Exercise, Milk Thistle, and Lactobacillus to Influence Plasma Bilirubin

Milk Thistle and Lactobacillus Supplementation to Improve Exercise Outcomes in Obese Patients

The proposed clinical trial will test our hypothesis that, during exercise, red blood cell (RBC) release of heme and catabolism to bilirubin is an essential process that mediates gene responses that reduce body fat. We will evaluate whether Milk Thistle extract or Lactobacillus Gasseri extends bilirubin circulating times to decrease body fat further. Thus we will perform a 12-week, 6-armed trial with one group performing aerobic exercise 5 times per week (EX) one group receiving a Milk Thistle extract (MT), one group receiving a lactobacillus gasseri supplement (LAC), a group receiving only a placebo (CON), and groups both exercising and receiving the MT (MT + EX) and lactobacillus and exercise (LAC + EX).

Study Overview

• Status: Completed
• Conditions: Obesity
• Intervention / Treatment: Dietary supplement: Milk Thistle (MT); Dietary supplement: Lactobacillus Gasseri (LAC); Behavioral: Exercise (EX); Dietary supplement: Control (CON)

Detailed Description

The investigative team's previous work has shown that BR binds to the PPARalpha protein in fat and liver tissues to activate genes that improve fatty acid oxidation via a hormone known as fibroblast growth factor-21 (FGF21). The investigators recently showed that in high capacity running rats (HCR) compared to low capacity running (LCR), in which the latter are obese, BR levels and PPARalpha-FGF21 were significantly raised in the high-capacity runners. New investigations have shown that Milk Thistle (MT) herbal supplement contains polyphenols that activate pathways that suppress the glucuronyl enzyme UGT1A1 that removes BR from the blood, improving liver function and moderately increasing BR blood levels by ~2-fold. Similar findings have been demonstrated with Lactobacillus Gasseri supplementation. Hence, there is a bilirubin-PPARalpha-FGF21 axis that can be driven by exercise and dietary supplementation. We will test whether exercise and milk thistle or exercise and lactobacillus gasseri synergistically increase bilirubin-PPARalpha-FGF21, further reducing body fat in patients with obesity.

Participants in the EX, EX + MT, and EX + LAC groups will complete five weekly exercise sessions on their own, expending roughly 600 kcal per session. Participants will be provided a Polar A-300 heart rate monitor programmed for their individual attributes (height, weight, age, training status, gender), which gives a real-time estimate of energy expenditure during exercise. Participants will report to the lab once per week to download the exercise sessions and verify compliance. If participants are not compliant (defined as completing 85% of their assigned exercise sessions per month), they will be disqualified. This intervention has been successfully used by the investigators in multiple studies to produce significant weight loss without dietary intervention in this population with a retention rate of over 90% Participants in the MT and EX + MT groups will be provided 900 mg of standardized milk thistle extract daily (300 mg three times per day before meals) over the 12-week regimen. The investigators will use the standardized Jarrow Formulas Milk Thistle Veggie Caps containing 30:1 extract that is standardized to contain 80% total Milk Thistle seed flavonoids (polyphenols), including the critical Silymarin fractions isosilybinins A and B, silybinins A and B, silychristin and silydianin that is active against suppressing the UGT1A1 enzyme increasing plasma bilirubin. The capsules are free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, and GMOs. Rationale for using this brand: There have been inconsistencies with previous studies that did not use a standardized silymarin extract, which may have contained low levels of the active polyphenolic flavonoids in the milk thistle plant, which varies in the plant's stems, leaves, roots, and flowers.

Participants in the LAC and LAC + EX groups will receive two doses of 3 billion CFU of lactobacillus gasseri per day for a total of 6 billion CFU, the recommended upper level for supplementation of probiotic cultures. The Swanson brand Lactobacillus gasseri will be used, as these capsules are also free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, and GMOs. Importantly, this brand uses acid-resistant designed release capsules to improve the viability of the lactobacillus in the human stomach.

Participants in the CON and EX group will receive a placebo (maltodextrin) made to look identical to the MT capsules.

