Intestinal permeability and inflammation mediate the association between nutrient density of complementary foods and biochemical measures of micronutrient status in young children: results from the MAL-ED study

Intestinal absorption area is correlated with cardiovascular risk factors associated with obesity and metabolic syndrome

BACKGROUND AND AIM

This study aimed to evaluate if the intestinal permeability is associated with overweight/obesity with or without metabolic syndrome (MetS) and correlate intestinal permeability parameters with cardiovascular risk factors.

METHODS AND RESULTS

This was a cross-sectional study that individuals were divided in three groups: 1) controls (n = 34), 2) overweight/obesity (n = 29), and 3) overweight/obesity + MetS (n = 29). Anthropometric and blood biochemical parameters were used to estimate cardiovascular risk factors. Intestinal permeability was evaluated using the lactulose/mannitol test in urine samples analyzed by High Performance Liquid Chromatography with Pulsed Amperometry Detection. Correlations between intestinal permeability and anthropometric and biochemical parameters were evaluated using Spearman's correlations (r2). Logistic regression models were performed to elucidate variables associated with intestinal permeability parameters. The percentage of urinary excretion of lactulose, mannitol, and the lactulose/mannitol ratio was similar between the studied groups. The percentage of urinary mannitol excretion was positively associated with diastolic blood pressure (r2 = 0.24, p = 0.23), fasting glucose (r2 = 0.26, p = 0.013), fasting insulin (r2 = 0.25, p = 0.015) and HOMA-IR (r2 = 0.26, p = 0.012). The logistic regression showed fasting insulin was associated with a higher mannitol urinary excretion (AOR = 1.08, 95 % CI = 1.02-1.14).

CONCLUSION

Intestinal permeability was not disrupted in overweight/obesity and MetS, however the results suggest that the increased cardiovascular risk factors were associated with a higher intestinal absorption area. Further studies should investigate other intestinal parameters related to overweight/obesity and MetS in humans.

Vitamin A-Integrated Cinnamaldehyde Nanoemulsion: A Nanotherapeutic Approach To Counteract Liver Fibrosis via Gut-Liver Axis Modulation

Liver fibrosis, a complex process resulting from most chronic liver diseases, remains devoid of effective treatments. An increasing body of evidence links liver fibrosis to the "gut-liver axis", with disruptions in the gut microbiota-host balance emerging as a critical contributor to its progression. Cinnamaldehyde (Cin), a natural compound with antioxidant, anti-inflammatory, and anticytotoxic properties, has shown potential in counteracting hepatic stellate cell (HSC) activation. Additionally, Cin has been shown to promote probiotics in the intestine, thereby restoring a healthy microbial community. These characteristics position Cin as a promising candidate for liver fibrosis treatment through modulation of the gut-liver axis. In this study, a Vitamin A (Va)-formulated Cin Nanoemulsion (Va-Cin@NM) was developed to enhance the physicochemical stability of Cin while preserving intestinal homeostasis and facilitating targeted liver deposition. In bile duct ligation (BDL)-induced liver fibrosis in rats, Va-Cin@NM intervention significantly reduced bile duct-like structure proliferation and collagen deposition in the liver. These effects are likely attributed to the restoration of gut microbiota, increased short-chain fatty acid (SCFA) concentrations, and improved intestinal integrity. Moreover, Va-Cin@NM treatment suppressed harmful bacterial populations in the liver, thus mitigating immune injury and inflammatory cell recruitment. Consequently, oxidative stress and HSC activation were attenuated. Overall, Va-Cin@NM demonstrates significant potential as a nanotherapeutic approach for liver fibrosis by modulating the gut-liver axis.

Risk factors for self-reports of diagnosed cataracts among older adults in Poland

PURPOSE

The aim of our study was to investigate sociodemographic factors, comorbidities and health behaviors associated with self-reported diagnosed cataracts in a large, nationally representative population of older adults in Poland, aged 60 and older.

PATIENT AND METHODS

An analysis was conducted using a survey of 5956 participants in the nationally representative PolSenior2 study conducted between 2018 and 2019. Multiple logistic regression analysis was used to evaluate the associations between self-reports of diagnosed cataracts and sociodemographic factors, health behaviors, and comorbidities.

RESULTS

According to the final multivariable model, the odds ratio (OR) of self-reported cataract diagnosis was 1.71 times greater for women than for men. Additionally, the odds increased significantly with age, with 70-79-year-olds having 3.38 times greater odds, 80-89-year-olds having 8.08 times greater odds, and those aged 90 years and older having 10.76 times greater odds than did the reference group (60-69 years old). The prevalence of self-reported diagnosed cataracts was found to be 1.47 times greater among individuals with diabetes, 1.20 times greater among those with hypertension, and 1.25 times greater among tobacco users than among their respective counterparts. Additionally, rural dwellers exhibited a lower risk of self-reported cataracts (OR = 0.63).

CONCLUSION

Our study revealed a positive relationship between several demographic and health factors-namely, older age, female sex, urban residence, hypertension, diabetes, and smoking-and an elevated risk of self-reports of diagnosed cataracts.

JM, Hubbard AE, Mertens AN, Lin A. Treatment heterogeneity of water, sanitation, hygiene, and nutrition interventions on child growth by environmental enteric dysfunction and pathogen status for young children in Bangladesh

BACKGROUND

Water, sanitation, hygiene (WSH), nutrition (N), and combined (N+WSH) interventions are often implemented by global health organizations, but WSH interventions may insufficiently reduce pathogen exposure, and nutrition interventions may be modified by environmental enteric dysfunction (EED), a condition of increased intestinal permeability and inflammation. This study investigated the heterogeneity of these treatments' effects based on individual pathogen and EED biomarker status with respect to child linear growth.

METHODS

We applied cross-validated targeted maximum likelihood estimation and super learner ensemble machine learning to assess the conditional treatment effects in subgroups defined by biomarker and pathogen status. We analyzed treatment (N+WSH, WSH, N, or control) randomly assigned in-utero, child pathogen and EED data at 14 months of age, and child HAZ at 28 months of age. We estimated the difference in mean child height for age Z-score (HAZ) under the treatment rule and the difference in stratified treatment effect (treatment effect difference) comparing children with high versus low pathogen/biomarker status while controlling for baseline covariates.

