Among the defendants – all aged 41 to 65 – are an elected official, a gallery owner and a teacher.
One – a man named Aurélien Poirson-Atlan – is accused of telling his 200,000 online followers that Mrs Macron is a transgender woman and that the 24-year age gap between her and Emmanuel Macron amounts to “state-sanctioned paedophilia”.
Mr Poirson-Atlan told the court on Tuesday that he was a “satirist” who had just wished to put forward “a point of view different to that of the mainstream media”.
Two other defendants – self-styled independent journalist Natacha Rey and internet fortune-teller Amandine Roy – were already found guilty of slander last year for claiming that France’s first lady had never existed, and that her brother had changed gender and started using her name. They were later acquitted by a court of appeals.
Other defendants also said they had employed their “freedom of expression”. One requested the Macrons publish photos of Brigitte Macron pregnant to prove she is a biological woman.
The Macrons have already said they will present such evidence in court proceedings against US right-wing influencer Candace Owens.
Owens has repeatedly promoted her view that Brigitte Macron is a man and in March 2024, she claimed she would stake her “entire professional reputation” on the allegation.
Earlier this year the Macrons’ lawyer in the case, Tom Clare, told the BBC the couple would present photographic and scientific evidence to a US court to prove Mrs Macron is a woman.
“It is incredibly upsetting to think that you have to go and subject yourself, to put this type of proof forward,” he said.
Mrs Macron first met her now-husband when she was a teacher at his secondary school.
The couple ended up marrying in 2007, when Mr Macron was 29 and Mrs Macron was 54.