Impact of Heat-Killed Lactobacillus casei Strain IMAU60214 on the Immune Function of Macrophages in Malnourished Children.

Malnutrition is commonly associated with immunological deregulation, increasing the risk of infectious illness and death. The objective of this work was to determine the in vitro effects of heat-killed Lactobacillus casei IMAU60214 on monocyte-derived macrophages (MDMs) from well-nourished healthy children, well-nourished infected children and malnourished infected children, which was evaluated by an oxygen-dependent microbicidal mechanism assay of luminol-increase chemiluminescence and the secretion of tumor necrosis factor (TNF-α), interleukin (IL-1ß), IL-6 and IL-10, as well as phagocytosis using zymosan and as its antibacterial activity against Salmonella typhimurium, Escherichia coli and Staphylococcus aureus. We found that reactive oxygen species (ROS), secretion cytokines (TNFα, IL-1ß, IL-6 and IL-10 levels), phagocytosis and bactericidal capacity increased in all groups after pre-treatment with heat-killed L. casei IMAU60214 at a ratio of 500:1 (bacteria:MDM) over 24 h compared with MDM cells without pre-treatment. The results could indicate that heat-killed L. casei IMAU60214 is a potential candidate for regulating the immune function of macrophages.

Proof-of-concept study of the efficacy of a microbiota-directed complementary food formulation (MDCF) for treating moderate acute malnutrition.

BACKGROUND: Childhood undernutrition remains a significant global health challenge accounting for over half of all under 5 child mortality. Moderate acute malnutrition (MAM), which leads to wasting [weight-for-length z-scores (WLZ) between - 2 and - 3], affects 33 million children under 5 globally and more than 2 million in Bangladesh alone. We have previously reported that acute malnutrition in this population is associated with gut microbiota immaturity, and in a small, 1-month pre-proof-of-concept (POC) study demonstrated that a microbiota-directed complementary food formulation (MDCF-2) was able to repair this immaturity, promote weight gain and increase plasma biomarkers and mediators of healthy growth. Here we describe the design controlled feeding study that tests whether MDCF-2 exhibits superior efficacy (ponderal growth, host biomarkers of a biological state) than a conventional Ready-to-use Supplementary Food (RUSF) in children with MAM over intervention period of 3 months. METHODS: Two separate cohorts of 12-18-month-old children will be enrolled: 124 with primary MAM, and 124 with MAM after having been treated for severe acute malnutrition (post-SAM MAM). We have established several field sites in an urban slum located in the Mirpur district of Dhaka, Bangladesh and at a rural site, Kurigram in the north of Bangladesh. The two groups of children receiving MDCF-2 and RUSF will be compared at baseline (pre-intervention), after 1 month, at the end of intervention (3 months), 1 month after cessation of intervention, and every 6 months thereafter for 4 years. DISCUSSION: This study will determine whether daily, controlled administration of MDCF-2 for 3 months provides superior improvements in weight gain, microbiota repair, and elevated levels of key plasma biomarkers/mediators of healthy growth compared to the control RUSF formulation. The pathogenesis of MAM is poorly defined and there are currently no WHO-approved treatments; results from the current study of children with primary MAM and post-SAM MAM will shed light on the effects of the gut microbiota on childhood growth/development and will provide a knowledge base that may help improve complementary feeding practices. TRIAL REGISTRATION: The primary MAM and post-SAM MAM trials are registered in Clintrials.gov (NCT04015999 and NCT04015986, registered on July 11, 2019, retrospectively registered).

Animal Models of Undernutrition and Enteropathy as Tools for Assessment of Nutritional Intervention.

: Undernutrition is a major public health problem leading to 1 in 5 of all deaths in children under 5 years. Undernutrition leads to growth stunting and/or wasting and is often associated with environmental enteric dysfunction (EED). EED mechanisms leading to growth failure include intestinal hyperpermeability, villus blunting, malabsorption and gut inflammation. As non-invasive methods for investigating gut function in undernourished children are limited, pre-clinical models are relevant to elucidating the pathophysiological processes involved in undernutrition and EED, and to identifying novel therapeutic strategies. In many published models, undernutrition was induced using protein or micronutrient deficient diets, but these experimental models were not associated with EED. Enteropathy models mainly used gastrointestinal injury triggers. These models are presented in this review. We found only a few studies investigating the combination of undernutrition and enteropathy. This highlights the need for further developments to establish an experimental model reproducing the impact of undernutrition and enteropathy on growth, intestinal hyperpermeability and inflammation, that could be suitable for preclinical evaluation of innovative therapeutic intervention.

