Short and Long-Term Effects of Prebiotic, Probiotic and Synbiotic on Appetite and Dietary Intake

Short and Long-Term Effects of Prebiotic, Probiotic and Synbiotic on Appetite and Dietary Intake

Prebiotics and probiotics are thought to play a role in appetite control and body weight regulation; but little is known about this topic. This study was planned to examine the effects of inulin and Lactobacillus casei 431 on short and long term fasting, satiety, dietary intake, and serum hunger and satiety hormone levels. The study consisted of 2 phases. In the first phase, a double-blind, randomized, crossover study design was used, and it was performed with 16 healthy male participants aged 19-30 years. In this phase, the prebiotic (200mL milk+16g inulin), probiotic (200mL milk + Lactobacillus casei 431 [>106 cfu/mL]+16g maltodextrin), synbiotic (200mL milk+16g inulin + Lactobacillus casei 431 [>106 cfu/mL]) and control (200mL milk+16g maltodextrin) test drinks were consumed with a standard breakfast on four separate test days by one week intervals, and their effects on dietary intake, hunger, satiety and appetite were assessed. The second phase was performed with 21 healthy male participants aged 19-30 years, using a placebo-controlled double-blind, randomized study design. Participants consumed the control (200mL milk+16g maltodextrin) or synbiotic (200mL milk+16g inulin+ Lactobacillus casei [>106 cfu/mL]) test drinks for 21 days with their habitual diet. At the beginning and end of the intervention, blood samples were collected at 0., 30., 60. and 120. minutes following the test day protocol to analyse serum glucose, insulin, ghrelin, obestatin and PYY (peptide tyrosine tyrosine) levels. In addition, dietary intake, hunger, satiety and appetite of participants were compared.

Inclusion Criteria:

• Healthy male
• 19-30 years old
• Body mass index (BMI) of 18.5-29.9 kg/m2

Exclusion Criteria:

• Being female
• Being younger than 19 years old or older than 30 years old
• Having a BMI that is lower than 18.5 kg/m2 or higher than 29.9 kg/m2
• Smoking
• Having any metabolic disease
• Losing or gaining weight in the past 3 months
• Following a special diet
• Using any medicine which could affect the outcome of the study
• Having food intolerance and allergies
• Taking regular probiotic or prebiotic foods or supplements
• Not consuming breakfast or lunch regularly
• Being a professional athlete
• Having unhealthy eating attitude that assessed using three factor eating questionnaire (having cognitive restraint score >13, uncontrolled eating score >18, and emotional eating > 6)
• Having depression that was assessed using Beck's Depression Inventory (having a score >9)