RESULTS

We analyzed data from 1,522 children who had a median HAZ of -1.56. We found that fecal myeloperoxidase (N+WSH treatment effect difference 0.0007 HAZ, WSH treatment effect difference 0.1032 HAZ, N treatment effect difference 0.0037 HAZ) and Campylobacter infection (N+WSH treatment effect difference 0.0011 HAZ, WSH difference 0.0119 HAZ, N difference 0.0255 HAZ) were associated with greater effect of all interventions on anthropometry. In other words, children with high myeloperoxidase or Campylobacter infection experienced a greater impact of the interventions on anthropometry. We found that a treatment rule that assigned the N+WSH (HAZ difference 0.23, 95% CI (0.05, 0.41)) and WSH (HAZ difference 0.17, 95% CI (0.04, 0.30)) interventions based on EED biomarkers and pathogens increased predicted child growth compared to the randomly allocated intervention.

CONCLUSIONS

These findings indicate that EED biomarkers and pathogen status, particularly Campylobacter and myeloperoxidase (a measure of gut inflammation), may be related to the impact of N+WSH, WSH, and N interventions on child linear growth.

The effect of supplementary parenteral nutrition with different energy intakes on clinical outcomes of patients after gastric cancer surgery

BACKGROUND

To investigate the effect of postoperative supplementary parenteral nutrition (SPN) containing varying energy intake levels during the early postoperative period on the clinical outcomes of patients diagnosed with gastric cancer.

METHODS

Data from 237 patients, who were diagnosed with gastric cancer between January 2016 and June 2022, were retrospectively analyzed. Patients were divided into 2 groups based on mean daily SPN energy intake: low (L-SPN; < 20 kcal/kg/day); and high (H-SPN; ≥ 20 kcal/kg/day). Data regarding gender, age, body mass index, preoperative Nutrition Risk Screening 2002 (NRS 2002) score, American Society of Anesthesiologists Physical Status classification system, age-adjusted Charlson Comorbidity Index, diabetes, hypertension, chronic lung disease, and the Tumor-Node-Metastasis (TNM [Eighth edition]) classification were collected for propensity score matching (PSM). Postoperative indicators were monitored. A power analysis was performed during the design phase of this study to ensure that statistical power exceeded 80% to reliably detect differences between the 2 groups.

RESULTS

After PSM, data from 128 patients were analyzed (H-SPN, n = 64; L-SPN, n = 64). The H-SPN group experienced shorter postoperative hospital stay (8.11 ± 6.00 days vs. 10.38 ± 7.73 days; P = 0.045) and a lower number of infectious complications (36 [56.3%] vs. 60 [93.8%]; P < 0.001), particularly pulmonary infections, compared with the L-SPN group. Additionally, no increase in hospitalization costs or non-infectious complications occurred in the H-SPN group. Subgroup analysis revealed that H-SPN significantly reduced the incidence of infectious complications among those < 65 years of age (hazard ratio [HR] [95% confidence interval (CI) 0.240 0.069-0.829]; P = 0.024), NRS 2002 score ≥ 3 (HR 0.417 [95% CI 0.156-0.823]; P = 0.028), age-adjusted Charlson Complexity Index < 2 (HR 0.106 [95% CI 0.013-0.835]; P = 0.033), and TNM stage III (HR 0.504 [95% CI 0.224-0.921]; P = 0.046).

CONCLUSIONS

H-SPN effectively reduced postoperative infectious complications and the length of hospital stay, suggesting that early postoperative H-SPN may be an advantageous nutritional support strategy for patients diagnosed with gastric cancer.

Review article: Faecal biomarkers for assessing small intestinal damage in coeliac disease and environmental enteropathy

BACKGROUND

In coeliac disease and environmental enteropathy, dietary gluten and enteric infections cause reversible inflammation and morphological changes to the small intestinal mucosa that can be detected in biopsy samples obtained by endoscopy. However, there is a clear need for non-invasive biomarkers. Constant shedding of mucosal material into the bowel lumen and faeces, together with easy availability of stool, makes it an interesting sample matrix.

AIMS

To conduct a systematic literature search and summarize the existing evidence for host mucosa-derived faecal biomarkers in evaluating small intestinal damage.

METHODS

We searched for studies on PubMed (MEDLINE) until 1 March 2024.

RESULTS

We identified 494 studies and included 35 original case-control and cohort studies. These assessed host mucosal transcripts and 14 other markers aiming specifically to reflect inflammation and cell-mediated, innate and gluten-induced immune responses. In coeliac disease, faecal calprotectin and anti-gliadin, tissue transglutaminase, endomysium and deamidated gliadin peptide antibodies were the most studied but with inconsistent results. Single studies reported positive findings about microRNA transcripts, β-defensin-2, lipocalin-2, zonulin-related proteins and angiotensin-converting enzyme. In environmental enteropathy, a non-significant association was reported between calprotectin and urine lactulose/mannitol ratio; there were conflicting results for neopterin, myeloperoxidase and host transcripts. Single studies reported a positive association for lactoferrin, and a negative association for regenerating islet-derived protein 1. Studies comparing faecal markers against small intestinal biopsy findings were not identified in environmental enteropathy.

CONCLUSIONS

Further studies are needed to determine reliable faecal markers as a proxy for small intestinal mucosal damage.

Treatment Heterogeneity of Water, Sanitation, Hygiene, and Nutrition Interventions on Child Growth by Environmental Enteric Dysfunction and Pathogen Status for Young Children in Bangladesh

Background

Water, sanitation, hygiene (WSH), nutrition (N), and combined (N+WSH) interventions are often implemented by global health organizations, but WSH interventions may insufficiently reduce pathogen exposure, and nutrition interventions may be modified by environmental enteric dysfunction (EED), a condition of increased intestinal permeability and inflammation. This study investigated the heterogeneity of these treatments' effects based on individual pathogen and EED biomarker status with respect to child linear growth.

