The effect of culturing temperature on the growth of the most dominant bacterial species of human gut microbiota and harmful bacterial species.

In recent years, the gut microbiota has attracted attention due to reported associations with various diseases and health conditions. Gut bacteria have been constantly cultured at 37°C, potentially limiting the understanding of the interaction between them and the host. However, the most dominant human gut microbial species have not been extensively cultured at temperatures other than 37°C. In this study, we analyzed the effects of various culturing temperatures on the growth of the 51 most dominant commensal species as well as 3 harmful bacteria, including Clostridium perfringens, a food poisoning bacterium, in the human intestine. The results showed that the growth of predominant gut microbes varied minimally at body temperatures conducive to human survival but that the growth of several bacteria involved in butyrate production in the intestinal lumen was repressed at temperatures other than 37°C. When cultured at 50°C, the growth of C. perfringens was less inhibited than that of other bacterial species. In addition, the growth of some gut bacteria was unaffected by a body temperature range that was not suitable for human survival.