Until recently, ecological analysis of human intestinal microbiota had been conducted with culture-dependent methods. However, the majority of our intestinal bacteria remain not-yet cultured. Many culture-independent, molecular ecological methods have been developed to investigate real compositions of microbiota in the last decade. Among them, fluorescencein situhybridization (FISH) is one of the most widely used methods, though it is time-consuming and requires laborious counting work of the detected bacteria. Development of FISH coupled with flow cytometry (FISH-FCM) has circumvented this problem. Since the development of FISH-FCM, it has been used in several fields of microbiology such as environmental microbiology and clinical microbiology. It is now being applied to more complex biological samples, such as feces. These days, intestinal microbiota analyses with FISH-FCM are being conducted not only at group or genus level, but also at the species level. Recently, we have succeeded in the development of a FISH-FCM method that is applicable to fecal samples containing high amounts of autofluorescent particles. Further development of specific probes for the bacteria of interest will contribute to the illustration of the real picture of our intestinal microbiota

抄録全体を表示

プロバイオティクスは多くの保健効果を持つ。その効果は腸内細菌叢とその活性を改善することによりもたらされる。摂取したプロバイオティック乳酸菌と常在腸内細菌の間には共生や競合関係が存在し、その結果、乳酸菌数の増加など腸内細菌叢、腸内環境が改善されると推察される。常在腸内細菌叢はその形成過程において様々な要因を受け、各個人により異なる。腸内細菌叢が個人により異なることは、摂取したプロバイオティック乳酸菌と常在腸内細菌の関係が各個人で異なることを示し、腸内細菌叢の違いによりプロバイオティクス摂取によってもたらされる保健効果に個人差が生じると考えられる。常在腸内細菌はプロバイオティクスの保健効果に影響する重要な要因の一つである。

抄録全体を表示

The role of tannase produced by Lactobacillus plantarum in tannin-rich medium was demonstrated by using strains with known tannase activities. After 20 h incubation in aerobic tannin-rich medium, the growth of L. plantarum KOG 19 with low activity was lower than that of L. plantarum ATCC 14917^T with high activity by approximately 1.5 orders of magnitude, whereas the growth of KOG 19 in aerobic medium without tannin was almost the same as that of ATCC 14917^T. The reduced growth of KOG 19 in aerobic tannin-rich medium was recovered by the addition of exogenous tannase or Mn²⁺ to the medium. A similar result was obtained in the comparison of growth levels between high and low tannase activity groups in aerobic tannin-rich medium, while no significant differences were observed between the groups in anaerobic tannin-rich medium. Furthermore, the growth of the low tannase activity group in aerobic tannin-rich medium was restored by the addition of catalase. These results suggest that tannase production allows L. plantarum strains to acquire and accumulate Mn²⁺ which is otherwise chelated by tannins, and then high intracellular Mn²⁺ compensates for the lack of the enzyme superoxide dismutase in L. plantarum resulting in resistance to oxygen toxicity under aerobic conditions.

抄録全体を表示

本研究では植物発酵食品由来の乳酸菌Lactobacillus plantarum ONRIC b0240株（以下L.p.b0240）の21日間継続摂取が健康成人女性の唾液及び糞便総IgA量に及ぼす影響を検討した。被験者は水摂取群（対照）、L.p.b0240（2x10⁹ CFU）摂取群、L.p.b0240（2x10¹⁰ CFU）摂取群に割り付けた。唾液総IgA増加量は、2x10⁹ CFU摂取群、2x10^l0 CFU摂取群ともに上昇し、21日間摂取では水摂取群に比べ統計学的に有意に高値を示した。糞便総IgA増加量は、個々のばらつきが大きかったために有意差は認められなかったが、2x10⁹ CFU摂取群、2x10¹⁰ CFU摂取群はいずれも21日間摂取により高値を示した。なお、被験物摂取による副作用は認められなかった。以上のことから、L.p.b0240の継続摂取は粘膜免疫を高め、生体防御に寄与することが示唆された。

抄録全体を表示