Effect of household air pollution (Biomass fuel and tobacco) on the microbiome (Gut- Respiratory-axis), growth and respiratory health of newborns from birth to their first birthday: Mutoto Cohort, South Kivu, Democratic Republic of the Congo

Background and Rationale Globally air pollution is the fourth cause of death accounting for nearly 7 million deaths every year. The report of the State of the Air Initiative (2022) highlighted the fact that people in Africa bear the disproportionate burden of the adverse effects of household air pollution (HAP). Air pollution attributed deaths ( 155 deaths/100,000 people) are much higher than the global average ( 85.6/100,000) accounting for 30% of the global disease burden from HAP. After malnutrition, air pollution was the second leading risk factor for death, accounting to 1,1 millions death in 2019. Of these, more than 63% were attributed to exposure to indoor air pollution resulting from incomplete burn of biomass fuels. Exposure to household air pollution trigger changes in proportion and type in the microbiome (gut-respiratory-axis) resulting from inflammation and oxidative stress. The human gut microbiome have a critical role in metabolism and immune defense. Pollution related microbiome dysbiosis increase susceptibility to severe lower respiratory illness as well as the risk of respiratory chronic disease such as asthma and COPD. In the Democratic Republic of the Congo, more than 90% of the population continues to rely on solid fuels for cooking. The number of people exposed to HAP has increased from 2010 to 2022. With 58. 000 air pollution related deaths in 2019, DRC is the third most affected country in Africa after Nigeria (128,200) and Ethiopia ( 67,800). Air pollution accounted for 50% lower respiratory illness deaths.. Early exposure to HAP increases risk of low birth weight, preterm birth and susceptibility to lower respiratory illness. While improvements in health have been linked with cleaner cooking fuels, intervention studies of cleaner burning biomass-fueled cookstove have provided mixed evidence of health benefits. Solid fuels (wood, charcoal) burning for domestic energy is widely use in Kivu, exposure to HAP from burning biomass has not yet been investigated. Primary data from the DRC assessing the association between exposure to air pollution and health outcomes are currently scarce, and possible links to major causes of morbidity such as respiratory illnesses have hardly been explored. The MUTOTO cohort project aims to assess deleterious health effects of HAP in the population of Kivu, with a focus on pregnant women and young children. This study will address the health outcomes by combining both PM estimates and biological monitoring for biomass cooking exposure. Policy-relevant results generated will influence planification for more effective interventions. Specific Aims of MUTOTO To quantify level of exposure (PM; Black carbon, CO) to HAP during and after pregnancy compared to the WHO standard. To compare the association between the level of exposure during and after pregnancy with birth outcomes (birth weight, premature birth, fetal distress) and frequency of severe respiratory diseases during the first anniversary. To assess the association between level of exposure to air pollution and the modification (proportion and type) on the microbiome (gut-lung-axis).