Systematic review: early feeding practices and the risk of coeliac disease. A 2022 update and revision

Background: The effects of early feeding practices on the risk of coeliac disease (CD) remain debated. Aims: To update evidence on these practices on the risk of CD and/or CD-related autoimmunity (CDA), defined as anti-transglutaminase or anti-endomysial antibody positivity METHODS: We searched MEDLINE, EMBASE and the Cochrane Library to May 2022 for randomised controlled trials (RCTs) and observational studies. Results: We included 36 publications (30 studies). In the population at genetic risk of developing CD (HLA DQ2/DQ8-positive), exclusive or any breastfeeding and longer breastfeeding duration did not reduce the risk of developing CD/CDA during childhood. While a meta-analysis of four case-control studies showed a decreased risk for CD when gluten was introduced during breastfeeding, this was not shown in RCTs and cohort studies. Age at gluten introduction was not associated with cumulative CD/CDA risk, although two RCTs suggested that earlier gluten introduction was associated with earlier CDA appearance. Evidence from six observational studies suggests that consumption of a higher amount of gluten at weaning and/or thereafter may increase CD risk. There is insufficient evidence to determine the amount of gluten associated with an increased CD/CDA risk. Regarding whether infant feeding practices modulate the risk conferred by different HLA genotypes results were inconsistent. Conclusions: For the population at genetic risk of CD, breastfeeding and age at gluten introduction have no effect on its cumulative incidence during childhood. There is some evidence for an effect of the amount of gluten consumed at weaning and/or thereafter on CD/CDA risk.