Lactic Acid Bacteria: Microbiological and Functional Aspects, 3rd Revised and Expanded Edition Edited by Seppo Salminen, Atte von Wright, and Arthur Ouwehand New York: Marcel Dekker, 2004. 633 pp. $229.95 (cloth)

The past 5 years has seen an explosion in studies on lactic acid bacteria, particularly on their applications to foods and probiotics. This textbook has been revised to cover the progress that has been made and the changes in direction of the field that have occurred during these past 5 years. The length of the book attests to the growing volume of studies that the authors had to review in order to present an overview of the interdisciplinary topics, especially those related to health. The author list has been expanded and includes some experts on probiotics and prebiotics (i.e., nondigestible substances that provide a beneficial physiological effect on the host by selectively stimulating the favorable growth or activity of a limited number of indigenous bacteria) [1]. The book is intended for clinicians, microbiologists, food technologists, nutritionists, product development experts, and regulatory experts, but it could also provide comprehensive reading for students, residents, and fellows who are interested in probiotics. Having said that, clinicians, medical students, and fellows may find that they have to plow through a lot of food-related and detailed information on taxonomy, biochemistry, and genomics to reach the critical, bottom-line information relevant to their practices.

The first chapter appropriately opens with definitions and classifications and is presented clearly and thoroughly in a manner most appropriate for students of biochemistry and food technologists. However, the introduction fails to define the term “probiotics,” and the reader must go to page 515 to read a European definition that is narrow and not representative of the breadth of probiotic applications. Sadly, the definition developed by the Food and Agriculture Organization of the United Nations and the World Health Organization and accepted by the International Scientific Association for Probiotics and Prebiotics has not been used: “Live microorganisms which when administered in adequate amounts confer a health benefit on the user” [1]. Restricting the definition to that of a food supplement essentially nullifies the important studies on the application of probiotics to the nasopharynx and urogenital tract and their use as medicinal drugs for conditions such as colitis. Indeed, the urogenital microbiota only warrants half a page.

Throughout the text, the authors fail to make sure that the reader understands that a genus or species is not a probiotic. In fact, probiotic effects have to be proven for strains and/or product formulations. This concept is best addressed in chapter 18, although the data is not analyzed thoroughly. Thus, the reader is left believing that Lactobacillus johnsonii LA1 is a probiotic on the basis of its ability to adhere to intestinal cells and that “balancing” the intestinal microbiota (neither of which has a proven health benefit) of Lactobacillus acidophilus NCFM is proven effective for the treatment of lactose intolerance (when the data is contradictory). Rather, a summary of the strains with clinical support that truly proves effectiveness should have been presented and should have included extensive data on Lactobacillus strains GR-1, B-54, RC-14, and CTV05.

Clinicians are interested in the scientific basis of new ways to manage patient care. Thus, for example, neonates are clearly colonized heavily within 2-5 days after birth by bifidobacteria, and in chapter 2, Ballongue argues well that these colonizing bacteria originate in the vaginal or fecal flora of the mother. Yet there are only 2 or 3 articles showing the presence of bifidobacteria in the vagina, and there are no discussions of specific receptor sites in the gut to which these organisms can bind. Discussion of the differential growth patterns induced by prebiotics is covered to some extent in chapter 3, but readers must go to page 408 to find the definition for prebiotics. Thus, it is not clear if clinicians should recommend vaginal birth, breast feeding, and use of bifidobacterium probiotic infant formula.

It is surprising that lactobacilli and lactococci do not warrant a chapter. Lactobacilli are discussed in chapter 16 and are strangely referred to as lactoflora, a term that should be dropped. The organization of chapters is somewhat puzzling: discussion of industrial applications comes long before the reader has been acquainted with the breadth of the topic, and it is not done from a medical perspective; thus sections on various aspects (e.g., the microbiota of infants) can be found in different chapters. Clinicians will be interested to read sections on organisms, such as propionibacteria and Enterococcus, which they normally might regard as pathogens. A chapter on antimicrobials produced by strains of lactic acid bacteria is very pertinent to medicine, although studies are needed to prove that these compounds actually are expressed in situ and affect the physiology of the host. Chapters 12-15 discuss effects of food or lactic acid bacteria in foods and are well written, although practical, interpretive recommendations would have been useful for clinicians. Chapter 10 (“Methods for Analyzing Gut Microbiotia”) could have benefited from more figures to help explain how organisms can be identified.

In summary, although there are problems with the book's organization and discussion of probiotics, its strength is that it provides the reader with a comprehensive bibliography, in-depth coverage of human, animal, and food science topics related to lactic acid bacteria, explanations of bacterial and phage functions, and exposure to an area of science that is current, exciting, and multi-dimensional.

Acknowledgment

Potential conflict of interest. G.R. owns patents associated with some strains of lactobacillus.

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