How does the analysis of your sample work? Nahibu examines the bacterial genes in your stool sample, which involves several successive steps carried out by highly qualified technicians. What are these steps, and why aren't your results uploaded immediately upon receiving your sample?
1) Reception of Your Stool Sample
When Nahibu receives your sample, an initial quality control is performed. It is then sent for sequencing at our partner laboratory.
2) DNA Extraction
Next, bacterial DNA is extracted in a specialized laboratory, following a delicate protocol. The manipulation is performed with care in a dedicated space to avoid contamination from external DNA. This step is crucial as it directly affects the reliability of the results.
The goal is to obtain the purest bacterial DNA in sufficient quantity for sequencing. This involves a series of steps using different solutions and centrifugation. At the end of the extraction, a quality check ensures there is enough DNA for reliable results.
3) Preparation of DNA Libraries
DNA cannot be sequenced as is. It is fragmented, and DNA libraries are prepared (one library per sample), which takes several days.
The purpose is to obtain fragments of uniform size with adapters at their ends to ensure proper analysis. After library preparation, another quality check and normalization are conducted.
4) Sequencing
The DNA fragments are then sequenced. This step uses high-tech machines, called sequencers, that identify the nucleotides present on the DNA strands.
Nucleotides are the building blocks of DNA or RNA, and there are four types for DNA: A, C, G, and T. The sequencing and library preparation are carried out by trained and qualified individuals. The protocols are long, complex, and must be followed carefully.
Once sequencing is complete, we obtain DNA sequences—chains of nucleotides. These nucleotides can be compared to words, where their sequence forms sentences, i.e., genes.
5) Interpreting the Results
Once your sample is sequenced, the raw data—sequences of A, T, C, or G making up fragments (called reads) of the microbiome’s metagenome—is obtained. These files can be several gigabytes in size.
An initial analysis is performed to once again check the quality of the sequencing. If the check is validated, the analysis continues. Bioinformatics processes are then applied to interpret the data and generate a functional map of the microbiome.
From the identified genes, we determine the species present in your microbiome, which is called taxonomic analysis. For this, we use various software tools commonly used in metagenomic analysis. These results help us calculate the richness (the number of different species) and the enterotype (the most represented bacterial type in your microbiome).
At Nahibu, we don’t stop at providing a list of bacteria found in your sample. We group the genes present in the microbiome into large functional families called "functional modules," based on their impact on the body’s metabolic pathways. This helps explain your microbiome’s potential strengths and weaknesses.
6) Receiving Your Analysis Results
Once all the steps are completed, your results are available in your personal Nahibu account in the form of a report with a detailed map of your microbiome and its functional analysis.
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