Placebo Controlled Study of Fecal Microbiota Transplant (FMT) to Impact Body Weight and Glycemic Control in Adults Using a Frozen Encapsulated Inoculum
Phase: PHASE1
Conditions: Obesity
Sponsor: Massachusetts General Hospital

 
 
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Placebo Controlled Study of Fecal Microbiota Transplant (FMT) to Impact Body 
Weight and Glycemic Control in Adults using a Frozen Encapsulated Inoculum 
 
 
Massachusetts General Hospital  
Endocrine Unit and Infectious Diseases Division  
PI: Elaine W. Yu, MD  
Co-I: Elizabeth L. Hohmann, MD 
Study Coordinators:  Petr Stastka, Mariam Torres 
 
 
 
Protocol Version 5.6 
Date: March 6, 2019 
IND Number: 16643 
PHRC Protocol Number: 2015P001632/MGH 
CT.gov number: NCT02530385 
 
 
 
 

 
 
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I. 
BACKGROUND AND SIGNIFICANCE 
 
Multiple lines of evidence suggest that gut microbiota play an important role in 
regulating human metabolism via effects on body weight and systemic insulin resistance.1 
In rodents, manipulation of the gut flora with fecal microbiota transfer (FMT) induces 
weight loss and prevents development of obesity.2,3 In human studies, FMT administered 
via duodenal bowel lavage may confer benefits of short-term improvements in metabolic 
endpoints including insulin sensitivity.4 Recently, a new protocol for FMT has been 
developed at MGH utilizing oral capsulization that greatly improves the safety and 
feasibility of FMT as an investigative and therapeutic tool.5  
 
Few safe and effective treatments for obesity 
Over one-third of U.S. adults are obese6 and nearly a quarter have metabolic syndrome7.  
Obesity and the metabolic syndrome are associated with disabling comorbidities and an 
increased risk for cardiovascular disease and mortality.8 Safe and effective treatments for 
obesity have been difficult to discover; indeed 4 FDA-approved drugs have been 
withdrawn from the market due to safety concerns.  Bariatric surgery, while effective, is 
accompanied by high costs and potential morbidities and is therefore reserved for the 
most severe categories of obesity.  Finding noninvasive low-cost alternatives to improve 
obesity and human metabolism is an imperative for our society.   
 
Effects of gut microbiota on energy balance 
The gut microbiota is a diverse collection of several thousand species that actively 
participate in gut physiology and metabolic energy balance.  These microbial species 
have been postulated to modulate energy absorption, gut motility, appetite, glucose and 
lipid metabolism, and hepatic fatty storage.9 The precise mechanisms by which gut 
microbiota perform these tasks are unclear.  The dominant theories involve (1) increased 
energy harvesting from fermentation of foods otherwise indigestible to the host, (2) 
enlarging the nutrient absorption surface by promoting the intestinal epithelial growth, 
and (3) interaction with enteroendocrine cells to promote hormonal changes that 
influence host appetite and satiety, and (4) absorption of bacterial fragments such as 
lipopolysaccharides leading to “metabolic endotoxinemia”, which promotes obesity and 
hyperinsulinemia. 
 
Gut microbiome and obesity 
Intestinal bacteria have been implicated in the etiology of obesity.1 Animal studies have 
demonstrated that germ-free mice have lower body fat content than conventionally raised 
mice, an effect that is independent of diet.10 These germ-free mice are also resistant to 
diet-induced obesity.11 Genetically obese mice (ob/ob) have a reduction in the relative 
abundance of Bacteroidetes, with a proportional increase in Firmicutes.12 Importantly, 
similarly altered ratios of firmicutes:bacteroidetes and overall reductions in microbial 
diversity have been demonstrated in comparisons of obese and lean adults12-14 and in 
diabetic adults15, although this finding has not been verified in all studies.16,17 Other 
studies have found that the obese state is accompanied by overall reductions in microbial 
diversity and a relative increase in pathogenic bacteria.18,19 
 

 
 
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Metabolic effects of altering the gut microbiome 
Antibiotics are known to alter the community structure of the gut microbiome, and are 
associated with increased risk of becoming overweight in both animal20,21 and human22,23 
studies. Interestingly, 7-day treatment with oral vancomycin led to a decrease in 
microbial diversity and was associated with a decrease in insulin sensitivity among men 
with metabolic syndrome.24   
 
