The role and mechanism of action of microbiota-derived short-chain fatty acids in neutrophils: From the activation to becoming potential biomarkers

Ameliorative Effects of Korean-Red-Ginseng-Derived Polysaccharide on Antibiotic-Associated Diarrhea

This study evaluated the ameliorative effects of Korean-red-ginseng-derived polysaccharide (KRG-P) on antibiotic-associated diarrhea (AAD) induced by administering lincomycin in mice. Changes of intestinal barrier proteins, the intestinal microbiome and short-chain fatty acid (SCFA) contents were investigated. Lincomycin was orally administered for 9 days to induce diarrhea; subsequently, 100 mg/kg and 300 mg/kg of KRG-P were administered orally for 12 days. The diarrhea was observed in the AAD group; further KRG-P administration improved the diarrhea. Analysis of changes in the intestinal microbial flora of the mice revealed that the harmful bacterial flora (such as Proteobacteria) were increased in the AAD group, whereas beneficial bacterial flora (such as Firmicutes) were decreased. However, KRG-P administration resulted in decreased Proteobacteria and increased Firmicutes, supporting the improvement of the microbial flora imbalance caused by AAD. Moreover, an analysis of the SCFAs (acetic acid, propionic acid, and butylic acid) in the caecum revealed that SCFAs' contents in the AAD group were substantially reduced but tended to increase upon KRG-P administration. Based on these results, KRG-P, which is primarily composed of carbohydrates can improve lincomycin-induced diarrhea, likely owing to the recovery of SCFA content by improving the intestinal microbial imbalance and intestinal barrier proteins.

Short Chain Fatty Acids: Essential Weapons of Traditional Medicine in Treating Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and recurrent intestinal inflammatory disease, mainly including Crohn's disease (CD) and ulcerative colitis (UC). In recent years, the incidence and prevalence of IBD have been on the rise worldwide and have become a significant concern of health and a huge economic burden on patients. The occurrence and development of IBD involve a variety of pathogenic factors. The changes in short-chain fatty acids (SCFAs) are considered to be an important pathogenic mechanism of this disease. SCFAs are important metabolites in the intestinal microbial environment, which are closely involved in regulating immune, anti-tumor, and anti-inflammatory activities. Changes in metabolite levels can reflect the homeostasis of the intestinal microflora. Recent studies have shown that SCFAs provide energy for host cells and intestinal microflora, shape the intestinal environment, and regulate the immune system, thereby regulating intestinal physiology. SCFAs can effectively reduce the incidence of enteritis, cardiovascular disease, colon cancer, obesity, and diabetes, and also play an important role in maintaining the balance of energy metabolism (mainly glucose metabolism) and improving insulin tolerance. In recent years, many studies have shown that numerous decoctions and natural compounds of traditional Chinese medicine have shown promising therapeutic activities in multiple animal models of colitis and thus attracted increasing attention from scientists in the study of IBD treatment. Some of these traditional Chinese medicines or compounds can effectively alleviate colonic inflammation and clinical symptoms by regulating the generation of SCFAs. This study reviews the effects of various traditional Chinese medicines or bioactive substances on the production of SCFAs and their potential impacts on the severity of colonic inflammation. On this basis, we discussed the mechanism of SCFAs in regulating IBD-associated inflammation, as well as the related regulatory factors and signaling pathways. In addition, we provide our understanding of the limitations of current research and the prospects for future studies on the development of new IBD therapies by targeting SCFAs. This review may widen our understanding of the effect of traditional medicine from the view of SCFAs and their role in alleviating IBD animal models, thus contributing to the studies of IBD researchers.