The effect of synbiotic supplementation on hypercholesterolaemia during a ketogenic diet: a randomised controlled trial
Hypercholesterolaemia
Here is your text with formatting cleaned, clarified, and made consistent, while keeping all original meaning intact and using no special formatting: DESIGN: The study will be a two-arm, 12‑week, parallel‑group, double‑blind randomised controlled trial (RCT) in men and women aged 18–65 years (N=64). One group will consume a daily synbiotic supplement (Polydextrose and Bifidobacterium animalis subsp. lactis B420), and the other group will consume a matched placebo. All participants will follow a low‑carbohydrate ketogenic diet. A subset of participants (50%) will be invited to complete a feeding‑trial assessment before and after the supplementation period. These participants will remain in the laboratory for an additional 10 hours so that postprandial changes (responses to feeding) can be examined. TIMELINE: Eligibility will be checked and confirmed during a screening visit (Visit 1, V1). Participants will then be provided with equipment to assess their diet and physical activity, as well as continuous monitors to measure normal glucose and ketone levels. Approximately two weeks later, participants will attend a main trial day (Visit 2), which will include various measurements such as blood samples and a DEXA scan. Participants will also be asked to provide a stool sample. After the first main trial day, participants will begin the 84‑day (12‑week) ketogenic diet and supplement period. After about 42 days (6 weeks), participants will attend an interim visit (Visit 3) where some measures will be repeated, including the DEXA scan and assessments of diet, glucose/ketones, and physical activity. Participants will continue on the ketogenic diet and daily supplement, and these measures will be repeated again during the final 14 days of the study. On day 84 (12 weeks), participants will attend a final main trial (Visit 4). MEASURES: The study will examine the effect of synbiotic supplementation on LDL‑C concentrations and lipoprotein profile using NMR spectroscopy. Gut m
1. Age 18-65 years 2. Body Mass Index (BMI) of 20.0-34.9 kg/m² 3. Able to provide informed consent 4. Willing and able to comply with all study procedures including, maintenance of habitual dietary intake, physical activity, and medication use during the study period.
1. Any reported condition or behaviour deemed to either pose undue personal risk to the participant or that would introduce bias and affect study outcomes 2. Any diagnosed disease(s) or prior surgical procedure that would affect study outcomes (e.g., Type 1 or Type 2 Diabetes Mellitus, cholecystectomy) 3. Severe hypertension (systolic blood pressure ≥ 180 mmHg and/or diastolic blood pressure ≥ 120 mmHg) 4. Taking prescribed medications that will interfere with the study outcomes (e.g., lipid‑lowering medication) 5. Current use of non‑prescribed supplements that could interfere with the study outcomes (e.g., laxatives) 6. Use of antibiotic medication in the last 3 months 7. Frequent use of prebiotic/fibre supplements or probiotic supplements in the last month (>15 times over the past month) 8. Already consuming a low carbohydrate ketogenic diet 9. Current or recent tobacco or recreational drug use (within prior 3 months) 10. Known negative reaction to lidocaine anaesthetic and/or taking warfarin 11. Not weight stable in the prior 3 months (>3% weight change) 12. Unable to understand the required instructions 13. Vegetarian or vegan 14. Women: Pregnant or planning to become pregnant 15. Women: Post‑menopausal (absence of menses for >12 months)