Gut microbial modulation in the treatment of chemotherapy-induced diarrhea with Shenzhu Capsule

Gut microbiota plays a crucial role in the treatment of gastrointestinal (GI) diseases such as chemotherapy-induced diarrhea (CID). Shenzhu Capsule (SZC) is a Chinese herbal formula, which is composed of Renshen (rhizomes of Panax ginseng C. A. Mey.) and Baizhu (rhizomes of Atractylodes macrocephala Koidz.). Many Chinese traditional anti-diarrheal formulae that contain Renshen and Baizhu are capable of effectively alleviating CID. However, the efficacy in vivo and potential mechanism of SZC (the form of compatibility of Renshen and Baizhu) in the treatment of CID had not been elucidated. Here, this study aimed to investigate whether SZC exhibited the anti-diarrheal activity, and whether gut microbiota was involved in the therapeutic effect of SZC on CID.

High performance liquid chromatography (HPLC), gas chromatography-mass spectrometer (GC-MS) and infrared spectroscopy (IR) analyses were used to characterize the extracted components in SZC. The mice were orally administrated with SZC in a preventive mode on the first 2 days of this experiment, and then intraperitoneally injected with 5-FU (40 mg/kg/d) for 6 days. SZC treatment lasted until the 3rd day after the end of 5-FU chemotherapy. We investigated the effects of SZC on body weights, diarrhea, thymus/spleen indexes, colonic tissues, and gut microbiota. Colonic histology was examined by hematoxylin-eosin (HE) staining. 16S rDNA Amplicon Sequencing was used to analyze the gut microbial structure from fecal samples.

SZC significantly increased the body weights and thymus/spleen indexes, alleviated diarrhea, and reversed histopathological changes of colons. In addition, gut microbiota analysis revealed that the overall structure of gut microbiota in CID mice was disturbed, but reversed to the normal state after SZC treatment. At genus level, SZC significantly inhibited the growth of some potential pathogens associated with diarrhea, such as Clostridiumm, Bacteroides, Parabacteroides, Alloprevotella, Acinetobacter and Pseudomonas.

In our study, these data illustrated that SZC inhibited the growth of many potential pathogens during the alleviation of CID. Gut microbial modulation was associated with the anti-diarrheal activity of SZC.