Replacing sparse paneling with floor chipboard, increased rigidity?

[jooohan]

Hello

I have a house built in '59, the floor joists are 2" x 8" with 60 cm spacing.
I was planning to check the floor anyway since I'm laying a new floor.

Currently, there is a sparse panel about 28x80 with about 30mm gaps.
The floor flexes a bit, so I was thinking of reinforcing it a little.
So my question is, replacing the sparse panel with a 22mm chipboard and glue-screwing them, will that noticeably stiffen the floor? Or perhaps it might make it worse?

I've removed a few planks in 2 places to check the insulation if you're wondering why there are some "missing."

Thankful for any answers

 

[SBH]

surely, there will be glue on the beams and in the joints.