Sleeve GastrectomyNCT07051824
Probiotic and Prebiotic Use in Early Postoperative Period of Sleeve Gastrectomy
A study testing Probiotic and Prebiotic in people with Sleeve Gastrectomy and Gastrointestinal Symptoms, run by Ayten Altunsaray at 1 site in Turkey (Türkiye).
Trial summary
This randomized controlled clinical study investigates the effects of daily synbiotic supplementation (containing Lactobacillus rhamnosus GG and partially hydrolyzed guar gum) in patients who underwent sleeve gastrectomy. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Sleeve Gastrectomy, Gastrointestinal Symptoms, Prebiotic
- What is being tested?
- Probiotic and Prebiotic
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 24 Dec 2024to 16 Jun 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Voluntary participation (provided informed consent)
- Age between 18 and 65 years
- Body mass index (BMI) ≥ 35 kg/m²
- Underwent laparoscopic sleeve gastrectomy
Who cannot join
- Use of antibiotics for more than 5 days after surgery
- Antibiotic use within 6 months prior to surgery
- Use of any prebiotic or probiotic supplement within 3 months prior to surgery
- Known intolerance to prebiotics or probiotics
- Use of immunosuppressive drugs or NSAIDs
- Diagnosed with liver or kidney failure
Show all 18Show fewer
- Age under 18 or over 65
- History of cholecystectomy or scheduled simultaneous cholecystectomy with sleeve gastrectomy
- Lactose intolerance
- Presence of early postoperative complications (e.g., bleeding, persistent vomiting, fistula, obstruction, leakage, infection, etc.)
- Diagnosed dumping syndrome after surgery
- Early postoperative food intolerance or dehydration
- Inability to undergo bioelectrical impedance analysis (e.g., pacemaker, metallic implants)
- Conditions affecting body composition analysis results, such as:
- Menstruation at the time of measurement
- Consumption of food or caffeinated beverages within 4 hours of measurement
- Intense physical activity within 48 hours of measurement
- Non-adherence to daily probiotic/prebiotic supplementation protocol during the intervention period Alcohol consumption within 48 hours of measurement
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Türk Obezite Cerrahisi Vakfı
Ankara, Çankaya, 06680
About this study
Official title: The Effect of Probiotic and Prebiotic Use on Gastrointestinal System and Some Biochemical Parameters in the Early Postoperative Period of Sleeve Gastrectomy Patients
This randomized controlled clinical study investigates the effects of daily synbiotic supplementation (containing Lactobacillus rhamnosus GG and partially hydrolyzed guar gum) in patients who underwent sleeve gastrectomy. 60 participants aged 18-65 with a BMI of 35 or higher were randomly assigned to intervention (n=30) and control (n=30) groups. The intervention group received a 5 g sachet daily for 12 weeks postoperatively, mixed into 200 ml of yogurt and consumed during afternoon snacks. The control group received no supplementation. Anthropometric measurements, biochemical parameters, and gastrointestinal outcomes were assessed at baseline, week 4, and week 12. The aim is to evaluate the influence of probiotic and prebiotic supplementation on gastrointestinal function and biochemical markers in the early postoperative period following bariatric surgery.
Read the detailed description
Obesity is a growing global health problem, and bariatric surgery particularly sleeve gastrectomy, has become an effective method for long-term weight management. However, postoperative gastrointestinal changes, dysbiosis, and metabolic adaptations remain significant challenges, especially during the initial recovery period. The gut microbiota plays a critical role in digestion, nutrient absorption, immune modulation, and metabolic regulation. Probiotics and prebiotics may contribute to restoring microbial balance, enhancing intestinal barrier integrity, and improving biochemical profiles following surgery.
This randomized controlled trial was designed to evaluate the impact of synbiotic supplementation on gastrointestinal symptoms and selected biochemical parameters in patients undergoing sleeve gastrectomy. A total of 60 patients aged 18 to 65 years, with a body mass index (BMI) of 35 or higher, were enrolled. Participants were randomly assigned to two groups in a 1:1 ratio. The intervention group (n = 30) received a 5 g sachet containing maltodextrin (4.9 g) and Lactobacillus rhamnosus GG (1×10⁹ CFU) in a partially hydrolyzed guar gum matrix, administered once daily mixed into 200 ml of yogurt for 12 weeks postoperatively. The control group (n = 30) received no supplementation.
