Functionally Enhanced Limosilactobacillus Reuteri Probiotic Preparation in Elderly Patients With Functional Bowel Disorders

An Exploratory Clinical Study on the Effects of a Functionally Enhanced Limosilactobacillus Reuteri Probiotic Preparation on Intestinal Immunity, Gut Microbiota Balance, and Intestinal Function in Elderly Patients With Functional Bowel Disorders

This is a single-center, open-label, single-arm interventional study designed to evaluate the effects of a functionally enhanced Limosilactobacillus reuteri probiotic preparation on intestinal immunity, gut microbiota balance, and intestinal function in elderly patients with functional bowel disorders. Participants aged 50-65 years with functional bowel disorders, including functional constipation, irritable bowel syndrome, or functional abdominal pain syndrome diagnosed according to Rome IV criteria, will receive the probiotic intervention.

The study will assess changes in senescence-associated secretory phenotype (SASP) expression levels to determine the extent of aging improvement, thereby evaluating the impact on intestinal immune aging. Clinical symptoms, including abdominal pain, abdominal distension, bowel movement frequency, and stool form, will also be recorded. In addition, changes in gut microbiota composition, key functional bacteria abundance, and tryptophan metabolites will be analyzed through fecal metagenomic and metabolomic approaches.

Safety and tolerability will be monitored throughout the study by recording adverse events and assessing routine laboratory parameters, including blood count and serum biochemical markers. This study aims to explore the potential mechanisms by which the probiotic preparation may improve gut immune function and microbiota balance, providing evidence for future clinical applications in elderly patients with functional bowel disorders.

Study Overview

• Status: Not yet recruiting
• Conditions: Functional Gastrointestinal Disorders
• Intervention / Treatment: Dietary supplement: Functionally Enhanced Limosilactobacillus reuteri Probiotic Preparation

Detailed Description

This single-center, open-label, single-arm interventional study is designed to evaluate the effects of a functionally enhanced Limosilactobacillus reuteri probiotic preparation on intestinal immunity, gut microbiota balance, and intestinal function in elderly patients with functional bowel disorders. Participants will be middle-aged and older adults, aged 50-65 years, diagnosed with functional constipation, irritable bowel syndrome, or functional abdominal pain syndrome according to Rome IV criteria. Patients with organic gastrointestinal diseases or severe systemic illnesses will be excluded.

Eligible participants will receive the functionally enhanced Limosilactobacillus reuteri probiotic preparation orally, in addition to continuing conventional symptomatic treatment as needed. The probiotic will be administered over a period of 8 consecutive weeks.

Participants will be instructed to maintain their usual diet and lifestyle and avoid additional probiotic supplements or antibiotics during the intervention period. Adherence will be monitored through capsule counts at each visit and participant diaries recording intake and any adverse events. Regular assessments will include in-person visits at baseline, Week 4, and Week 8, as well as telephone follow-ups at Weeks 1, 2, and 6 to ensure compliance and capture any tolerability issues. Safety monitoring will include routine laboratory tests (blood count, liver and renal function, and serum biochemical markers) and recording of all adverse events throughout the study period.

Primary outcome measures include changes in senescence-associated secretory phenotype (SASP) expression levels, which will be assessed to determine the extent of aging improvement and thereby evaluate intestinal immune aging.Clinical symptoms, including abdominal pain, abdominal distension, bowel movement frequency, and stool form assessed using the Bristol Stool Form Scale, will also be recorded. In addition, gut microbiota composition and key functional bacterial abundance will be analyzed through fecal metagenomic sequencing, along with metabolomic profiling of tryptophan-related metabolites. Safety outcomes include monitoring adverse events and routine laboratory parameters, such as complete blood count, liver and renal function, and serum biochemical indicators.

