Type 1 diabetes (T1D), a lifelong autoimmune disease, is on the rise in adults and children. The disease is commonly associated with altered gut microbiota and reduced production of short chain fatty acids (SCFAs). SCFAs have many beneficial properties on the gut and immune system and are able to prevent diabetes in mice. A recent study explored a novel anti-T1D approach, a specially designed dietary supplement that could restructure the gut microbiota, boost the production of SCFAs, and change the human immune system across time. The study shows that after six weeks of supplementation, the patients’ stool and plasma concentrations of the SCFAs acetate, propionate, and butyrate were significantly increased. Circulating B and T cells and antigen-presenting cells developed a more regulatory phenotype during and post-intervention. Bifidobacterium longum and Bifidobacterium adolescentis abundance and vitamin B7 production were associated with the highest SCFA concentrations and with reduced HbA1c and basal insulin requirements indicating better glucose control. Although a placebo-controlled trial is necessary, the study is an example of a diet-microbiota-immunity axis, demonstrating how the human immune system may be modulated by an inexpensive and safe dietary supplement through changes in the microbiome and suggesting that dietary SCFA supplementation may be a helpful therapeutic strategy for T1D.