Pilot: Combining HIIT and n-3 PUFA Supplementation to Reduce Inflammation and Improve Metabolic Health (HIIT&PUFA)

The goal of this pilot study is to understand the combined effects of fish oil and exercise in obesity-associated inflammation acutely. We hypothesize that fish oil will improve gut bacteria profiles, which will in turn potentiate the benefits of an exercise program and reduce inflammation and metabolic risk.

Incidence of obesity continues to increase in the United States and worldwide, making its prevention or reduction a public health priority. Nutrition research that can lead to effective prevention strategies is greatly needed. Inflammation is a major underlying cause for obesity, and it is imperative that we understand how anti-inflammatory food sources, such as fish oil, could aid in reducing obesity. Moreover, exercise is effective at reducing systemic inflammation and improving insulin resistance. Both exercise and diet can influence health through changes in the gut microbiome; however, no studies have investigated how together these affect gut microbiome and overall metabolic health. The goal is to understand the combined effects of fish oil and exercise in obesity-associated inflammation. The investigators hypothesize that fish oil will improve gut bacteria profiles, which will in turn potentiate the benefits of an exercise program reduce inflammation and metabolic risk. This study will provide the foundation for development of novel strategies for obesity, inflammation, dyslipidemia and dysglycemia.

Aim 1: Determine combined effects of n-3 PUFA and HIIT on improving metabolic risk:

The investigators will test the hypothesis that n-3 PUFA in addition to HIIT will have beneficial effects on obesity-related markers of inflammation, dyslipidemia and insulin resistance in placebo, n-3 or exercise alone, and combined n-3 and exercise.

Aim 1.1: Investigate the influence of n-3 PUFA and HIIT on body weight and composition:

At baseline (week 0), anthropometric assessments will be performed, including: (1) height (m); (2) weight (kg); (3) waist circumference (cm); (4) hip circumference (cm); and body composition which will be assessed utilizing dual-energy X-ray absorptiometry (DXA) scanning. Anthropometric measures will be repeated at post-intervention (week 6).

Aim 1.2: Investigate the influence of n-3 PUFA and HIIT on serum markers associated with obesity

Fasting blood samples collected at weeks 1 and 6 will be analyzed for (1) markers of inflammation, including high sensitivity C-reactive protein (hs-CRP), IL-6, IL-10, MCP-1, and TNF-α; (2) adipokines, including adiponectin, resistin, and leptin; and (3) indices of systemic insulin resistance, including insulin and fasting blood glucose and (4) indices of dyslipidemia, including total cholesterol, high-density, lipoprotein (HDL), non-HDL, low- and very low-density lipoproteins (LDL and VLDL), total/HDL cholesterol, and triglycerides (TG) utilizing ELISA kits or Luminex analyzer \[1\] in the Nutrition, Exercise, \& Translational (NExT) Medicine Lab in the Department of Kinesiology \& Sport Management, TTU, Lubbock.

Aim 2: Determine combined effects of n-3 PUFA and HIIT on improving gut dysbiosis:

The investigators will test the hypothesis that n-3 PUFA supplementation will improve gut microbiota composition and related metabolites, which will result in reduced inflammation and ameliorate the metabolic response to a HIIT exercise intervention in an overweight population. This will be accomplished by identifying alterations in gut microbiota profiles following n-3 supplementation, HIIT or the interactive effects of both HIIT and n-3 PUFA.

Aim 2.1: Investigate the influence of n-3 PUFA and exercise on gut microbiota composition

Fecal samples will be collected by participants at their convenience in their homes and less than 24 hours prior to visiting the lab. Samples will be brought to the lab at weeks 1 and 6. Samples will be collected at home with investigator prepared kits and will be stored at -80°C until DNA extraction. Metagenomics analyses will be conducted in consultation with our collaborators at the University of Houston.

Aim 2.2: Investigate the influence of n-3 PUFA and exercise on microbiota produced metabolites

Fecal and serum short-chain fatty acid (SCFA)s, including acetate, propionate and butyrate, will be measured as markers of the above gut bacteria changes and in association with changes in serum markers of inflammation, dyslipidemia and dysglycemia. Fecal and serum SCFAs will be measured utilizing gas chromatography. Analyses will be conducted on fasting blood samples collected at baseline and post-intervention.

Participants will be randomly allocated to 1 of 4 treatment groups (n = 120), each balanced for sex, BMI, lipid profile, and dietary intake.

1. placebo (safflower oil, AlaskOmega®) + flexibility (exercise control)
2. n-3 PUFA (4 grams, 3000 mg EPA and 1000 mg DHA, AlaskOmega®) + flexibility training (exercise control)
3. placebo (safflower oil, AlaskOmega®) + HIIT
4. n-3 PUFA + HIIT

The goal is to conduct the study in smaller cohorts, such as 10-15 participants/group (n = 40-60).

4 grams n-3 PUFA (AlaskOmega®) per day (3000 mg EPA and 1000 mg DHA) will be taken by participants in n-3 PUFA groups for 6 weeks

Placebo (safflower oil, AlaskOmega®, from Organic Technologies Inc.) will be taken by participants in placebo groups for 6 weeks

A 4 x 4 HIIT exercise (4 intervals for 4 min at 85-95% HRmax with 3min active recovery at 50-70% HRmax) program, 3 days/week, conducted under virtual investigator supervision and utilizing cycle ergometers (Keiser M3i Indoor Bike) equipment in collaboration with the TTU Department of Kinesiology \& Sport Management for 6 weeks.

If not asked to exercise, participants will be instructed to maintain their normal level of physical activity but will participate in time-matched control consisting of flexibility training led by investigators for 6 weeks.

All participants will wear a heart rate monitor (Polar H10) provided by TTU throughout the training (HIIT and control) to monitor exertion level.

Capsules will be administered in a double-blind fashion and will be identical in appearance. To ensure compliance, subjects will be reminded via phone (text message or phone call based on participant preference) to take their capsules and counts will be conducted when they come in for study visits.

At the end of the 6-week study, assessments will be repeated.

Eligibility Criteria:
Inclusion Criteria:

* 18-65 years old. Overweight/ Obese. Elevated Triglycerides. Fasting blood glucose \< 126 mg/dL

Exclusion Criteria:

* Diagnosed with diabetes, liver disease, or any lower gastrointestinal disease. Currently taking blood pressure, diabetes, or lipid lowering medication. Received antibiotic treatment within the last 6 months. Are pregnant, lactating, have an irregular menstrual cycle, or are menopausal. Currently following a structured or formal weight loss program. Exercise ≥ 1 time/week or a moderate-high score on the International Physical Activity Questionnaire.

Currently taking fish oil supplements (within 4 weeks prior to participant randomization) or eat ≥1 fatty fish meal/week.

Do not have access to a smartphone. Feel uncomfortable riding a stationary bike for 30 minutes.