Board Thread:Naruto Discussions/@comment-24847491-20140921145042/@comment-25387973-20140925163539

Seriously Hashirama's sage mode doesn't have anything to do with slugs(no reference at all in the manga/not once did Hashi say hi to Katsuyu).Although much is not known about the Shikkotsu forest if there are other animals so it might still be possible its from there.I don't believe Hashi's healing is related to Tsunade's.Medical ninjutsu is a product of yang(physical energy).Hashirama's sage mode amplifies his physical energy and medical ninjutsu allowing regeneration.