Disease signature based on one of the following: ribosomal RNA, bacterial RNA, mitochondrial RNA

Question

[bart]

Hi,

Is there any research that has looked at creating a biomarker signature for differentiating between (human) groups using non-mRNAs especially ribosomal RNA, bacterial RNA or mitochondrial RNA (in tissue or liquids such as blood, urine etc)? I've been looking for some time now but cannot find any protocols that can be used to achieve this

Answer 1

[Mensur Dlakic]

I am not a medical doctor, and I don't even play one on TV. Still, I can state confidently that there will be no bacterial RNA in bodily fluids under normal conditions. The same is true for tissues excluding skin, airways and intestines. Ribosomal RNA should be identical for all humans.

Mitochondrial DNA is inherited from the mother, and can trace maternal lineages regardless of their partners. It has been used for a long time to track human populations, especially migration patterns. You should be able to find plenty of information on that subject by Googling.

[Santosh Anand]

I can state confidently that there will be no bacterial RNA in bodily fluids under normal conditions.

As eerie as it may sound (Quoting from https://pubmed.ncbi.nlm.nih.gov/30785061) >>>

Bacteria are not only ubiquitous throughout the human body, but also, as shown by recent microbiome sequencing studies of the 16S rRNA gene, bacterial community structures are distinct across body sites.

...

Overall, our findings indicate that bacterial markers are a promising avenue for forensic body fluid/tissue identification.

[bart]

About bacterial RNA: Using Kraken and FASTQ files from RNA seq datasets from circulating cells, I could find nucleotide sequences which should belong to bacteria and viruses. So can this mean that bacteria have transferred their RNA into the circulating cells or are these sequences found because of contamination of these bacteria with the samples during the wet-lab procedures? Would it be possible to create a signature based on differential expression of these sequences between two groups?