The effect of legume supplementation on the gut microbiota in rural Malawian infants aged 6 to 12 months

Gut Microbiome-Targeted Nutrition Interventions and Growth among Children in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Background

Childhood malnutrition is a public health challenge of much interest and concern globally. However, a perturbed gut microbiome (GM) may limit some nutrition interventions' effects among healthy children with undernutrition.

Objectives

This review aimed to evaluate the effects of GM-targeted nutrition interventions on growth outcomes among children (0-59 mo) using published studies in low- and middle-income countries.

Methods

The methods were guided by the Cochrane methodology. The literature search was conducted to include articles published from inception to July 2023 in PubMed, Google Scholar, and Cochrane Databases. We identified and included 35 studies among 11,047 children. The analysis was conducted considering various growth parameters in the qualitative synthesis and weight gain (kg) in the meta-analysis.

Results

In the qualitative synthesis, 55.6% of prebiotics, 66.7% of probiotics, 71.4% of synbiotics, and 28.6% of "microbiome complementary feed" studies had significant effects on growth outcomes. Also, prebiotics had more studies with significant effects among healthy children, whereas probiotics, synbiotics, and "microbiome complementary feeds" had more studies with significant effects among children with undernutrition. Nineteen studies were included in the meta-analyses, of which 7 (36.8%) measured GM outcomes. The meta-analysis showed that prebiotics exhibited heterogeneity but had significant effects on weight in the intervention as compared with the control (mean difference [MD]: 0.14 kg; 95% CI: 0.02, 0.25; I2 = 63%, P = 0.02; 4 studies, n = 932). Probiotics had significant effects on weight in the intervention (MD: 0.15 kg; 95% CI: 0.06, 0.25; I2 = 42%, P = 0.05; 8 studies, n = 2437) as compared to the control. However, synbiotics (MD: 0.26 kg; 95% CI: -0.04, 0.56; I2 = 41%, P = 0.17; 4 studies, n = 1896] and "microbiome complementary feed" (MD: -0.03 kg; 95% CI: -0.18, 0.11; I2 = 0%, P = 0.60; 3 studies, n = 733] had no significant effects on weight in the intervention as compared with control.

Conclusions

Although probiotics and synbiotics may be effective at enhancing growth among children, the selection of interventions should be contingent upon health status.This trial was registered at www.crd.york.ac.uk/prospero/ as CRD42023434109.

Malnourished Microbes: Host-Microbiome Interactions in Child Undernutrition

Childhood undernutrition is a major global health burden that is only partially resolved by nutritional interventions. Both chronic and acute forms of child undernutrition are characterized by derangements in multiple biological systems including metabolism, immunity, and endocrine systems. A growing body of evidence supports a role of the gut microbiome in mediating these pathways influencing early life growth. Observational studies report alterations in the gut microbiome of undernourished children, while preclinical studies suggest that this can trigger intestinal enteropathy, alter host metabolism, and disrupt immune-mediated resistance against enteropathogens, each of which contribute to poor early life growth. Here, we compile evidence from preclinical and clinical studies and describe the emerging pathophysiological pathways by which the early life gut microbiome influences host metabolism, immunity, intestinal function, endocrine regulation, and other pathways contributing to child undernutrition. We discuss emerging microbiome-directed therapies and consider future research directions to identify and target microbiome-sensitive pathways in child undernutrition.

