Altered Gut Microbiota Taxonomic Compositions of Patients With Sepsis in a Pediatric Intensive Care Unit

Abstract

Background: The gut is thought to play an important role in the pathogenesis of sepsis. Changes in the gut microbiota are closely related to the occurrence and development of human diseases, but few studies have focused on taxonomic composition of gut microbiota in septic patients. Knowledge of changes in the gut microbiota is a key issue in intensive care. Clinicians must understand how an altered gut microbiota affects the susceptibility and prognosis of septic patients.Measurements and Main Results: In the single-center case control study, 20 septic patients and 20 healthy children were recruited. The taxonomic composition of gut microbiota was determined via 16S rRNA gene sequencing. Gut microbiota diversity in children with sepsis was significantly reduced compared with that in healthy children. The taxonomic composition of gut microbiota can effectively distinguish children with sepsis from healthy children. Thirteen taxa of gut microbiota were significantly increased in the guts of children with sepsis compared with those of healthy children. The increased abundances of Enterococcaceae, Enterococcus, and Enterococcus durans in gut of septic patients were significantly positively correlated with blood inflammation indicators CRP and WBC. The abundances of seven bacteria were significantly decreased in the guts of septic children compared with those of healthy children. The decreased abundance of Bifidobacteriales in gut of septic patients is significantly negatively correlated with blood inflammation index WBC. A machine-learning classifier was built for distinguishing sepsis and achieved the AUC value of 81.25%. It shows that the composition of gut microbiota has certain potential for diagnosis of sepsis.Conclusions: Gut microbiota alterations in septic patients exhibit proliferation of opportunistic pathogenic bacteria, the massive reduction of the commensal flora, and the significant decrease in the diversity of the gut microbiota. Dysbiosis may also account for some changes in the inflammation indexes.

Loss of Health Promoting Bacteria in the Gastrointestinal Microbiome of PICU Infants with Bronchiolitis: A Single-Center Feasibility Study

“…Herein, RSV infants had a higher relative abundance of Bifidobacterium compared to controls, which conflicts with the previously published data that demonstrated loss of Bifidobacterium within infants with severe illness. However, we did observe that infants with RSV had an increased abundance of Enterobacteriaceae , a potentially pathogenic bacteria in the gut, which was one of the previously observed pathogenic taxa to be increased in a similar patient population [ 19 , 28 ]. Infant age, mode of feeding, and the built environment of the PICU all contribute to the development of individual gut microbiomes.…”

“…These results are consistent with prior reports [ 19 , 20 ]. The loss of commensal bacterial taxa that provide resistance against pathogenic bacteria has been observed in children with critical illness residing in the PICU [ 19 , 20 , 28 ]. Decreased taxa level abundances of Bacteroides and Bifidobacterium [ 19 , 28 ], Faecalibacterium and Ruminococcus [ 20 ] establish that PICU patients have a depletion of commensals in their GI microbiomes.…”

“…The loss of commensal bacterial taxa that provide resistance against pathogenic bacteria has been observed in children with critical illness residing in the PICU [ 19 , 20 , 28 ]. Decreased taxa level abundances of Bacteroides and Bifidobacterium [ 19 , 28 ], Faecalibacterium and Ruminococcus [ 20 ] establish that PICU patients have a depletion of commensals in their GI microbiomes. Additionally, an increase in potentially pathogenic bacteria in the gut microbiotas of patients in the PICU and NICU settings has been documented, including Enterobacteriaceae [ 19 , 28 ] and Enterococcus [ 20 , 28 ].…”

“…Decreased taxa level abundances of Bacteroides and Bifidobacterium [ 19 , 28 ], Faecalibacterium and Ruminococcus [ 20 ] establish that PICU patients have a depletion of commensals in their GI microbiomes. Additionally, an increase in potentially pathogenic bacteria in the gut microbiotas of patients in the PICU and NICU settings has been documented, including Enterobacteriaceae [ 19 , 28 ] and Enterococcus [ 20 , 28 ]. Herein, RSV infants had a higher relative abundance of Bifidobacterium compared to controls, which conflicts with the previously published data that demonstrated loss of Bifidobacterium within infants with severe illness.…”

Gut-Lung Crosstalk in Sepsis-Induced Acute Lung Injury

“…Furthermore, the abundance of the following seven bacteria was significantly decreased in the guts of septic children: Bifidobacteria, Selenomonas, Aminococcus acidaceae, Daentosaceae UCG-003, Dialister, Dorea longicatena, and Ruminococcus sp.5_1_39bFAA. The decrease of intestinal bifidobacteria abundance is negatively correlated to WBC ( Liu et al, 2021 ). The mechanisms behind these shifts in the microbiota composition are unclear ( Haak and Wiersinga, 2017 ).…”