Establishment of intestinal bacteriology

Abstract

Research on intestinal bacteria began around the end of the 19th century. During the last 5 decades of the 20th century, research on the intestinal microbiota made rapid progress. At first, in my work, I first developed a method of comprehensive analysis of the intestinal microbiota, and then I established classification and identification methods for intestinal anaerobes. Using these methods I discovered a number of ecological rules governing the intestinal microbiota and the role of the intestinl microbiota in health and disease. Moreover, using germfree animals, it was proven that the intestinal microbiota has a role in carcinogenesis and aging in the host. Thus, a new interdisciplinary field, "intestinal bacteriology" was established.

Keywords: functional foods; intestinal bacteria; intestinal bacteriology; intestinal microbiota.

Fig. 1.

Photomicrograph of the Gram-stained fecal stool of an adult.

Fig. 2.

Discovery of BL agar and predominant flora of bifidobacteria in an adult fecal specimen. 1, 2, 3, 7: Bifidobacterium. 4: Megasphaera elsdenii. 5, 6: Bacteroides. 8: Eubacterium. 9: Veillonella

Fig. 3.

Plate-in-bottle method.

Fig. 4.

Composition of fecal microbiota of adults. Figures in parentheses indicate the frequency (%) of detection. Bacterial groups without parentheses: the frequency of detection is 100%.

Fig. 5.

Microbiota of various regions of the GI tract of human adults. O, oral cavity; S, stomach; D, duodenum; J, jejunum, I, ileum; C, cecum; R, rectum.

Fig. 6.

Changes in the fecal microbiota during the first 7 days after birth.

Fig. 7.

Changes in the fecal microbiota with increasing age.

Fig. 8.

The metabolic activities of intestinal bacteria.

Fig. 9.

Relationship between intestinal bacteria and the host.