A more directed method of altering the microbiome involves the direct delivery of donor 
fecal material into the gut.  Colonization of germ-free mice with intestinal flora from 
obese mice led to greater increases in body weight and fat tissue than colonization with 
flora from lean mice.25 Other studies demonstrate that fecal microbiota transfer (FMT) 
from thin or obese adults can transmit the lean or fat phenotype when transplanted into 
mice, in the setting of the correct dietary conditions.3 Furthermore, fecal transplants from 
mice who sustained weight loss after gastric bypass surgery led to weight loss and 
improvements in insulin sensitivity among germ-free mice recipients.2 In human studies, 
fecal transfer from lean donors delivered at a single timepoint by duodenal bowel lavage 
led to improvements in insulin sensitivity at 6 weeks among men with metabolic 
syndrome, even in the absence of a dietary intervention.4 
 
Skeletal effects of altering the gut microbiome 
Recent data suggest that the gut microbiome may also have a direct impact on bone 
health. Germ-free mice have increased bone mass and decreased osteoclast number, and 
transplant of gut microbiota into germ-free mice led to normalization of bone mass.26 
Antibiotics and probiotics causing shifts in the microbiota spectra can also increase bone 
mass in animals models (Ohlsson et al Endo Metab 2014).27  Mouse models have 
indicated that the gut microbiome has an effect on the immune system, hormonal 
pathways, and production of bacterial metabolites that could signal bone cells and affect 
bone density.28  
 
Oral capsulized FMT protocol 
Standard FMT protocols involve invasive procedures such as colonoscopy, nasogastric / 
duodenal tubes, or retention enemas, which are accompanied by procedural challenges, 
risks, and costs.  Recently, we have developed a new FMT protocol that involves the 
capsulization of frozen fecal material.5 These oral capsules were highly effective in 
resolving otherwise refractory cases of C. difficile infection. The increased ease, 
tolerability, and safety of oral administration now allow study of FMT for sustained 
therapeutic intervention.  This extended exposure is a major advance, and more likely to 
durably alter the microbiome.   
 
Contributions of this study to the field 
We believe that transfer of the “lean” microbiota to an obese recipient may lead to weight 
loss and metabolic improvements.  Therefore, we propose to conduct a randomized 
double-blind placebo-controlled pilot study to evaluate the safety and effectiveness of 
oral FMT administration on weight and metabolism in obese adults.  This highly 
innovative study will leverage this new non-invasive FMT technique to promote durable 
changes in the gut microbiome, and could represent a new horizon of treatments for 

 
 
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obesity and insulin resistance.  Future studies including microbiomic analysis may 
identify specific strains of beneficial organisms to help narrow treatments from generic 
FMT to specific probiotic strains.  Identification of specific microbes and metagenomic 
pathways will also aid in our understanding of the mechanism by which the gut 
microbiome controls response metabolism.  
 
 
II.  
SPECIFIC AIMS 
 
We propose a randomized placebeo-controlled trial to study the impact of gut 
microbiome alterations on weight, insulin sensitivity, and other important metabolic 
endpoints. 
 
Aim 1. To identify and characterize healthy lean donors from a phenotypic 
perspective to generate FMT capsules for a clinical trial in obese subjects.   
 
Aim 2.  To determine the impact of oral capsulized FMT from healthy lean 
donors on insulin sensitivity in obese adults in a 3-month randomized double-
blind placebo-controlled trial. Secondary outcomes include changes in body 
weight, metabolic markers, and FMT-related adverse events.  We hypothesize that 
FMT recipients will experience an improvement in insulin sensitivity and other 
metabolic endpoints. An optional extension study will evaluate the durability of 
gut microbiome change at 12 months. 
 
Aim 3. To explore associations between the gut microbiome and bone density. 
 
 
III.  
PATIENT/SUBJECT SELECTION  
 
Lean donors for FMT are being recruited from Dr. Hohmann’s IRB-approved protocol 
2014P002706 “Placebo Controlled Study of Fecal Microbiota Transplant (FMT) for a 
second episode of C. difficile infection in adults using a frozen encapsulated inoculum”.  
Lean donors must meet all the eligibility criteria as noted in protocol 2014P002706.  
Briefly, they must be age 20-60 years, have no significant past medical history, no use of 
antibiotics for the previous 6 months, and must pass a rigorous infectious disease 
screening protocol.  In addition, donors must pass stricter weight and metabolic criteria 
than as outlined in protocol 2014P002706; in particular, they must have a BMI 18.5-23 
kg/m2 with no history of BMI exceeding 25 other than for pregnancy, stable weight for 
the preceding 6 months, and they must pass an 2-hour oral glucose tolerance test (fasting 
glucose <100 mg/dl, 2 hour OGTT glucose <140 mg/dl) to be eligible to donate for this 
obesity study. 
 
24 obese recipients will be recruited to participate in the study from the greater Boston 
area.  The obese recipients will be randomized 1:1 to weekly FMT vs. placebo capsules 
(n=12 FMT, n=12 placebo) for 6 weeks, with a total follow-up time of 24 weeks, or 12 
months if they choose to participate in the optional substudy.   