A Scoping Review Evaluating the Current State of Gut Microbiota Research in Africa

The gut microbiota has emerged as a key human health and disease determinant. However, there is a significant knowledge gap regarding the composition, diversity, and function of the gut microbiota, specifically in the African population. This scoping review aims to examine the existing literature on gut microbiota research conducted in Africa, providing an overview of the current knowledge and identifying research gaps. A comprehensive search strategy was employed to identify relevant studies. Databases including MEDLINE (PubMed), African Index Medicus (AIM), CINAHL (EBSCOhost), Science Citation index (Web of Science), Embase (Ovid), Scopus (Elsevier), WHO International Clinical Trials Registry Platform (ICTRP), and Google Scholar were searched for relevant articles. Studies investigating the gut microbiota in African populations of all age groups were included. The initial screening included a total of 2136 articles, of which 154 were included in this scoping review. The current scoping review revealed a limited number of studies investigating diseases of public health significance in relation to the gut microbiota. Among these studies, HIV (14.3%), colorectal cancer (5.2%), and diabetes mellitus (3.9%) received the most attention. The top five countries that contributed to gut microbiota research were South Africa (16.2%), Malawi (10.4%), Egypt (9.7%), Kenya (7.1%), and Nigeria (6.5%). The high number (n = 66) of studies that did not study any specific disease in relation to the gut microbiota remains a gap that needs to be filled. This scoping review brings attention to the prevalent utilization of observational study types (38.3%) in the studies analysed and emphasizes the importance of conducting more experimental studies. Furthermore, the findings reflect the need for more disease-focused, comprehensive, and population-specific gut microbiota studies across diverse African regions and ethnic groups to better understand the factors shaping gut microbiota composition and its implications for health and disease. Such knowledge has the potential to inform targeted interventions and personalized approaches for improving health outcomes in African populations.

Maternal-Child Microbiome and Impact on Growth and Neurodevelopment in Infants and Children: A Scoping Review

BACKGROUND

Pathologic changes in the microbiome (dysbiosis) have been implicated in affecting the growth and neurodevelopment of infants and children. There is evidence to suggest that prenatal and postnatal stressors may be a factor in dysbiosis and there is also a growing body of evidence to suggest that interventions may reduce this negative impact. A scoping review was undertaken to identify association between maternal and/or child microbiome with child growth and neurodevelopment. Additionally, intervention studies such as use of nutritional supplementation and its impact on the microbiome, growth and neurodevelopment were reviewed.

METHODS

An exhaustive literature search identified 654 relevant citations. After review of abstracts, 557 were eliminated, and 97 remained for full text review. We identified and reported on 42 articles which met inclusion criteria.

RESULTS

Seven studies examined associations between microbiome and neurodevelopment and 36 studies evaluated anthropometric measurements, most commonly weight, and microbiota relationships. One study evaluated both growth and neurodevelopment and microbiota. Fourteen studies evaluated supplemental nutrients. Preterm, low birth weight (LBW), and very low birth weight (VLBW) infants were most studied. Findings were inconclusive for consistent associations between microbiota and growth and neurodevelopment. Further, there were no consistent conclusive changes with prescribed treatment interventions.

DISCUSSION

There is a need for high-quality longitudinal studies evaluating repeated developmental assessment measures using consistent microbial analysis techniques to inform conclusions regarding the association between microbiome and infant and child growth and neurodevelopment. Additional intervention studies that may mitigate dysbiosis are warranted.

Early-life chemical exposome and gut microbiome development: African research perspectives within a global environmental health context

The gut microbiome of neonates, infants, and toddlers (NITs) is very dynamic, and only begins to stabilize towards the third year of life. Within this period, exposure to xenobiotics may perturb the gut environment, thereby driving or contributing to microbial dysbiosis, which may negatively impact health into adulthood. Despite exposure of NITs globally, but especially in Africa, to copious amounts and types of xenobiotics - such as mycotoxins, pesticide residues, and heavy metals - little is known about their influence on the early-life microbiome or their effects on acute or long-term health. Within the African context, the influence of fermented foods, herbal mixtures, and the delivery environment on the early-life microbiome are often neglected, despite being potentially important factors that influence the microbiome. Consequently, data on in-depth understanding of the microbiome-exposome interactions is lacking in African cohorts. Collecting and evaluating such data is important because exposome-induced gut dysbiosis could potentially favor disease progression.