In the early postoperative period, patients commonly experience gastrointestinal symptoms such as bloating, gas, and constipation. This study aims to determine whether synbiotic supplementation can alleviate these symptoms and positively affect gastrointestinal function, anthropometric measurements, and specific biochemical markers. Additionally, it explores participants' knowledge and awareness of microbiota-related concepts, including probiotics and prebiotics. Data were collected through validated questionnaires assessing gastrointestinal symptoms, constipation severity, dietary habits, and microbiota-related knowledge. Anthropometric and biochemical assessments were conducted at baseline and at weeks 4 and 12 postoperatively.
- Conditions
- Sleeve Gastrectomy, Gastrointestinal Symptoms, Prebiotic, Probiotic
- Being tested
- Probiotic and Prebiotic
- Keywords
- Gastrointestinal Symptoms, Prebiotic, Probiotic, Sleeve Gastrectomy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Probiotic and PrebioticDietary supplement
Also called Maltodextrin + Guar Gum + L. rhamnosus GG, Prebiotic + Probiotic Blend, PHGG + LGG
This synbiotic intervention aims to minimize postoperative gastrointestinal symptoms in sleeve gastrectomy patients. The 5 g sachet contains:
- Partially hydrolyzed guar gum (PHGG; 4.9 g): Clinically shown to reduce diarrhea and improve stool consistency,
- Lactobacillus rhamnosus GG (LGG; 1×10⁹ CFU): Evidence-based for alleviating abdominal pain and bloating,
- Maltodextrin (0.1 g): Excipient for stability.
Administered daily in yogurt for 12 weeks post-surgery, this combination directly targets:
① Diarrhea and constipation (via PHGG's soluble fiber),
② Abdominal pain and bloating (via LGG's anti-inflammatory effects),
③ Overall GI symptom burden.
**Distinctive features vs. other studies:
- Symptom-specific formulation: PHGG (high-dose fiber) + LGG (symptom-targeted probiotic) synergy,
- Surgical context: Optimized for rapid gastric transit post-sleeve gastrectomy,
- Delivery innovation: Yogurt matrix protects probiotics against surgical gut pH changes.
| Study group | Role | What they receive |
|---|---|---|
| Intervention Group (Probiotic and Prebiotic) | Experimental | Participants received a daily 5 g sachet containing:
* Partially hydrolyzed guar gum (PHGG): 4.9 g (prebiotic fiber),
* Lactobacillus rhamnosus GG (LGG): 1×10⁹ CFU (probiotic),
* Maltodextrin: 0.1 g (excipient).
The sachet was mixed with 200 ml yogurt and consumed as an afternoon snack for 12 weeks post-surgery. Receives: Dietary Supplement: Probiotic and Prebiotic |
| Control Group (No intervention) | No intervention | Standard Care Control Participants followed routine post-operative care without dietary supplements. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Gastrointestinal Symptom Rating Scale (GSRS) Scores
The Gastrointestinal Symptom Rating Scale (GSRS) was used to evaluate participants' gastrointestinal symptoms before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. The scale has five subscales targeting abdominal pain, reflux, diarrhea, indigestion, and constipation. Higher scores on the scale indicate more severe symptoms. Between-group comparisons were conducted using independent t-test and changes over time were analyzed with 2 (group) × 3 (time) repeated measures ANOVA.
Measured: Baseline, Week 4, Week 12
Constipation Severity Scale (CSS) Score
The Constipation Severity Scale (CSS) was administered to participants before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. It is a measure designed to determine the frequency, intensity, and difficulty/strain of bowel movements. The scale consists of 16 questions. The CCS has three subscales: Stool Impaction, Colon Sluggishness, and Pain. The score for the Stool Impaction subscale ranges from 0 to 28, the score for the Colon Sluggishness subscale ranges from 0 to 29, and the score for the Pain subscale ranges from 0 to 16. The total score that can be obtained from the CSS ranges from a minimum of 0 to a maximum of 73. A high score on the scale indicates the severity of the symptoms. Between-group comparisons were conducted using independent t-test and changes over time were analyzed with 2 (group) × 3 (time) repeated measures ANOVA.
Measured: Baseline, week 4, week 12
Gas/Bloating Scale
The Gas/Bloating Scale was used to determine participants' gas/bloating symptoms before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. It is designed to measure the frequency, severity, impact, and discomfort caused by gas/bloating symptoms. The scale consists of 12 questions, with each question scored on a scale from 0 to 4. According to the scoring system, 0 points indicate no symptoms, 1 point indicates minimal symptoms, 2-5 points indicate mild symptoms, 6-13 points indicate moderate symptoms, and 14 or more points indicate severe symptoms. Between-group comparisons were conducted using the chi-square and changes over time were analyzed with 2 (group) × 3 (time) repeated measures ANOVA.