Assessments will be performed at baseline, Week 4, and Week 8, including in-person visits and telephone follow-up to ensure participant compliance and timely collection of samples. Fecal samples will be collected for metagenomic and metabolomic analyses to explore the relationship between probiotic intervention, gut microbiota metabolic function, and intestinal immune aging. This study aims to provide comprehensive evidence for the potential mechanism by which this functionally enhanced probiotic preparation may regulate the gut immune-microbiota network, maintain mucosal barrier integrity, and improve intestinal aging-related microenvironment in elderly patients with functional bowel disorders, thereby informing future clinical application and larger-scale trials.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1.Diagnosis and Symptom Presentation: Participants must be diagnosed with functional gastrointestinal disorders (FGID) according to Rome IV criteria, including but not limited to:

1. Functional constipation;
2. Irritable bowel syndrome (IBS);
3. Functional abdominal pain syndrome;
4. Participants must have clear intestinal dysfunction-related symptoms such as abdominal pain, abdominal distension, difficulty in defecation, or changes in bowel habits, with organic gastrointestinal diseases excluded by clinical evaluation.

2.Age and Disease Duration: Participants aged 50-65 years, with relevant symptoms persisting for at least 6 months, and having inadequate response to prior conventional treatment. Conventional treatments include but are not limited to: antidiarrheal agents (e.g., loperamide), gastrointestinal motility regulators (e.g., pinaverium bromide, trimebutine), intestinal microbiota products, or other commonly used drugs to improve diarrhea or regulate bowel function.

3.Symptom Severity Assessment: Participants must have a total score of 10-20 on the functional bowel symptom scoring scale as specified in the study protocol (see Appendix).

4.General Condition and Compliance: Participants must be able to understand the study purpose, provide written informed consent, and comply with the study procedures, including scheduled visits and collection of blood and fecal samples.

Exclusion Criteria:

1. History or current presence of organic gastrointestinal diseases, such as gastrointestinal malignancy, inflammatory bowel disease (IBD), intestinal obstruction, or intestinal polyps.
2. Presence of serious systemic diseases, including severe cardiovascular or cerebrovascular diseases (e.g., myocardial infarction within the past 6 months, New York Heart Association (NYHA) class III-IV heart failure, uncontrolled hypertension), significant liver or kidney dysfunction (alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2× upper limit of normal, estimated glomerular filtration rate (eGFR) <45 mL/min/1.73m²), or uncontrolled diabetes (HbA1c ≥9%).
3. Use of antibiotics, probiotics, or other drugs significantly affecting gut microbiota within 4 weeks prior to enrollment, or anticipated need to continue these drugs during the study.
4. Pregnant or breastfeeding women, or those planning pregnancy during the study period.
5. Participation in other clinical trials within 3 months prior to enrollment.
6. Any other health conditions deemed unsuitable for participation by the investigator.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Probiotic Intervention Group; All participants receive the functionally enhanced Limosilactobacillus reuteri probiotic preparation orally, in addition to continuing conventional symptomatic treatment as needed. The intervention is administered over a period of 8 consecutive weeks. Participants are instructed to maintain their usual diet and lifestyle and to avoid additional probiotic supplements or antibiotics during the study. Adherence will be monitored through capsule counts and participant diaries recording intake and any adverse events. Clinical assessments include abdominal pain, abdominal distension, bowel movement frequency, and stool form (assessed using the Bristol Stool Form Scale). Blood and fecal samples will be collected at baseline, Week 4, and Week 8 for analysis of intestinal immune function.

