Mechanistic insight into the gut microbiome and its interaction with host immunity and inflammation

Abstract

The intestinal tract is a host to 100 trillion of microbes that have co-evolved with mammals over the millennia. These commensal organisms are critical to the host survival. The roles that symbiotic microorganisms play in the digestion, absorption, and metabolism of nutrients have been clearly demonstrated. Additionally, commensals are indispensable in regulating host immunity. This is evidenced by the poorly developed gut immune system of germ-free mice, which can be corrected by transplantation of specific commensal bacteria. Recent advances in our understanding of the mechanism of host–microbial interaction have provided the basis for this interaction. This paper reviews some of these key studies, with a specific focus on the effect of the microbiome on the immune organ development, nonspecific immunity, specific immunity, and inflammation.

Common Inflammatory Mechanisms in COVID-19 and Parkinson’s Diseases: The Role of Microbiome, Pharmabiotics and Postbiotics in Their Prevention

“…314 It has been shown that lactobacteria in the gut microbiome can reduce inflammatory and autoimmune processes by activating the proliferation of regulatory T cells, decreasing the TLR activity and levels of TNFα and proinflammatory cytokines. [315][316][317][318] Inflammation and oxidative stress in the intestine disrupt the function of the intestinal barrier, as a result of which the number of toxins and metabolites entering the bloodstream, causing inflammation and oxidative stress in organs and tissues, increases. 319,320 Lactobacteria of the gut microbiome can prevent inflammation and oxidative stress in organs and tissues by reducing oxidative stress caused by hydrogen peroxide molecules, hydroxyl, and superoxide radicals in the intestine through the production of substances with antioxidant activity, such as thioredoxin reductase, superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, glutathione S-transferase, thiols (cysteine and glutathione), exopolysaccharides.…”

Lactobacillus rhamnosus GG for the prevention of reactive arthritis relapse in children

“…Последние достижения в технологии секвенирования дали возможность получить глубокую характеристику микробиоты кишечника человека. Это позволило исследовать изменения в структуре кишечных комменсальных сообществ (дисбиоз), которые могут быть вовлечены в возникновение и поддержание различных хронических аутоиммунных заболеваний, таких как воспалительные заболевания кишечника и артриты [26]. Дисбиоз может привести к изменениям в слое эпителиальных клеток кишечника с повышенным воздействием на них различных бактерий и бактериальных продуктов, что приводит к хронической антигенной стимуляции, распространению медиаторов воспаления, активации Т-клеток и развитию воспалительных заболеваний внекишечной локализации [27].…”

Inflammatory Bowel Disease Therapeutics: A Focus on Probiotic Engineering

“…Interestingly, the enteric system microbiome in human comprises over 100 times the genes compared to the genome of its human host [ 38 ]. Majority of intestinal bacteria belong to 4 phyla, Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, where the healthy human gut has predominantly Firmicutes and Bacteroidetes [ 39 , 40 ]. Bacterial population also vary throughout the gastrointestinal tract with colon having both the greatest number and diversity of species compared to stomach and small intestine [ 41 ].…”