The Effect of Probiotic Foods on Depression
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Depressive symptom severity assessed by the Beck Depression Inventory (BDI)
研究概览
简要总结
This exploratory study examined whether different frequencies of consuming three fermented foods commonly eaten in Türkiye-kefir, tarhana, and mixed pickles-were associated with short-term changes in body measurements and psychological well-being in adults.
Thirty adults aged 18 to 55 years were randomly assigned to one of three groups for four weeks. The control group followed an individualized dietary plan that excluded fermented foods. The lower-frequency group followed a similar dietary plan and consumed kefir, tarhana, and mixed pickles once per week. The higher-frequency group consumed kefir daily, tarhana four times per week, and mixed pickles three times per week.
Body weight, body mass index, waist circumference, mid-upper arm circumference, estimated body fat measures, depressive symptoms, and general psychological distress were assessed at the beginning and end of the four-week intervention. The study was designed as an exploratory dietary intervention and did not have a prespecified primary outcome.
详细描述
This was an exploratory, three-arm, parallel-group randomized dietary intervention conducted in adults living in Istanbul, Türkiye. The study evaluated two different frequencies of incorporating kefir, tarhana, and mixed pickles into individualized dietary plans over a four-week period.
Thirty participants were randomly allocated in a 1:1:1 ratio to a control group, a lower-frequency fermented-food group, or a higher-frequency fermented-food group. All participants received individualized dietary plans based on estimated daily energy and nutrient requirements. The control-group plan excluded fermented foods. In the intervention groups, the study foods were added to the individualized dietary plans rather than replacing other prescribed food servings.
Participants in the lower-frequency group were instructed to consume one serving each of kefir, tarhana, and mixed pickles once per week. Participants in the higher-frequency group were instructed to consume kefir daily, tarhana soup four times per week, and mixed pickles three times per week. One serving was defined as 200 mL of kefir, one serving of tarhana soup prepared with 20 g of powdered tarhana, and 100 g of mixed pickles. The intervention schedules were intended to create a pragmatic contrast between occasional and more frequent fermented-food consumption rather than microbiologically standardized doses.
Anthropometric assessments included body weight, body mass index, waist circumference, mid-upper arm circumference, estimated body fat percentage, and estimated body fat mass. Psychological outcomes included depressive symptom severity assessed using the Beck Depression Inventory and general psychological distress assessed using the General Health Questionnaire-28. Assessments were performed at baseline and after the four-week intervention.
The study was exploratory and did not have a prespecified primary outcome. All anthropometric and psychological outcomes were analyzed as exploratory study outcomes.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- Single (Outcomes Assessor)
盲法说明
Participants and intervention providers were not blinded because the dietary assignments were apparent from the prescribed foods. Outcome assessors and data analysts were blinded to group allocation.
入排标准
- 年龄范围
- 18 Years 至 55 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 18-55 years
- •Residence in Istanbul, Türkiye
- •BMI 18.0-24.9 kg/m²
- •No regular physical exercise
排除标准
- •Chronic medical condition
- •Regular medication use
- •Antidepressant use
- •Probiotic supplement use
- •Psychotherapy
- •Pregnancy
- •Breastfeeding
- •Psychological symptom scores were not used as exclusion criteria.
研究组 & 干预措施
Control Diet
Participants received an individualized dietary plan based on estimated daily energy and nutrient requirements. The dietary plan excluded fermented foods, and participants were instructed not to consume additional fermented foods or probiotic supplements during the four-week intervention.
干预措施: Individualized diet excluding fermented foods (Other)
Lower-Frequency Fermented-Food Diet
Participants received an individualized dietary plan based on estimated daily energy and nutrient requirements. In addition to the base dietary plan, participants were instructed to consume one serving each of kefir, tarhana soup, and mixed pickles once per week for four weeks.
干预措施: Lower-frequency fermented-food dietary intervention (Other)
Higher-Frequency Fermented-Food Diet
Participants received an individualized dietary plan based on estimated daily energy and nutrient requirements. In addition to the base dietary plan, participants were instructed to consume kefir daily, tarhana soup four times per week, and mixed pickles three times per week for four weeks.
干预措施: Higher-frequency fermented-food dietary intervention (Other)
结局指标
主要结局
Depressive symptom severity assessed by the Beck Depression Inventory (BDI)
时间窗: Baseline and Week 4
Depressive symptom severity was assessed using the 21-item Beck Depression Inventory (BDI). Each item is scored from 0 to 3, yielding a total score from 0 to 63. Higher total scores indicate greater depressive symptom severity. The BDI was administered at baseline and after the four-week dietary intervention. The original ethics application focused on depression and general health but did not formally classify outcomes as primary or secondary. For retrospective registration, depressive symptom severity assessed by the BDI is listed as the primary outcome because depression was the principal focus reflected in the original study title.
次要结局
- Body weight (kg)(Baseline and Week 4)
- Body mass index (BMI) (kg/m²)(Baseline and Week 4)
- General psychological distress assessed by the General Health Questionnaire-28 (GHQ-28)(Baseline and Week 4)
- Waist circumference (cm)(Baseline and Week 4)
- Mid-upper arm circumference (cm)(Baseline and Week 4)
- Estimated body fat percentage (%)(Baseline and Week 4)
- Estimated body fat mass (kg)(Baseline and Week 4)
研究者
Nadide Gizem Tarakci Filiz
Assistant Professor, Department of Nutrition and Dietetics
Fenerbahce University