Alteration of Intestinal Microbiota in Mice with Irritable Bowel Syndrome upon Oral Administration of Microalgae - based Biomaterials

All animal studies were approved by the Institutional Animal Care and Use Committee of Zhejiang University (AIRB-2021-952) and were carried out in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals. Experiments utilized 5 week old C57BL/6J male mice. Construction of IBS-D model: Overall, it is divided into two parts, namely CR infection and the subsequent WAS procedure. CR infection: CR was expanded by culturing in Luria Broth medium, and each mouse was orally administered.WAS procedure: After the infection completely disappeared, the mice were placed on an elevated platform 1 cm above the water surface for 10 consecutive days, for 1 hour each day. To minimize diurnal variations, WAS was only performed between 9 am and 11 am. The control group was also placed on the platform, with no water around it (sham WAS). Treatment (PBS, SP, MY, SP@MYnn) was carried out after the daily WAS. Grouping information: 1. Control: Normal mice were given gavage to PBS; 2. PI-WA: The treatment administered to IBS-D mice was an equal volume of PBS as that of the drug group; 3. SP: The treatment administered to IBS-D mice was SP (250 mg/kg); 4. MY: The treatment administered to IBS-D mice was MY (50 mg/kg). 5. SP@MYnn: The treatment administered to IBS-D mice was SP@MYnn (50 mg MY/kg). After the experiment, the colon contents were quickly transferred to dry ice for preservation and transportation. MY, Myricetin. SP, spirulina.