Almonds to Improve Gut Health and Decrease Inflammation

Not Applicable

Active, not recruiting

Brief Summary: Almonds are a good source of beneficial compounds. This study will investigate if eating almonds everyday for 12 weeks can affect gut health and inflammation in persons with metabolic syndrome. Investigators will measure changes in metabolism, heart health, and the levels of vitamins and other compounds from almonds.

Detailed Description: Metabolic Syndrome (MetS) affects over a billion people world-wide. MetS progression and further health complications are driven by chronic inflammation. Major causes of inflammation in MetS are gut barrier breakdown and the absorption of harmful bacteria. What causes the gut barrier breakdown is not clear, but a poor diet, especially low micronutrient intakes like vitamin E, is implicated by propagating a vicious cycle that promotes oxidative stress, inflammation and further gut barrier damage. This study will assess the impact of daily consumption of 2 ounces of almonds for 12 weeks on gut health, markers of inflammation and cardiometabolic health, and micronutrient status in persons with MetS.

Recruitment & Eligibility

Inclusion Criteria

Age 35-60 years
3 or more of the following: hypertension (systolic BP 130-179 mmHg or diastolic BP 85-119 mmHg); hyperglycemia (fasting glucose 100-599 mg/dL); central obesity [waist circumference greater than 40.1 inches (M) or 34.6 inches (F); hypertriglyceridemia (150-499 mg/dL); low HDL [lower than 40 mg/dL (M) or 50 mg/dL (F)]
Willing to restrict consumption of nuts other than study nuts for 1 week prior to and throughout the study (13 weeks)
Willing to stop probiotic supplements one week prior to and during the study (13 weeks)
Willing to stop multivitamins and supplements containing vitamin E, magnesium, calcium, iron, zinc and copper one week prior to and during the study (13 weeks)
Willing to complete intake diaries during the study
Willing to maintain current eating patterns (no significant diet change during study)

Exclusion Criteria

Weekly consumption of almonds, hazelnuts, peanuts and sunflower seeds combined greater than 2 servings (about 2 oz) in the past 3 months
Nut, wheat, or gluten allergy/intolerance
Regular use of vitamin E supplements
Consume more than 2 alcoholic drinks daily
Tobacco use, including e-cigarettes, or smoking of any substance (e.g. cannabis) in the past 3 months
Pregnancy, breastfeeding, or planning to become pregnant before completing the study
Vigorous exercise greater than 7 hours/week
History of cardiovascular disease, liver disease or cancer
Have had bariatric surgery (e.g. gastric bypass, gastric banding, sleeve gastrectomy, etc.), other gastrointestinal procedures (e.g. cholecystectomy), disorders (e.g. Crohn's disease, celiac disease, ulcerative colitis) or chronic diarrhea
Diagnosis of hemochromatosis
Chronic use (daily intake in past 30 days) of anti-inflammatory medication (steroid or NSAID)
Use of ezetimibe or orlistat
Use of oral antibiotic medication within the past month
Body Mass Index (BMI) <25.0 or >35.0 kg/m2
Regular use of multivitamin supplements in the past 3 months
Physician prescribed use of probiotic, vitamin E, magnesium, calcium, iron, zinc or copper supplements

Arm && Interventions

Group	Intervention	Description
Almonds	Almond	Daily consumption of 2 ounces of unsalted, dry roasted almonds for 12 weeks
Crackers	Crackers	Daily consumption of non-whole grain crackers for 12 weeks (caloric equivalent to 2 ounces of dry roasted almonds)

Primary Outcome Measures

Name	Time	Method
Gut permeability and health: Short chain fatty acids	0 and 4 weeks	Change from baseline at week 4: Markers of gut barrier function and health fecal short chain fatty acids profiles
Oxidative stress status: isoprostanes	0 and 4 weeks	Change from baseline at week 4: Urinary isoprostanes
Cardiometabolic health	0 and 12 weeks	Change from baseline at week 12: Total cholesterol, LDL, HDL, and triglycerides
Gut permeability and health: Inflammatory biomarkers	0 and 4 weeks	Change from baseline at week 4: Gut inflammatory biomarkers calprotectin and myeloperoxidase
Biomarkers of inflammation	0 and 4 weeks	Change from baseline at week 4: Plasma inflammatory markers (ex. TNF and IL-6)
Vitamin E status	0, 4 and 12 weeks	Change from baseline at week 4 and week 12: Plasma α-tocopherols
Gut permeability and health: Serum endotoxin	0 and 4 weeks	Change from baseline at week 4: Marker of gut barrier function and health, serum endotoxin
Vitamin E status: Urinary catabolite	0, 4 and 12 weeks	Change from baseline at week 4 and week 12: Urinary vitamin E catabolite (α-CEHC)
Oxidative stress status: malondialdehyde	0 and 4 weeks	Change from baseline at week 4: Plasma malondialdehyde

Secondary Outcome Measures

Name	Time	Method
BMI	0, 4 and 12 weeks	Change from baseline at week 4 and week 12: BMI (weight and height will be combined to report BMI in kg/m\^2)
Waist circumference	0, 4 and 12 weeks	Change from baseline at week 4 and week 12: Waist circumference
Mineral status	0 and 12 weeks	Change from baseline at week 12: Plasma magnesium, calcium, iron, zinc, and copper (microgram/mL)
Glycemic control: glucose	0 and 12 weeks	Change from baseline at week 12: Fasting blood glucose
Blood pressure	0, 4 and 12 weeks	Change from baseline at week 4 and week 12: Systolic, and diastolic blood pressure
Weight	0, 4 and 12 weeks	Change from baseline at week 4 and week 12: Weight
Glycemic control: HOMA-IR	0 and 12 weeks	Change from baseline at week 12: HOMA-IR
Glycemic control: Insulin	0 and 12 weeks	Change from baseline at week 12: Insulin
Other almond-based bioactives (polyphenol levels)	0 and 12 weeks	Change from baseline at week 12: Urinary metabolites of flavonoids like (+)-catechin, (-)-epicatechin and naringenin