Human Intestinal Microflora in Health and Disease

Contributors

Preface

Part I. Microflora Composition and Development


1. Normal Indigenous Intestinal Flora

I. Introduction

II. Problems Associated with the Study of Intestinal Flora

III. Culture Techniques

IV. Normal Microbial Flora of the Stomach

V. Normal Microbial Flora of the Small Intestine

VI. Normal Microbial Flora of the Colon

VII. Previous Fecal Flora Studies

VIII. Fecal Flora Studies—V.A. Wadsworth Anaerobe Laboratory

IX. Effect of Diet and Age on Normal Intestinal Microflora

X. Effect of Geographic Location on Normal Intestinal Microflora

XI. Stability of Intestinal Flora over Time

References


2. Mechanisms That Control the Microflora in the Large Intestine

I. Introduction

II. Models for Study

III. Properties of Large Intestinal Flora

IV. Dynamics of Bacterial Growth in the Large Intestine

V. Inhibitors of Bacterial Multiplication

VI. Physiological Adaptation

VII. Competition for Limiting Nutrients

VIII. Theoretical Aspects of the Role of Adhesion

IX. Beginnings of a General Theory

References


3. Associations of Indigenous Microorganisms with Gastrointestinal Epithelial Surfaces

I. Introduction

II. Problems in the Study of Microorganisms Associating with Epithelial Surfaces in Man

III. Microorganisms Associating with Gastrointestinal Epithelial Surfaces in Man

IV. Summary and Conclusions

References


4. Intestinal Flora of Infants

I. Development of Intestinal Flora in Infant Animals

II. Succession of Fecal Bacterial Genera in Human Infants

III. Intestinal Bacterial Habitats

IV. Species and Strains of Bacteria in Infants

V. Importance of Intestinal Flora to the Infant Host

VI. Clostridium difficile

VII. Conclusion

References


5. Host Immune Response to Antigens of the Indigenous Intestinal Flora

I. Introduction

II. "Natural Antibodies" to Antigens of Indigenous Intestinal Bacteria

III. Immune Antibodies to Indigenous Intestinal Bacteria

IV. Comparison of the Immune Response to Indigenous and Nonindigenous Intestinal Bacteria

V. Influence of Indigenous Intestinal Bacteria on the Host Immune Response

VI. Influence of the Host Immune System on the Ecology of Indigenous Intestinal Bacteria

VII. Conclusion

References

Part II. Metabolic Activities of the Intestinal Microflora


6. Carbohydrate Metabolism in the Human Colon

I. Introduction

II. Natural Sources of Fermentable Carbohydrate

III. Mechanisms of Polysaccharide Catabolism

IV. Growth Yields, Maintenance, and Affinity

V. Polysaccharide Fermentation and the Colonic Ecosystem

References


7. Carbohydrate Fermentation

I. Overall Fermentation

II. Role of Pyruvate in Carbohydrate Fermentation

III. Microbial Interactions

IV. Quantitative Aspects of Overall Fermentation

V. Overall Energetics

VI. Summary

References


8. Utilization of Nitrogen Sources by Gastrointestinal Tract Bacteria

I. Introduction

II. Bacterial Species and Their Nitrogen Requirements

III. Degradation of Proteins

IV. Degradation of Amino Acids

V. Biosynthesis of Amino Acids

VI. Urea Hydrolysis and Ammonia Production

VII. Ammonia Utilization

References


9. Biotransformation of Bile Acids and Cholesterol by the Intestinal Microflora

I. Introduction

II. Major Biotransformations Catalyzed by Intestinal Bacteria

III. Biotransformation of Chenodeoxycholic Acid and Ursodeoxycholic Acid during Cholesterol Gallstone Dissolution Therapy