A multicenter, randomized controlled comparison of three renutrition strategies for the management of moderate acute malnutrition among children aged from 6 to 24 months (the MALINEA project).

BACKGROUND: The aim of this open-label, randomized controlled trial conducted in four African countries (Madagascar, Niger, Central African Republic, and Senegal) is to compare three strategies of renutrition for moderate acute malnutrition (MAM) in children based on modulation of the gut microbiota with enriched flours alone, enriched flours with prebiotics or enriched flours coupled with antibiotic treatment. METHODS: To be included, children aged between 6 months and 2 years are preselected based on mid-upper-arm circumference (MUAC) and are included based on a weight-for-height Z-score (WHZ) between - 3 and - 2 standard deviations (SD). As per current protocols, children receive renutrition treatment for 12 weeks and are assessed weekly to determine improvement. The primary endpoint is recovery, defined by a WHZ ≥ - 1.5 SD after 12 weeks of treatment. Data collected include clinical and socioeconomic characteristics, side effects, compliance and tolerance to interventions. Metagenomic analysis of gut microbiota is conducted at inclusion, 3 months, and 6 months. The cognitive development of children is evaluated in Senegal using only the Developmental Milestones Checklist II (DMC II) questionnaire at inclusion and at 3, 6, and 9 months. The data will be correlated with renutrition efficacy and metagenomic data. DISCUSSION: This study will provide new insights for the treatment of MAM, as well as original data on the modulation of gut microbiota during the renutrition process to support (or not) the microbiota hypothesis of malnutrition. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03474276 Last update 28 May 2018.

Gut bacteria that prevent growth impairments transmitted by microbiota from malnourished children.

Undernourished children exhibit impaired development of their gut microbiota. Transplanting microbiota from 6- and 18-month-old healthy or undernourished Malawian donors into young germ-free mice that were fed a Malawian diet revealed that immature microbiota from undernourished infants and children transmit impaired growth phenotypes. The representation of several age-discriminatory taxa in recipient animals correlated with lean body mass gain; liver, muscle, and brain metabolism; and bone morphology. Mice were cohoused shortly after receiving microbiota from healthy or severely stunted and underweight infants; age- and growth-discriminatory taxa from the microbiota of the former were able to invade that of the latter, which prevented growth impairments in recipient animals. Adding two invasive species, Ruminococcus gnavus and Clostridium symbiosum, to the microbiota from undernourished donors also ameliorated growth and metabolic abnormalities in recipient animals. These results provide evidence that microbiota immaturity is causally related to undernutrition and reveal potential therapeutic targets and agents.

Unrest at home: diarrheal disease and microbiota disturbance.

Diarrhea and malnutrition, two intertwined worldwide problems, are both associated with lower diversity of the intestinal microbiota in children in low-income countries.

Persistent gut microbiota immaturity in malnourished Bangladeshi children.

Therapeutic food interventions have reduced mortality in children with severe acute malnutrition (SAM), but incomplete restoration of healthy growth remains a major problem. The relationships between the type of nutritional intervention, the gut microbiota, and therapeutic responses are unclear. In the current study, bacterial species whose proportional representation define a healthy gut microbiota as it assembles during the first two postnatal years were identified by applying a machine-learning-based approach to 16S ribosomal RNA data sets generated from monthly faecal samples obtained from birth onwards in a cohort of children living in an urban slum of Dhaka, Bangladesh, who exhibited consistently healthy growth. These age-discriminatory bacterial species were incorporated into a model that computes a 'relative microbiota maturity index' and 'microbiota-for-age Z-score' that compare postnatal assembly (defined here as maturation) of a child's faecal microbiota relative to healthy children of similar chronologic age. The model was applied to twins and triplets (to test for associations of these indices with genetic and environmental factors, including diarrhoea), children with SAM enrolled in a randomized trial of two food interventions, and children with moderate acute malnutrition. Our results indicate that SAM is associated with significant relative microbiota immaturity that is only partially ameliorated following two widely used nutritional interventions. Immaturity is also evident in less severe forms of malnutrition and correlates with anthropometric measurements. Microbiota maturity indices provide a microbial measure of human postnatal development, a way of classifying malnourished states, and a parameter for judging therapeutic efficacy. More prolonged interventions with existing or new therapeutic foods and/or addition of gut microbes may be needed to achieve enduring repair of gut microbiota immaturity in childhood malnutrition and improve clinical outcomes.