Methods

We applied cross-validated targeted maximum likelihood estimation and super learner ensemble machine learning to assess the conditional treatment effects in subgroups defined by biomarker and pathogen status. We analyzed treatment (N+WSH, WSH, N, or control) randomly assigned in-utero, child pathogen and EED data at 14 months of age, and child LAZ at 28 months of age. We estimated the difference in mean child length for age Z-score (LAZ) under the treatment rule and the difference in stratified treatment effect (treatment effect difference) comparing children with high versus low pathogen/biomarker status while controlling for baseline covariates.

Results

We analyzed data from 1,522 children, who had median LAZ of -1.56. We found that myeloperoxidase (N+WSH treatment effect difference 0.0007 LAZ, WSH treatment effect difference 0.1032 LAZ, N treatment effect difference 0.0037 LAZ) and Campylobacter infection (N+WSH treatment effect difference 0.0011 LAZ, WSH difference 0.0119 LAZ, N difference 0.0255 LAZ) were associated with greater effect of all interventions on growth. In other words, children with high myeloperoxidase or Campylobacter infection experienced a greater impact of the interventions on growth. We found that a treatment rule that assigned the N+WSH (LAZ difference 0.23, 95% CI (0.05, 0.41)) and WSH (LAZ difference 0.17, 95% CI (0.04, 0.30)) interventions based on EED biomarkers and pathogens increased predicted child growth compared to the randomly allocated intervention.

Conclusions

These findings indicate that EED biomarker and pathogen status, particularly Campylobacter and myeloperoxidase (a measure of gut inflammation), may be related to impact of N+WSH, WSH, and N interventions on child linear growth.

A Model-Based 13C-Sucrose Breath Test Diagnostic for Gut Function Disorders Characterized by a Loss of Sucrase-Isomaltase Enzymatic Activity

BACKGROUND

Environmental enteric dysfunction (EED) causes malnutrition in children in low-resource settings. Stable-isotope breath tests have been proposed as noninvasive tests of altered nutrient metabolism and absorption in EED, but uncertainty over interpreting the breath curves has limited their use. The activity of sucrose-isomaltase, the glucosidase enzyme responsible for sucrose hydrolysis, may be reduced in EED. We previously developed a mechanistic model describing the dynamics of the 13C-sucrose breath test (13C-SBT) as a function of underlying metabolic processes.

OBJECTIVES

This study aimed to determine which breath test curve dynamics are associated with sucrose hydrolysis and with the transport and metabolism of the fructose and glucose moieties and to propose and evaluate a model-based diagnostic for the loss of activity of sucrase-isomaltase.

METHODS

We applied the mechanistic model to 2 sets of exploratory 13C-SBT experiments in healthy adult participants. First, 19 participants received differently labeled sucrose tracers (U-13C fructose, U-13C glucose, and U-13C sucrose) in a crossover study. Second, 16 participants received a sucrose tracer accompanied by 0, 100, and 750 mg of Reducose, a sucrase-isomaltase inhibitor. We evaluated a model-based diagnostic distinguishing between inhibitor concentrations using receiver operator curves, comparing with conventional statistics.

RESULTS

Sucrose hydrolysis and the transport and metabolism of the fructose and glucose moieties were reflected in the same mechanistic process. The model distinguishes these processes from the fraction of tracer exhaled and an exponential metabolic process. The model-based diagnostic performed as well as the conventional summary statistics in distinguishing between no and low inhibition [area under the curve (AUC): 0.77 vs. 0.66-0.79] and for low vs. high inhibition (AUC 0.92 vs. 0.91-0.99).

CONCLUSIONS

Current summary approaches to interpreting 13C breath test curves may be limited to identifying only gross gut dysfunction. A mechanistic model-based approach improved interpretation of breath test curves characterizing sucrose metabolism.

Effect of a Homestead Food Production and Food Hygiene Intervention on Biomarkers of Environmental Enteric Dysfunction in Children Younger Than 24 Months in Rural Bangladesh: A Cluster-Randomized Controlled Trial

Poor sanitation and hygiene practices and inadequate diets can contribute to environmental enteric dysfunction (EED). We evaluated the impact of a combined homestead food production and food hygiene intervention on EED biomarkers in young children in rural Bangladesh. The analysis was conducted within the Food and Agricultural Approaches to Reducing Malnutrition (FAARM) cluster-randomized trial in Sylhet, Bangladesh. The FAARM trial enrolled 2,705 married women and their children younger than 3 years of age in 96 settlements (geographic clusters): 48 intervention and 48 control. The 3-year intervention (2015-2018) included training on gardening, poultry rearing, and improved nutrition practices and was supplemented by an 8-month food hygiene behavior change component, implemented from mid-2017. We analyzed data on 574 children age 0 to 24 months with multilevel linear regression. We assessed fecal myeloperoxidase (MPO), neopterin (NEO), and alpha-1-antitrypsin (AAT) as biomarkers of EED, and serum C-reactive protein (CRP) and alpha-1-acid glycoprotein (AGP) as biomarkers of systemic inflammation, using ELISA. There was no intervention effect on NEO, AAT, CRP, and AGP concentrations, but, surprisingly, MPO levels were increased in children of the intervention group (0.11 log ng/mL; 95% CI, 0.001-0.22). This increase was greater with increasing child age and among intervention households with poultry that were not kept in a shed. A combined homestead food production and food hygiene intervention did not decrease EED in children in our study setting. Small-scale poultry rearing promoted by the intervention might be a risk factor for EED.

Paracellular permeability and tight junction regulation in gut health and disease

Epithelial tight junctions define the paracellular permeability of the intestinal barrier. Molecules can cross the tight junctions via two distinct size-selective and charge-selective paracellular pathways: the pore pathway and the leak pathway. These can be distinguished by their selectivities and differential regulation by immune cells. However, permeability increases measured in most studies are secondary to epithelial damage, which allows non-selective flux via the unrestricted pathway. Restoration of increased unrestricted pathway permeability requires mucosal healing. By contrast, tight junction barrier loss can be reversed by targeted interventions. Specific approaches are needed to restore pore pathway or leak pathway permeability increases. Recent studies have used preclinical disease models to demonstrate the potential of pore pathway or leak pathway barrier restoration in disease. In this Review, we focus on the two paracellular flux pathways that are dependent on the tight junction. We discuss the latest evidence that highlights tight junction components, structures and regulatory mechanisms, their impact on gut health and disease, and opportunities for therapeutic intervention.