Gut Microbiota Development: Influence of Diet from Infancy to Toddlerhood

Early life is a critical period as our gut microbiota establishes here and may impact both current and future health. Thus, it is of importance to understand how different factors govern the complex microbial colonization patterns in this period. The gut microbiota changes substantially during infancy and toddlerhood in terms of both taxonomic composition and diversity. This developmental trajectory differs by a variety of factors, including term of birth, mode of birth, intake of antibiotics, presence of furred pets, siblings and family members, host genetics, local environment, geographical location, and maternal and infant/toddler diet. The type of milk feeding and complementary feeding is particularly important in early and late infancy/toddlerhood, respectively. Breastfeeding, due to the supply of human milk oligosaccharide into the gut, promotes the growth of specific human milk oligosaccharide (HMO)-utilizing Bifidobacterium species that dominate the ecosystem as long as the infant is primarily breastfed. These species perform saccharolytic fermentation in the gut and produce metabolites with physiological effects that may contribute to protection against infectious and immune-related diseases. Formula feeding, due to its lack of HMOs and higher protein content, give rise to a more diverse gut microbiota that contains more opportunistic pathogens and results in a more proteolytic metabolism in the gut. Complementary feeding, due to the introduction of dietary fibers and new protein sources, induces a shift in the gut microbiota and metabolism away from the milk-adapted and toward a more mature and diverse adult-like community with increased abundances of short chain fatty acid-producing bacterial taxa. While the physiological implication of these complementary diet-induced changes remains to be established, a few recent studies indicate that an inadequately matured gut microbiota may be causally related to poor growth and development. Further studies are required to expand our knowledge on interactions between diet, gut microbiota, and health in the early life setting.

Nutritional Interventions and the Gut Microbiome in Children

The gut microbiome plays an integral role in health and disease, and diet is a major driver of its composition, diversity, and functional capacity. Given the dynamic development of the gut microbiome in infants and children, it is critical to address two major questions: (a) Can diet modify the composition, diversity, or function of the gut microbiome, and (b) will such modification affect functional/clinical outcomes including immune function, cognitive development, and overall health? We synthesize the evidence on the effect of nutritional interventions on the gut microbiome in infants and children across 26 studies. Findings indicate the need to study older children, assess the whole intestinal tract, and harmonize methods and interpretation of findings, which are critical for informing meaningful clinical and public health practice. These findings are relevant for precision health, may help identify windows of opportunity for intervention, and may inform the design and delivery of such interventions. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Modifying gut integrity and microbiome in children with severe acute malnutrition using legume-based feeds (MIMBLE): A pilot trial

Case fatality among African children with severe acute malnutrition remains high. We report a 3-arm pilot trial in 58 Ugandan children, comparing feeds targeting disordered gastrointestinal function containing cowpea (CpF, n = 20) or inulin (InF, n = 20) with conventional feeds (ConF, n = 18). Baseline measurements of gut permeability (lactulose:mannitol ratio 1.19 ± SD 2.00), inflammation (fecal calprotectin 539.0 μg/g, interquartile range [IQR] 904.8), and satiety (plasma polypeptide YY 62.6 pmol/l, IQR 110.3) confirm gastrointestinal dysfunction. By day 28, no differences are observable in proportion achieving weight gain >5 g/kg/day (87%, 92%, 86%; p > 0.05), mortality (16%, 30%, 17%; p > 0.05), or edema resolution (83%, 54%, 91%; p > 0.05) among CpF, InF, and ConF. Decreased fecal bacterial richness from day 1 (abundance-based coverage estimator [ACE] 53.2) to day 7 (ACE 40.8) is observed only in ConF (p = 0.025). Bifidobacterium relative abundance increases from day 7 (5.8% ± 8.6%) to day 28 (10.9% ± 8.7%) in CpF (corrected p = 1.000). Legume-enriched feeds support aspects of gut function and the microbiome. Trial registration PACTR201805003381361.