Measured: Baseline, week 4, week 12
Bristol Stool Consistency Scale
The Bristol Stool Consistency Scale is a scale of stool types ranging from the hardest to the softest. Type 1 stool is considered to be hard, nut-like lumps that are difficult to pass through the intestines. Type 2 stool is also lumpy but sausage-shaped. Types 1 and 2 are considered abnormally hard stools. Type 3 stools have cracks on the surface and are sausage-shaped, Type 4 stools are smooth and soft like a snake, and Type 5 stools are soft pieces with distinct edges and are easy to pass. Types 3, 4, and 5 are generally considered "normal" stool forms. The Friedman test was applied to evaluate the distribution of changes in Bristol scores over time in the study and control groups before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. The chi-square test was used to compare the distribution and statistical comparisons of the study and control groups before surgery and at 4 and 12 weeks post-surgery according to the Bristol Stool Consistency Scale.
Measured: Baseline, week 4, week 12
Change in Blood Glucose and Insulin Parameters
Blood glucose homeostasis was evaluated using fasting glucose (mg/dL), fasting insulin (µIU/mL), and HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) index, calculated using the formula [fasting blood sugar (mg/dL) x fasting insulin (µIU/mL)/405]. All values were extracted from clinical records at three time points. These variables were analyzed separately.An independent t-test was used to assess whether there were statistically significant differences between the groups.
Measured: Baseline, Week 4, Week 12
Change in Lipid Biomarkers
To evaluate the participants' blood lipid profiles, the following parameters were assessed:
Cholesterol (mg/dL), HDL (High-Density Lipoprotein) (mg/dL), LDL (Low-Density Lipoprotein) (mg/dL), Triglycerides (mg/dL). Each value was extracted from medical records and analyzed separately. Independent t-tests were used to compare values between intervention and control groups.
Measured: Baseline, Week 4, Week 12
Change in Liver Function and Related Biochemical Parameters
Liver function and associated biomarkers were evaluated through the following laboratory values:
Alanine Aminotransferase - ALT (U/L) Aspartate Aminotransferase - AST (U/L) Gamma-Glutamyl Transferase - GGT (U/L) Values were obtained from participants' medical records and assessed at baseline, 4th and 12th postoperative weeks. Independent t-tests were used to compare values between intervention and control groups.
Measured: Baseline, Week 4, Week 12
Other biochemical parameters
Serum uric acid (mg/dL) Total Bilirubin (mg/dL) Direct Bilirubin (mg/dL) levels were assessed in all participants at three time points: before surgery, and at 4 and 12 weeks postoperatively. Values were obtained from patient medical records. Differences between intervention and control groups were analyzed using independent t-tests.
Measured: Baseline, Week 4, Week 12
Secondary outcomes (4)
Change in anthropometric measurements
Anthropometric data were collected at three different time points to assess changes in body composition. Body mass index (BMI) was calculated using the formula kg/m^2 based on the obtained height and body weight. At each time point (baseline, week 4, week 12), intergroup comparisons were reported using independent t-tests to identify statistically significant differences. Measurements were performed under standard conditions at each time point.
Measured: Baseline, Week 4, Week 12
Change in Body Composition Parameters
Body composition was evaluated using a standardized protocol and the same device (Tanita MC-780, bioelectrical impedance analyzer) across all time points. The following parameters were assessed:
Body weight (kg) Body fat mass (kg) Skeletal muscle mass (kg) Total body water (kg) All values were measured under fasting and standardized conditions. Results were analyzed individually.
Measured: Baseline, Week 4, Week 12
Change in physical activity levels
Participants' physical activity levels were assessed using the International Physical Activity Questionnaire - Short Form (IPAQ-SF). Scores were calculated in weekly MET-minutes. Higher scores indicate higher activity levels. The Total Physical Activity Score (TPAS) was calculated as Walking (+) Moderate-intensity activity (+) Vigorous-intensity activity score.
As a result, physical activity level was classified as:
- TPAS <600 MET: 'Not physically active'
- TPAS = 600-3000 MET is defined as 'Low Physical Activity Level'
- TPAS ≥ 3000 MET is defined as 'Adequate Physical Activity Level' To assess differences in physical activity levels over time, independent t-tests were used at each time point to compare groups.
