Escherichia coli, Staphylococcus aureus, Citrobacter freundii, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhimurium, Streptococcus faecalis, Streptococcus pyogenes, Helicobacter Pylori – these are all bacterial and fungi threats that Manuka honey can deal with. 
As for gallstones, they might be a result of some infection, 
and the infection might be treated with Manuka. 

All gallbladder problems are not due to gallstones

Herbs can help prevent and soothe gallbladder attacks. Rosemaryturmericdandelionyellowroot
goldenseal, chicory, calendula, wild yam root, garlic, catnip, marshmallownettle, barberry bark, 
fennel seedginger, yellow dock, and milk thistle may help. Regular doses of chamomilepeppermint, or alfalfa tea 
taken over a period of four to six weeks may dissolve 
gallstones. Take up to five cups of tea a day until symptoms disappear.
But remember that all gallbladder problems do not involve stones.)

Use herbal compresses to soothe gallbladder pain

Essential oils can help soothe a gallbladder attack. Soak a clean cloth with a few drops of Scotch pine essential oil in warm water. Apply as a compress over painful area. Repeat as necessary. Castor oil packs may also bring relief.

Old remedy for gallbladder problems

An old fashioned remedy for gallbladder problems 
calls for taking a glass of cider vinegar and honey 
in water each morning. 
A teaspoon of olive oil should be taken upon 
rising and with meals.

Prevent gallbladder disease with diet

Gallbladder disease may be prevented by 
following a low fat diet, switching from 
shortening to olive oil, drinking plenty of water, 
adding fiber and vitamin C rich foods to the diet, eating smaller meals, and cutting back on sugar. Increasing consumption of artichokes, pears, apples, carrots, beets, cucumbers, cherries, grapefruits, greens, and lemons is also recommended.

Use massage and reflexology to help treat the gallbladder

Reflexology also helps improve gallbladder health. Massage the instep of the right foot with small circular motions as often as possible.

Use gallbladder flushes with caution

In many cultures, gallbladder problems are treated at home with a gallbladder flush. It involves taking a pint of olive oil mixed with the juice of a dozen lemons. The patient is given some of the mixture every 15 minutes for three hours. They are then instructed to sleep on their right side. The treatment is repeated frequently until gallstones are passed. (This intensive gallbladder flush can cause serious problems if stones are not small enough to pass through bile ducts.)