The Claim

Mycobacterium tuberculosis lacks the ability to scavenge methionine from its environment on solid surfaces, while Mycobacterium canettii and environmental mycobacteria retain this ability, indicating a evolutionary loss of metabolic flexibility in Mycobacterium tuberculosis.

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.

Description
1 study reviewed
In plain English

Mycobacterium tuberculosis cannot absorb methionine from solid surfaces, whereas its ancestor Mycobacterium canettii and related environmental bacteria can still do so, showing that Mycobacterium tuberculosis has lost this metabolic function over time.

See the scientific wording

Mycobacterium tuberculosis cannot scavenge methionine from its environment on solid surfaces, unlike its ancestor M. canettii and environmental mycobacteria, which retain this ability, suggesting a loss of metabolic flexibility during evolution.

Why this might work

Mycobacterium tuberculosis cannot absorb methionine from its surroundings and cannot make methionine without vitamin B12. It lost the ability to produce vitamin B12 on its own and shut down its backup system for making methionine when B12 is missing. This forces it to steal B12 from the host to survive, and if the host lacks B12, the bacteria starve. Its ancient relatives still make their own B12 and can grab methionine from outside, so they don't depend on the host.

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 TB bacterium can't make methionine unless it gets vitamin B12 from the host, and it lost the ability to make B12 or grab methionine from outside — unlike its ancient relatives that can still do both. This means TB became dependent on its host, which is why it's more vulnerable when B12 is low.

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

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