Although very specialized (one bacterial genus) this book is a useful guide to how microbiology is developing. The subtitle is misleading; the book starts with probiotics and ends with 'living drugs', but on the way takes in taxonomy, metabolism, genomics, intestinal and vaginal microflora studies, etc., thus a wide range of important topics. The authors are drawn from several countries; their workplaces contribute to the authoritative air of the text. Production is beautiful, with clear diagrams, a nice typeface and two text columns per 17x25 cm page. Every chapter has a good list of (generally) recent references. For lactic acid bacteria specialists (not just Lactobacillus fans) and those interested in host animal/symbiotic bacteria interactions this will be a most valuable text, and I thoroughly enjoyed examining it. However, the price will probably constrain sales to libraries that can be persuaded to buy a highly specialized text, and a few experts for whom the book's utility will override any cost considerations; a great pity.