Microbiome and Malnutrition in Pregnancy

This project represents the first systematic investigation of the impact of the microbiome on nutritional status during pregnancy in young women and directly aligns with global health initiatives focused on this vulnerable cohort. The goal of the study is to define the relationships between host nutritional status and microbiome dynamics during pregnancy and how they contribute to birth outcomes. The gut microbiome has a profound influence on host nutritional status. Dysbiosis (loss of diversity/beneficial microbes and gain of pathobionts) has emerged as a major factor in the development of undernutrition. Despite the importance of nutrition during pregnancy, few studies have examined the role of the microbiome on maternal health and birth outcomes. Further, little is known concerning the influence of enteric eukaryotic microbes, such as parasites, on the bacterial microbiome and host nutrition.

At the core of this study are two complementary cohorts of young women that provide an exceptional opportunity to obtain longitudinal samples to monitor the dynamic relationships between microbiome community structure and function with gut health and host nutritional status. This registration is for the the Toronto cohort of the study, which will focus on refugee and young adult obstetric clinics in Toronto, a population of specific relevance to undernutrition. This cohort is expected to yield insights into the influence of eukaryotic microbes that are often viewed as asymptomatic. The target demographic of the study is young mothers, 28 years of age and younger, in the Toronto and Greater Toronto Area. The investigators have identified this younger demographic due to the lack of knowledge on the microbiome of young women, and their vulnerability to undernutrition. A second complementary cohort will be based in the Matiari district of Pakistan. This project will yield unprecedented insights into the relationships between prokaryotic and eukaryotic microbes in the gut and their associations with maternal health and birth outcomes.

The central hypothesis of the study is that alterations of the microbiota in the maternal gut (dysbiosis) exacerbated by nutritional status or pathogen exposure during pregnancy, impacts weight gain because of impaired nutrient absorption, leading to corresponding negative birth outcomes.

The study will be a prospective, longitudinal, observational study to investigate the impact and relationship between prokaryotic and eukaryotic microbes in the gut and their association with maternal health and birth outcomes among young women, 28 years of age and younger in the Toronto and Greater Toronto Area. The study will aim to recruit 400 women into two groups based on BMI at time of recruitment (Normal BMI will be defined as between 20 and 24.9 kg/m2 and Low BMI will be defined as less than 20 kg/m2). With a goal of having 200 participants within the normal BMI group and 200 participants within the low BMI group. Although this is the recruitment aim, in the event that the investigators are unable to recruit 200 women with a low BMI, more women will be recruited that fall within the normal BMI range. The study will follow women and their infants over the course of their pregnancy and for a year post-partum, collecting stool, rectal and blood samples, nutritional information, heath assessments, anthropometric measurements and empowerment metrics at different time points.

Inclusion criteria

• Consent provided
• Participant is between 8-20 weeks post-conception
• Female aged 28 years of age and younger
• Confirmation of pregnancy
• Intend to comply with study procedures and follow up

Exclusion criteria

• Women who do not meet the enrolment age criteria
• Women who are 20 + weeks post-conception
• Women who have taken antibiotics within the past 3 months Note: it is common practice to give the mother penicillin in perinatal period if they are GBS positive; because this is standardized across the board it would not act as an exclusion factor.