Loman BR, Shrestha CL, Thompson R, et al. - In the present study, the researchers sought to define the effect of secondhand smoke exposure (SHSe) and other external factors upon the fecal bacteriome in early cystic fibrosis (CF). There were 20 CF infants and children registered, clinical data reported, and hair nicotine assessed as an objective SHSe surrogate. Fecal samples have been obtained at clinic visits and bacteriome 16S rRNA gene sequencing performed. Findings suggested an association of SHSe with increased alpha diversity and increased relative abundance of Acinetobacter and Akkermansia, along with decreased Bifidobacterium and Lactobacillus. Recent antibiotic exposure in children less than 2 years of age expected bacterial population structure and was associated with decreased relative abundance of Bacteroides. SHSe and other external factors like antibiotics seem to alter fecal bacterial composition in young CF children, but the strongest predictor of overall composition was age. Such results have implications for the perception of intestinal microbiome in young CF children.