 
 
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Inclusion criteria 
 BMI ≥30 kg/m2 and stable weight for the previous 3 months 
 Willingness to accept risk of unrelated donor stool. 
 Age 25-60 
 Able to consent for self in English language 
 Subjects are not expected to receive antibiotics in the next 12 weeks.  
 Patient must be willing to have screening labs for Hepatitis B and C, and HIV (as 
required by the FDA for past studies).  
 Mild-moderate abnormal glucose metabolism: HOMA-IR >2.0 or fasting plasma 
glucose ≥ 100 mg/dl; however subjects will be excluded for HOMA-IR >8.0 
 
Exclusion criteria 
 Initiation or discontinuation of a medication known to affect body weight or 
insulin sensitivity within 3 months of enrollment (e.g. hormonal contraception, 
psychiatric medications: tricyclic antidepressants, monoamine oxidase inhibitors, 
paroxetine, escitalopram, lithium, olanzapine, clozapin, risperidone, 
carbamazepine, valproate, divalproex, mirtazapine) 
 Use of weight-loss medications or diabetic medications in the preceding 1 year 
(e.g. metformin, sulfonylureas, insulin, etc) 
 Antibiotic use in the preceding 6 months 
 Delayed gastric emptying syndrome  
 Known chronic aspiration 
 Swallowing dysfunction or oral-motor dyscoordination, or inability or 
unwillingness to swallow multiple large capsules 
 Malabsorptive disorders including celiac disease, cystic fibrosis, irritable bowel 
syndrome, prior gastrectomy, bariatric surgery and any state of chronic diarrhea 
 Pregnant women or women trying to conceive or women who are breastfeeding; 
women of child-bearing potential will have a urine or serum hCG test.  
 Patients with an acute illness or an acute exacerbation of underlying co-morbid 
condition 
 Subjects on high dose steroids (>40 mg daily)  
 Subjects on multiple/combination immunosuppressive regimens including high 
dose corticosteroids, calcineurin inhibitors, mTOR inhibitors, lymphocyte 
depleting biologic agents, anti-TNF agents.  
 Patients with a history of HIV, hepatitis B, hepatitis C, decompensated cirrhosis, 
recent bone marrow transplant, other causes of severe immunodeficiency. 
 Patients with a history of significant allergy to foods not excluded from the donor 
diet (excluded foods are tree nuts, peanuts, shellfish, eggs) 
 Allergy to chocolate/cocoa or gelatin, or unwillingness to ingest gelatin (in 
placebo capsules).  
 Screening labs: AST or ALT >3x normal; Hematocrit <33%; White Blood Cell 
count <3000 cells/uL; ANC<500; Creatinine >2.0 mg/dL 
 Patients with abnormal bowel habits, e.g. constipation with <4 bowel 
movements/week 

 
 
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IV.  
SUBJECT ENROLLMENT 
 
Methods of enrollment:   
Obese adults will be recruited from the MGH Weight Center. The PI does not perform 
clinical work at the MGH Weight Center. However, if a patient of the PI’s is identified 
who may be eligible for the study, the PI will ask a physician colleague to explain the 
study and will provide patients the Consent Form to review at home. In addition, 
recruiting advertisements will be posted on email, the internet, and by flyer.  Finally, we 
will add the study to the https://register.clinicaltrials.gov database. All letters and 
advertisements will be approved by the Partners IRB before they are used. All eligible 
obese subjects will be invited to participate in the hyperinsulinemic-euglycemic clamp 
substudy.  
 
Optional Substudies 
All participants will be asked if they are interested in participating in the optional 
substudies as part of the initial screening process. The first substudy is to examine 
associations of gut microbiome with bone density (Aim 3). The second substudy is an 
extension the main study’s stool and blood sampling to determine the longevity of any 
effects observed as a result of FMT. If participants express interest, they will be enrolled 
in the substudies. 
 
Informed consent 
Written informed consent will be obtained by a nurse practitioner or physician 
investigator. In situations where a nurse practitioner is obtaining consent, subjects will be 
offered the option for further discussion with a physician investigator if they have any 
remaining questions. This offer will be documented in the research record.  
Any consent problems will be reported to the PHRC in real-time. 
 
  
Randomization 
Obese recipients will be randomized to receive either FMT or placebo capsules in a 1:1 
ratio. Double blinding is important. Subjects will be assigned by a computer generated 
randomization order known to an individual not involved in assessing the patients.  This 
individual will identify the assignment, take appropriate capsules from relevant freezer 
locations, and place them on dry ice as usual for administration, but place them in a vial 
labelled “STUDY Caps” for administration so neither physician nor subject will be able 
to identify real vs placebo capsules.  The actual labeled containers identifying caps as real 
or placebo will then be sealed in an opaque envelope and saved for review at the time of 
unblinding.  This will serve as a “double check” on actual assignment.  
 
