Effects of Lactococcus lactis and Bifidobacterium longum on Helicobacter pylori- or aspirin-induced gastritis and neuroinflammation in mice

국문 초록 (Abstract)

Helicobacter pylori (HP)는 위염과 소화성 궤양을 유발합니다. 따라서 HP 성장과 KATO III 세포에서 HP 유도 IL-8 발현을 억제하는 프로바이오틱스 Lactococcus lactis LL와 Bifidobacterium longum BL이 마우스에서 HP 유도 위염과 정신 장애를 완화할 수 있는지 조사했습니다. LL와 BL의 경구 투여는 HP 또는 아스피린 유도 위염, 대장염, 신경 염증 및 우울증/인지 장애와 유사한 행동을 완화했습니다. 또한 위에서 HP 감염, 호중구 침윤 및 NF-κB 활성화와 대장 및 해마에서 TNF-α 발현 및 NF-κB 활성화를 억제했습니다. LL 및/또는 BL이 HP 또는 아스피린으로 유발된 장내 미생물 불균형을 완화했습니다. 즉, Lachnospiracease, Helicobacteriaceae, Akkermansiaceae 개체군을 감소시키고 Bacteroidaceae와 Muribaculaceae 개체군을 증가시켰습니다. 이러한 결과는 HP 성장/염증 억제 LL 및/또는 BL의 호중구 침윤, NF-κB 활성화 및 HP 성장을 억제하여 장 염증(위염 및 대장염)과 신경 염증을 완화하여 전신 염증과 정신 장애를 완화할 수 있음을 시사합니다.

다국어 초록 (Multilingual Abstract)

Helicobacter pylori (HP) causes gastritis and peptic ulcer. Therefore, we examined whether probiotics Lactococcus lactis LL and Bifidobacterium longum BL, which inhibited HP growth and HP-induced IL-8 expression in KATO III cells, could mitigate HP-induced gastritis and neuroinflammation in mice. Oral administration of LL and/or BL alleviated HP- or aspirin-induced gastritis, colitis, neuroinflammation, and depression-like behavior. They also suppressed HP infection, neutrophil infiltration, and NF-κB activation in the stomach and TNF-α expression and NF-κB activation in the colon and hippocampus. LL and/or BL decreased Lachnospiracease, Helicobacteriaceae, and Akkermansiaceae populations and increased Bacteroidaceae and Muribaculaceae populations in HP- or aspirin-exposed mice. These findings suggest that HP growth/inflammation-inhibitory LL and/or BL may alleviate gastritis and neuroinflammation through the suppression of neutrophil infiltration, NF-κB activation, and HP growth, thereby leading to the attenuation of psychiatric disorder.

목차 (Table of Contents)

• Abstract ix
• 1. Introduction 1
• 1.1 Gastritis 1
• 1.1.1 Helicobacter pylori-induced gastritis 1
• 1.1.2 Aspirin-induced gastritis 2
• 1.2 Helicobacter pylori and psychiatric disorder 3
• 1.3 Aspirin and psychiatric disorder 3
• 1.4 Gastritis and gut microbiota 4
• 1.5 Treatment for gastritis 4
• 1.6 Study purpose 5
• 2. Materials and Methods 6
• 2.1 Culture of Helicobacter pylori 6
• 2.2 Isolation and culture of probiotics 6
• 2.3 Helicobacter pylori growth-inhibiting activity assay 6
• 2.4 Cell culture 6
• 2.4.1 Culture of KATO III cells 6
• 2.4.2 Cell seeding and treatment HP and probiotics protocol 7
• 2.5 Experimental animal models 7
• 2.5.1 Mouse gastritis model through Helicobacter pylori infection 7
• 2.5.2 Mouse gastritis model through aspirin induction 8
• 2.6 Behavioral tasks 9
• 2.6.1 Open field test 9
• 2.6.2 Y-maze test 9
• 2.6.3 Tail-suspension test 9
• 2.7 Urease activity assay 10
• 2.8 Inflammation score 10
• 2.9 Enzyme-linked immunosorbent assay (ELISA) 11
• 2.10 Immunoblotting 11
• 2.11 Immunostaining and hematoxylin & eosin (H&E) staining 11
• 2.12 Real-time quantitative polymerase chain reaction (RT-PCR) 12
• 2.13 Microbiota analysis 13
• 2.14 Whole-genome sequencing 13
• 2.15 Statistical analysis 14
• 3. Results 15
• 3.1 Effect of probiotics on Helicobacter pylori growth in vitro and Helicobacter
• pylori infection in KATO III cells 15
• 3.1.1 Screening of probiotics inhibiting Helicobacter pylori growth 15
• 3.1.2 Effects of probiotics against Helicobacter pylori infection in KATO III cells 17
• 3.1.3 The properties of selected probiotics 20
• 3.2 Effects of probiotics on gastritis and neuropsychiatric disorder in Helicobacter
• pylori infected mice 23
• 3.2.1 Probiotics alleviate gastric inflammation and inhibit urease and adhesion 23
• 3.2.2 Probiotics reduce proinflammatory cytokine levels in the blood 29
• 3.2.3 Probiotics attenuate psychiatric disorder-like behaviors and neuroinflammation 31
• 3.2.4 Probiotics alleviate colitis 33
• 3.2.5 Effects of probiotics on the gut microbiota composition 40
• 3.3 Effects of probiotics on aspirin-induced gastritis and neuropsychiatric disorder
• in mice 44
• 3.3.1 Probiotics alleviate gastritis 44
• 3.3.2 Probiotics reduce proinflammatory cytokine levels in the blood 49
• 3.3.3 Probiotics attenuate psychiatric disorder-like behaviors and neuroinflammation 51
• 3.3.4 Probiotics alleviate colitis 53
• 3.3.5 Effects of probiotics on the gut microbiota composition 60
• 4. Discussion 64
• 5. References 69
• 6. Acknowledgments 73
• 7. 국문 초록 74