Fecal Microbiota Transplantation to Restore Residual Beta Cell Function In Patients With Long-Duration Type 1 Diabetes Mellitus

The incidence of Type 1 diabetes mellitus (T1D) has tripled in the last thirty
years, and T1D is associated with a lifelong increase of considerable morbidity
and mortality compared to healthy subjects. In fact, T1D diagnosed in childhood
leads to an almost 20 year loss of life-expectancy, more than most childhood
cancers. Notwithstanding decades of intensive research in animals, the
environmental factors driving T1D are still unknown and therapeutic strategies
have invariably failed to halt disease progression.

As the increased T1D incidence is primarily observed in subjects who are not
genetically predisposed, environmental factors including altered diet,
antibiotic use as well as mode of birth have been suggested to play a role, and
these factors have invariably been linked to changes in the gut microbiome.
Indeed, an altered composition of the fecal microbiota composition was observed
in adolescent T1D patients. Moreover, an increased amount of pathogenic
bacterial species has been observed in fecal samples of T1D patients at the
time of diagnosis. Interestingly, this altered fecal microbiota is already
present before the clinical onset of T1D and is related to islet autoantibodies.
Interestingly, non-obese diabetic (NOD) mouse studies suggested that
interaction of intestinal microbes with the innate immune system is a critical
factor in developing T1DM [16], most likely by inducing an altered T-helper
cell type 17 (Th17) population in the small-intestinal lamina propria. One of
the current hypotheses linking the gut microbiome to immunological tone is
production of microbial metabolites such as the short-chain fatty acids
(SCFAs). Production of these compounds is indeed altered in T1D, and the best
known SCFA butyrate is known to stabilize T-cell function in mice. Furthermore,
irritation of the pancreatic duct by microbiota in the proximal gut may
contribute to beta cell inflammation. By introducing beneficial fecal
microbiota to the proximal gut, the organisms that alter immunological tone and
irritate the pancreatic duct may be attenuated, resulting in improved beta cell
function and restoration. Thus, intestinal microbiota, their metabolites and
their associated gut immune system alterations, may either promote or protect
from beta cell autoimmunity. We hypothesize that if one is able to shape the
(small) intestinal microbiota with fecal microbiota transplantation (FMT) it
may be possible to stabilize or even reverse β-cell destruction, reducing
exogenous insulin needs and subsequently associated complications in T1D.

FMT is a promising treatment for T1D, not only because of potential efficacty,
but also because it is a safe procedure, that in our institute has been
performed >500 times without any serious adverse events. In short, a fecal
microbiota suspension is delivered through a duodenal tube after large bowel
lavage. This procedure is usually repeated 3 times with a 2-month interval.
Using an extensive screening protocol for infectious agents in accordance with
European guidelines, to date no infections attributable to the procedure have
been recorded in our group. The FMT procedure itself is tasteless and odorless
and in general generates few side-effects outside of the discomfort of placing
a duodenal tube.

Based on this notion, we initiated in 2013 a randomized pilot trial using
repetitive donor (healthy donor) vs. autologous (own) FMT on residual β-cell
function in new-onset T1D (DIMID trial, please see attached manuscript). Newly
diagnosed male/female patients with T1D were included and randomized (figure
1a,b). Moreover, healthy aged matched males/females were used as donors.


Surprisingly, autologous FMT in 10 new onset T1D subjects had a significant
(p<0.01) effect on preserving residual β-cell function as determined by
Sustacal Boost (Nestle HS) stimulated C-peptide AUC0-120min response after 12
months, whereas donor FMT in 10 new onset T1D had a less obvious beneficial
effect and showed overall a similar β-cell decline as seen in other trials with
placebo use. We have found several changes induced by both donor and autologous
FMT on gut microbiome composition and identified several bacterial strains and
plasma metabolites and T-cell signatures that predicted response to FMT.

