Type  1  diabetes  (T1D)  is  a  chronic  autoimmune  disease  targeting  insulin-  producing  pancreatic beta cells. T1D is a multifactorial disease incorporating genetic and envi-ronmental factors.

In recent years, the advances in high-throughput sequencing have allowed  researchers  to  elucidate  the  changes  in  the  gut  microbiota  taxonomy  and  functional capacity that accompany T1D development. An increasing number of stud-ies have shown a role of the gut microbiota in mediating immune responses in health and  disease,  including  autoimmunity.  Fecal  microbiota  transplantations  (FMT)  have  been largely used in murine models to prove a causal role of the gut microbiome in disease progression and have been shown to be a safe and effective treatment in in-flammatory human diseases. In this review, we summarize and discuss recent research regarding  the  gut  microbiota–host  interactions  in  T1D,  the  current  advancement  in  therapies  for  T1D,  and  the  usefulness  of  FMT  studies  to  explore  microbiota–host  immunity  encounters  in  murine  models  and  to  shape  the  course  of  human  type  1  diabetes.