Impact of Dietary Fiber as Prebiotics on Chemotherapy-related Diarrhea in Patients With Gastrointestinal Tumors

• Prebiotic Fiber Supplement + loperamide hydrochloride capsule (Dietary supplement): 2-week sequential supplementation with prebiotic fiber supplement (3.5g, twice a day). The initial dose of loperamide hydrochloride capsules is 4 mg (2 capsules) followed by 2 mg/4 h if diarrhea persists.
• Maltodextrin + loperamide hydrochloride capsule (Dietary supplement): 2-week sequential supplementation with placebo of of maltodextrin (3.5g, twice a day). The initial dose of loperamide hydrochloride capsules is 4 mg (2 capsules) followed by 2 mg/4 h if diarrhea persists.

Primary outcomes

• Therapeutic effect on the chemotherapy-related grade 2 to 4 diarrhea [2 weeks]: Numbers of bowel movements per day

Secondary outcomes

• onset time [2 weeks]
• Adverse events [2 weeks]: Incidence of mild (e.g. self-resolving), moderate (e.g. those that warrant medical evaluation and treatment) and serious (e.g. those that cannot be resolved by medical treatment) adverse events based on criteria adopted by the National Institute of Health common terminology criteria for adverse events (NIH severity) will be evaluated
• Changs in Karnofsky Performance Status [2 weeks]
• Gut microbiota changes in response to intervention [Change from baseline in gut microbiota at 1 and 2 weeks ]]: 16S rRNA sequencing

Sex: All, ages: 18 Years to 65 Years

Inclusion Criteria:

* Age 18-65, be able to comply with the protocol
* Life expectancy greater than 3 months
* Patients with cytologically or histologically confirmed diagnosis of gastrointestinal cancers
* Undergoing chemotherapy, not synchronized with radiotherapy and other anti-tumor treatments
* Chemotherapy-related diarrhea grade 2-4
* Not experience diarrhea before chemotherapy

Exclusion Criteria:

* age<18 or >65
* Patients who cannot eat by mouth for example chewing disorders, difficulty swallowing, intractable vomiting, gastrointestinal obstruction or gastrointestinal tract bleeding
* Other acute or chronic diarrhea or colostomy
* Patients with other severe adverse effects of chemotherapy other than diarrhea
* Patients with severe diseases of heart, kidney, liver and other major organs
* Use of any other drug for promoting intestine movement
* Use of any other drug or dietary supplement for chemotherapy-related diarrhea such as other fiber supplements, probiotics, octreotide
* Allergic to the components of the intervention dietary supplements;
* Pregnancy (positive serum pregnancy test) and lactation
* Any other serious or uncontrolled illness which the investigator think is undesirable for the patient to enter the trial

• Pianhong Zhang, Principal investigator, Second Affiliated Hospital, Zhejiang University, School of Medicine