ESPE Abstracts

Mounting evidence indicates an intricate relationship between the gut microbiome (GM) and type 1 diabetes (T1D). Controlled experiments with non-obese diabetic (NOD) mouse model have demonstrated that the gut microbiome harbours both protective and harmful features that may influence the type 1 diabetes disease process. Common findings from human studies are, for example, that individuals who later developed T1D had increased abundance of Bacteroides spp. and decrease of bacteria producing short chain fatty acids (SCFAs). The DIABIMMUNE study found that Bacteroides spp. harboured immunologically silent forms of lipopolysaccharide (LPS) which, unlike immunostimulant E. coli LPS, did not protect NOD mice from T1D, suggesting that early exposures to LPS have important roles in immune system development and may also modify individual’s risk of developing T1D. SCFAs (acetate, propionate, butyrate) have multitude of benefits to the gut health that include protection from future diabetes in NOD mouse and improved glycaemic control in humans with T1D. Both epidemiological and metagenomic evidence from the TEDDY study suggests that neonatal probiotics may also alleviate T1D risk. While there is still much to learn about the differences between various probiotic strains, B. longum subsp. infantis (B. infantis) stands out. This strain has a unique ability to establish itself in the infant gut during breastfeeding, even if other bacteria colonized first. While B. infantis is ubiquitous in many non-western populations, its prevalence is currently low in many western populations – even though it has likely been historically more prevalent in western populations as well. It has therefore been hypothesized that early supplementation with B. infantis could provide protection against T1D but evidence is lacking. The gut microbiome also plays a role in the progression of T1D after the diagnosis. Data from humans with T1D link the gut microbiome composition with host glycaemic control and hint at the potential to use microbiome therapies to interfere with T1D progression, potentially slowing it down. Further research and experiments are crucial to pinpoint specific microbial strains, substances, and other microbiome features that relate to host responses and markers associated with T1D.