The association of infant and mother gut microbiomes with development of allergic diseases in children: a systematic review

OBJECTIVE

It is believed that gut microbiota alteration leads to both intestinal and non-intestinal diseases in children. Since infants inherit maternal microbiota during pregnancy and lactation, recent studies suggest that changes in maternal microbiota can cause immune disorders as well. This systematic review was designed to assess the association between the child and mother's gut microbiome and allergy development in childhood.

DATA SOURCES

In this systematic review, international databases including PubMed, Scopus, and ISI/WOS were searched until January 2023 to identify relevant studies.

STUDY SELECTIONS

Observational studies that analyzed infant or maternal stool microbiome and their association with allergy development in children were included in this study. Data extraction and quality assessment of the included studies were independently conducted by two researchers.

RESULTS

Of the 1694 papers evaluated, 21 studies examined neonate gut microbiome by analyzing stool samples and six studies examined maternal gut microbiota. A total of 5319 participants were included in this study. Asthma followed by eczema and dermatitis were the most common allergy disorders among children. Urbanization caused a lack of diversity in the bacterial microbiota as well as lower levels of Bifidobacterium and Lachnospira associated with a higher risk of allergy. In contrast, higher levels of Roseburia and Flavonifractor were associated with lower allergy risk.

CONCLUSIONS

This systematic review shows that gut microbiota may be associated with allergy development. Further studies are required to provide a definitive answer.

Association of greenspaces exposure with cardiometabolic risk factors: a systematic review and meta-analysis

BACKGROUND

Cardiometabolic conditions are major contributors to the global burden of disease. An emerging body of evidence has associated access to and surrounding public open spaces (POS) and greenspace with cardiometabolic risk factors, including obesity, body mass index (BMI), hypertension (HTN), blood glucose (BG), and lipid profiles. This systematic review aimed to synthesize this evidence.

METHODS

This systematic review was conducted based on the PRISMA guidelines. Four electronic databases including Web of Science, PubMed, Scopus, and Google Scholar were searched for eligible articles published until July 2023. All observational studies which assessed the association of greenspace and POS with cardiometabolic risk factors including obesity, BMI, HTN, BG, and lipid profiles were included and reviewed by two authors independently. Heterogeneity between studies was assessed using the I2 index and Cochrane's Q test. Random/fixed effect meta-analyses were used to combine the association between greenspace exposure with cardiometabolic risk factors.

RESULTS

Overall, 118 relevant articles were included in our review. The majority of the articles were conducted in North America or Europe. In qualitative synthesis, access or proximity to greenspaces or POS impacts BMI and blood pressure or HTN, BG, and lipid profiles via various mechanisms. According to the random effect meta-analysis, more access to greenspace was significantly associated with lower odds of HTN (odds ratio (OR): 0.81, 95% confidence intervals (CIs): 0.61-0.99), obesity (OR: 0.83, 95% CIs: 0.77-0.90), and diabetes (OR:0.79, 95% CI: 0.67,0.90).

CONCLUSIONS

Findings of this systematic review and meta-analysis suggested that greenspace accessibility is associated with some cardiometabolic risk factors. Improving greenspace accessibility could be considered as one of the main strategies to reduce cardiometabolic risk factors at population level.

Association of socioeconomic status with psychiatric problems and violent behaviours in a nationally representative sample of Iranian children and adolescents: the CASPIAN-IV study

OBJECTIVES

The aim of the present study was to evaluate the association between socioeconomic status (SES) and psychiatric problems and violent behaviours in a nationally representative sample of Iranian children and adolescents, based on nationwide surveillance programme data, 2011-2012.

METHODS

Overall, 14 880 students, aged 6-18 years, were selected using a multistage cluster sampling method from rural and urban areas of 30 provinces in Iran. SES was estimated based on a main summarised component, extracted from principle component analysis of family assets and parents' jobs and education. For statistical analysis, SES was classified as 'low', 'middle' and 'high'. The WHO-Global School Based Student Health Survey (WHO-GSHS) questionnaire was used to assess psychiatric problems and violent behaviours.

RESULTS

In total, 13 486 students (participation rate 90.6%) completed the study: 50.8% were boys and 75.6% were urban residents, with a mean age of 12.47±3.36 years. In the multivariate model, the ORs of depression, anxiety, feeling worthless, anger, insomnia, confusion and physical fights were lower in students with high SES compared with those with low SES (p<0.05) but physical fights was lower in the high SES group than in the low SES group (p<0.05). No significant relationship was documented between SES and other variables, including getting worried, history of bullying and being victimised.

CONCLUSIONS

Children and adolescents with low SES were at higher risk for psychiatric problems and violent behaviours. Mental health policies and public interventional strategies should be considered at the public level, notably for low SES families.

Years of life lost due to gastric cancer is increased after Bayesian correcting for misclassification in Iranian population

AIM

To estimate the change in years of life lost (YLL) due to gastric cancer mortality after correcting for misclassification in registering causes of death using the Bayesian method.

BACKGROUND

For evaluating the health status of a country and determining priority of risk factors, some epidemiologic indicators are needed. Due to premature death, YLL is one of the most widely used indicators. To have an exact estimate of YLL, an accurate death registry data is needed, but the Iranian death registry is subject to misclassification error.

MATERIAL AND METHODS

Gastric cancer mortality data from 2006 to 2010 for Iran were extracted from national death statistics. The rate of misclassification in registered causes of deaths was estimated, using Bayesian method for each year. Then YLL of gastric cancer is estimated for different age-sex categories before and after implementing Bayesian method.

RESULTS

Using Bayesian method, the estimated misclassification rate for gastric cancer in cancer without label group were 5%, 3%, 3%, 7% and 7% respectively from 2006 to 2010. Estimated Years of life lost due to gastric cancer before correcting misclassification were respectively 111684.93, 114957.31, 112391.93, 112250.53 and 113300.92 person-years for years 2006 to 2010. After correcting misclassification, the total YLL of gastric cancer increased to 1535.19, 921.11, 908.39, 2566.39 and 2507.00 person-years, respectively from 2006 to 2010.

CONCLUSION

If health policy makers ignore the existence of misclassification in registered causes of death, they may underestimate the burden of some causes of death and overestimate some others.