Intestinal Epithelial Digestive, Transport, and Barrier Protein Expression Is Increased in Environmental Enteric Dysfunction

Environmental enteric dysfunction (EED) is characterized by malabsorption and diarrhea that result in irreversible deficits in physical and intellectual growth. We sought to define the expression of transport and tight junction proteins by quantitative analysis of duodenal biopsies from patients with EED. Biopsies from Pakistani children with confirmed EED diagnoses were compared to those from age-matched North American healthy controls, patients with celiac disease, and patients with nonceliac disease with villous atrophy or intraepithelial lymphocytosis. Expression of brush border digestive and transport proteins and paracellular (tight junction) proteins was assessed by quantitative multiplex immunofluorescence microscopy. EED was characterized by partial villous atrophy and marked intraepithelial lymphocytosis. Epithelial proliferation and enteroendocrine, tuft, and Paneth cell numbers were unchanged, but there was significant goblet cell expansion in EED biopsies. Expression of proteins involved in nutrient and water absorption and that of the basolateral Cl- transport protein NKCC1 were also increased in EED. Finally, the barrier-forming tight junction protein claudin-4 (CLDN4) was significantly upregulated in EED, particularly within villous enterocytes. In contrast, expression of CFTR, CLDN2, CLDN15, JAM-A, occludin, ZO-1, and E-cadherin was unchanged. Upregulation of a barrier-forming tight junction protein and brush border and basolateral membrane proteins that support nutrient and water transport in EED is paradoxical, as their increased expression would be expected to be correlated with increased intestinal barrier function and enhanced absorption, respectively. These data suggest that EED activates adaptive intestinal epithelial responses to enhance nutrient absorption but that these changes are insufficient to restore health.

Adequacy of Iodine Status and Associations with Gut Health: A Prospective Cohort Study among Infants in 8 Low- and Middle-Income Countries

BACKGROUND

Environmental enteric dysfunction increases the likelihood of micronutrient deficiencies among infants, but few studies have assessed the potential impact of gut health on urinary iodine concentration (UIC) among this vulnerable group.

OBJECTIVES

We describe the trends of iodine status among infants from 6 to 24 mo old and examine the associations between intestinal permeability, inflammation, and UIC from 6 to 15 mo of age.

METHODS

Data from 1557 children enrolled in this birth cohort study conducted in 8 sites were included in these analyses. UIC was measured at 6, 15, and 24 mo of age by using the Sandell-Kolthoff technique. Gut inflammation and permeability were assessed using the concentrations of fecal neopterin (NEO), myeloperoxidase (MPO) and alpha-1-antitrypsin (AAT), and lactulose-mannitol ratio (LM). A multinomial regression analysis was used to assess the classified UIC (deficiency or excess). Linear mixed regression was used to test the effect of interactions among biomarkers on logUIC.

RESULTS

All studied populations had adequate (≥100 μg/L) to excess (≥371 μg/L) median UIC at 6 mo. Between 6 and 24 mo, 5 sites displayed a significant decline in the infant's median UIC. However, median UIC remained within the optimal range. An increase of NEO and MPO concentrations by +1 unit in ln scale reduced the risk of low UIC by 0.87 (95% CI: 0.78-0.97) and 0.86 (95% CI: 0.77-0.95), respectively. AAT moderated the association between NEO and UIC (P < 0.0001). The shape of this association appears to be asymmetric and in a reverse J-shape, with a higher UIC observed at both lower NEO and AAT concentrations.

CONCLUSIONS

Excess UIC was frequent at 6 mo and tended to normalize at 24 mo. Aspects of gut inflammation and increased permeability appear to reduce the prevalence of low UIC in children aged 6 to 15 mo. Programs addressing iodine-related health should consider the role of gut permeability in vulnerable individuals.

Infections and nutrient deficiencies during infancy predict impaired growth at 5 years: Findings from the MAL-ED study in Pakistan

BACKGROUND

Socio-economic, nutritional, and infectious factors have been associated with impaired infant growth, but how the presence of these factors during infancy affects growth around 5 years is not well understood.

METHODS

This secondary analysis of the MAL-ED cohort included 277 children from Pakistan for whom socio-demographic, breastfeeding, complementary foods, illness, nutritional biomarkers, stool pathogens and environmental enteropathy indicators between 0 and 11 months were recorded. We used linear regression models to analyze associations of these indicators with height-for-age (HAZ), weight-for-age (WAZ) and weight-for-height (WLZ) at 54-66 months (~5 years), and Poisson regression with robust standard errors to estimate risk ratios for stunting and underweight ~5 years, controlling for gender, first available weight, and income.

RESULTS

Among the 237 infants followed longitudinally and evaluated at about 5 years of age, exclusive breastfeeding was short (median = 14 days). Complementary feeding started before 6 months with rice, bread, noodles, or sugary foods. Roots, dairy products, fruits/vegetables, and animal-source foods were provided later than recommended (9-12 months). Anemia (70.9%), deficiencies in iron (22.0%), zinc (80.0%), vitamin A (53.4%) and iodine (13.3%) were common. Most infants (>90%) presented with diarrhea and respiratory infections in their first year. At ~5 years, low WAZ (mean-1.91 ± 0.06) and LAZ (-2.11 ± 0.06) resulted in high prevalence of stunting (55.5%) and underweight (44.4%) but a relatively low rate of wasting (5.5%). While 3.4% had concurrent stunting and wasting ~5 years, 37.8% of children had coexisting stunting and underweight. A higher income and receiving formula or dairy products during infancy were associated with a higher LAZ ~5 years, but infant's history of hospitalizations and more respiratory infections were associated with lower LAZ and higher risk of stunting ~5 years. Infants' intake of commercial baby foods and higher serum-transferrin receptors were associated with higher WAZ and lower risk of underweight ~5 years. Presence of Campylobacter and fecal neopterin >6.8 nmol/L in the first year were associated with increased risk of underweight ~5 years.

CONCLUSION

Growth indicators ~5 years were associated with poverty, inappropriate complementary feeding, and infections during the first year of life, which supports the early start of public health interventions for preventing growth delay ~5 years.

