The Associations Between Gut Length, Gut Microbiota and Food Assimilation

The focus of this work is to characterize the relationship between gut length, gut microbiota and food energy assimilation rate in healthy individuals.

The gut will be scanned using Magnetic Resonance Imaging (MRI) to calculate gut length. To obtain clearer images, volunteers will be asked to drink 1/1.5 sachet of He Shuang (polyethylene glycol electrolyte powder, molecular weight of 4000) and injected Raceanisodamine Hydrochloride Injection with 10 mg by intramuscular. Volunteers will be asked to drink He Shuang, which dissolved in 1/1.5L of water for the purpose of filling the intestines. As a contrast to improve imaging during scanning.

Volunteers will be given the experimental meal, which providing enough energy for volunteers to eat as much as they want. Feces and urine will be collected to calculate the assimilation rate. To more accurately label the food, edible polyethylene glycol with a molecular weight of 3350(PEG3350) is used. Provides 1.5g of PEG3350 per day, to be used with meals. PEG3350 reaches a steady state in the intestinal tract for 3 days. Food will be provided for seven days during the test period, the first three days are aimed at stabilizing the PEG3350 in the intestine, and the samples to be counted are mainly collected in the last four days. Food assimilation rate and metabolizable energy will be calculated for the 4-day.

The gut microbiota will be analyzed by metagenomics and metabolomics. This study combines metabolomics analysis techniques with imaging and physiological measurements to focus on the potential relationship between gut length and food absorption rates. Researchers anticipate recruiting up to 100 healthy volunteers (body mass index ≥ 18.5).

Inclusion criteria

• Age between 18-40 years old, healthy and disease free.
• Regular bowel movements.

Exclusion criteria

• Individuals who are constipated or suffer from intestinal disorders;
• Individuals with mental illnesses such as depression and claustrophobia;
• Individuals with glaucoma and prostate hypertrophy;
• Metal implants in the body;
• Pregnant and lactating women;
• Individuals with blood phobia, pathologic hypotension or hypertension;
• Use of antibiotics, probiotics, oral laxatives within 8 weeks;
• Individuals with metabolic diseases (e.g., chronic diseases such as diabetes mellitus); recent weight loss due to various medical reasons;
• Individuals with infectious diseases (e.g. HIV);
• Irregular diet, lifestyle, addiction to tobacco, alcohol or drugs.