Commuters have been warned to think twice before doing their makeup on the Tube after a new study found faecal bacteria on some London Underground lines.

A study conducted by Vision Direct swabbed poles and seats of each of the tube lines, as well as three escalator handrails in busy stations.

In a stomach-churning discovery, it found an unsettling range of bacteria to which tube riders are exposing themselves.

The swabs found a staggering 16,000 colony-forming units (CFU) of E.coli on the Victoria line seats.

Meanwhile, the Metropolitan line housed traces of Pseudomonas aeruginosa (400 CFU) and Faecal Streptococci - bacteria found in the digestive tracts of humans and animals - and enterococci on the seats (960 CFU) and poles (80 CFU).

Pseudomonas aeruginosa was also spotted on an Oxford Circus escalator handrail (720 CFU), the Northern line seats (200 CFU), and the Waterloo & City line poles (40 CFU).

Microbiologist and immunologist Jason Tetro highlighted two significant risks associated with applying makeup on the tube.

He said: "The first is contamination of the cosmetics themselves with unsafe hands.

"This can lead to the introduction of unwanted microbes on the skin such as bacteria causing cellulitis, impetigo, and acne.

"Then there is the risk of putting unsafe hands in the mouth to aid in the application of makeup.

"This can lead to exposure to a variety of different pathogens including SARS-CoV-2.”

Nimmi Mistry, a professional services optician at Vision Direct, explained the possible health repercussions of these bacteria, particularly in causing eye infections.

She indicated how Pseudomonas aeruginosa can cause severe inflammation of the cornea, a condition commonly known as microbial keratitis, particularly in individuals who wear contact lenses or are immunocompromised.

Moreover, both E.coli and Streptococci can be responsible for infectious bacterial conjunctivitis which includes symptoms like redness, irritation, discharge, and crusting of the eyelids.

E-coli and Streptococci could also cause significant visual damage, leading to significant pain, blurred vision, and potential corneal scarring.

The study also measured pollutants on the Underground and found that the Central line and Jubilee line recorded dangerous PM2.5 levels, a form of particulate matter that can deeply penetrate respiratory organs and enter the bloodstream.

This can lead to cardiovascular, cerebrovascular, respiratory effects and toxic changes to the intraocular tissues of the eye.

The Central and Jubilee lines had PM2.5 levels of 125 and 124.2 ug/m3 respectively - and anything above 50 ug/m3 should raise concern.