Measured: Baseline, Week 4, Week 12
Baseline group differences in Microbiota Awareness Scores (MAS)
Participants' awareness of concepts such as microbiota, probiotics, and prebiotics was assessed before surgery using the Microbiota Awareness Scale (MAS). The scale includes four subdomains: general knowledge, product knowledge, chronic diseases, and probiotics/prebiotics. A total awareness score was also calculated. Scores range from 18 to 100, with higher scores indicating greater awareness. Differences between the intervention and control groups were analyzed using independent t-tests. Additionally, subgroup comparisons were conducted to evaluate awareness levels across different educational backgrounds.
Measured: Baseline only
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jul 2025
- Study start24 Dec 2024
- Primary completion11 Jun 2025
- Study completion16 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Sleeve GastrectomyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ayten Altunsaray
- Sponsor type
- Other government
- Responsible party
- Sponsor-investigator, Ayten Altunsaray, Lokman Hekim University
- Investigators
- Ayhan Dağ, Assoc. Prof., Study chair, Lokman Hekim University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07051824
- Sponsor's protocol ID
- 20240239
- Status last verified
- Jul 2025
- First submitted
- 17 Jun 2025
- Last updated
- 15 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: This is a graduate thesis project. Individual participant data will not be shared. The data is stored securely and used solely for academic research, as approved by the ethics committee.
Publications
Altunsaray A, Dag B, Dag A. Effects of early postoperative synbiotic supplementation on gastrointestinal outcomes after sleeve gastrectomy: A randomized controlled trial. Clin Nutr. 2026 Aug;63:106717. doi: 10.1016/j.clnu.2026.106717. Epub 2026 Jun 24.
PubMed 42400993
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Probiotic and Prebiotic Use on Gastrointestinal System and Some Biochemical Parameters in the Early Postoperative Period of Sleeve Gastrectomy Patients
- ClinicalTrials.gov ID
- NCT07051824
- Acronym / sponsor ID
- 20240239
- Conditions
- Sleeve Gastrectomy, Gastrointestinal Symptoms, Prebiotic, Probiotic
- Keywords
- Gastrointestinal Symptoms, Prebiotic, Probiotic, Sleeve Gastrectomy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Ayten AltunsarayOther government
- Study start
- 24 Dec 2024 (actual)
- Primary completion
- 11 Jun 2025 (actual)
- Study completion
- 16 Jun 2025 (actual)
- First posted
- 4 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized controlled clinical study investigates the effects of daily synbiotic supplementation (containing Lactobacillus rhamnosus GG and partially hydrolyzed guar gum) in patients who underwent sleeve gastrectomy. 60 participants aged 18-65 with a BMI of 35 or higher were randomly assigned to intervention (n=30) and control (n=30) groups. The intervention group received a 5 g sachet daily for 12 weeks postoperatively, mixed into 200 ml of yogurt and consumed during afternoon snacks. The control group received no supplementation. Anthropometric measurements, biochemical parameters, and gastrointestinal outcomes were assessed at baseline, week 4, and week 12. The aim is to evaluate the influence of probiotic and prebiotic supplementation on gastrointestinal function and biochemical markers in the early postoperative period following bariatric surgery.
Detailed description
Obesity is a growing global health problem, and bariatric surgery particularly sleeve gastrectomy, has become an effective method for long-term weight management. However, postoperative gastrointestinal changes, dysbiosis, and metabolic adaptations remain significant challenges, especially during the initial recovery period. The gut microbiota plays a critical role in digestion, nutrient absorption, immune modulation, and metabolic regulation. Probiotics and prebiotics may contribute to restoring microbial balance, enhancing intestinal barrier integrity, and improving biochemical profiles following surgery.
This randomized controlled trial was designed to evaluate the impact of synbiotic supplementation on gastrointestinal symptoms and selected biochemical parameters in patients undergoing sleeve gastrectomy. A total of 60 patients aged 18 to 65 years, with a body mass index (BMI) of 35 or higher, were enrolled. Participants were randomly assigned to two groups in a 1:1 ratio. The intervention group (n = 30) received a 5 g sachet containing maltodextrin (4.9 g) and Lactobacillus rhamnosus GG (1×10⁹ CFU) in a partially hydrolyzed guar gum matrix, administered once daily mixed into 200 ml of yogurt for 12 weeks postoperatively. The control group (n = 30) received no supplementation.
