Effects of fermented ginseng on the gut microbiota and immunity of rats with antibiotic-associated diarrhea

Ginseng (Panax ginseng Meyer) is a well-known herb in traditional Chinese medicine and has been used to treat many diseases for thousands of years. Recent studies have shown that ginseng is a promising agent for improving the gut microbiota and treating ulcerative colitis. Fermentation is a common process in traditional Chinese medicine making that can be used to enhance efficacy and reduce toxicity. The purpose of the present study was to research the efficacy of ginseng fermented with probiotics (Lactobacillus fermentum) on the gut microbiota and immunity of rats with antibiotic-associated diarrhea (AAD). SPF Sprague-Dawley rats were randomly divided into eight groups: control group, antibiotic group, natural recovery group, and five groups treated with different doses of fermented ginseng (FG1 to FG5). A model of AAD was established by treating the rats with triple antibiotics, and obvious symptoms of AAD were observed. A histopathological analysis of the colon was performed. The total bacteria in the intestinal microbiota and five types of gut microbes in the feces were detected by quantitative PCR. The expression levels of related immune factors TLR4 and NF-κB in the colon were assayed. An appropriate dose of fermented ginseng (0.5 g/kg/d) relieved some of the symptoms of AAD and colon inflammation and reduced the expression of the immune factors TLR4 and NF-κB in the colon. The alteration of the gut microbiota observed in the rats treated with antibiotics also returned to normal after treatment with fermented ginseng. Moreover, different doses of fermented ginseng exerted different influences on the gut microbiota, and excessively high or low doses of fermented ginseng were disadvantageous for resolving the symptoms of AAD and promoting recovery. These results demonstrate that fermented ginseng can treat AAD symptoms and colon inflammation and restore the gut microbiota to its original state.