Associations of bacterial enteropathogens with systemic inflammation, iron deficiency, and anemia in preschool-age children in southern Ghana

Anemia remains a pervasive public health problem among preschool-age children in Ghana. Recent analyses have found that anemia in Ghanaian children, particularly in Southern regions, is largely attributable to infectious causes, rather than nutritional factors. Infections with enteropathogens can reduce iron absorption and increase systemic inflammation, but few studies have examined direct links between enteropathogens and anemia. This study investigated associations between detection of individual bacterial enteropathogens and systemic inflammation, iron deficiency, and anemia among 6- to 59-month-old children in Greater Accra, Ghana. Serum samples were analyzed from a cross-sectional sample of 262 children for concentrations of hemoglobin (Hb), biomarkers of systemic inflammation [C-reactive protein (CRP) and α-1-acid glycoprotein (AGP)], and biomarkers of iron status [serum ferritin (SF) and serum transferrin receptor (sTfR)]. Stool samples were analyzed for ten bacterial enteropathogens using qPCR. We estimated associations between presence of each enteropathogen and elevated systemic inflammation (CRP > 5 mg/L and AGP > 1 g/L), iron deficiency (SF < 12 μg/L and sTfR > 8.3 mg/L) and anemia (Hb < 110 g/L). Enteropathogens were detected in 87% of children’s stool despite a low prevalence of diarrhea (6.5%). Almost half (46%) of children had anemia while one-quarter (24%) had iron deficiency (low SF). Despite finding no associations with illness symptoms, Campylobacter jejuni/coli detection was strongly associated with elevated CRP [Odds Ratio (95% CI): 3.49 (1.45, 8.41)] and elevated AGP [4.27 (1.85, 9.84)]. Of the pathogens examined, only enteroinvasive Escherichia coli/Shigella spp. (EIEC/Shigella) was associated with iron deficiency, and enteroaggregative Escherichia coli (EAEC) [1.69 (1.01, 2.84)] and EIEC/Shigella [2.34 (1.15, 4.76)] were associated with anemia. These results suggest that certain enteroinvasive pathogenic bacteria may contribute to child anemia. Reducing exposure to enteropathogens through improved water, sanitation, and hygiene practices may help reduce the burden of anemia in young Ghanaian children.

Essential Factors for a Healthy Microbiome: A Scoping Review

Recent discoveries of the purpose and potential of microbial interactions with humans have broad implications for our understanding of metabolism, immunity, the host−microbe genetic interactions. Bioavailability and bioaccessibility of phytonutrients in foods not only enrich microbial diversity in the lower human gastrointestinal tract (GIT) but also direct the functioning of the metagenome of the microbiota. Thus, healthy choices must include foods that contain nutrients that satisfy both the needs of humans and their microbes. Physical activity interventions at a moderate level of intensity have shown positive effects on metabolism and the microbiome, while intense training (>70% VO2max) reduces diversity in the short term. The microbiome of elite endurance athletes is a robust producer of short-chain fatty acids. A lifestyle lacking activity is associated with the development of chronic disease, and experimental conditions simulating weightlessness in humans demonstrate loss of muscle mass occurring in conjunction with a decline in gut short-chain fatty acid (SCFA) production and the microbes that produce them. This review summarizes evidence addressing the relationship between the intestinal microbiome, diet, and physical activity. Data from the studies reviewed suggest that food choices and physical fitness in developed countries promote a resource “curse” dilemma for the microbiome and our health.

Chicken liver and eggshell crackers as a safe and affordable animal source food for overcoming micronutrient deficits during pregnancy and lactation in Indonesia: a double-blind, randomised placebo-controlled trial (SISTIK Growth Study)

Background: Indonesia ranks fifth in terms of the number of stunted children and there has been little change in the stunting prevalence in the last decade. In earlier observational studies conducted in 2014-2015, we identified several key underlying problems with the potential to impact stunting in Sumedang district, West Java, Indonesia. Deficits in intakes of growth-limiting micronutrients were observed, most notably calcium, iron, zinc, and vitamin A, emphasizing the need for a food-based intervention to overcome these micronutrient deficits in the diets of mothers and their infants.

Methods: A double-blind placebo-controlled cluster randomised trial comparing the effect of daily consumption of 75 grams of locally produced micronutrient-enriched crackers (MEC) (intervention group) compared to placebo crackers (control group) by mothers at two-time intervals: (i) from the 8-14 weeks of pregnancy to delivery (i.e., 28-34 weeks of consumption of MEC) on birth length, and (ii) from the 8-14 weeks of pregnancy to 5 months post-partum on attained linear growth and linear growth velocity of breast-fed infants. A total of 324 pregnant women from 28 clusters (villages) located in 3 sub-districts in Sumedang district, West Java, Indonesia, will be randomly assigned to either intervention (n=14 villages) or control (n=14 villages).

Discussion: This will be the first study in Indonesia to use crackers based on powdered eggshells and chicken liver, in a form which is acceptable, safe, and has a long shelf life. If daily consumption of MEC for 6 months during pregnancy can enhance birth length, or their continued daily consumption for 5 months postpartum improves both attained and incremental linear growth at 5 months of age, then scaling-up in Indonesia may be considered.

Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04564222; 25 ^th September 2020

A Randomized Controlled Trial of Dietary Rice Bran Intake on Microbiota Diversity, Enteric Dysfunction, and Fecal Secretory IgA in Malian and Nicaraguan Infants

BACKGROUND

Malnutrition and diarrhea are leading causes of death in children aged <5 y. Rice bran is a nutrient-dense prebiotic available globally.

OBJECTIVES

The objective of this secondary analysis was to evaluate the effects of daily rice bran supplementation on environmental enteric dysfunction (EED) markers, total fecal secretory IgA (sIgA), and microbiota in infants at high risk of malnutrition.

METHODS

Six-month-old Malian and Nicaraguan infants were randomly assigned to control or daily rice bran supplementation cohorts (1 to 5 g/d). Feces were collected monthly for 6 mo to evaluate fecal sIgA, markers of EED, and microbiota diversity. Statistical methods included linear mixed models, generalized mixed models, Spearman correlation, and Wilcoxon rank-sum tests.

