I am studying gut flora and had a few questions 1 why do mic

I am studying gut flora and had a few questions.

1.) why do microbiologist use 16S RNA to study microbes and how do they do it? (sequencing methods, dat analyzing....)

2.) how does diet change the composition of the gut microbiome?

3.) what dietary fibers do gut flora ferment?

Solution

16 S rRNA is a part of 30s ribosomal subunit .It is coded by 16S rRNA gene.This gene is used most commonly in phylogenetic studies beacuse it is conserved between different species of bactera and archea.16SrRNA genes have evolved very little over the years,Therefore can be used to establish relatedness between different bacteria.16SrRNA gene is 1500 base pair long and has both conserved and variable regions.16SrRNA sequences are known for a large number of strains and there are many databases where they have been stored.Examples of these databases are: ribosomal database project,SILVA, greengenes.

Scientists use 16Sr RNA gene to compare with unknown stains of baceria ,to find out the percentage of relatedness.Bacteria are identified by sequence alignment based similarities from the databases.16srRNA gene can be used to identify bacteria to species and genus levels.

2. Diet is a very important factor determining gut microbiota.The food componenets which cannot be broken down by enzymatic action such as fibres act as a substrate for microbial growth.Fermentation of fibres leads to the production of short chain fatty acids which provides energy to colorectal tissue.They also help in reducing the pH ,thereby inhibiting the proliferation of pathogenic bacteria.Short chain fatty acids also reach the circulatory system and boost the immunity.They reduce the incidence of colorectal cancer.

Proteins act as major source of nitrogen for microbes in the colon.