Did you know that bacterial composition in the gut is potentially modifiable at a young age? It has been established that early-life microbial composition plays a large role in shaping the immune system, and the disruption of the intestinal microbiota balance, also termed dysbiosis, is associated with several autoimmune diseases. Thus, an effective T1D prevention approach may be altering bacterial composition at an early age, and in turn establishing optimal intestinal microflora and immune maturation during early life.
Evidence from NOD mice:
- Lack of the gene MyD88 has a connection between the intestinal microbiota and the innate immune system.
- NOD mice carrying the susceptible T1D genes will likely develop diabetes, while MyD88-deficient NOD mice will not develop T1D under normal conditions.
- The protective effect in MyD88-deficient NOD mice resulted from the favorable alteration of gut microbial communities, suggesting the profile of the gut microbiome was determined by the innate immune system.
- Germ-free (GF) MyD88-deficient mice developed T1D, but when a bacterial consortium was orally introduced, T1D development in these mice decreased.
- This result indicates that interaction of the gut commensals with the innate immune system, a key factor regulating the pathogenesis of T1D.
Along with T1D, early life microbial composition may also be a predictor of obesity. Recent research findings have provided evidence that the early-life gut microbiome may help identify children who are at risk of obesity and/or T1D later in life.
- The first study examined the association between gut microbiota composition during the first two years of life and BMI at age 12
- The gut microbiota at ages of 10 days and 2 years had the highest correlation with BMI at age 12
- The gut microbiota at 2 years of age explained 53% of variation in childhood BMI
- The other study exploring whether the gut microbiome in early life could be a predictor of T1D found that:
- The gut microbiome of children who did not develop T1D later in childhood had a high amount of genes related to fermentation and short-chain fatty acid production, which have a protective role in metabolic conditions.
- Children who developed T1D had a gut microbiota rich in Bacteroides species with depleted levels of SCFA-producing bacteria.
These discoveries associating early-life gut microbiota composition with both obesity and autoimmune disorders, like T1D, are very important because there may be opportunities for early prevention strategies.
- Andreu PradosAndreu Prados holds a Bachelor of Science Degree in Pharmacy & Human Nutrition and Dietetics. Science writer specialised in gut microbiota and probiotics. “Early Life Gut Microbiome as an Obesity and Type 1 Diabetes Predictor.” Gut Microbiota for Health, 6 Apr. 2020, www.gutmicrobiotaforhealth.com/early-life-gut-microbiome-as-an-obesity-and-type-1-diabetes-predictor/.
- JF. Bach, L. Chatenoud, et al. “The Crucial Role of Early-Life Gut Microbiota in the Development of Type 1 Diabetes.” Acta Diabetologica, Springer Milan, 1 Jan. 1970, link.springer.com/article/10.1007/s00592-020-01563-z.
- Stanislawski, Maggie A., et al. “Gut Microbiota in the First 2 Years of Life and the Association with Body Mass Index at Age 12 in a Norwegian Birth Cohort.” MBio, American Society for Microbiology, 7 Nov. 2018, mbio.asm.org/content/9/5/e01751-18.
- Vatanen, Tommi, et al. “The Human Gut Microbiome in Early-Onset Type 1 Diabetes from the TEDDY Study.” Nature News, Nature Publishing Group, 24 Oct. 2018, www.nature.com/articles/s41586-018-0620-2.