 
V.  
STUDY PROCEDURES  
 

 
 
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Lean donors will undergo testing and follow procedures outlined in protocol 
2014P002706.  Main procedures will occur in the primary 12-week study period; a 
supplemental week 24 phone-call will be performed for a safety check. In addition, 
samples of the fecal collection will be stored at -80°C for further microbiome analysis. 
 
Obese recipients will undergo the following procedures: 
 
Phone Screen (10-20 minutes) 
 
Screen Visit (30 minutes) 
 Review eligibility and understand/see size of capsules 
 Obtain informed consent 
 Height, weight measurements to determine eligibility 
 Screening labs: Complete blood cell count w/ differential, comprehensive 
metabolic panel, HIV Ab, HBV sAb/sAg, HCV Ab, fasting insulin and glucose.  
 Subjects will be counseled not to start any new major dietary changes, exercise 
regimens, or medications throughout the primary 12-week study period 
 Subjects will be given information about how to perform fecal collections (see 
Stool Collection document) 
 
Baseline Visit, Week 0 (Day 1: 5 hours, Day 2: 15 minutes, Day 3: 15 minutes) 
 Fasting blood samples for measurements of HOMA-IR, lipids, CRP, and HbA1c. 
 Women of child bearing potential will have a urine pregnancy test  
 Height, weight measurements  
 48-hour food recall  
 Whole body DXA scan for body composition analysis 
 DXA scan of lumbar spine and hip to assess baseline BMD (optional substudy) 
 Fecal collection 
 Indirect Calorimetry 
 Hyperinsulinemic euglycemic clamp 
 After above study procedures are complete, subjects will receive FMT (or 
placebo) caps, 15 capsules on each of 2 successive days.  Note that participants 
will need to either fast for 4 hours after the clamp or return on the subsequent day 
for their first capsule administration. 
 
Weeks 1-5 (15 minutes) 
 Interval side effect assessment (see Side Effect Assessment document) 
 Subjects return for weekly administration of 15 capsules (for a total of 6 weeks, 
including Week 0)  
 Fecal collection at weeks 1, 3 and 5. 
 
Week 6 (5 hours) 
 Interval side effect assessment (see Side Effect Assessment document) 
 Height, weight  measurements  
 Women of child bearing potential will have a urine pregnancy test 

 
 
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 Fasting blood samples for measurements of HOMA-IR, lipids, CRP, and HbA1c. 
 48-hour food recall  
 Fecal collection 
 Whole body DXA scan for body composition analysis 
 Fecal collection 
 Indirect Calorimetry 
 Hyperinsulinemic euglycemic clamp 
 Note that we will allow a +1 week window for scheduling the week 6 visit 
 
Week 12 (1 hour) 
 Interval side effect assessment (see Side Effect Assessment document) 
 Height, weight measurements  
 Fasting blood samples for measurements of HOMA-IR, lipids, CRP and HbA1c. 
 48-hour food recall  
 Women of child bearing potential will have a urine pregnancy test  
 Whole body DXA scan for body composition analysis 
 Fecal Collection  
 
Week 24 (Month 6) Follow Up (5-20 minutes) 
 If not enrolled in the extension study, interval side effect and self-reported weight 
assessment will occur by phone (see Phone Follow-Up document)  
 If enrolled in the optional extension substudy, subjects will come for an in-person 
visit to MGH.  
 Fecal collection 
 Fasting blood samples for measurements of HOMA-IR, lipids, CRP and HbA1c. 
 Interval side effect assessment will be conducted. 
 Note that we will allow a ±2 month window for scheduling this visit 
 
Month 12 (1 hour; optional extension study) 
 Interval side effect assessment (see Side Effect Assessment document) 
 Height, weight measurements  
 Fasting blood samples for measurements of HOMA-IR, lipids, CRP and HbA1c. 
 48-hour food recall  
 Women of child bearing potential will have a urine pregnancy test  
 Whole body DXA scan for body composition analysis and DXA scan of lumbar 
spine and proximal femur to assess bone mineral density 
 Fecal Collection  
 Note that we will allow a ±2 month window for scheduling this visit 
 
 
C. Technical Methods 
 
Phone screen: Phone discussion to explain approach and alternatives briefly (10-20 
minutes).  The purpose of this discussion is to ensure subjects who cannot get past the 
aesthetic concerns of this procedure do not spend time coming to the hospital for an in 

 
 
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person discussion. People may wish time to consider after having this discussion. Those 
who wish to have an in person discussion, even if not decided upon having the procedure 
are welcome to come in for further discussion. The consent form is provided at this time, 
if desired.  
 
