Potential Effects of Horizontal Gene Exchange in the Human Gut

Abstract

Many essential functions of the human body are dependent on the symbiotic microbiota, which is present at especially high numbers and diversity in the gut. This intricate host–microbe relationship is a result of the long-term coevolution between the two. While the inheritance of mutational changes in the host evolution is almost exclusively vertical, the main mechanism of bacterial evolution is horizontal gene exchange. The gut conditions, with stable temperature, continuous food supply, constant physicochemical conditions, extremely high concentration of microbial cells and phages, and plenty of opportunities for conjugation on the surfaces of food particles and host tissues, represent one of the most favorable ecological niches for horizontal gene exchange. Thus, the gut microbial system genetically is very dynamic and capable of rapid response, at the genetic level, to selection, for example, by antibiotics. There are many other factors to which the microbiota may dynamically respond including lifestyle, therapy, diet, refined food, food additives, consumption of pre- and probiotics, and many others. The impact of the changing selective pressures on gut microbiota, however, is poorly understood. Presumably, the gut microbiome responds to these changes by genetic restructuring of gut populations, driven mainly via horizontal gene exchange. Thus, our main goal is to reveal the role played by horizontal gene exchange in the changing landscape of the gastrointestinal microbiome and potential effect of these changes on human health in general and autoimmune diseases in particular.

Processed Food Additive Microbial Transglutaminase and Its Cross-Linked Gliadin Complexes Are Potential Public Health Concerns in Celiac Disease

“…Processed food additive [6,8,9,[11][12][13][14]20] Pathobionts [24][25][26] Probiotics [27,28] Plants [29,30] Vegetables [31] Meat [32,33]…”

“…The potential pathogenic mechanisms connecting the mTG to CD pathogenesis were summarized recently [7,[12][13][14]25,27,56,58]. The following paragraphs will update and add some additional pathways for the mTG-CD cross-talks.…”

Shifting Climates, Foods, and Diseases: The Human Microbiome through Evolution

“…For example, Helicobacter pylori appears to have been acquired through meat consumption, [93] and novel viral recombinants (SIVcpz) have their origins in bush meat. [95] Even increased consumption and/or domestication of certain plants may have introduced novel microbes and gene variants into the human microbiome. [95] Even increased consumption and/or domestication of certain plants may have introduced novel microbes and gene variants into the human microbiome.…”

“…[94] Domestication of animals may have further intensified microbial transmission as humans and animals became more closely associated. [95] Even increased consumption and/or domestication of certain plants may have introduced novel microbes and gene variants into the human microbiome. A classic example is the presence of a seaweeddegrading microbe in the guts of human populations that ingest high amounts of seaweed.…”

Sığır ve Koyunlarda Plasmidik AmpC Beta Laktamaz Üreten Escherichia coli Araştırılması ve İzolatların Antibiyogram Profilleri, Filogenetik ve Virulans Karakterizasyonları

“…It has been reported that use of beta-lactams for treatment of several infections causes development of AmpC beta-lactamase producing E. coli isolates in animal and human intestinal microflora. This casual use also triggers an increase in AmpC beta-lactamase production in Gram-negative pathogens in humans and animals due to the horizontal transfer of resistance genes [8,9] .…”