In the early postoperative period, patients commonly experience gastrointestinal symptoms such as bloating, gas, and constipation. This study aims to determine whether synbiotic supplementation can alleviate these symptoms and positively affect gastrointestinal function, anthropometric measurements, and specific biochemical markers. Additionally, it explores participants' knowledge and awareness of microbiota-related concepts, including probiotics and prebiotics. Data were collected through validated questionnaires assessing gastrointestinal symptoms, constipation severity, dietary habits, and microbiota-related knowledge. Anthropometric and biochemical assessments were conducted at baseline and at weeks 4 and 12 postoperatively.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention Group (Probiotic and Prebiotic) | Experimental | Dietary Supplement: Probiotic and PrebioticParticipants received a daily 5 g sachet containing: * Partially hydrolyzed guar gum (PHGG): 4.9 g (prebiotic fiber), * Lactobacillus rhamnosus GG (LGG): 1×10⁹ CFU (probiotic), * Maltodextrin: 0.1 g (excipient). The sachet was mixed with 200 ml yogurt and consumed as an afternoon snack for 12 weeks post-surgery. |
| Control Group (No intervention) | No intervention | –Standard Care Control Participants followed routine post-operative care without dietary supplements. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Voluntary participation (provided informed consent)
- Age between 18 and 65 years
- Body mass index (BMI) ≥ 35 kg/m²
- Underwent laparoscopic sleeve gastrectomy
Key exclusion criteria (18 listed)
- Use of antibiotics for more than 5 days after surgery
- Antibiotic use within 6 months prior to surgery
- Use of any prebiotic or probiotic supplement within 3 months prior to surgery
- Known intolerance to prebiotics or probiotics
- Use of immunosuppressive drugs or NSAIDs
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Probiotic and PrebioticAlso: Maltodextrin + Guar Gum + L. rhamnosus GG, Prebiotic + Probiotic Blend, PHGG + LGGThis synbiotic intervention aims to minimize postoperative gastrointestinal symptoms in sleeve gastrectomy patients. The 5 g sachet contains: * Partially hydrolyzed guar gum (PHGG; 4.9 g): Clinically shown to reduce diarrhea and improve stool consistency, * Lactobacillus rhamnosus GG (LGG; 1×10⁹ CFU): Evidence-based for alleviating abdominal pain and bloating, * Maltodextrin (0.1 g): Excipient for stability. Administered daily in yogurt for 12 weeks post-surgery, this combination directly targets: ① Diarrhea and constipation (via PHGG's soluble fiber), ② Abdominal pain and bloating (via LGG's anti-inflammatory effects), ③ Overall GI symptom burden. **Distinctive features vs. other studies: * Symptom-specific formulation: PHGG (high-dose fiber) + LGG (symptom-targeted probiotic) synergy, * Surgical context: Optimized for rapid gastric transit post-sleeve gastrectomy, * Delivery innovation: Yogurt matrix protects probiotics against surgical gut pH changes. | Dietary supplement | Intervention Group (Probiotic and Prebiotic) |
Primary outcome
Change in Gastrointestinal Symptom Rating Scale (GSRS) Scores
Time frame: Baseline, Week 4, Week 12
The Gastrointestinal Symptom Rating Scale (GSRS) was used to evaluate participants' gastrointestinal symptoms before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. The scale has five subscales targeting abdominal pain, reflux, diarrhea, indigestion, and constipation. Higher scores on the scale indicate more severe symptoms. Between-group comparisons were conducted using independent t-test and changes over time were analyzed with 2 (group) × 3 (time) repeated measures ANOVA.
Constipation Severity Scale (CSS) Score
Time frame: Baseline, week 4, week 12
The Constipation Severity Scale (CSS) was administered to participants before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. It is a measure designed to determine the frequency, intensity, and difficulty/strain of bowel movements. The scale consists of 16 questions. The CCS has three subscales: Stool Impaction, Colon Sluggishness, and Pain. The score for the Stool Impaction subscale ranges from 0 to 28, the score for the Colon Sluggishness subscale ranges from 0 to 29, and the score for the Pain subscale ranges from 0 to 16. The total score that can be obtained from the CSS ranges from a minimum of 0 to a maximum of 73. A high score on the scale indicates the severity of the symptoms. Between-group comparisons were conducted using independent t-test and changes over time were analyzed with 2 (group) × 3 (time) repeated measures ANOVA.
