With commentary by lead study author Ulla Uusitalo, Ph.D., associate professor in the department of pediatrics at the University of South Florida in Tampa.
“Early exposure to supplemental probiotics may decrease the risk of islet autoimmunity among children at elevated risk of type 1 diabetes,” said lead study author Ulla Uusitalo, Ph.D., associate professor in the department of pediatrics at the University of South Florida in Tampa. The research was published online November 9, 2015 in JAMA Pediatrics, ahead of print.
The researchers found that infants given probiotics—whether via drops or fortified infant formula—during the first 27 days of life were 60% less likely to develop type 1 diabetes-related islet autoimmunity (IA) compared with those given probiotics after 27 days or not at all. IA is a pre-clinical stage for onset of type 1 diabetes. Type 1 diabetes is diagnosed once the insulin-producing beta cells in the pancreatic islets are destroyed.
“These are exciting results, but we need more evidence about the association before we can conclude that probiotics be recommended as a preventive measure among the high-risk group,” Uusitalo said. The benefit was seen only in children with the greatest genetic risk of the disorder—those with the genotype DR3/4.
The findings are the latest from an ongoing trial involving six centers in Europe and the U.S. and ultimately included 7,473 children ranging in age from 4 to 10. Researchers checked for persistent islet autoimmunity in blood samples collected every three months between three and 48 months of age and every six months thereafter.
While the cause or causes of type 1 diabetes remain unknown, the condition is thought to evolve from interplay between genes and the environment. Growing evidence suggests that the gut may play a leading role.
Animal studies have shown that dietary interventions, changes in intestinal microbiota and exposure to pathogens can all increase the risk of type 1 diabetes. And evidence in humans suggests that both the absence and presence of certain types of bacteria in the gut can influence beta-cell autoimmunity and type 1 diabetes. Other data point to a link between abnormal functioning of the gut’s immune system and development of the disease.
Probiotics, meanwhile, are thought to affect immune response to a variety of environmental exposures by supporting heathy gut microbiota. Animal studies have shown that probiotics can manipulate gut microbiota and affect type 1 diabetes risk.
The World Health Organization has defined probiotics as live microorganisms which, when given in adequate amounts, confer a health benefit to the host. Probiotics are found in fermented foods with active live cultures such as sauerkraut, kefir and yogurt, and are also available as supplements.
While the authors of the recent study concede that the varieties and amount of microbes in the probiotics given to the newborns weren’t measured, the results are still considered significant.
“This is an example of precision medicine, where knowing the genotype of the individual tells you what treatment would be worthwhile,” said George Weinstock, Ph.D., of the Jackson Laboratory for Genomic Medicine in Farmington, CT, who wrote an editorial accompanying the study in JAMA Pediatrics.
The trial, known as the TEDDY study, was designed to identify environmental causes of type 1 diabetes. It began in 2004 and involves three centers in Europe (Finland, Germany and Sweden) and three in the U.S. (Colorado, Georgia/Florida and Washington).
Type 1 diabetes, formerly known as juvenile diabetes, is an autoimmune disease that occurs when the body’s immune system attacks and destroys insulin-producing cells in the pancreas known as beta cells.
The incidence of type 1 diabetes has been on the rise around the world over the last several decades and is particularly high in Finland and other Nordic countries. In the U.S., a recent study documented a steady rise in the incidence of type 1 diabetes among those 19 years old and younger. The greatest increase was seen in children 5 to 9 years old. The peak age for type 1 diabetes diagnosis in the U.S. is around age 14.