Clinical Study to Evaluate the Body Fat Reducing Effect and Safety of GTB1

Inclusion Criteria: * Males and females aged between 19\~65 years at the screening * Participants who were BMI 25.0\~34.9 kg/m\^2 (Excluding those who need to take or be prescribed medication that affects fat reduction, if the BMI is between 30.0\~34.9 kg/m\^2) * Participants who have a waist circumference of 90 cm for men and 85 cm or more for women * Participants who have fully understood the information provided about the study voluntarily decided to participate and agreed to comply with precautions Exclusion Criteria: * Participants who decrease 10% more of weight within 3 months period to the screening * Participants who have undergone surgical procedures (such as gastrectomy) for weight loss * Participants who have a history of malignant tumors within 5 years prior to participating in the clinical study * Participants who have a systolic blood pressure of 160 mmHg or higher, or a diastolic blood pressure of 100 mmHg or higher (those who are stably controlling their blood pressure with medication can participate) * Participants who are taking beta-blockers or diuretics as part of their hypertension treatment * Patients who have been diagnosed with Type 1 or Type 2 diabetes and are taking oral hypoglycemic agents and insulin * Participants who have taken antibiotics within 4 weeks prior to the screening examination * Participants who have taken health functional foods, herbal medicine, or general foods for the purpose of weight loss within 4 weeks prior to the screening visit * Participants with clinically significant acute or chronic diseases of the cardiovascular system, endocrine system, immune system, respiratory system, liver biliary system, kidney and urinary system, neuropsychiatry system, musculoskeletal system, inflammatory and hematologic, gastrointestinal diseases, and other diseases requiring treatment * Participants with a past history of gastrointestinal diseases (e.g., Crohn's disease) or gastrointestinal surgery (but, excluding simple cecal surgery and hernia surgery) that can affect the absorption of products of the human trial * Participants who have participated in other clinical study within 3 months prior to the screening examination * Women who are pregnant or breastfeeding * Women who may become pregnant and have not used appropriate contraceptives * Participants who show the following relevant results in a Laboratory test * Aspartate Transaminase (AST), Alanine Transaminase (ALT) \> Reference range 3 times upper limit * Serum Creatinine \> 2.0 mg/dl * Participants who the principal investigator judged inappropriate for the participant in this study because of a laboratory test result, etc.