About this trial
Malnutrition in women of reproductive age remains a public health concern in Sub-Saharan Africa (SSA). Malnutrition during pregnancy affects foetal growth with a tendency of the exposed infants to also develop it. The interaction of the mother with the infant shapes the seeding and the trajectory of the infant intestinal microbiota which is crucial for development of a healthy immune system Malnutrition has been associated with intestinal inflammation, intestinal leakage and reduced calorie absorption. Early life malnutrition and environmental enteric dysfunction (EED) immunopathology remains poorly described in the context of mother-infant dyads. This is essential as malnutrition, poor water, sanitation and hygiene (WASH), including the presence of infectious diseases limit the developmental potential of the exposed infants in SSA, including Zimbabwe. In addition, maternal stress and poor mental health may also affect standard hygiene practices, including how a mother cares for her baby, potentially aggravating EED and the risk of the infant being malnourished.
Primary outcomes
1. Infant malnutrition and recovery. 2. Gut dysfunction (gut inflammation, leaky gut, malabsorption, dysbiosis) 3. Diarrhea episodes, defined as any episode of acute diarrhoea (≥3 passages of loose stool within 24 hours as reported by the mother) occurring before the next study visit.
Definition of malnutrition outcomes to be assessed in babies born to malnourished women, is a mid- upper arm circumference (MUAC) \<23cm;
* MUAC for age: Malnourished defined as those below -2 standard (SD) of the World Health Organisation (WHO) reference * Weight-for-age: Underweight defined as those below -2SD WHO reference * Weight-for-height: Wasted defined as those below -2SD WHO reference * Height-for-age: Stunted defined as those below -2SD WHO reference * Z-scores (as they are i.e. a continuous variable, taking age of infants into account) * A composite variable, any of malnourished, underweight, wasted or stunted.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
MUAC ≤23 cm in pregnancy
≥18 years' old
At least 20 weeks' gestational age
Height ≥150 cm
Disqualifiers
Acute or chronic conditions in mothers interfering with the study according to the judgment of the investigator (HIV infection is not an exclusion criterion)
Presence of severe mental health disorders interfering with study procedures according to the judgment of the investigator.
Trial population
Pregnant women at least 20 weeks gestational age seeking antenatal care services at any of the two primary health care centres, Kuwadzana and Hopely.
Trial design
Case-control
Prospective
Treatments tested in this trial
Malnutrition in pregnancy as exposure
Other interventionMUAC ≤23 cm in pregnancy at least 20 weeks gestational age
Poor WASH living conditions as exposure
Other interventionPoor water (source, quality, access, reliability), sanitation (toilet type, cleanliness, number of people using toilet) and personal (hand wash practices) and household hygiene (dumpster availability and emptying frequency) index scores. WASH Index score ranges; 1.Basic services (76-100%), 2.Semi-basic services (51-75%) 3.Poor services (26-50%) 4.No services (0-25%)
Treatment groups
Trial outcomes
Primary outcomes
Alpha diversity of maternal gut microbiota
Alpha diversity of maternal stool microbiota will be assessed by shotgun metagenomic sequencing, and calculated using the Shannon index. This measure reflects within-sample diversity and evenness of microbial communities. Unit of Measure: Shannon index (unitless; typical range 1-6)
Beta diversity of maternal gut microbiota
Beta diversity of maternal stool microbiota will be assessed by shotgun metagenomic sequencing and calculated using Bray-Curtis dissimilarity. This measure reflects between-sample differences in community composition. Unit of Measure: % variance explained
Alpha diversity of human breast milk microbiota
Alpha diversity of maternal breast milk microbiota will be assessed by shotgun metagenomic sequencing, and calculated using the Shannon index. This measure reflects within-sample diversity and evenness of microbial communities. Unit of Measure: Shannon index (unitless; typical range 1-6)
Beta diversity of human breast milk microbiota
Beta diversity of breast milk microbiota will be assessed by shotgun metagenomic sequencing, and calculated using Bray-Curtis dissimilarity. This measure reflects between-sample differences in community composition. Unit of Measure: % variance explained.
Secondary outcomes
Concentrations of anti-Gal natural antibodies and memory B cell frequencies in infant blood and stool across early life
Anti-Gal natural antibody levels and memory B cell responses will be characterized in infant serum, stool, and peripheral blood mononuclear cells (PBMCs) over the first three years of life. Anti-Gal IgG, IgA, and IgM concentrations will be quantified using ELISA in both serum and stool. Additionally, memory B cells specific for the α-Gal epitope will be identified and quantified by B cell ELISpot and/or flow cytometry with α-gal-conjugated tetramers or labeled glycoconjugates. This outcome will assess the ontogeny and maturation of the anti-Gal antibody response and its relationship with microbial colonization, nutritional status, and WASH exposure. Functional immune memory will be evaluated in the context of microbial antigen exposure and early-life health outcomes. Arm/Group title: Children will be assigned to one of the four groups defined by maternal nutritional status (MUAC ≤23 cm vs. 25-35 cm) and household WASH conditions (improved vs. poor) at the time of pregnancy.
Serum concentrations of anti-Gal antibodies
Concentrations of anti-Gal IgG, IgA, and IgM will be quantified in infant serum using ELISA to characterize the ontogeny of the anti-Gal response and its relationship with microbial colonization, nutritional status, and WASH exposure. These measurements will provide insight into the systemic development of natural antibody repertoires across early life. Unit of Measure: µg/mL
Stool concentrations of anti-Gal antibodies
Concentrations of anti-Gal IgA and IgM will be quantified in infant stool using ELISA to assess mucosal anti-Gal antibody responses. These data will reveal how gut-associated natural antibodies develop in relation to early microbial colonization and nutritional status. Unit of Measure: µg/g
Frequency of anti-Gal-specific memory B cells
Frequencies of memory B cells specific to the α-Gal epitope will be quantified in infant PBMCs using B cell ELISpot and/or flow cytometry with α-Gal-conjugated tetramers or labeled glycoconjugates. This measure captures the functional development of immune memory directed against microbial glycans in early life. Unit of Measure: % of total B cells or spot-forming units (SFU) per 10⁶ PBMCs
Sponsors and contacts
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University of Zimbabwe
Lead sponsor
University of Bern
Collaborator
Insel Gruppe AG, University Hospital Bern
Collaborator
LMU Klinikum
Collaborator