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Blood Lipopolysaccharide (LPS) Rifaximin Study

Dietary Fat, Lipoprotein and Lipopolysaccharide: Role in Insulin Resistance

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02124512
Enrollment
12
Registered
2014-04-28
Start date
2015-03-31
Completion date
2019-05-31
Last updated
2019-08-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Insulin Resistance, Metabolic Syndrome, Obese

Keywords

obese, insulin resistance, metabolic syndrome

Brief summary

Metabolic syndrome is a condition involving elevated levels of fat in the blood, a tendency towards diabetes, hypertension, and too much fat around the abdomen (an increased waistline). Individuals with metabolic syndrome often have impaired glucose tolerance, which is a condition where blood sugar is normal when fasting (before eating), but is too high after drinking a sugary drink. This is due to an abnormality in the body's sensitivity to insulin (insulin resistance), which is due in part to an inability of the muscle to take up glucose. People with metabolic syndrome have inflammation in their fat tissue and in their blood stream, and the changes in the level of inflammatory chemicals produced by cells in your fat tissues will be studied. One possible source of the inflammation may be the bacteria in the intestine. When individuals eat fatty foods, some of the bacterial products become attached to the fat in their blood and then get directed to fat tissue. The investigators wish to determine whether individuals have an excessive amount of inflammation in their fat tissues, and whether this inflammation comes from the bacteria in their intestines. To determine this, the investigators wish to treat individuals with an antibiotic that reduces the bacteria in their intestines and in their blood, and determine whether this reduces their overall level of inflammation.

Detailed description

This is a randomized, placebo-controlled proof of concept study that will examine the investigational drug Rifaximin Soluble Solid Dispersion (SSD) ability to reduce gut microbiota and thereby reduce adipose inflammation and improve insulin resistance. Each subject enrolled will undergo a fat tolerance test with a high-fat meal, an oral glucose tolerance test, a fat biopsy, and a euglycemic clamp. Following their successful completion of those procedures subjects will be randomized to study treatment. That treatment will involve receiving the investigational drug,80 mg per day of rifaximin-soluble solid dispersion (SDD), or placebo for 12 weeks. All procedures will be performed on the Clinical Services Core of the CCTS. The initial visit will involve informed consent, and routine labs (comprehensive metabolic panel, lipid panel, TSH, CBC with platelets). These routine labs are for safety purposes and to rule out exclusionary disorders. A stool sample will also be collected and frozen for possible future analysis of bacterial microflora. Subjects will be asked to allow the principal investigator to bank blood and tissue samples collected during this study that are not used for other study-related tests. No additional blood or tissue samples will be collected. If the subject agrees to the banking of their blood and tissue samples they will be stored in the Principal Investigator's laboratory at the University of Kentucky for an indefinite period of time or until they are used up. Stored samples will be used for future research testing to learn about how to prevent, detect, or treat insulin resistance, metabolic syndrome, diabetes or other health problems. Each subject will undergo total body composition testing using a total body dual-energy x-ray absorptiometry (DXA) scan. The DXA scan measures the subject's bond density and body fat.

Interventions

Study Drug dosing will be 80 mg SSD once daily

OTHERPlacebo

80 mg placebo once daily

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
CollaboratorNIH
Philip Kern
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
35 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

* Obese * Insulin resistance or metabolic syndrome * Body Mass Index between 27 and 45 * Waist circumference \>40 (M) or \>35 (F) * Impaired glucose tolerance (IGT) * Normal glucose tolerance (NGT) with at least three features of MetS * A1C \<6.5 * Blood pressure 130/85

Exclusion criteria

* Pregnant or breastfeeding * Recent or unstable cardiovascular disease * cancer, * Renal insufficiency (GFR\<30) * Steroid use * chronic inflammatory conditions * Anticoagulant use * Lipodystrophy * Irritable Bowel Syndrome * Allergy to local anesthetic * Lactose intolerance

Design outcomes

Primary

MeasureTime frameDescription
Circulating LPS0, 4 and 8 hours at Baseline, and 0, 4 and 8 hours after 12 weeks of treatmentPlasma lipopolysaccharide (LPS) will be measured both in the fasting state and after a lipid-rich meal in obese subjects (Pre-Treatment: 0, 4 and 8 hr timepoints). The subjects will then be treated with the antibiotic rifaximin for 12 weeks to substantially reduce gut bacteria. LPS measurements at fasting and after a lipid-rich meal will be repeated (Post-Treatment: 0, 4 and 8 hr timepoints). The lipid tolerance tests before and after treatment with rifaximin will be assessed to determine whether there is a reduction in post-prandial LPS. LPS measurements were obtained using a modified LAL Assay.

Secondary

MeasureTime frameDescription
Tissue InflammationPre-Treatment (baseline) and Post-Treatment (12 weeks after baseline).Subjects will undergo a baseline fat biopsy (pre-treatment). They will then be treated with rifaximin for 12 weeks and biopsies will be repeated to determine if disruption of the microbiota reduces tissue inflammation. Data are reported as normalized mRNA expression levels (arbitrary units) of TNFalpha.

Other

MeasureTime frameDescription
Improved Insulin SensitivityUp to 12 weeksWe hypothesize that a change in the microbial flora with rifaximin will alter plasma LPS, adipose tissue inflammation, and insulin sensitivity. Therefore, we will examine, before and after rifaximin/placebo treatment: 1. LPS associated with lipoproteins, 2. insulin sensitivity and hepatic glucose production, 3. plasma inflammatory markers (TNFα, IL-6, MCP-1, adiponectin), 4. adipose inflammatory markers (CD68, MCP1, TNFα, PAI1, IL12, IL10, TLR4 and others).

