Does anybody have any idea why some young men get recurring UTIs? Even if they are non smoker, rare alcohol intake, eat healthy and exercise and also maintain very high personal hygiene?

What you eat can also be a cause
Sugars, hydrogenated oils, fried foods and processed foods can contribute
If you are put on anti biotics on a rather regular basis that can be a problem too because they destroy good bacteria as well as the bad so you want to either take probiotics or
Eat yogurt. Also eat plenty of fresh fruits and vegetables and drink water and juices like cranberry.

Thanks for the answer. Perhaps you missed that I have written that the person eats healthy! That includes fruits, veggies, yougurt with active culture, daily multivitamin, unsweetened cranberry juice.

What I am looking for is, is there something deeper issue other than that caused by poor hygiene, appetite, bacteria.

Eats healthy means a lot of different things to different people.
A bacterial infection along the urinary tract.
An infection occurs when microorganisms, usually bacteria from the digestive tract, cling to the bladder and the urethra — the hollow tube that carries urine from the bladder to the outside of the body — and begin to multiply.

There are natural detox remedies for UTI's but I don't know which products are the best.

Can you please suggest where to get natural detox for UTIs? Is this something I can ask the doctor to recommend? Thanks.

What medications does he take regularly?
Some alternative supplements are not good with certain medicines because they can counteract or amplify the prescribed meds.
I usually have an idea of what is okay but I am not too familiar with UTI and the alternative supplements.

Go to a health food store and ask the employees for guidance. A doctor is unlikely to know what to use for this purpose.