FMT and placebo capsule preparation: We will generate FMT capsules from donors per 
our FDA-approved operating procedures. Donors will be asked to refrain from eating 
common allergens within 5 days of the donation (tree nuts, eggs, peanuts, shellfish) but 
otherwise not alter their diets.  Volunteers will have an interim health query for febrile, 
system, and GI symptoms at the time of donation, and defer collection if there is any 
change in health status.  Processing is carried out under aerobic conditions. A fecal 
suspension is generated in normal saline without preservatives. Materials are sequentially 
sieved to remove particulate material. The final slurry is concentrated by centrifugation 
and re-suspended in saline at 1/10 volume of the initial sample with 10% glycerol added 
as a bacterial cryoprotectant. Fecal 
matter solution is pipetted in size 0 
capsules (650µL), which are closed and 
then secondarily sealed in size 00 
capsules. Capsules are stored frozen at -
800C for up to 6 months at which point 
they are discarded if not used. 1-2 hours 
prior to administration they will be 
transferred to -200C and then 
transported to the dosing site on dry ice. 
Commercially available acid-resistant 
hypromellose capsules (DRCaps, 
Capsugel, Cambridge, MA, USA) are 
used. Each inoculum is prepared from 
the feces of a single donor.  This project 
is under FDA IND #16643.  
 
Placebo capsules will consist of a 
combination of powdered cocoa and gelatin in normal saline/glycerol (same vehicle as 
FMT capsules). Gelatin is added to make the placebo solution more viscous and 
physically fill capsules in the same way that the standard FMT inoculum does for 
appearance purposes. Placebo capsules are identical in appearance to FMT capsules, and 
are included in the above mentioned FDA IND # 16643.  
 
FMT and placebo capsule administration: Subjects will be NPO at least 4 h prior to and 
for 1 hour following capsule intake on each day, to minimize risk of vomiting during 
ingestion of capsules.  Subjects will be handed each capsule by an investigator and asked 
to take each capsule with a sip of water. Subjects will be asked to drink at least 12 oz of 
water during administration to facilitate dilution of stomach contents and transit into the 
small intestine. In the event of vomiting subjects will be observed, and not re-dosed. 
 
 

 
 
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Subjects are evaluated after taking capsules by the study investigators, typically for 15 
minutes.  Immediate side effects are very uncommon in our experience. Capsules are 
odorless and tasteless and do not dissolve in the acidic environment of the stomach.   (In 
our study of capsules to date we have had 1/61 subjects who complained of nausea during 
administration, and this individual had concurrent psychiatric illness and concurrent 
irritable bowel syndrome diagnosed by an outside gastroenterologist. One child vomited 
4 hours after capsules were administered.).  
 
Subjects receive a copy of the signed consent form to take home and an information sheet 
(attached) on symptoms to monitor and study physician phone numbers.  All patients 
have our contact numbers and will be encouraged to call for any concerns. Subjects are 
asked to inform us if they require the initiation of antibiotics for intercurrent clinical 
illness, during the study period.  
 
Subjects will receive capsules at weekly intervals (± 2 days) for  weeks 0-5.   
 
Subject counseling: Subjects will be counseled to remain on the same diet that they are 
currently on and not to initiate any major exercise regimens throughout the primary 12  
week study period.  In addition, women with child-bearing potential will be informed that 
they need to use contraception throughout the study.  If they are taking a hormonal 
contraceptive, they need to remain on such until the end of the study.  If they are not 
using a hormonal contraceptive, they will need to use other forms of birth control, such as 
barrier methods with a spermicide, IUD, or abstinence.  We will ask that they not actively 
initiate or discontinue hormonal treatments during the study, as this may confound our 
assessments of body weight and insulin sensitivity. 
 
Height, weight measurements: Height and weight measurements will be performed in 
triplicate in light clothing without shoes. Waist circumference will be measured as the 
narrowest circumference between the lower costal margin and iliac crest in the standing 
position at the end of a normal exhalation. All measurements will be performed using 
standardized protocols by bionutritionists at the MGH Clinical Research Center. 
 
Fecal sampling: Fecal samples will be collected from recipients at weeks 0, 1, 3, 5, 6, and 
12 (and 6 and 12 months if subjects choose to participate in the optional extension study), 
and stored in a -80°C freezer according to established protocols.28 Recipients will be 
given instructions and stool collection kits to bring home (see Stool Collection 
document). All samples will be brought to MGH by the patient.  
 
DXA: Whole body, hip and spine DXA scans will be performed. DXA scans of the whole 
body will be obtained at baseline, 6 and 12 weeks (and 12 months if subjects choose to 
participate in the optional extension study). For those participating in the optional bone 
density substudy, DXA scans on the spine and hip will be obtained at baseline and 12 
months. Measurements will be performed on QDR Hologic Discovery A machines. Body 
composition (lean body, fat mass including subcutaneous and visceral compartments) and 
bone density (PA spine, total hip, and femoral neck) will be measured using standard 
DXA analysis procedures as recommended by the manufacturer. The effective absorbed 

 
 
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radiation dose for each full body DXA scan is 0.0084 mSv and for the hip and spine DXA 
scans is 0.022 mSv. The total amount of radiation from participation in this study and the 
optional extension study is 0.076 mSv for these procedures. 
 