RESULTS

Six-month-old Malian infants had significantly elevated sIgA (4.0× higher, P < 0.001), fecal myeloperoxidase (31.6× higher, P < 0.001), fecal α1-antitrypsin (1.8× higher, P = 0.006), and lower fecal neopterin (0.13× higher, P < 0.001) than the age-matched Nicaraguan infants. In the Nicaraguan rice bran cohort from 6 to 12 mo of age, there was a significant decrease in sIgA concentrations (0.4×, P < 0.05) and a correlation between sIgA and the EED marker α1-antitrypsin (0.523, P < 0.0001) at 12 mo of age. In Malian infants, daily rice bran ingestion resulted in decreased EED scores (0.71×, P = 0.02) and a stable sIgA concentration over time. The rice bran group of Malian infants also had correlation between sIgA and the EED marker neopterin (0.544, P < 0.001) at 12 mo of age and a significant (P < 0.05) increase in microbiota α-diversity at a younger age (9 mo with rice bran compared with 10 mo in control group), which supports earlier microbiota maturation.

CONCLUSIONS

These results support rice bran as a functional food ingredient targeting gut mucosa in children at high-risk of malnutrition.

Ulcerative colitis: focus on colonic mucosal resistance

In recent decades, following cooperation between scientists in various specialties, new unique data on the pathogenesis of ulcerative colitis have been obtained. The role of an impaired immune response to antigens of gut microbiota in genetically predisposed individuals under the effect of certain environmental factors was proven. 

Assessing the interaction between the colonic mucosa and gut microbiota will help to understand the mechanisms of ulcerative colitis and develop new treatment strategies for the disease.

This review presents modern views on the pathogenesis of ulcerative colitis with a focus on the imbalance between local protective and aggressive factors of the gastric and intestinal mucosa. The structure and role of the epithelial barrier both under normal conditions and in ulcerative colitis are considered in detail.

The aim of this review was to summarize the data on resistance of the colonic mucosa and its damage in ulcerative colitis.

Inadequate Vitamin C Intake and Intestinal Inflammation Are Associated with Multiple Micronutrient Deficiency in Young Children: Results from a Multi-Country Birth Cohort Study

Children living in resource-limited settings often suffer from multiple micronutrient deficiencies (MMD). However, there lacks evidence on the correlates of MMD in young children. We investigated the role of diets, water, sanitation and hygiene practice, enteric infections, and impaired gut health on MMD in children at 24 months of age using data from the multi-country MAL-ED birth cohort study. Co-existence of more than one micronutrient deficiency (e.g., anemia, iron, zinc, or retinol deficiency) was considered as MMD. We characterized intestinal inflammation by fecal concentrations of myeloperoxidase (MPO) and neopterin (NEO) measured in the non-diarrheal stool samples. Bayesian network analysis was applied to investigate the factors associated with MMD. A total of 1093 children were included in this analysis. Overall, 47.6% of the children had MMD, with the highest prevalence in Pakistan (90.1%) and lowest in Brazil (6.3%). MMD was inversely associated with the female sex [OR: 0.72, 95% CI: 0.54, 0.92]. A greater risk of MMD was associated with lower vitamin C intake [OR: 0.70, 95% CI: 0.48, 0.94] and increased fecal concentrations of MPO [OR: 1.31, 95% CI: 1.08, 1.51]. The study results imply the importance of effective strategies to ameliorate gut health and improve nutrient intake during the early years of life.

Malnutrition and Dietary Habits Alter the Immune System Which May Consequently Influence SARS-CoV-2 Virulence: A Review

COVID-19, resulting from the SARS-CoV-2 virus, is a major pandemic that the world is fighting. SARS-CoV-2 primarily causes lung infection by attaching to the ACE2 receptor on the alveolar epithelial cells. However, the ACE2 receptor is also present in intestinal epithelial cells, suggesting a link between nutrition, virulence and clinical outcomes of COVID-19. Respiratory viral infections perturb the gut microbiota. The gut microbiota is shaped by our diet; therefore, a healthy gut is important for optimal metabolism, immunology and protection of the host. Malnutrition causes diverse changes in the immune system by repressing immune responses and enhancing viral vulnerability. Thus, improving gut health with a high-quality, nutrient-filled diet will improve immunity against infections and diseases. This review emphasizes the significance of dietary choices and its subsequent effects on the immune system, which may potentially impact SARS-CoV-2 vulnerability.

Nutritional evaluation of complementary porridge formulated from orange-fleshed sweet potato, amaranth grain, pumpkin seed, and soybean flours

Supplementing breastmilk with poor energy and nutrient-dense complementary foodstuffs for young children and infants has resulted in malnutrition, poor growth, and retardation of infant development in many sub-Saharan African countries. Ensuring nutrient adequacy for infants because of their lower consumption requires energy and nutrient-dense food. In this context, the nutritional composition of porridge from complementary flour blends of locally available foodstuffs (orange-fleshed sweet potato, pumpkin seeds, amaranth grains, and soybeans) was carried out. Complementary flours formulated from flour blends of pumpkin seeds, extrusion cooked soybean, and orange-fleshed sweet potato, as well as germinated and extrusion cooked amaranth grains, resulted in varieties of complementary porridges (SAPO1-SAPO5). From these, proximate composition, mineral content (sodium, iron, magnesium, calcium, phosphorus, and zinc), vitamin contents (A and C), and nutrient density of the formulated complementary porridge were determined. Results showed that all the formulated complementary porridge were able to meet the stipulated standards of energy and nutrient (zinc, iron, vitamin A, and protein) densities. Flour blend ratio, germination process, and extrusion cooking significantly (p < .05) influenced the targeted nutrients of interest, as well as the nutrient and energy densities of the formulated complementary porridge. Specifically, the formulated complementary porridge with 40% amaranth grain, 25% orange-fleshed sweet potato, 20% soybean, and 15% pumpkin seed composite mixture had 76.92% compliance level with recommended standards, which assure adequate nutrient complementation to breastfeeding. The present study provides a valuable insight that complementary foods from locally obtainable foodstuffs are potential solutions for mitigating childhood malnutrition and adequate complementation to breastfeeding by proffering the needed energy and nutrient densities required for the immunity, well-being, growth, and development of young children and infants, without fortification.

