Honey-B-Healthy found to be helpful against Nosema Ceranae.

http://www.ars.usda.gov/SP2UserFiles/Program/305/FY08ARSReporttoBeekeepers122808_Final.pdf

2008: Products developed to control pests, parasites, and diseases in honey bee colonies. ARS scientists at Weslaco tested six products, some in a dose series, against moderate to heavy nosema infections in honey bees. All were less effective than the standard dose of Fumagilin-B. Fumagilin-B, while significantly lowering spore levels, did not reduce nosema disease below the economic threshold. Only one product, Honey Bee Healthy, was comparable to the efficacy level of Fumagilin-B.

http://www.beesource.com/forums/archive/index.php/t-220945.html

"As far as HBH for nosema control, I was at the summer meeting of the Colorado
beekeepers and the guest speaker was Dr. Frank Eischen from the Weslaco bee lab. They
just finished a nosema study they are getting ready to publish. They fed bees with fumidel
and HBH and found that the HBH was just as good at controlling nosema as the fumidel.
He said they were in shock! He said he was sure it would not work when the study
started, and now is convinced it is a good alternative to fumidel. They did not try it in a
mega-dose like some guys are doing; but just fed it in syrup. I am putting a bunch of it in
my patties, and the bees just love it.”