Hyperinsulinemic-euglycemic clamp: Subjects will undergo clamp studies to assess 
peripheral insulin sensitivity at week 0 and week 6. This procedure is performed at the 
MGH CRC.  Peripheral insulin sensitivity will be determined during the last 20 minutes 
of the clamp using the DeFronzo method.29  Clamp procedure will be as follows.  
 Subjects will be asked for fast for 12 hours prior to their study visit.   
 Insulin infusate will be prepared by the MGH pharmacy. 
 Two intravenous (IV) catheters will be inserted:  (1) one placed in the hand when 
access is available, otherwise in the forearm or antecubital space, to be used for 
venous sampling; (2) one placed in the antecubital space or proximal forearm and 
used for administration of insulin and 20% dextrose as below.  
 The hand/forearm with the IV that will be used for venous sampling will be 
placed in a warming box for the duration of the clamp procedure, although it may 
be withdrawn if the subject finds the warmth uncomfortable.  
 At time “0” (approximately 9am), a priming dose of 300 mU/m2/min of insulin 
will be given for 2 minutes followed by a continuous infusion of 60 mU/m2/min 
for the next 118 minutes.  
 From 0-120 minutes, a sample (≤ 0.5cc) of venous blood will be drawn every 5 
minutes for assessment of glucose using a Hemocue glucose analyzer.  Each 
sample is run twice in the Hemocue analyzer, with an additional third run if the 
difference between the first two runs is ≥4mg/dL.  Samples for serum insulin 
concentration will be drawn at times 0, 80, 100, 120 minutes. 
 Starting at 5 minutes, a variable 20% dextrose infusion will be administered to 
achieve a target glucose of 90mg/dL (range 85-95mg/dL).  The rate will be 
adjusted by the investigator, an MD or NP who is trained in clamp 
procedure.  The initial infusion rate of 20% dextrose will be 0-30cc/hr, with the 
exact rate determined by the investigator based on the subject’s fasting glucose, 
available clinical information, and, if available, data from the subject’s previous 
clamp procedure for the study.  (For example, a subject who is known clinically to 
be insulin resistant and has a fasting glucose of 110mg/dL would be started at a 
rate of 0cc/hr, whereas a lean, muscular subject who exercises regularly and has a 
fasting glucose of 70mg/dL would be started at 30cc/hr.) 
 The rate of 20% dextrose infusion will be adjusted up or down for the duration of 
the clamp procedure by the investigator.  Rate changes of 0-40cc/hr will be made 
by the investigator every 5 minutes, based on the subject’s venous glucose and 
rate of change in glucose, to achieve target glucose of 90mg/dL.  
 At 120 minutes, the insulin infusion will be discontinued, and the glucose infusion 
will continue for 30 more minutes.  During this time, subjects will be given a 
meal.  At 150 minutes, venous glucose will be checked, and the glucose infusion 
will be discontinued if venous glucose ≥80mg/dL.  If glucose is <80mg/dL, the 
glucose infusion will be continued and will be weaned by the investigator at the 
bedside, with repeat venous glucose sampling every 10 minutes until the glucose 
is ≥80mg/dL and the infusion is stopped.  

 
 
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 After the clamp, all subjects are counseled concerning the symptoms of 
hypoglycemia and are asked to report immediately any symptoms.  Subjects are 
observed on the CRC for at least 20 minutes following discontinuation of glucose 
infusion.  
This procedure assumes that the hyperinsulinemic state is sufficient to completely 
suppress hepatic glucose production and that there is no net change in blood glucose 
concentrations under steady-state conditions. Under such conditions, the rate of glucose 
infused is equal to the rate of whole-body glucose disposal (GDR) or metabolizable 
glucose (M) and reflects the amount of exogenous glucose necessary to fully compensate 
for the hyperinsulinemia. 
 
Indirect Calorimetry: A ventilated hood calorimeter (VMAX Encore; Carefusion Corp, 
Yorba Linda, CA) will be utilized to assess resting energy expenditure (REE) and 
respiratory quotient (RQ) by determining oxygen consumption (VO2) and carbon dioxide 
production (VCO2) for 20 minutes under fasting conditions before the clamp.  REE will 
be normalized to lean body mass as determined by dual-energy x-ray absorptiometry. 
 
