The human gut resistome

Abstract

The human gut is home to a myriad of organisms. While some are harmless commensals, others are transient, pathogenic flora. The gut microbiome is composed of diverse bacterial flora, and apart from playing a major role in protecting from various infectious and non-infectious diseases, it plays an important role in resistance to antimicrobials. The collection of genes or genetic material that confers antimicrobial resistance constitutes the gut resistome, and it may involve the pathogens or commensals of the intestinal tract. The diversity of this gut resistome is influenced by various environmental factors including the diet and antibiotic exposure. This review highlights the recent concepts pertaining to the human gut resistome, factors affecting it, how it impacts human health and diseases, methods to study the resistome and potential therapeutic approaches.

Influence of Human Eating Habits on Antimicrobial Resistance Phenomenon: Aspects of Clinical Resistome of Gut Microbiota in Omnivores, Ovolactovegetarians, and Strict Vegetarians

“…Several studies have already highlighted the role of fecal contamination in the process of ARG spread, showing high prevalence of ARG in animal and human feces, sewage waste, and water treatment plants. Through soil and irrigation water, ARG may reach vegetables [ 6 , 22 , 23 ].…”

“…These tet genes are commonly associated with transposons and mobile genetic elements, which may contribute to their wide distribution among environments [ 35 ]. Variants such as tet(Q) , tet(O) , and tet(M) are highly frequent genes in the human gut resistome [ 22 ]. It is known that tet(Q) is highly prevalent among isolates of Bacteroides spp., major anaerobic bacilli resident in the human gut microbiota.…”

“…Still, according to the literature, tet transcripts could play several additional roles, such as cell signaling, communication, or transport. Besides, toxic heavy metals and antimicrobials of the MLS group could participate in co-selection of tetracycline resistance [ 22 , 38 , 39 ].…”

Gut resistome presents a unique biome signature in chronic multi-symptom illness patients and links persistent pro-inflammatory phenotype in a mouse model reversible by fecal microbiota transfer

“…Resistance to antibiotics is conferred on bacteria by antibiotic resistance genes (ARGs). All of the ARGs collectively form a resistome, and usually are carried by the opportunistic pathogens, humans may encounter thus increasing the risk of acquired infection that are difficult to treat with currently approved antibiotics [3], [4], [5], [6]. The evolution of drug resistance in such pathogens is driven by chromosomal mutation and the acquisition of ARGs.…”

“…The most frequently reported genes are those directed against tetracycline, βlactams, aminoglycosides and glycopeptides. Tetracycline and glycopepetide resistant genes are most common in fecal samples of human [4], [11], [12], [13]. On the other side, human microbiota is also influenced by environmental factors that can contribute to alteration of microbial composition and affect colonization resistance to pathogens [14].…”