Intestinal dysbiosis and necrotizing enterocolitis: assessment for causality using Bradford Hill criteria

Jennifer B. Fundora, Pallabi Guha, Darla R. Shores, Mohan Pammi, Akhil Maheshwari

Research output: Contribution to journalReview articlepeer-review

11 Scopus citations


In recent years, several studies have shown that premature infants who develop NEC frequently display enteric dysbiosis with increased Gram-negative bacteria for several days to weeks prior to NEC onset. The importance of these findings, for the possibility of a causal role of these bacteria in NEC pathogenesis, and for potential value of gut dysbiosis as a biomarker of NEC, is well-recognized. In this review, we present current evidence supporting the association between NEC in premature infants and enteric dysbiosis, and its evaluation using the Bradford Hill criteria for causality. To provide an objective appraisal, we developed a novel scoring system for causal inference. Despite important methodological and statistical limitations, there is support for the association from several large studies and a meta-analysis. The association draws strength from strong biological plausibility of a role of Gram-negative bacteria in NEC and from evidence for temporality, that dysbiosis may antedate NEC onset. The weakness of the association is in the low level of consistency across studies, and the lack of specificity of effect. There is a need for an improved definition of dysbiosis, either based on a critical threshold of relative abundances or at higher levels of taxonomic resolution.

Original languageEnglish (US)
Pages (from-to)235-248
Number of pages14
JournalPediatric research
Issue number2
StatePublished - Jan 1 2020

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health


Dive into the research topics of 'Intestinal dysbiosis and necrotizing enterocolitis: assessment for causality using Bradford Hill criteria'. Together they form a unique fingerprint.

Cite this