F3 and cancer: However, low-abundant species also exhibit beneficial talents, such as B. xylanisolvens, which was confirmed to promote the suppression of cancer development via inducing the TFα-specific immunoglobulin M serum antibodies (Ulsemer et al., 2016), and B. acidifaciens JCM10556, which facilitates the maintenance of intestinal mucosa by stimulating the secretion of immunoglobulin A and thereby elevating pathogens that have breached the epithelial walls (Yanagibashi et al., 2013).