Reduced Fractional Absorption of Zinc in Children With Environmental Enteropathy in Zambia

OBJECTIVES

We measured fractional absorption of zinc (FAZ) in children with environmental enteropathy (EE) and carried out transcriptomic analysis of biopsies from these children in order to compare FAZ to histology of intestinal biopsies, expression of zinc transporter genes, and biomarkers of enteropathy.

METHODS

Fractional absorption of a standardized aqueous dose of zinc was measured by a dual isotope ratio technique in a cohort of children ages between 9 and 24 months in Lusaka, Zambia, who all had non-responsive stunting. Gene expression analysis was carried out on biopsies through RNA sequencing using an Illumina HiSeq2000 platform.

RESULTS

All 33 children had histological features of environmental enteropathy and plasma zinc concentrations below the lower limit of normal. Measured FAZ ranged from 0.18 to 0.93; all values >0.55 were observed in girls. FAZ was negatively correlated with faecal myeloperoxidase (MPO) (ρ = -0.51, n = 17; P = 0.04) and faecal calprotectin (ρ = -0.50, n = 16; P = 0.05), but not blood biomarkers. Of 41 genes with known roles in zinc metabolism, only three metallothionein genes were significantly correlated with FAZ.

CONCLUSIONS

Zinc homeostasis is impaired in children with environmental enteropathy, and was inversely correlated with mucosal inflammation. Reduced FAZ without specific changes in expression of most zinc transporter genes could be explained by reduced absorptive surface area due to villus/microvillus atrophy.

Enteropathogen Changes After Rotavirus Vaccine Scale-up

OBJECTIVES

To inform next steps in pediatric diarrhea burden reduction by understanding the shifting enteropathogen landscape after rotavirus vaccine implementation.

METHODS

We conducted a case-control study of 1788 medically attended children younger than 5 years, with and without gastroenteritis, after universal rotavirus vaccine implementation in Peru. We tested case and control stools for 5 viruses, 19 bacteria, and parasites; calculated coinfection-adjusted attributable fractions (AFs) to determine pathogen-specific burdens; and evaluated pathogen-specific gastroenteritis severity using Clark and Vesikari scales.

RESULTS

Six pathogens were independently positively associated with gastroenteritis: norovirus genogroup II (GII) (AF 29.1, 95% confidence interval [CI]: 28.0-32.3), rotavirus (AF 8.9, 95% CI: 6.8-9.7), sapovirus (AF 6.3, 95% CI: 4.3-7.4), astrovirus (AF 2.8, 95% CI: 0.0-4.0); enterotoxigenic Escherichia coli heat stable and/or heat labile and heat stable (AF 2.4, 95% CI: 0.6-3.1), and Shigella spp. (AF 2.0, 95% CI: 0.4-2.2). Among typeable rotavirus cases, we most frequently identified partially heterotypic strain G12P[8] (54 of 81, 67%). Mean severity was significantly higher for norovirus GII-positive cases relative to norovirus GII-negative cases (Vesikari [12.7 vs 11.8; P < .001] and Clark [11.7 vs 11.4; P = .016]), and cases in the 6- to 12-month age range relative to cases in other age groups (Vesikari [12.7 vs 12.0; P = .0002] and Clark [12.0 vs 11.4; P = .0016]).

CONCLUSIONS

Norovirus is well recognized as the leading cause of pediatric gastroenteritis in settings with universal rotavirus vaccination. However, sapovirus is often overlooked. Both norovirus and sapovirus contribute significantly to the severe pediatric disease burden in this setting. Decision-makers should consider multivalent vaccine acquisition strategies to target multiple caliciviruses in similar countries after successful rotavirus vaccine implementation.

Nutritional status, diet and viral respiratory infections: perspectives for severe acute respiratory syndrome coronavirus 2

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was recognised by the WHO as a pandemic in 2020. Host preparation to combat the virus is an important strategy to avoid COVID-19 severity. Thus, the relationship between eating habits, nutritional status and their effects on the immune response and further implications in viral respiratory infections is an important topic discussed in this review. Malnutrition causes the most diverse alterations in the immune system, suppressing of the immune response and increasing the susceptibility to infections such as SARS-CoV-2. On the other hand, obesity induces low-grade chronic inflammation caused by excess adiposity, which increases angiotensin-converting enzyme 2. It decreases the immune response favouring SARS-CoV-2 virulence and promoting respiratory distress syndrome. The present review highlights the importance of food choices considering their inflammatory effects, consequently increasing the viral susceptibility observed in malnutrition and obesity. Healthy eating habits, micronutrients, bioactive compounds and probiotics are strategies for COVID-19 prevention. Therefore, a diversified and balanced diet can contribute to the improvement of the immune response to viral infections such as COVID-19.

The contribution of environmental enteropathy to the global problem of micronutrient deficiency

Sometimes referred to as hidden hunger, micronutrient deficiencies persist on a global scale. For some micronutrients this appears to be due to inadequate intake, for others intake may not match increased requirements. However, for most micronutrient deficiencies there is uncertainty as to the dominant driver, and the question about the contribution of malabsorption is open. Environmental enteropathy (EE), formerly referred to as tropical enteropathy and also referred to as environmental enteric dysfunction, is an asymptomatic disorder of small intestinal structure and function which is very highly prevalent in many disadvantaged populations. Recent studies of the pathology and microbiology of this disorder suggest that it is driven by very high pathogen burdens in children and adults living in insanitary environments and is characterised by major derangements of the epithelial cells of the intestinal mucosa. Transcriptomic data suggest that it may lead to impaired digestion and absorption of macronutrients. Given the very high prevalence of EE, marginal malabsorption could have large impacts at population scales. However, the relative contributions of inadequate soil and crop micronutrient contents, inadequate intake, malabsorption and increased requirements are unknown. Malabsorption may compromise attempts to improve micronutrient status, but with the exception of zinc there is currently little evidence to confirm that malabsorption contributes to micronutrient deficiency. Much further research is required to understand the role of malabsorption in hidden hunger, especially in very disadvantaged populations where these deficiencies are most prevalent.

