Efficacy and Safety of Low-Carbohydrate Diet Combined With Probiotics for Weight Loss in Male Obese Patients.：A Randomized, Double-blind, Placebo, Controlled Clinical Trial.

This study is a randomized, double-blind, placebo-controlled clinical trial. According to the preliminary experimental results, the decrease in weight of the experimental group intervening by low-carbohydrate diet combined with probiotics compound preparation was up to (6.5±1.1) kg over the whole study period compared to that in control group adopted low-carbohydrate diet combined with placebo, which was about (4.1±0.8) kg. When taking superiority cutoff (δ) of 1.5kg, in α = 0.025 (one-sided) and the power (1-β) = 0.8, on the premise that the two groups of research objects are equal in number, the sample size of the experimental group and the control group is 19 cases respectively by using the PASS11.0 software to calculate (N1=N2=19 cases). Considering that a dropout rate of no more than 10% may occur during follow-up, this study included a total sample size of no less than 44.

Forty-four obese participants who meet the inclusion/exclusion criteria are randomly assigned to group A and group B at a ratio of 1:1. As the trial group, group A was treated with a 12-week low-carbohydrate diet combined with probiotic compound preparations, and group B was treated as a placebo control group with a 12-week low-carbohydrate diet combined with placebo treatment. Since the probiotic compound preparation is made of Lactobacillus reuteri, Lactobacillus gasseri, Lactobacillus acidophilus, Bifidobacterium lactis, and resistant dextrin (water-soluble dietary fiber), to eliminate the effect of resistant dextrin (water-soluble meal fiber) on the experimental results, the placebo is prepared from resistant dextrin (water-soluble meal fiber) and is packaged to be consistent with the appearance of the probiotic compound preparation.

During the trial period, participants will attend face-to-face visits at 4-week (visit 3), 8-week (visit 4), and 12-week (visit 5). During each follow-up visit, participants will be asked about their dietary structure, average daily calorie intake, exercise volume, adverse events, and so on. Research assistants will record their heart rate, blood pressure, height, weight, BMI, waist circumference, and waist-to-hip ratio. During the 12-week (visit 5), research assistants will record fasting blood glucose, fasting insulin, insulin resistance index (HOMA-IR), biomarkers of lipids metabolism (TG/TC/LDL/HDL), subcutaneous fat and visceral fat volume, the fat fraction (FF). Fecal samples will be collected by participants at baseline as well as at the end stage and be divided into 10 parts, each one is about 200-300mg. All fecal samples will be stored in a -80 ℃ freezer by researchers. At the end of the experiment, fecal samples will be uniformly sent to Metabo-Profile Biotechnology (Shanghai) Co., Ltd. to detect the composition of gut microbes.

The data of this project will be collected from the Department of Endocrinology and Metabolism, Zhujiang Hospital of Southern Medical University. Relevant information will be obtained by consulting the inspection system and asking patients. All data will be recorded independently by two specialized statisticians.

Data management strictly abides by relevant regulations, and any transfer of electronic data or subject-related data must be approved by the data management department. In case data is transmitted through non-secure electronic networks, corresponding data protection rules must be followed.