Compensation: Recipients will be compensated $750 for completion of the study. $100 
for completing the baseline visit, $400 for completing the week 6 visit ($100 for the 
clamp visit, $50 per capsule administration visit), and $250 for the week 12 visit. If 
subjects choose to participate in the optional extension study, they will be compensated 
an additional $100 ($25 for 6 month visit and $75 for 12 month,visit).They will also 
receive either a parking voucher or up to $20 to cover travel expenses at each visit 
 
D. Safety Monitoring 
Obese recipients will be monitored for clinical safety by history (and standard exams 
when seen in person) by asking open ended and then directed questions. Subjects will be 
followed closely, as noted above. Follow up calls made by a study coordinator will be 
documented and follow up information is reviewed on the same day with a study 
physician if any symptoms of concern are identified.  A physician plan for ongoing 
follow-up will be noted and implemented.  In any case of adverse events identified as 
grade 2 (moderate severity) an in-person visit with an investigator, either in the GI or ID 
outpatient practices, will be encouraged.   
 
An AE will be considered related if, in the judgment of the treating physician it is both 
temporally related to administration of the capsules, and there is no other reasonable 
alternative explanation, and the AE is not more reasonably attributed to progression of 
the underlying illnesses.  
 
Any serious adverse event (SAE) assessed as possibly, probably, or definitively related to 
fecal transplantation will be reported in an expedited fashion to the IRB and FDA. SAE’s  
are defined as any Grade 3 or 4 events as described on the attached AE grading chart, in 
addition to any event temporally associated with the study procedure that:  
 results in death; 
 is life threatening (places the subject at immediate risk of death from the event as 
it occurred); 

 
 
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 requires inpatient hospitalization or prolongation of existing hospitalization; 
 results in a persistent or significant disability/incapacity; 
 results in a congenital anomaly/birth defect;  
 any other adverse event that, based upon appropriate medical judgment, may 
jeopardize the subject’s health and may require medical or surgical intervention to 
prevent one of the outcomes listed above. 
 
Investigator monitoring with IRB and FDA oversight/reporting is proposed.   
 
E. Study Stop Rules 
The study will have a stop/safety pause in the event of any probably or definitely related 
SAE, or any apparent transmission of enteric, viral, or other infection from a donor to 
recipient. (Given the careful screening of donors, we believe this is highly unlikely). A 
safety pause will also be initiated in the event of a clinically significant complication of 
ingestion of a large number of capsules, for example medication bezoar (not observed to 
date in over 125 C. difficile patients treated, many with concurrent GI disease). We think 
this is very unlikely, given that we have demonstrated capsule dissolution occurs 
reasonably rapidly at neutral pH (i.e. once caps reach the small intestine.) We will track 
but not specifically stop the study if the following possible expected events occur:  
 Transient fever after FMT (up to 102.5◦ F for 12 hours or less); this is 
occasionally noted, particularly in younger patients.  
 
F. Individual Subject Stop Rules 
By individual, people will not continue dosing if the following happens:  
 If the individual is unable to swallow at least 10 capsules at a sitting.  Twenty 
capsules at week 0 and 10 capsules in subsequent weeks are the 
minimums considered a "full dose" for treatment and analysis purposes.   
 If subject requests withdrawal. 
 If subject vomits with clinically evident aspiration (by exam or xray; not observed 
to date) 
 If subject experiences an SAE attributed by the study physician to the capsules  
 
G. Sample Sharing 
We may share coded samples containing no PHI from both donors and recipients with 
academic and commercial collaborators researching the microbiome, obesity, insulin 
sensitivity and probiotics/ecobiotics.  Both groups will be notified of this sharing using 
standard language in the consent forms.  We have no current plans or funding for these 
analyses but wish to keep this option open.  
 
 
VI.  
BIOSTATISTICAL ANALYSIS   
 
Change in insulin sensitivity is the primary outcome and will be compared between 
placebo and FMT groups over 12 weeks using longitudinal regression models.  
Secondary outcomes including change in insulin sensitivity, lipids, CRP, and DXA body 
composition will be similarly investigated. This is a pilot study to determine feasibility 

 
 
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and safety, and to obtain data for power calculations for a larger powered study. After 
accounting for 15% dropout rate, and assuming a standard deviation of insulin sensitivity 
of 30-45% and a two-sided alpha of 0.05, this pilot study (n=12 per group) has 80% 
power to detect a 40-60% difference in insulin sensitivity between groups, and a 30-45% 
difference from baseline within each group.  After accounting for 15% dropout rate, and 
assuming a standard deviation of weight loss of 5% and a two-sided alpha of 0.05, this 
pilot study (n=12 per group) has 80% power to detect a 6.6% difference in weight loss 
between groups, and a 5% difference in weight loss from baseline within each group.  
 