• Study Type: Interventional
• Enrollment (Actual): 42
• Phase: Phase 3

Contacts and Locations

Study Locations

• United States
  • Kentucky
    • Lexington, Kentucky, United States, 40506
      • University of Kentucky- Nutrition Assessment Lab

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Classified as obese (BMI 30-45)
• Sedentary (do not currently exercise)
• Aged 18-50 years
• Without contraindications to exercise

Exclusion Criteria:

• Dieting for weight control
• Tobacco users
• Have a ragweed allergy
• Taking antibiotics, hypoglycemic agents, anticoagulants, statins, or NSAIDs
• Nursing, pregnant, or planning on becoming pregnant
• Supplementing with a probiotic

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: MT; Participants in the MT group will be supplemented with Milk Thistle extract for 12 weeks	Dietary supplement: Milk Thistle (MT); Participants in the MT and EX + MT groups will be provided 900 mg of standardized milk thistle extract daily (300 mg three times per day before meals) over the 12-week regimen. We will use the standardized Jarrow Formulas Milk Thistle Veggie Caps containing 30:1 extract that is standardized to contain 80% total Milk Thistle seed flavonoids (polyphenols), including the critical Silymarin fractions isosilybinins A and B, silybinins A and B, silychristin and silydianin that is active against suppressing the UGT1A1 enzyme increasing plasma bilirubin. The capsules are free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, and GMOs. Rationale for using this brand: There have been inconsistencies with previous studies that did not use a standardized silymarin extract, which may have contained low levels of the active polyphenolic flavonoids in the milk thistle plant, which varies in the plant's stems, leaves, roots, and flowers.
Experimental: LAC; Participants in the LAC group will be supplemented with Lactobacillus Gassri for 12 weeks	Dietary supplement: Lactobacillus Gasseri (LAC); Participants in the LAC and LAC + EX groups will receive two doses of 3 billion CFU of lactobacillus gasseri per day for a total of 6 billion CFU, the recommended upper level for supplementation of probiotic cultures. We will use Swanson brand Lactobacillus gasseri, whose capsules are also free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, and GMOs. Importantly, this brand uses acid-resistant designed release capsules to improve the viability of the lactobacillus in the human stomach.
Experimental: EX; Participants in the EX group will perform aerobic exercise, 5 days per week for 12 weeks	Behavioral: Exercise (EX); Participants in the EX, EX + MT, and EX + LAC groups will complete five weekly exercise sessions on their own, expending roughly 600 kcal per session. Participants will be provided a Polar A-300 heart rate monitor programmed for their individual attributes (height, weight, age, training status, gender), which gives a real-time estimate of energy expenditure during exercise. Participants will report to the lab once per week to download the exercise sessions and verify compliance. If participants are not compliant (defined as completing 85% of their assigned exercise sessions per month), they will be disqualified. This intervention has been successfully used by Dr. Flack in multiple studies to produce significant weight loss without dietary intervention in this population with a retention rate of over 90%; Dietary supplement: Control (CON); Participants in the CON and EX group will receive a placebo (maltodextrin) made to look identical to the MT and LAC capsules.
Experimental: MT + EX; Participants in the MT + EX group will be supplemented with Milk Thistle extract and exercise for 12 weeks	Dietary supplement: Milk Thistle (MT); Participants in the MT and EX + MT groups will be provided 900 mg of standardized milk thistle extract daily (300 mg three times per day before meals) over the 12-week regimen. We will use the standardized Jarrow Formulas Milk Thistle Veggie Caps containing 30:1 extract that is standardized to contain 80% total Milk Thistle seed flavonoids (polyphenols), including the critical Silymarin fractions isosilybinins A and B, silybinins A and B, silychristin and silydianin that is active against suppressing the UGT1A1 enzyme increasing plasma bilirubin. The capsules are free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, and GMOs. Rationale for using this brand: There have been inconsistencies with previous studies that did not use a standardized silymarin extract, which may have contained low levels of the active polyphenolic flavonoids in the milk thistle plant, which varies in the plant's stems, leaves, roots, and flowers.; Behavioral: Exercise (EX); Participants in the EX, EX + MT, and EX + LAC groups will complete five weekly exercise sessions on their own, expending roughly 600 kcal per session. Participants will be provided a Polar A-300 heart rate monitor programmed for their individual attributes (height, weight, age, training status, gender), which gives a real-time estimate of energy expenditure during exercise. Participants will report to the lab once per week to download the exercise sessions and verify compliance. If participants are not compliant (defined as completing 85% of their assigned exercise sessions per month), they will be disqualified. This intervention has been successfully used by Dr. Flack in multiple studies to produce significant weight loss without dietary intervention in this population with a retention rate of over 90%
