Do you carry on backing trips?

Looking to get back into backpacking this summer but my wife is nervous about me going off for a night or two alone in the woods. It’s been a good 10-15 years since I’ve been backpacking and I’ve never had any issues with wildlife on my trips but it would probably give my wife some piece of mind if I had some kind if defense system on me.

I own a couple 9mm pistols but I doubt those would be very effective against something like a bear. Curious if others bring a side arm with them on trips and if so, what caliber would be effective against a bear? Thanks in advance