Implication of ‘Harmful’ Intestinal Microflora in the Pathogenesis of Diseases with Immune Dysfunction

Abstract

The implication of an abnormal spectrum of intestinal microflora in the pathogenesis of diseases with immune disorders was examined in patients with sternocostoclavicular hyperostosis, rheumatoid arthritis and atopic dermatitis. In these patients, frequent episodes of severe constipation or diarrhea were observed before the onset of the diseases. Serum biotin levels in the patients were low and remained almost unchanged even after oral administration of biotin. However, supplementary administration of a probiotic agent with biotin significantly increased serum biotin levels and maintained the vitamin levels high enough to improve clinical manifestations. Biotin is mainly synthesized by members of the microflora in the intestine and absorbed from the intestine into the circulation. Therefore, low serum biotin levels may be attributable to the proliferation of‘Harmful’intestinal microflora to degrade or ingest biotin. The results presented here suggest that biotin-limited conditions produced by ‘Harmful’ intestinal microflora in the patients with immune disorders play a causal role in the pathogenesis of the diseases. Biotin administration with a probiotic agent may provide a therapeutic effect on the diseases.