be possible to intervene or direct the assembly of the microbiome with probiotics," he said.
"It is also possible that autoimmune effects begin during this early window and that is a critical period to interfere with the deleterious activation of the immune response," Weinstock said.
So, should parents with a family history of type 1 diabetes start giving their babies probiotics?
"It's too early in the research to give any recommendations," Uusitalo said. But, she added, if you know your child is at higher risk, you might ask your child's doctor about supplementing with probiotics early in the baby's life.