Microbial biomarkers for type 1 diabetes may be present in infants as young as 12 months old, suggesting the potential to mitigate disease onset by nurturing a healthy gut microbiome early, show data from the Swedish general population.
“Our findings indicate that the gut of infants who go on to develop type 1 diabetes is notably different from healthy babies,” said Malin Bélteky, MD, from the Crown Princess Victoria’s Children’s Hospital, Linköping, Sweden, who jointly led the work, which was recently published in Diabetologia, alongside Patricia L. Milletich, PhD candidate, from the University of Florida, Gainesville.
“This discovery could be used to help identity infants at [the] highest risk of developing type 1 diabetes before or during the first stage of disease and could offer the opportunity to bolster a healthy gut microbiome to prevent the disease from becoming established,” added Bélteky.
Currently, beta-cell autoantibodies are used to predict disease, which are usually only identifiable between 9 and 36 months of age.
Marian Rewers, MD, PhD, professor of pediatrics & medicine, University of Colorado School of Medicine, Denver, and principal investigator of The Environmental Determinants of Diabetes in the Young (TEDDY) study, welcomed the findings, saying it is a well-designed study from a strong group of investigators.
“While the effective number of cases was very small [n=16], the results were apparently adjusted for multiple comparisons, and significant differences were noted in the microbiome of cases versus controls at 1 year of age. This was 12 years prior to the average age of type 1 diabetes diagnosis in the cases,” he said.
“The differences in diversity and abundances of specific bacteria need to be interpreted with caution; however, the study results are consistent with several previous reports,” he noted.
Differences in Microbial Diversity and Function
Data were drawn from children participating in the longitudinal, general population All Babies In Southeast Sweden (ABIS) study. Microbiota from stool samples, taken at age 1 year, were sequenced and analyzed to establish diversity, abundance, and functional status of the component bacteria. Questionnaires were completed at birth and at 1 year of age, allowing for the study of environmental factors that might influence the microbiota or type 1 diabetes risk independently. Parent diaries provided information on pregnancy, nutrition, and lifestyle factors.
Of the cohort of 167 children who developed type 1 diabetes by 2020, stool samples were available for 16 of these participants, which were compared with 268 healthy controls. The microbiomes of the 16 infants who later developed type 1 diabetes were compared with 100 iterations of 32 matched control infants (matched by geographical region, siblings at birth, residence type, duration of breastfeeding, and month of stool collection) who didn’t develop type 1 diabetes by the age of 20.
Specific bacteria found in greater abundance in children who later developed type 1 diabetes, compared with those who didn’t, included Firmicutes (Enterococcus, Gemella, and Hungatella), as well as Bacteroides (Bacteroides and Porphyromonas), known to promote inflammation and be involved in the immune response.
Bacteria with greater abundance in children who didn’t develop type 1 diabetes, compared with those who did, were Firmicutes (Anaerostipes, Flavonifractor, and Ruminococcaceae UBA1819, and Eubacterium). These species help maintain metabolic and immune health and produce butyrate, an important short-chain fatty acid that helps prevent inflammation and fuels the cells of the gut lining.
Alistipes were more abundant in infants who didn’t develop type 1 diabetes, and various abundances of Fusicatenibacter were the strongest factors for differentiating future type 1 diabetes, reported the researchers.
“Gut microbial biomarkers at 12 months would benefit the prediction opportunity well before the onset of multiple autoantibodies,” write the authors.
The youngest age at type 1 diabetes diagnosis was aged 1 year, 4 months, and the oldest was aged 21 years, 4 months. The mean age at diagnosis was 13.3 years.
The microbial differences found between infants who go on to develop type 1 diabetes and those who don’t also shed light on interactions between the developing immune system and short-chain fatty acid production and metabolism in childhood autoimmunity, write the authors.
Prior studies have found fewer short-chain fatty acid-producing microbiota in the gut of children with early onset autoantibody development. This study confirmed these data, finding a decrease in butyrate-producing bacteria (Anaerostipes, Flavonifractor, Ruminococcaceae UBA1819, and Eubacterium) in infants who went on to develop type 1 diabetes. Likewise, a reduction in pyruvate fermentation was found in those infants with future disease.
According to co-author Eric Triplett, PhD, from the University of Florida: “The autoimmune processes usually begin long before any clinical signs of disease appear, highlighting how differences in the make-up of the infant gut microbiome could shed important light on the complex interaction between the developing immune system, environmental exposures in childhood, and autoimmunity. Studies with much larger cohorts of prospectively traced individuals will be required to establish which are the strongest biomarkers and how effectively they can predict disease.”
Diabetologia. Published online March 25, 2023. Abstract
The authors and Rewers have reported no relevant financial relationships.
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