Compositional variation of the human fecal microbiome in relation to azo-reducing activity: a pilot study

Abstract

Background Through an arsenal of microbial enzymes, the gut microbiota considerably contributes to human metabolic processes, affecting nutrients, drugs, and environmental poisons. Azoreductases are a predominant group of microbiota-derived enzymes involved in xenobiotic metabolism and drug activation, but little is known about how compositional changes in the gut microbiota correlate with its azo-reducing activity. Results To this end, we used high-throughput 16S rRNA amplicon sequencing, with Illumina MiSeq, to determine the microbial community composition of stool samples from 16 adults with different azo-reducing activity. High azo-reducing activity positively correlated with the relative abundance of phylum Firmicutes (especially genera Streptococcus and Coprococcus) but negatively with phylum Bacteroidetes (especially genus Bacteroides). Typical variations in the Firmicutes-to-Bacteroidetes and Prevotella-to-Bacteroides ratios were observed among samples. Multivariate analysis of the relative abundance of key microbial taxa and other diversity parameters confirmed the Firmicutes proportion as a major variable differentiating high and non-azo-reducers, while Bacteroidetes relative abundance was correlated with azo-reduction, sex, and BMI. Conclusions This pilot study showed that stool samples with higher azo-reducing activity were enriched in Firmicutes but with relatively fewer Bacteroidetes. More samples and studies from different geographical areas are needed to bolster this conclusion. Better characterization of different azoreductase-producing gut microbes will increase our knowledge about the fate and differential human responses to azodye-containing drugs or orally consumed chemicals, thus contributing to efforts towards implementing microbiome testing in precision medicine and toxicology.

Inonotus obliquus polysaccharide are linear molecules that alter the abundance and composition of intestinal microbiota in Sprague Dawley rats

“…In the control group, the abundance of Actinobacteriota was significantly higher in males than that in female rats, while Bacteroidota abundance was significantly lower in males than that in female rats. The abundance of Bacteroidota is thought to be associated with gender and body index (BMI) ( 59 ), while Actinobacteriota is positively correlated with body weight ( 60 ). After IOP intake, the dominant bacteria in the cecum of female and male rats changed.…”

Bacterial community assembly driven by temporal succession rather than spatial heterogeneity in Lake Bosten: a large lake suffering from eutrophication and salinization

“…HgcI_clade , associated with Actinobacteria, has been widely detected in various freshwater environments, including lakes of different trophic states, reservoirs, rivers, and even oligosaline water ( Liu et al, 2015 ; Aguilar et al, 2018 ; Camara dos Reis et al, 2019 ; Cruaud et al, 2019 ; Mohapatra et al, 2019 ). Firmicutes, Bacteroidetes, and Cyanobacteria are predominant phyla in the planktonic prokaryote communities of lakes, with Cyanobacteria often reflecting eutrophication status due to nitrogen and phosphorus inputs ( Qin et al, 2019 ; Chakraborty et al, 2020 ), while Firmicutes and Bacteroidetes are commonly associated with the human intestinal environment ( Fan and Pedersen, 2021 ; Zahran et al, 2021 ).…”

Microbial communities and metabolic pathways involved in reductive decolorization of an azo dye in a two-stage AD system

“…Members of Firmicutes predominated in all conditions, with relative abundance values of 66-80% (PI), 53-67% (PII), 72-76% (PIII) and 76-81% (PIV) (Supplementary materials). This phylum is often favored under acidogenic conditions (Ribeiro et al, 2022) and was recently associated with azo-reducing activity in the gut microbiota (Zahran et al, 2021).…”