Single and multiple cholesterol gallstones and the influence of bacteria

Single and multiple cholesterol gallstones constitute at least 80% of the g allstone population observed at chorecystectomy in Western countries. While supersaturation of bile with cholesterol is necessary for gallstone growth , the kinetic determinant of crystal nucleation is perhaps the critical fac tor leading to the incidence of gallstones. Nucleation involves aggregation of nidus-forming materials like pigment precipitates and mucus proteins. I n combination with cholesterol precipitates and crystal formation, gallston e propagation is enhanced. Bacterial species may augment the process of nuc leation and gallstone growth by contributing specific enzyme activities res ulting in the formation of insoluble precipitates in bile, or by acting as a nidus upon which the deposition of cholesterol crystals may initiate gall stone formation. The utilization of Raman microscopic techniques permits de tailed mapping of the distribution of the gallstone components Leading to i dentification and characterization of the site of nucleation. This, when co upled to molecular genetic tools such as PCR DNA amplification, would permi t elucidation of the role of bacteria in vivo gallstone propagation mechani sms. (C) 2000 Harcourt Publishers Ltd.