The Claim

The metE gene in Mycobacterium tuberculosis is repressed by a vitamin B12 riboswitch in the presence of vitamin B12, and mutations in this riboswitch eliminate repression and restore bacterial growth under vitamin B12-replete conditions.

Source: Dependency on host vitamin B12 has shaped Mycobacterium tuberculosis Complex evolution

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
9score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

In Mycobacterium tuberculosis, a specific RNA structure that senses vitamin B12 turns off the metE gene when vitamin B12 is available. Mutations in this RNA structure prevent gene silencing and allow the bacteria to grow even when vitamin B12 is present.

See the scientific wording

The metE gene in Mycobacterium tuberculosis is regulated by a vitamin B12 riboswitch that represses its expression when B12 is present, and mutations in this riboswitch can restore bacterial growth under B12-replete conditions by bypassing repression.

Why this might work

When vitamin B12 is present, it binds to a genetic switch in the bacterial RNA that turns off a methionine-making enzyme called MetE. This forces the bacteria to use a different enzyme, MetH, that needs B12 to work. If B12 is available, MetH makes enough methionine for the bacteria to grow. If the genetic switch is broken by a mutation, MetE stays on even when B12 is present, so the bacteria can make methionine without relying on B12 and keep growing.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: Dependency on host vitamin B12 has shaped Mycobacterium tuberculosis Complex evolution

    The study shows that when vitamin B12 is around, the tuberculosis bacteria turn off one of their methionine-making tools (metE) using a genetic switch. If that switch didn’t work, the bacteria could still make methionine even with B12 present — which helps them survive.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.