PurposePrevious studies reported a higher risk of food allergy for cesarean-born children than vaginal-born children. This study aims to systematically compare the prevalence of food allergy among cesarean-born and vaginal-born children aged 0–3 years.MethodsThree English and two Chinese databases were searched using terms related to food allergies and cesarean sections. Cohort studies that reported the prevalence of food allergy in cesarean-born and vaginal-born children aged 0–3 years were included. Two reviewers performed study selection, quality assessment, and data extraction. The pooled prevalence of food allergy in cesarean-born and vaginal-born children was compared by meta-analysis.ResultsNine eligible studies, with 9,650 cesarean-born children and 20,418 vaginal-born children aged 0–3 years, were included. Of them, 645 cesarean-born children and 991 vaginal-born children were identified as having food allergies. The pooled prevalence of food allergy was higher in cesarean-born children (7.8%) than in vaginal-born children (5.9%). Cesarean section was associated with an increased risk of food allergy [odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03–2.05] and cow's milk allergy (OR: 3.31; 95% CI: 1.98–5.53). Additionally, cesarean-born children with a parental history of allergy had an increased risk of food allergy (OR: 2.60; 95% CI: 1.28–5.27).ConclusionThis study suggests that cesarean sections was associated with an increased risk of food and cow's milk allergies in children aged 0–3 years. Cesarean-born children with a parental history of allergy demonstrated a higher risk for food allergy than did vaginal-born children. These results indicate that caregivers should be aware of the risks of food allergies in cesarean-born children, reducing the risk of potentially fatal allergic events. Further research is needed to identify the specific factors affecting food allergies in young children.Systematic Review Registrationhttp://www.crd.york.ac.uk/prospero, identifier: International Prospective Register of Systematic Reviews (NO. CRD42019140748).

The biogeochemistry of iron (Fe) could affect arsenic (As) fate and change its availability. Fe(II) oxidation mediated by Fe oxidizing bacteria (FeOB) has the potential for As contamination remediation due to the formation of biogenic minerals. However, microbial Fe(II) oxidation coupled with the immobilization of As and the effect of FeOB on As remediation in soils has not been thoroughly investigated. In this study, a FeOB was isolated from a paddy soil and identified as Ochrobactrum sp. EEELCW01. The kinetics reactions were used to investigate how biological and chemical reactions were involved in the Fe(II)-NO 3 − -FeOB system. Microbial Fe(II) oxidation coupled As mineralization, as well as its application in As contaminated paddy soils was studied. The results suggested that biological pathway contributed to the Fe(II) oxidation and NO 3 − reduction in the whole process, in which the chemical Fe(II) oxidation by biogenic NO 2 − was involved. Meanwhile, Fe(II) facilitated the reduction of NO 2 − while inhibited the reduction of NO 3 −. Adding 2% or more bacteria led to a significant removal effect for aqueous As, resulting in the formation of lepidocrocite and two As-containing minerals (angelellite, loellingite). With the simultaneous application of FeOB and NO 3 − , the available As content in soils decreased by 37.6% and stabilized at 0.80 mg kg −1 finally. In addition, the immobilization showed long-term effect compared to the treatment with Fe(II) or NO 3 − alone.The study proved that the isolated FeOB had a significant ability for As mineralization and immobilization, which provided theoretical and application basis for the remediation of As contaminated soils.

Background Cesarean delivery is considered as a potential risk factor for childhood overweight/obesity; however, its risk magnitude remains unknown. To estimate the risk of being overweight/obese in children under 6 years old following cesarean delivery. Methods Three English and two Chinese databases were searched. The quality of studies was appraised using the Newcastle-Ottawa Scale. Meta-analyses were conducted to estimate the pooled rates and relative risk (RR) of overweight/obesity, with RR estimates to compare the risks between children delivered by cesarean section and children delivered vaginally under 6 years old. Results Eighteen cohort studies with a total of 125,042 children under 6 years old were included. Of them, 33,551 children were delivered by cesarean section. The rates of pooled estimate of overweight combined with obesity, overweight alone, and obesity alone in children delivered by cesarean section were 18.2%, 14.1%, and 8.6%, respectively, while corresponding rates in children delivered vaginally were 14.0%, 12.5%, and 6.6%. Cesarean delivery was associated with significantly increased risks of childhood overweight combined with obesity (RR 1.18, 95% confidence interval [CI] 1.13–1.23), overweight alone (RR 1.09, 95% CI 1.02–1.17), and obesity alone (RR 1.26, 95% CI 1.13–1.40) as compared with vaginal delivery. Subgroup analyses showed a low degree of heterogeneity among all subgroups. Sensitivity analysis showed that overall estimates remained essentially the same when omitting one study at a time. Conclusion Children delivered by cesarean section may have an increased risk of overweight and / or obesity than children delivered vaginally in the first 6 years of life.