Fecal samples from lean donors and obese recipients will be stored, as noted above.  If 
funding allows in the future, these samples will undergo microbial analysis using 16S 
ribosomal DNA-based identification and deep sequencing techniques. Changes in the 
composition of the gut microbiota and metagenomic pathways will be correlated with 
clinical changes in metabolism. 
 
Bone mineral density (BMD) of the spine, hip, and whole body will be assessed at 
baseline and at 12 months.  This pilot study will provide preliminary data to expore the 
associations between BMD and gut microbiota prior to manipulation and after FMT.   
 
VII. 
RISKS AND DISCOMFORTS 
 
Capsule administration: The risks of FMT include transmission of an infectious agent 
from an unrelated individual, or the potential for acquisition of medical illnesses not 
currently understood to be related to altered GI flora (for example inflammatory 
conditions, obesity, etc).  We believe these risks are low.  Other possible risks include 
nausea, vomiting, diarrhea, fever (all rare based upon experience to date). The risk of 
bezoar is very low as capsules dissolve promptly in non-acidic environments. We believe 
there is no risk to placebo capsules which contain gelatin, cocoa, and the same liquid 
vehicle as FMT caps (IV grade saline and USP glycerol).  
 
Blood drawing: The amount of blood drawn for subjects completing the study is 
approximately 200 ml over a period of 12 weeks (or 260 mL over 12 months if subjects 
agree to enroll in optional substudy extension). This does not pose excessive risk to 
patients and are within Institutional Review Board guidelines.  There is a small risk of 
bleeding, bruising and infection with phlebotomy.   
 
Euglycemic Hyperinsulinemic clamp/insulin: Administration of insulin infusion can 
cause hypoglycemia. Blood sugar will be monitored every 5 minutes during the insulin 
clamp, and 20% dextrose is infused per protocol to achieve target blood glucose of 
90mg/dL. In the event of hypoglycemia, 50% dextrose is available at the bedside, and a 
physician or nurse practitioner is present throughout the insulin clamp procedure. There 
is a minimal risk of burning when using a warming box. This is extremely rare. The 
warming box has an alarm that prevents the temperature from rising above the set limit.  
 
DXA: Each whole body DXA scan delivers an effective radiation dose of 0.0084 mSv, 
and the hip and spine DXA scan delivers an additional 0.022mSv. The total amount of 

 
 
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radiation is 0.0472 mSv over 12 weeks, or 0.0776 mSv over 12 months for those 
participating in the optional study extension. 
 
Indirect Calorimetry: Indirect calorimetry for the measurement of resting energy 
expenditure is not known to cause any health risks. 
 
 
VIII. POTENTIAL BENEFITS 
 
It is hoped that subjects receiving FMT will experience weight loss and/or improvements 
in insulin sensitivity as a result of this intervention. Obese subjects may not benefit from 
being in the study.  They can receive some medical information (labs, DXA) and will be 
referred to their physicians at the end of the study for continued care.   
 
The study is likely to benefit the overall population of individuals with obesity, as it will 
contribute to an improved understanding of the physiologic and microbiomic mechanisms 
that control weight and glucose metabolism. An interesting scientific aspect of this study 
is analysis of the microbiome over time after prolonged FMT in obese but otherwise 
generally healthy subjects without a markedly altered microbiome at baseline.  This may 
lead to future targeted therapies for weight loss and improving insulin sensitivity. 
 
 
IX. 
MONITORING AND QUALITY ASSURANCE 
 
Clinical data 
The study coordinator and study physicians will carefully review testing on donors 
together, prior to sample collection, to ensure all inclusion criteria are met and that no 
exclusion criteria are met. This is also re-checked for capsules at the time of each 
administration with a Certificate of Analysis. Case report forms and follow-up 
questionnaires for recipients will be reviewed on a weekly or twice weekly basis for 
completeness and missing data points will be sought from records or phone contact if 
needed.   Weight measurements and 48-hour food recalls will be evaluated by trained 
bionutritionists at the Clinical Research Center. 
 
Capsule stability 
We do not expect, and have not previously observed a decrement in the viability or 
efficacy of the capsules, which will be stored at -80 C in an alarmed freezer. Capsules 
will be discarded if not used by their expiration date.   We have extensive experience 
with both frozen, and lyophilized bacterial vaccines for human use,30-34 and previously 
generated SOPs for short and long term analysis/stability testing of those mono-microbial 
frozen materials over time (under FDA IND # 12760 and 13937). Capsules which are not 
structurally intact cannot be used (see Certificate of Analysis).  FMT Capsules are saved 
for analysis in the event of infection transmission. FMT Capsule lots where numbers 
allow have assessment of aerobic colony forming units over time (0 and 6 months) as a 
measure of stability. Placebo capsules containing frozen food grade material are not 
analyzed, and simply discarded at the expiration date.   

 
 
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