IV. Biotransformation of Cholesterol

V. Summary

References


10. Biotransformation of Steroids

Abbreviations

I. Introduction

II. Enterohepatic Circulation

III. Metabolic Transformations of Steroids

IV. Technique for Isolating Steroid-Metabolizing Organisms and Steroid Metabolites

V. Purification of Enzymes Involved in Steroid Metabolism

VI. Bacterial Steroid Metabolism from the Host's Viewpoint

VII. Steroid Metabolism from the Bacterial Viewpoint

VIII. Practical Application

References


11. Biochemical Pharmacology and Toxicology Involving the Intestinal Flora

I. Introduction

II. Drugs and the Flora

III. Food Constituents

IV. Environmental Compounds

V. Conclusion

References


12. Production of Intestinal Mutagens

I. Introduction

II. Production of Intestinal Mutagens by the Intestinal Microflora

III. Mutagens in Human Feces

IV. Conclusions

References

Part III. Importance of the Intestinal Microflora to the Host


13. Impact of the Intestinal Microflora on Intestinal Structure and Function

I. Introduction

II. Impact of the Indigenous Microflora on Intestinal Structure

III. Impact of the Indigenous Microflora on Intestinal Function

IV. Indigenous Microflora and the Pathogenesis of Intestinal Disease

V. Impact of the Indigenous Microflora beyond the Intestinal Habitat

References


14. Role of the Intestinal Microflora in Host Defense against Infection

I. Stability of the Intestinal Microflora

II. Suppression of the Multiplication of Pathogens by the Intestinal Microflora

III. Mechanisms Responsible for Antagonism against Pathogens

References


15. Translocation of Indigenous Bacteria from the Intestinal Tract

I. Historical Background

II. Definition of Bacterial Translocation

III. Bacterial Translocation Models

IV. Mechanisms Promoting Bacterial Translocation

V. Bacterial Translocation in Humans

VI. Conclusion

References

Part IV. Consequences of Upsetting the Ecology of the Intestinal Microflora


16. Changes in Human Intestinal Flora Related to the Administration of Antimicrobial Agents

I. Introduction

II. Deficiencies of Reported Studies

III. Other Aspects of the Effects of Drugs on Bowel Flora

IV. Indirect Measures of the Effect of Antimicrobial Agents on Bowel Flora

V. Shifts in Susceptibility Patterns

VI. Shifts in Flora That Predispose to Infection

VII. Adverse Influence of Antimicrobial Agents on Certain Enteric Infections

VIII. Use of Antimicrobial Agents for Preoperative Bowel Preparation

IX. Bowel Decontamination as Prophylaxis in Patients with Granulocytopenia and Malignancy

X. Antimicrobial Therapy as Prophylaxis for Neonatal Necrotizing Enterocolitis

XI. Sterilization of Feces

XII. Antimicrobial Drug Residues in Food

XIII. Selective Modification of Bowel Flora

References


17. Pseudomembranous Colitis

I. Introduction

II. Historical Perspective

III. Clinical and Pathological Observations

IV. Clostridium difficile and Antibiotic-Associated Colitis

V. Management

VI. Pathophysiology

VII. Clostridium difficile Toxins

VIII. Summary

References


18. Role of the Intestinal Microflora in Ulcerative Colitis

I. Introduction

II. Search for Specific Pathogens

III. Alternative Approaches

IV. Animal Models for Ulcerative Colitis

V. Experimental Studies Utilizing the Carcageenan Model

VI. Other Animal Models for Ulcerative Colitis

VII. Summary

References


19. The Contaminated Small Bowel Syndrome

I. Introduction

II. Lessons from Germfree Animals

III. Pathophysiological Consequences of Intestinal Bacterial Contamination

IV. Some Clinical Settings for the Contaminated Small Bowel Syndrome

V. Clinical Features

VI. Diagnosis

VII. Treatment

References


20. Effect of Dietary and Environmental Stress on the Gastrointestinal Microbiota

I. Introduction

II. Stress

III. How Does Stress Influence the Gastrointestinal Ecosystem?

IV. Can We Adequately Measure Changes in Microbial Populations in the Gastrointestinal Tract?

V. Indigenous Microbiota of Stressed Animals

VI. Consequences to the Host Animal of Stress-Induced Changes in the Gastrointestinal Ecosystem

VII. The Future: Improved Experimental Approaches

References

Index