Experimental: LAC + EX; Participants in the LAC + EX group will be supplemented with Lactobacillus Gassri and exercise for 12 weeks	Dietary supplement: Lactobacillus Gasseri (LAC); Participants in the LAC and LAC + EX groups will receive two doses of 3 billion CFU of lactobacillus gasseri per day for a total of 6 billion CFU, the recommended upper level for supplementation of probiotic cultures. We will use Swanson brand Lactobacillus gasseri, whose capsules are also free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, and GMOs. Importantly, this brand uses acid-resistant designed release capsules to improve the viability of the lactobacillus in the human stomach.; Behavioral: Exercise (EX); Participants in the EX, EX + MT, and EX + LAC groups will complete five weekly exercise sessions on their own, expending roughly 600 kcal per session. Participants will be provided a Polar A-300 heart rate monitor programmed for their individual attributes (height, weight, age, training status, gender), which gives a real-time estimate of energy expenditure during exercise. Participants will report to the lab once per week to download the exercise sessions and verify compliance. If participants are not compliant (defined as completing 85% of their assigned exercise sessions per month), they will be disqualified. This intervention has been successfully used by Dr. Flack in multiple studies to produce significant weight loss without dietary intervention in this population with a retention rate of over 90%
Placebo Comparator: CON; Participants in the CON group will be supplemented with maltodextrin pills made to look like the pills received by the MT and LAC groups for 12 weeks	Dietary supplement: Control (CON); Participants in the CON and EX group will receive a placebo (maltodextrin) made to look identical to the MT and LAC capsules.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lean mass	kg of lean mass will be assessed by air displacement plethysmography (BodPod, Cosmed USA)	baseline (prior to initiation of study)
Lean mass	kg of lean mass will be assessed by air displacement plethysmography (BodPod, Cosmed USA)	12 weeks (immediately after 12 week exercise and/or supplement intervention)
Fat mass	kg of fat mass will be assessed by air displacement plethysmography (BodPod, Cosmed USA)	baseline (prior to initiation of study)
Fat mass	kg of fat mass will be assessed by air displacement plethysmography (BodPod, Cosmed USA)	12 weeks (immediately after 12 week exercise and/or supplement intervention)
Plasma bilirubin	Plasma bilirubin will be assessed in the fasted state	baseline (prior to initiation of study)
Plasma bilirubin	Plasma bilirubin will be assessed in the fasted state	12 weeks (immediately after 12 week exercise and/or supplement intervention)
Plasma FGF21	fibroblast growth factor-21 will be assessed in the fasted state	baseline (prior to initiation of study)
Plasma FGF21	fibroblast growth factor-21 will be assessed in the fasted state	12 weeks (immediately after 12 week exercise and/or supplement intervention)
Red blood cell count	Red blood cell count will be assessed in the fasted state	baseline (prior to initiation of study)
Red blood cell count	Red blood cell count will be assessed in the fasted state	12 weeks (immediately after 12 week exercise and/or supplement intervention)
Urobilin	Plasma Urobilin will be assessed in the fasted state	baseline (prior to initiation of study)
Urobilin	Plasma Urobilin will be assessed in the fasted state	2 weeks (immediately after 12 week exercise and/or supplement intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Liver function	AST and ALT enzymes will be assessed in the fasted state to demonstrate liver health	baseline (prior to initiation of study)
Liver function	AST and ALT enzymes will be assessed in the fasted state to demonstrate liver health	12 weeks (immediately after 12 week exercise and/or supplement intervention)

Collaborators and Investigators

• Sponsor: Kyle Flack

Study record dates

Study Major Dates

• Study Start (Actual): February 24, 2021
• Primary Completion (Actual): July 19, 2023
• Study Completion (Actual): July 19, 2023

Study Registration Dates

• First Submitted: January 13, 2021
• First Submitted That Met QC Criteria: January 15, 2021
• First Posted (Actual): January 22, 2021

Study Record Updates

• Last Update Posted (Actual): July 28, 2023
• Last Update Submitted That Met QC Criteria: July 26, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: Exercise; obesity; weight loss; Lactobacillus; Milk Thistle; Bilirubin
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity
• Other Study ID Numbers: 63147

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: unidentified participant data will be shared on figshare data repository
• IPD Sharing Time Frame: Within 6 months of study completion data, for 5 years.
• IPD Sharing Access Criteria: available to public, has not been created yet
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No