Dietary Yeasts Reduce Inflammation in Central Nerve System via Microflora
Candida kefyr ameliorates experimental autoimmune encephalomyelitis (EAE)
K. Takata , Attending Staff, Y. Nakatsuji , Associate Professor, and H. Mochizuki , Professor, et al., Department of Neurology, Osaka University Graduate School of Medicine have discovered that dietary Yeast C. Kefyr ameliorates EAE, an animal model of Multiple Sclerosis (MS).
MS is a demyelinating autoimmune disease of the central nervous system (CNS) and a leading cause of lasting neurological disabilities in young adults. While the prevalence of MS in Japan had been relatively low, it is increasing in recent decades. The changes of environment especially food habits are supposed to be a reason of increasing prevalence. Food habits and intestinal microflora have been shown to modulate the intestinal and systemic immune states, thereby affecting human health. For example, fermented foods and lactic acid bacteria are thought to have healthful effects, and recent studies have shown that modification of intestinal microflora ameliorates clinical symptoms of experimental disease models such as EAE and inflammatory bowel disease.
Kefir is fermented milk originating from the Caucasus mountains. Kefir grains represent a natural symbiosis of yeasts and lactic acid bacteria. In this study, we sought to determine whether yeasts found in fermented foods have beneficial effects on EAE. Our results suggested that ingestion of C. kefyr, one of the yeasts examined in this study, is a novel therapeutic strategy for overcoming autoimmune disease.
The intestinal microflora affects the pathogenesis of several autoimmune diseases by influencing immune system function. Some bacteria, such as lactic acid bacteria, have been reported to have beneficial effects on immune function. However, little is known about the effects of yeasts. Here, we aimed to investigate the effects of various dietary yeasts contained in fermented foods on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), and to elucidate the mechanisms underlying these effects.
The effects of eight yeasts selected from 18 types of yeasts contained in fermented foods were examined using an EAE model. Of these, Candida kefyr ameliorated the severity of EAE. Reduced numbers of Th17 cells, suppressed IL-6 production by intestinal explants, and increased Tregs and CD103-positive regulatory dendritic cells in mesenteric lymph nodes (MLNs) were observed. Analysis of 16s-rDNA from feces of C. kefyr-treated mice demonstrated increased Lactobacillales and decreased Bacteroides compared to control flora. Transfer of intestinal microbiota also resulted in decreased Bacteroides and ameliorated symptoms of EAE. Thus, oral administration of C. kefyr ameliorated EAE by altering the microflora, accompanied by increased Tregs and CD103-positive regulatory dendritic cells in MLNs and decreased Th17 cells in the intestinal lamina propria. These results suggest that oral ingestion of C. kefyr may have beneficial effects on MS by modifying microflora. In addition, it is also suggested the potential health benefits of dietary yeasts.
To learn more about this research, please view the full research report entitled " Dietary Yeasts Reduce Inflammation in Central Nerve System via Microflora " at this page of the Wiley Online Library website.