Associations of HIV and iron status with gut microbiota composition, gut inflammation and gut integrity in South African school-age children: a two-way factorial case-control study.

BACKGROUND: Human immunodeficiency virus (HIV) and iron deficiency (ID) affect many African children. Both HIV and iron status interact with gut microbiota composition and related biomarkers. The study's aim was to determine the associations of HIV and iron status with gut microbiota composition, gut inflammation and gut integrity in South African school-age children. METHODS: In this two-way factorial case-control study, 8- to 13-year-old children were enrolled into four groups based on their HIV and iron status: (1) With HIV (HIV+) and ID (n = 43), (2) HIV+ and iron-sufficient nonanaemic (n = 41), (3) without HIV (HIV-) and ID (n = 44) and (4) HIV- and iron-sufficient nonanaemic (n = 38). HIV+ children were virally suppressed (<50 HIV RNA copies/ml) on antiretroviral therapy (ART). Microbial composition of faecal samples (16S rRNA sequencing) and markers of gut inflammation (faecal calprotectin) and gut integrity (plasma intestinal fatty acid-binding protein [I-FABP]) were assessed. RESULTS: Faecal calprotectin was higher in ID versus iron-sufficient nonanaemic children (p = 0.007). I-FABP did not significantly differ by HIV or iron status. ART-treated HIV (redundancy analysis [RDA] R2 = 0.009, p = 0.029) and age (RDA R2 = 0.013 p = 0.004) explained the variance in the gut microbiota across the four groups. Probabilistic models showed that the relative abundance of the butyrate-producing genera Anaerostipes and Anaerotruncus was lower in ID versus iron-sufficient children. Fusicatenibacter was lower in HIV+ and in ID children versus their respective counterparts. The prevalence of the inflammation-associated genus Megamonas was 42% higher in children with both HIV and ID versus HIV- and iron-sufficient nonanaemic counterparts. CONCLUSIONS: In our sample of 8- to 13-year-old virally suppressed HIV+ and HIV- children with or without ID, ID was associated with increased gut inflammation and changes in the relative abundance of specific microbiota. Moreover, in HIV+ children, ID had a cumulative effect that further shifted the gut microbiota to an unfavourable composition.

The effect of oral iron supplementation on the gut microbiota, gut inflammation, and iron status in iron-depleted South African school-age children with virally suppressed HIV and without HIV.

PURPOSE: Both HIV and oral iron interventions may alter gut microbiota composition and increase gut inflammation. We determined the effect of oral iron supplementation on gut microbiota composition, gut inflammation, and iron status in iron-depleted South Africa school-aged children living with HIV (HIV+) but virally suppressed on antiretroviral therapy and children without HIV (HIV-ve). METHODS: In this before-after intervention study with case-control comparisons, we provided 55 mg elemental iron from ferrous sulphate, once daily for 3 months, to 33 virally suppressed (< 50 HIV RNA copies/mL) HIV+ and 31 HIV-ve children. At baseline and endpoint, we assessed microbial composition of faecal samples (16S rRNA sequencing), and markers of gut inflammation (faecal calprotectin), anaemia (haemoglobin) and iron status (plasma ferritin, soluble transferrin receptor). This study was nested within a larger trial registered at clinicaltrials.gov as NCT03572010. RESULTS: HIV+ (11.3y SD ± 1.8, 46% male) and HIV-ve (11.1y SD ± 1.7, 52% male) groups did not significantly differ in age or sex ratio. Following iron supplementation, improvements were observed in haemoglobin (HIV+ : 118 to 124 g/L, P = 0.003; HIV-ve: 120 to 124 g/L, P = 0.003), plasma ferritin (HIV+ : 15 to 34 µg/L, P < 0.001; HIV-ve: 18 to 37 µg/L, P < 0.001), and soluble transferrin receptor (HIV+ : 7.1 to 5.9 mg/L, P < 0.001; HIV-ve: 6.6 to 5.7 mg/L, P < 0.001), with no significant change in the relative abundance of any genera, alpha diversity of the gut microbiota (HIV+ : P = 0.37; HIV-ve: P = 0.77), or faecal calprotectin (HIV+ : P = 0.42; HIV-ve: P = 0.80). CONCLUSION: Our findings suggest that oral iron supplementation can significantly improve haemoglobin and iron status without increasing pathogenic gut microbial taxa or gut inflammation in iron-depleted virally suppressed HIV+ and HIV-ve school-age children.

Examining Associations of HIV and Iron Status with Nutritional and Inflammatory Status, Anemia, and Dietary Intake in South African Schoolchildren.

