If you are concerned about your porter, give him a good scrub first and make sure you clean under his fingernails.
Seriously though dont get too hung up on the detailed hygiene of the porters as for most of the time they will be hidden away in a tent and you will have no idea what they are up to, except when they bring out copious amounts of lovely food.
However that all depends though upon which company you are going with.
Take some Lomotil with you just in case.
Roger