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NCT Number: NCT07258732

The Impact of Probiotics on Bariatric Treatment Outcomes

The planned study aims to assess whether probiotics improve the quality of life in patients during the early postoperative period following sleeve gastrectomy, and whether they influence the absorption of micro- and macronutrients.

Patients eligible for inclusion will have a BMI of 40 kg/m² or higher and must have successfully completed the qualification process for sleeve gastrectomy. Exclusion criteria include chronic gastrointestinal diseases, antibiotic use within 4 weeks prior to surgery, and lack of consent to participate in the study.

On the day before surgery, a stool sample will be collected from each patient for microbiological analysis to assess the composition of gut bacteria. Patients will then undergo sleeve gastrectomy using a standard surgical technique.

After the operation, participants will be randomized into two groups. The first group will receive probiotics containing Bifidobacterium animalis AMT30, Bifidobacterium breve AMT32, and Lactobacillus plantarum AMT14. These strains are deposited in the Polish Collection of Microorganisms at the Polish Academy of Sciences in Wrocław and are protected by Polish, European, and U.S. patents. The second group will receive a placebo.

As part of follow-up, stool samples will be collected again one month and three months after surgery for comparative microbiological analysis.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Obesity &Amp; Overweight Body Weight Constipation Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Digestive

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Warmia and Mazury

Olsztyn, 10-015, Poland

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age over 18 years.
  • BMI over 40 kg/m² or over 35 kg/m² with obesity-related comorbidities.
  • Successful qualification for sleeve gastrectomy.
  • Informed consent to participate in the study.

Exclusion criteria

  • Age under 18 years.
  • Chronic gastrointestinal diseases.
  • Use of antibiotic therapy within 4 weeks prior to surgery.
  • Lack of consent to participate in the study.

Treatment and study plan

Probiotic

Dietary Supplement

Probiotics containing Bifidobacterium animalis AMT30, Bifidobacterium breve AMT32, and Lactobacillus plantarum AMT14.

Diet

Other

Placebo

Primary outcomes

  1. Assessment of the impact of probiotics on the resolution of constipation after sleeve gastrectomy

    Time frame: one and three months after surgery

    The primary outcome of the study is to assess the effect of probiotics on the frequency of defecation in the early weeks following surgery. The patient would be asked whether constipation occurred (yes or no).

Secondary outcomes

  1. Assessment of the impact of probiotics on gastrointestinal symptoms after SG

    Time frame: one and three months after surgery

    The secondary outcome of the study is to assess the effect of probiotics on the frequency of defecation in the early weeks following surgery. The patient would be asked about the number of stools passing per week.

  2. Assessment of the impact of probiotics on gastrointestinal symptoms after SG

    Time frame: one and three months after surgery

    The secondary outcome of the study is to assess the effect of probiotics on the frequency of defecation in the early weeks following surgery. The patient would be asked about the subjective assessment of the ease of defecation.

    A Likert scale of 1-5 was used, where 1 indicated great difficulty with defecation, and 5 indicated no difficulty with defecation.

  3. Assessment of the impact of probiotics on gastrointestinal symptoms after SG

    Time frame: one and three months after surgery

    The secondary outcome of the study is to assess the effect of probiotics on the frequency of defecation in the early weeks following surgery. The patient would be asked about the feeling of bowel movement completeness.

    A Likert scale of 1-5 was used, where 1 indicated a complete feeling of incomplete defecation, and 5 indicated a complete feeling of defecation.

  4. Metabolic changes after the probiotics use in patients after SG

    Time frame: one and three months after surgery

    The secondary aim is to evaluate laboratory tests to identify any metabolic changes associated with probiotic use.

    It would be: Hemoglobin (Hb): g/dL

  5. Metabolic changes after the probiotics use in patients after SG

    Time frame: one and three months after surgery

    The secondary aim is to evaluate laboratory tests to identify any metabolic changes associated with probiotic use.

    It would be: Creatinine: mg/dL

  6. Metabolic changes after the probiotics use in patients after SG

    Time frame: one and three months after surgery

    The secondary aim is to evaluate laboratory tests to identify any metabolic changes associated with probiotic use.

    It would be: Total Protein: g/L

  7. Metabolic changes after the probiotics use in patients after SG

    Time frame: one and three months after surgery

    The secondary aim is to evaluate laboratory tests to identify any metabolic changes associated with probiotic use.

    It would be: Total Cholesterol: mg/dL

  8. Metabolic changes after the probiotics use in patients after SG

    Time frame: one and three months after surgery

    The secondary aim is to evaluate laboratory tests to identify any metabolic changes associated with probiotic use.

    It would be: HbA1c: %

  9. Metabolic changes after the probiotics use in patients after SG

    Time frame: one and three months after surgery

    The secondary aim is to evaluate laboratory tests to identify any metabolic changes associated with probiotic use.

    It would be: Ferritin: µg/L (ng/mL)

Sponsors and collaborators

Lead sponsor

University of Warmia and Mazury in Olsztyn

Other

Registry information

Official study title

Study on the Impact of Probiotics on Postoperative Gastrointestinal Symptoms and Gut Microbiota After Sleeve Gastrectomy: A Randomized-Control Trial

Acronym: PROBE

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Dec 2, 2025
Registry last updated
Dec 2, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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