A minor longterm study of the effects of a vegan diet entirely free of animal products on the severity of the symptoms of asthma patients showed an improvement of the condition in 92 of the 25 people who went through with the experiment

Can you repeat this sentence, but add in punctuation?
A minor long-term study of the effects of a vegan diet (entirely free of animal products) on the severity of the symptoms of asthma patients showed an improvement of the condition in 92% of the 25 people who went through with the experiment.