The etiology of multifactorial morbidities such as undernutrition and anemia in children living with the human immunodeficiency virus (HIV) (HIV+) on antiretroviral therapy (ART) is poorly understood. Our objective was to examine associations of HIV and iron status with nutritional and inflammatory status, anemia, and dietary intake in school-aged South African children. Using a two-way factorial case-control design, we compared four groups of 8 to 13-year-old South African schoolchildren: (1) HIV+ and low iron stores (inflammation-unadjusted serum ferritin ≤ 40 µg/L), n = 43; (2) HIV+ and iron sufficient non-anemic (inflammation-unadjusted serum ferritin > 40 µg/L, hemoglobin ≥ 115 g/L), n = 41; (3) children without HIV (HIV-ve) and low iron stores, n = 45; and (4) HIV-ve and iron sufficient non-anemic, n = 45. We assessed height, weight, plasma ferritin (PF), soluble transferrin receptor (sTfR), plasma retinol-binding protein, plasma zinc, C-reactive protein (CRP), α-1-acid glycoprotein (AGP), hemoglobin, mean corpuscular volume, and selected nutrient intakes. Both HIV and low iron stores were associated with lower height-for-age Z-scores (HAZ, p < 0.001 and p = 0.02, respectively), while both HIV and sufficient iron stores were associated with significantly higher CRP and AGP concentrations. HIV+ children with low iron stores had significantly lower HAZ, significantly higher sTfR concentrations, and significantly higher prevalence of subclinical inflammation (CRP 0.05 to 4.99 mg/L) (54%) than both HIV-ve groups. HIV was associated with 2.5-fold higher odds of iron deficient erythropoiesis (sTfR > 8.3 mg/L) (95% CI: 1.03-5.8, p = 0.04), 2.7-fold higher odds of subclinical inflammation (95% CI: 1.4-5.3, p = 0.004), and 12-fold higher odds of macrocytosis (95% CI: 6-27, p < 0.001). Compared to HIV-ve counterparts, HIV+ children reported significantly lower daily intake of animal protein, muscle protein, heme iron, calcium, riboflavin, and vitamin B12, and significantly higher proportions of HIV+ children did not meet vitamin A and fiber requirements. Compared to iron sufficient non-anemic counterparts, children with low iron stores reported significantly higher daily intake of plant protein, lower daily intake of vitamin A, and lower proportions of inadequate fiber intake. Along with best treatment practices for HIV, optimizing dietary intake in HIV+ children could improve nutritional status and anemia in this vulnerable population. This study was registered at clinicaltrials.gov as NCT03572010.

The Development of a Quantified Food Frequency Questionnaire for Assessing Iron Nutrition in Schoolchildren from Resource-Limited Settings in Cape Town, South Africa.

Children are vulnerable to developing iron deficiency anemia, especially in resource-limited settings. Information on habitual dietary intake informs dietary interventions aimed at improving iron deficiency. Dietary assessment in school-aged children is challenging and requires concerted efforts to mitigate the pitfalls of long complex methods. Nested within an intervention trial, we aimed to obtain dietary intake information to assess iron nutrition in 8 to 13-year-old children from resource-limited settings in Cape Town, South Africa. Following careful consideration of the study objective, participant characteristics, research setting, available resources, and features of the different dietary intake assessment methods, we identified an iron quantified food frequency questionnaire (QFFQ) as the best method to obtain the information. The QFFQ reflected the study population's habitual intake and the nutrients of interest (protein, iron, vitamin A, vitamin C, calcium, zinc, and fiber). In addition, strategies such as interview-administration of the QFFQ, interviewing the child participant and caregiver together, simplifying frequency reporting, a strategic food list order and a variety of interesting portion size estimation aids collectively supported dietary intake assessment in this young study population. Using a methodical, multiphase approach and strategies that promote participant engagement, we developed the QFFQ, achieved interview success, and obtained comparable data.

Infant Feeding Practices during the First 6 Months of Life in a Low-Income area of the Western Cape Province

Background. Exclusive breastfeeding during the first 6 months of life protects against infant morbidity and mortality. Few studies describe the infant feeding practices of mothers living in low-income areas of the Western Cape Province of South Africa (SA).Objective. To describe the infant feeding practices of mothers of infants younger than 6 months in two low-income communities of SA. Methods. A cross-sectional community-based study using a structured questionnaire; and seven focus group discussions were conducted from February to August 2011 in Avian Park and Zwelethemba in Worcester; an urban area in the Western Cape. Results. Seventy-seven per cent of participants (n=108) had initiated breastfeeding. At the time of the study; 6 (n=8) breastfed exclusively. Ninety-four per cent (n=132) applied suboptimal breastfeeding practices: 36 (n=51) breastfed predominantly; 27 (n=38) breastfed partially and 31 (n=43) did not breastfeed. Ninety per cent (n=126) of the mothers had introduced water; of whom 83 (n=104) had done so before their infants were 1 month old. Forty-four per cent (n=61) of the mothers had introduced food or formula milk; of whom 75 (n=46) had done so before their infants were 3 months old. Qualitative findings indicated that gripe water; Lennon's Behoedmiddel and herbal medicines were also given to infants. Nutritive liquids and/or food most commonly given as supplementary feeds were formula milk and commercial infant cereal. Conclusion. Exclusive breastfeeding (EBF) during the first 6 months of life was a rare practice in these low-income communities. Water; non-prescription medicines and formula milk and/or food were introduced at an early age