Dan Ballard and Brian Brobbey struck the goals for the hosts, with Arsenal scoring through Bukayo Saka and Leandro Trossard.
Le Bris said afterwards: “We showed our character and togetherness once again.
“We struggled as expected against a really strong squad who had many different options to cause trouble for your defence.
“Even when we went through difficult moments, we showed that it was possible to change the dynamic and create something.
“We had to be the best Sunderland possible in different phases.
“The first half was interesting because we were balanced, organised out of possession, and really difficult to beat - but we also had the ability to threaten the opponent from set-pieces.
“We also had some good periods on the ball as well. It was a bit tougher in the second half - we were more fragile with the ball.
“It is a good lesson because we have a really young squad that doesn’t yet have the experience of playing in the Premier League.
“We have to go through these different experiences to learn, so today will be a good step for us.
He continued: “Dan Ballard and Trai Hume were here last season and the year before - they are our connection between the past and the future.
“They have shown good qualities as players but also have a strong mentality, good character, and the belief that we can change anything.
“Brian (Brobbey) has worked hard since the beginning of the season, so I am happy for him. It’s not easy because he hasn’t started many games and expects to start - he’s a really good player.
“Wilson (Isidor) and Eli (Mayenda) have also done well, so now we have three options - and another profile. Brian has the ability to hold the ball, be really combative, and he also has the ability to score.
“Our dynamic is still in the learning process. We have some good qualities, and we want to learn and improve as a squad - so we’ll see what the future brings.”