Countries

United States

Participant flow

Participants by arm

ArmCount
Arm 1 Rifaximin SSD
Subjects randomized to this arm of the study will receive 80 mg per day Rifaximin SSD Rifaximin SSD: Study Drug dosing will be 80 mg SSD once daily
6
Arm 2 Placebo
Placebo Placebo: 80 mg placebo once daily
6
Total12

Baseline characteristics

CharacteristicArm 1 Rifaximin SSDArm 2 PlaceboTotal
Age, Continuous50 years
STANDARD_DEVIATION 3
50 years
STANDARD_DEVIATION 2.9
50 years
STANDARD_DEVIATION 3
Body Mass Index (BMI)38.5 kg/m^2
STANDARD_DEVIATION 4.2
36.1 kg/m^2
STANDARD_DEVIATION 3.4
37.3 kg/m^2
STANDARD_DEVIATION 3.8
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
1 Participants1 Participants2 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
5 Participants5 Participants10 Participants
Region of Enrollment
United States
6 participants6 participants12 participants
Sex: Female, Male
Female
5 Participants5 Participants10 Participants
Sex: Female, Male
Male
1 Participants1 Participants2 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 60 / 6
other
Total, other adverse events
0 / 60 / 6
serious
Total, serious adverse events
0 / 60 / 6

Outcome results

Primary

Circulating LPS

Plasma lipopolysaccharide (LPS) will be measured both in the fasting state and after a lipid-rich meal in obese subjects (Pre-Treatment: 0, 4 and 8 hr timepoints). The subjects will then be treated with the antibiotic rifaximin for 12 weeks to substantially reduce gut bacteria. LPS measurements at fasting and after a lipid-rich meal will be repeated (Post-Treatment: 0, 4 and 8 hr timepoints). The lipid tolerance tests before and after treatment with rifaximin will be assessed to determine whether there is a reduction in post-prandial LPS. LPS measurements were obtained using a modified LAL Assay.

Time frame: 0, 4 and 8 hours at Baseline, and 0, 4 and 8 hours after 12 weeks of treatment

ArmMeasureGroupValue (MEAN)Dispersion
Arm 1 Rifaximin SSDCirculating LPSPre-treatment 0hr2.44 EU/mLStandard Error 0.4
Arm 1 Rifaximin SSDCirculating LPSPre-treatment 4hr13.66 EU/mLStandard Error 2.93
Arm 1 Rifaximin SSDCirculating LPSPre-treatment 8hr1.71 EU/mLStandard Error 0.26
Arm 1 Rifaximin SSDCirculating LPSPost-treatment 0hr1.89 EU/mLStandard Error 0.35
Arm 1 Rifaximin SSDCirculating LPSPost-treatment 4hr8.45 EU/mLStandard Error 1.87
Arm 1 Rifaximin SSDCirculating LPSPost-treatment 8hr2.14 EU/mLStandard Error 0.49
Arm 2 PlaceboCirculating LPSPost-treatment 4hr9.97 EU/mLStandard Error 4.3
Arm 2 PlaceboCirculating LPSPre-treatment 0hr1.86 EU/mLStandard Error 0.33
Arm 2 PlaceboCirculating LPSPost-treatment 0hr1.86 EU/mLStandard Error 0.43
Arm 2 PlaceboCirculating LPSPre-treatment 4hr10.00 EU/mLStandard Error 1.55
Arm 2 PlaceboCirculating LPSPost-treatment 8hr2.29 EU/mLStandard Error 0.81
Arm 2 PlaceboCirculating LPSPre-treatment 8hr1.04 EU/mLStandard Error 0.48
Comparison: Comparison of the pre- and post-treatment timecourse between untreated and rifaximin-treated participants.p-value: >0.05ANOVA
Secondary

Tissue Inflammation

Subjects will undergo a baseline fat biopsy (pre-treatment). They will then be treated with rifaximin for 12 weeks and biopsies will be repeated to determine if disruption of the microbiota reduces tissue inflammation. Data are reported as normalized mRNA expression levels (arbitrary units) of TNFalpha.

Time frame: Pre-Treatment (baseline) and Post-Treatment (12 weeks after baseline).

ArmMeasureGroupValue (MEAN)Dispersion
Arm 1 Rifaximin SSDTissue InflammationPre-Treatment2.00 arbitrary unitsStandard Error 0.25
Arm 1 Rifaximin SSDTissue InflammationPost-Treatment1.67 arbitrary unitsStandard Error 0.25
Arm 2 PlaceboTissue InflammationPre-Treatment1.30 arbitrary unitsStandard Error 0.13
Arm 2 PlaceboTissue InflammationPost-Treatment1.46 arbitrary unitsStandard Error 0.28
Comparison: Treatment difference (change in placebo pre- and post-treatment versus change in rifaximin pre- and post-treatment).p-value: 0.12t-test, 2 sided
Other Pre-specified

Improved Insulin Sensitivity

We hypothesize that a change in the microbial flora with rifaximin will alter plasma LPS, adipose tissue inflammation, and insulin sensitivity. Therefore, we will examine, before and after rifaximin/placebo treatment: 1. LPS associated with lipoproteins, 2. insulin sensitivity and hepatic glucose production, 3. plasma inflammatory markers (TNFα, IL-6, MCP-1, adiponectin), 4. adipose inflammatory markers (CD68, MCP1, TNFα, PAI1, IL12, IL10, TLR4 and others).

Time frame: Up to 12 weeks

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026