Dietary supplement: Functionally Enhanced Limosilactobacillus reuteri Probiotic Preparation; The probiotic preparation is a functionally enhanced Limosilactobacillus reuteri formulation, optimized with peptide prebiotics to improve colonic adhesion and support tryptophan metabolism. This intervention is intended to modulate intestinal immunity and gut microbiota composition. Participants receive the preparation orally over a period of 8 consecutive weeks while maintaining their usual diet and avoiding additional probiotics or antibiotics. Safety monitoring includes routine laboratory tests and recording of any adverse events throughout the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Concentrations of Senescence-Associated Secretory Phenotype Factors	Senescence-associated secretory phenotype factors will be measured at baseline, Week 4, and Week 8. Results will be reported as concentrations and changes from baseline to evaluate the effect of the functionally enhanced Limosilactobacillus reuteri probiotic preparation on intestinal immune aging-related inflammatory status.	Baseline, Week 4, and Week 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut microbiota composition and functional bacteria abundance	Fecal metagenomic analysis to evaluate changes in gut microbiota structure and abundance of key functional bacteria following probiotic intervention.	Baseline, Week 4, and Week 8
Change From Baseline in Serum Tryptophan Metabolism Concentrations	Serum concentrations of tryptophan metabolism will be measured using serum metabolomic analysis at baseline, Week 4, and Week 8. Results will be reported as concentrations and changes from baseline. The unit of measure will be reported as serum concentration, such as ng/mL or μmol/L, as appropriate for the analytical method.	Baseline, Week 4, and Week 8
Change From Baseline in Fecal Tryptophan Metabolism Concentrations	Fecal concentrations of tryptophan metabolism by gut microbiota will be measured using fecal metabolomic analysis at baseline, Week 4, and Week 8. Results will be reported as concentrations and changes from baseline. The unit of measure will be reported as concentration per fecal sample weight, such as ng/g feces or μmol/g feces, as appropriate for the analytical method.	Baseline, Week 4, and Week 8
Change From Baseline in Bristol Stool Form Scale Score	Stool form will be assessed using the Bristol Stool Form Scale. The Bristol Stool Form Scale classifies stool form from Type 1 to Type 7, where Type 1 indicates separate hard lumps and Type 7 indicates watery stool with no solid pieces. Higher scores indicate looser or more watery stool consistency and do not necessarily indicate a better or worse outcome. Results will be reported as scores and changes from baseline.	Baseline, Week 4, and Week 8
Change From Baseline in Bowel Movement Frequency	Bowel movement frequency will be assessed based on the number of bowel movements per day or per week. Results will be reported as frequency counts and changes from baseline.	Baseline, Week 4, and Week 8
Change From Baseline in Abdominal Pain Severity Score	Abdominal pain severity will be assessed using an 11-point numerical rating scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate more severe abdominal pain and a worse outcome. Results will be reported as scores and changes from baseline.	Baseline, Week 4, and Week 8
Change From Baseline in Abdominal Distension Severity Score	Abdominal distension severity will be assessed using an 11-point numerical rating scale ranging from 0 to 10, where 0 indicates no abdominal distension and 10 indicates the most severe abdominal distension. Higher scores indicate more severe abdominal distension and a worse outcome. Results will be reported as scores and changes from baseline.	Baseline, Week 4, and Week 8

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]	Treatment-emergent adverse events will be monitored throughout the 8-week intervention period. Results will be reported as the number and percentage of participants experiencing adverse events after initiation of the probiotic intervention.	Throughout 8-week intervention
Number of Participants With Clinically Significant Laboratory Abnormalities	Routine laboratory tests, including complete blood count, liver function, kidney function, and serum biochemical markers, will be performed to assess safety. Results will be reported as the number and percentage of participants with clinically significant laboratory abnormalities during the intervention period.	Throughout the 8-week intervention period
Number of Participants With Participant-Reported Tolerability Symptoms	Participant-reported tolerability symptoms, including gastrointestinal discomfort or other symptoms potentially related to the probiotic intervention, will be collected throughout the 8-week intervention period. Results will be reported as the number and percentage of participants reporting tolerability symptoms.	Throughout the 8-week intervention period

Collaborators and Investigators

• Sponsor: Maanshan Shiqiye Hospital
• Collaborators: Institute of Process Engineering, Chinese Academy of Sciences

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: June 1, 2026
• First Posted (Actual): June 3, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Functional Gastrointestinal Disorders; Probiotic Intervention; Functionally Enhanced Limosilactobacillus reuteri
• Additional Relevant MeSH Terms: Digestive System Diseases; Gastrointestinal Diseases
• Other Study ID Numbers: IPE_Maanshan

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No