Intestinal and systemic inflammation induced by symptomatic and asymptomatic enterotoxigenic E. coli infection and impact on intestinal colonization and ETEC specific immune responses in an experimental human challenge model

Recent studies have gained a better appreciation of the potential impacts of enteric infections beyond symptomatic diarrhea. It is recognized that infections by several enteropathogens could be associated with growth deficits in children and intestinal and systemic inflammation may play an important underlying role. With enterotoxigenic E. coli (ETEC) being one of the leading causes of diarrhea among children in the developing world and important contributor to stunting, a better understanding of the impact of ETEC infection beyond diarrhea is timely and greatly needed. To address this, we evaluated if ETEC infection induces intestinal and systemic inflammation and its impact on colonization and immune responses to ETEC vaccine-specific antigens in a dose descending experimental human challenge model using ETEC strain H10407. This study demonstrates that the concentrations of myeloperoxidase (MPO) in stool and intestinal fatty acid-binding protein (an indicator of compromised intestinal epithelial integrity) in serum, significantly increased following ETEC infection in both diarrhea and asymptomatic cases and the magnitudes and kinetics of MPO are dose and clinical outcome dependent. Cytokines IL-17A and IFN-γ were significantly increased in serum post-ETEC challenge. In addition, higher pre-challenge concentrations of cytokines IL-10 and GM-CSF were associated with protection from ETEC diarrhea. Interestingly, higher MPO concentrations were associated with higher intestinal colonization of ETEC and lower seroconversions of colonization factor I antigen, but the reverse was noted for seroconversions to heat-labile toxin B-subunit. Together this study has important implications for understanding the acute and long-term negative health outcomes associated with ETEC infection.

Methylmercury Impact on Adult Neurogenesis: Is the Worst Yet to Come From Recent Brazilian Environmental Disasters?

Worldwide environmental tragedies of anthropogenic origin causing massive release of metals and other pollutants have been increasing considerably. These pollution outbreaks affect the ecosystems and impact human health. Among those tragedies, recent large-scale environmental disasters in Brazil strongly affected riverside populations, leading to high-risk exposure to methylmercury (MeHg). MeHg is highly neurotoxic to the developing brain. This toxicant causes neural stem cell dysfunction and neurodevelopmental abnormalities. However, less is known about the effects of MeHg in the postnatal neurogenic niche, which harbors neural stem cells and their progeny, in the adult brain. Therefore, taking in consideration the impact of MeHg in human health it is urgent to clarify possible associations between exposure to mercury, accelerated cognitive decline, and neurodegenerative diseases. In this perspectives paper, we discuss the neurotoxic mechanisms of MeHg on postnatal neurogenesis and the putative implications associated with accelerated brain aging and early-onset cognitive decline in populations highly exposed to this environmental neurotoxicant.

The Intestinal Barrier and Current Techniques for the Assessment of Gut Permeability

The intestinal barrier is essential in human health and constitutes the interface between the outside and the internal milieu of the body. A functional intestinal barrier allows absorption of nutrients and fluids but simultaneously prevents harmful substances like toxins and bacteria from crossing the intestinal epithelium and reaching the body. An altered intestinal permeability, a sign of a perturbed barrier function, has during the last decade been associated with several chronic conditions, including diseases originating in the gastrointestinal tract but also diseases such as Alzheimer and Parkinson disease. This has led to an intensified interest from researchers with diverse backgrounds to perform functional studies of the intestinal barrier in different conditions. Intestinal permeability is defined as the passage of a solute through a simple membrane and can be measured by recording the passage of permeability markers over the epithelium via the paracellular or the transcellular route. The methodological tools to investigate the gut barrier function are rapidly expanding and new methodological approaches are being developed. Here we outline and discuss, in vivo, in vitro and ex vivo techniques and how these methods can be utilized for thorough investigation of the intestinal barrier.

Markers of Environmental Enteric Dysfunction Are Associated with Poor Growth and Iron Status in Rural Ugandan Infants

BACKGROUND

Environmental enteric dysfunction (EED), characterized by altered intestinal permeability/inflammation, microbial translocation, and systemic inflammation (SI), may be a significant contributor to micronutrient deficiencies and poor growth in infants from low-resource settings.

OBJECTIVE

We examined associations among EED, SI, growth, and iron status at 6 mo of age.

METHODS

We performed a cross-sectional analysis of 6-mo-old infants (n = 548) enrolled in a Ugandan birth-cohort study (NCT04233944). EED was assessed via serum concentrations of anti-flagellin and anti- LPS immunoglobulins (Igs); SI was assessed via serum concentrations of ɑ1-acid glycoprotein (AGP) and C-reactive protein (CRP); iron status was assessed via serum concentrations of hemoglobin (Hb), soluble transferrin receptor (sTfR), and ferritin. Associations were assessed using adjusted linear regression analysis.

RESULTS

At 6 mo, ∼35% of infants were stunted [length-for-age z score (LAZ) < -2] and ∼53% were anemic [hemoglobin (Hb) <11.0 g/dL]. Nearly half (∼46%) had elevated AGP (>1 g/L) and ∼30% had elevated CRP (>5 mg/L). EED and SI biomarkers were significantly correlated (r = 0.142-0.193, P < 0.001 for all). In adjusted linear regression models, which included adjustments for SI, higher anti-flagellin IgA, anti-LPS IgA, and anti-LPS IgG concentrations were each significantly associated with lower LAZ [β (95% CI): -0.21 (-0.41, 0.00), -0.23 (-0.44, -0.03), and -0.33 (-0.58, -0.09)]. Furthermore, higher anti-flagellin IgA, anti-flagellin IgG, and anti-LPS IgA concentrations were significantly associated with lower Hb [β (95% CI): -0.24 (-0.45, -0.02), -0.58 (-1.13, 0.00), and -0.26 (-0.51, 0.00)] and higher anti-flagellin IgG and anti-LPS IgG concentrations were significantly associated with higher sTfR [β (95% CI): 2.31 (0.34, 4.28) and 3.13 (0.75, 5.51)].

CONCLUSIONS

EED is associated with both low LAZ and iron status in 6-mo-old infants. Further research on the mechanisms by which EED affects growth and micronutrient status is warranted.