Gas/Bloating Scale
Time frame: Baseline, week 4, week 12
The Gas/Bloating Scale was used to determine participants' gas/bloating symptoms before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. It is designed to measure the frequency, severity, impact, and discomfort caused by gas/bloating symptoms. The scale consists of 12 questions, with each question scored on a scale from 0 to 4. According to the scoring system, 0 points indicate no symptoms, 1 point indicates minimal symptoms, 2-5 points indicate mild symptoms, 6-13 points indicate moderate symptoms, and 14 or more points indicate severe symptoms. Between-group comparisons were conducted using the chi-square and changes over time were analyzed with 2 (group) × 3 (time) repeated measures ANOVA.
Bristol Stool Consistency Scale
Time frame: Baseline, week 4, week 12
The Bristol Stool Consistency Scale is a scale of stool types ranging from the hardest to the softest. Type 1 stool is considered to be hard, nut-like lumps that are difficult to pass through the intestines. Type 2 stool is also lumpy but sausage-shaped. Types 1 and 2 are considered abnormally hard stools. Type 3 stools have cracks on the surface and are sausage-shaped, Type 4 stools are smooth and soft like a snake, and Type 5 stools are soft pieces with distinct edges and are easy to pass. Types 3, 4, and 5 are generally considered "normal" stool forms. The Friedman test was applied to evaluate the distribution of changes in Bristol scores over time in the study and control groups before surgery, at 4 weeks post-surgery, and at 12 weeks post-surgery. The chi-square test was used to compare the distribution and statistical comparisons of the study and control groups before surgery and at 4 and 12 weeks post-surgery according to the Bristol Stool Consistency Scale.
Change in Blood Glucose and Insulin Parameters
Time frame: Baseline, Week 4, Week 12
Blood glucose homeostasis was evaluated using fasting glucose (mg/dL), fasting insulin (µIU/mL), and HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) index, calculated using the formula [fasting blood sugar (mg/dL) x fasting insulin (µIU/mL)/405]. All values were extracted from clinical records at three time points. These variables were analyzed separately.An independent t-test was used to assess whether there were statistically significant differences between the groups.
Change in Lipid Biomarkers
Time frame: Baseline, Week 4, Week 12
To evaluate the participants' blood lipid profiles, the following parameters were assessed: Cholesterol (mg/dL), HDL (High-Density Lipoprotein) (mg/dL), LDL (Low-Density Lipoprotein) (mg/dL), Triglycerides (mg/dL). Each value was extracted from medical records and analyzed separately. Independent t-tests were used to compare values between intervention and control groups.
Change in Liver Function and Related Biochemical Parameters
Time frame: Baseline, Week 4, Week 12
Liver function and associated biomarkers were evaluated through the following laboratory values: Alanine Aminotransferase - ALT (U/L) Aspartate Aminotransferase - AST (U/L) Gamma-Glutamyl Transferase - GGT (U/L) Values were obtained from participants' medical records and assessed at baseline, 4th and 12th postoperative weeks. Independent t-tests were used to compare values between intervention and control groups.
Other biochemical parameters
Time frame: Baseline, Week 4, Week 12
Serum uric acid (mg/dL) Total Bilirubin (mg/dL) Direct Bilirubin (mg/dL) levels were assessed in all participants at three time points: before surgery, and at 4 and 12 weeks postoperatively. Values were obtained from patient medical records. Differences between intervention and control groups were analyzed using independent t-tests.
4 secondary outcomes
Change in anthropometric measurements
Time frame: Baseline, Week 4, Week 12
Change in Body Composition Parameters
Time frame: Baseline, Week 4, Week 12
Change in physical activity levels
Time frame: Baseline, Week 4, Week 12
Baseline group differences in Microbiota Awareness Scores (MAS)
Time frame: Baseline only
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Oct 2026.
- Derived from this study: PubMed 42400993Altunsaray A, Dag B, Dag A. Effects of early postoperative synbiotic supplementation on gastrointestinal outcomes after sleeve gastrectomy: A randomized controlled trial. Clin Nutr. 2026 Aug;63:106717. doi: 10.1016/j.clnu.2026.106717. Epub 2026 Jun 24.
- Individual participant dataSharing planned: No. This is a graduate thesis project. Individual participant data will not be shared. The data is stored securely and used solely for academic research, as approved by the ethics committee.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ayhan Dağ, Assoc. Prof. study chair
Lokman Hekim University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Probiotic and Prebiotic in people with Sleeve Gastrectomy and Gastrointestinal Symptoms, run by Ayten Altunsaray at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Gastrointestinal Symptom Rating Scale (GSRS) Scores (time frame: Baseline, Week 4, Week 12). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07051824, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.