The immunological consequence of flooding the small intestine with large bowel
microbiota by FMT may be an important immunological event. Based on our pilot
data, we therefore formulate a paradigm shift, in which we hypothesize that the
molecular mimicry against microbiome-associated antigens that drives T1D can be
exhausted by challenging the immune system though FMT administered in the
duodenum. Exhausted T-cells are ineffective T-cells that express high levels of
the so-called check-point proteins that inhibit immunological responses. Slow
progression of T1D is linked to more exhausted CD8 cells in infiltrated islets
[23], while increased circulating exhausted T cells predicted response to
anti-CD3 therapy in T1D.

In most people with longstanding T1D the remaining residual β-mass eventually
stabilizes, for reasons that are still not understood [39]. In fact, T1D is
even considered a relapsing remitting-disease, in which β-cell proliferation
increases over time. Therefore, even in longstanding T1D the residual β-cell
function may be improved. We hypothesize that the apparent anti-diabetic effect
of autologous FMT can be improved further if an FMT from individuals with a
proven durable preserved beta cell function is used, as these individuals
presumably carry a gut microbioma that best induces immuno-tolerance.
Therefore, we will compare in long-standing T1D autologous FMT to donor FMT
from T1D with preserved β-cell function, presuming that both treatments improve
residual β-cell function and immune cell activities.

Our aim is to use FMTs to shift the *permanent honeymoon-phase* from a rare to
the default phenotype. This will be, if achieved, a major breakthrough for the
treatment of T1D.

To investigate whether fecal microbial transplantation (FMT) from either
allogenic (individuals with type 1 diabetes and a highly preserved beta cell
fraction) or autologous (own) donor, administered every 8 weeks during 6 months
through a small intestinal tube, restores residual beta cell function up until
12 months after intervention in patients with longstanding type 1 diabetes.

This is a double blind randomised clinical trial. Patients will be treated with
infusion of allogenic or autologous feces by duodenal tube after bowel lavage.
Type 1 diabetes mellitus patients will be randomized to the following 2
treatment arms:
1. Multiple allogenic Type 1 diabetes donor fecal infusions at 0, 8 and 16
weeks.
2. Multiple autologous (own) feces infusions at 0, 8 and 16 weeks.

6 months before initial treatment, at baseline, 6 and 12 months residual beta
cel function, microbial composition, and immune cel function will be
characterised.

Patients will be treated with infusion of allogenic or autologous feces by
duodenal tube after bowel lavage.

Type 1 diabetes mellitus patients will be randomized to the following 2
treatment arms:
1. Multiple allogenic Type 1 diabetes donor fecal infusions at 0, 8 and 16
weeks.
2. Multiple autologous (own) feces infusions at 0, 8 and 16 weeks.

Participant may benefit in terms of helping to further unravel the relation
between the gut microbiome and residual beta cell function. The DIMID study was
very promising, suggesting that manipulation of the gut microbiome may indeed
preserve the residual beta
cell mass. This study will investigate if FMT is also beneficial in the setting
of longstanding type 1 diabetes. Participants may benefit from an increased
redisual beta cell function, which is associated with a lower risk of diabetic
complications and hypoglycemia. In the long therm, the FMT procedure may be
refined to a probiotic formation or a combination of potent microbial
metabolites and antigens that induce immunotolerance. Therefore, the risks
described below outweigh the potential gain from this study.

For the mixed meal test, morning long- and short acting insulin must be
withheld. This carries a small risk of hypo- and hyperglycemia. The study
participants will be carefully instructed and no major risk is expected in the
context of this procedure, especially given the current use of continuous
glucose-monitoring technologies. The placing of the intravenous cannula in our
study can be an unpleasant experience for the subjects and may result in (self
limiting) bruising.

Gastroscopy is a procedure associated with discomfort, but when participants
are well fasted is very safe. The required fasting is associated with a small
risk of hypoglycemia, for which participants will be adequately instructed. In
the age of continuous glucose monitoring this risk is also very low.

In our centre, FMT procedures have not been associated with major adverse
events, and donors are extensively screened to mitigate the risk of potential
infections by the FMT procedure.