The Intestinal Microbiota as a Reservoir and a Therapeutic Target to Fight Multi-Drug-Resistant Bacteria: A Narrative Review of the Literature

Abstract

The appearance and dissemination of antibiotic-resistant bacteria, particularly in specific closed environments such as intensive care units of acute care hospitals, have become a major health concern. The intestinal microbiota has various functions including host protection from overgrowth or colonization by unwanted bacteria. The exposure to antibiotics significantly reduces the bacterial density of intestinal microbiota leaving an ecologic void that can be Enhanced Digital Features To view enhanced digital features for this article go to https://doi.org/10.6084/ m9.figshare.9988634. Key Summary PointsThe human gut acts as a major reservoir of MDR bacteria, where they overgrow and share genetic determinants of resistance with other species, perpetuating their spread.The most common strategy for gut decolonization is the use of oral, nonabsorbable antibiotics, although fecal microbiota transference (FMT) is a promising intervention.We summarize 145 FMTs performed for intestinal decolonization of MDR bacteria in the last 5 years from 25 publications.According to our analysis, FMT was significantly more successful against GPC than GNB, with no antibiotic consumption after FMT in the case of concomitant CDI and in older versus recent reports.

Gut Microbiome Modulation and Faecal Microbiota Transplantation Following Allogenic Hematopoietic Stem Cell Transplantation

“…The prevalence of multidrug-resistant bacteria (MDRB) is a growing problem worldwide [ 58 ], as a result of the inappropriate use of antibiotics [ 59 ]. Notably, bacteria should be considered as a MDR if it is resistant to at least one agent in ≥3 antibiotic classes (in which these bacteria are known to be susceptible) [ 60 ]. Patients with hematological malignancies are treated with broad spectrum antibiotics and multiple chemotherapeutic agents, thus with high risk of altered gut microbiota composition and consequently gut colonization of these bacteria [ 58 ].…”

“…In a retrospective study, the efficacy of FMT before or after allo-HSCT in decolonization of MDRB was evaluated [ 60 ]. Ten participants (in four cases, FMT was given before allo-HSCT, and in six cases, it was given after this procedure) were enrolled in the study.…”

“…Moreover, all patients (n = 4) treated with FMT before allo-HSCT achieved persistent decolonization. Overall, FMT was presented as a safe method and adverse events included one case of constipation, one suffering from grade I diarrhea, and one having GvHD [ 60 ].…”

Nutritional Status and the Critically Ill Patient: Gut Microbiota and Immuno-Nutrition in I.C.U. at the Time of SARS-COV 2 Pandemic

“…FMT resembles the most direct approach to restore gut dysbiosis currently available in clinical and experimental practice. It consists in the infusion of feces from a healthy donor directly to the gastrointestinal tract of the recipient, restoring both the complexity and diversity of the gut microbiota [46][47][48]. From a bench point of view, FMT has also been associated with a reduction of antimicrobial resistance genes in stool microbiota [49].…”

Histone methyltransferase EHMT2 degradation by propionate derived from Bacteroides thetaiotaomicron induced colon cancer apoptosis via epigenetic regulation of TNFAIP1

“…In the human body, the microbiota mainly colonizes the large intestine and promotes food digestion, regulation of the human immune system, production of vitamins (B12, K, riboflavin), and protection against disease-related bacteria [7][8][9]. In the colon, the Bacteroides genus is a major group of the human microbiome, and Bacteroides thetaiotaomicron (BT) is the second most commonly isolated bacteria after B. fragilis [10][11][12].…”