Contribution of enteric infection, altered intestinal barrier function, and maternal malnutrition to infant malnutrition in Bangladesh.

BACKGROUND: Malnourished children are at increased risk for death due to diarrhea. Our goal was to determine the contribution of specific enteric infections to malnutrition-associated diarrhea and to determine the role of enteric infections in the development of malnutrition. METHODS: Children from an urban slum in Bangladesh were followed for the first year of life by every-other-day home visits. Enteropathogens were identified in diarrheal and monthly surveillance stools; intestinal barrier function was measured by serum endocab antibodies; and nutritional status was measured by anthropometry. RESULTS: Diarrhea occurred 4.69 ± 0.19 times per child per year, with the most common infections caused by enteric protozoa (amebiasis, cryptosporidiosis, and giardiasis), rotavirus, astrovirus, and enterotoxigenic Escherichia coli (ETEC). Malnutrition was present in 16.3% of children at birth and 42.4% at 12 months of age. Children malnourished at birth had increased Entamoeba histolytica, Cryptosporidium, and ETEC infections and more severe diarrhea. Children who became malnourished by 12 months of age were more likely to have prolonged diarrhea, intestinal barrier dysfunction, a mother without education, and low family expenditure. CONCLUSIONS: Prospective observation of infants in an urban slum demonstrated that diarrheal diseases were associated with the development of malnutrition that was in turn linked to intestinal barrier disruption and that diarrhea was more severe in already malnourished children. The enteric protozoa were unexpectedly important causes of diarrhea in this setting. This study demonstrates the complex interrelationship of malnutrition and diarrhea in infants in low-income settings and points to the potential for infectious disease interventions in the prevention and treatment of malnutrition.

Enterobacter sakazakii: an emerging problem in paediatric nutrition.

Recently there has been considerable concern related to the presence of bacteria, in particular Enterobacter sakazakii, in powdered infant formula milk. E. sakazakii, a member of the family Enterobacteriaceae, is an emerging opportunistic pathogen that has been associated with cases of meningitis, necrotizing enterocolitis and sepsis in premature and full-term infants. Feeding with powdered infant formula has been epidemiologically implicated in several clinical cases. Powdered infant formula is not a sterile product; good hygienic practice is, therefore, necessary in its reconstitution to reduce the risk of infection. The ingestion of raised numbers of E. sakazakii resulting from storage at room temperature after reconstitution is highlighted as well as the uncertain routes of E. sakazakii product contamination.

Evaluation of urinary tract infection in malnourished black children.

Urinary tract infection (UTI) is a well recognized complication in malnourished children. The need to investigate these patients for underlying renal pathology has not been clearly defined. Seventy-five children with malnutrition were evaluated for UTI by culture of urine obtained suprapubically prior to antibiotic therapy. All patients with UTI were investigated with renal ultrasonography, intravenous pyelography (IVP) and voiding cystourethrography (VCU). Haemoglobin, white cell count, serum urea, creatinine and electrolytes were determined in all the children. The mean age of the children was 15.5 months (range 3-60 months). UTI was diagnosed in 26 (34.7%), of whom 21 (81%) were boys. The overall prevalence of UTI in those with kwashiorkor/marasmic kwashiorkor was 42%. Escherichia coli was the organism most commonly cultured (84.6%). Renal sonography, IVP and VCU were normal in all infected cases and vesicoureteric reflux was not detected in any. This study confirms the high prevalence of UTI in malnourished children. As no anatomical abnormalities were demonstrated in the patients with UTI, imaging of the renal tract other than real sonography does not appear to be indicated in the malnourished child in a first episode of UTI with normal renal function.

Jejunal microflora in malnourished Gambian children.

Growth of bacteria greater than 10-5 organisms/ml was found in 22 children, of whom 17 gave a histroy of chronic diarrhoea. The other 8 children had either no diarrhoea or where having an acute attack lasting for a few days. In those with chronic diarrhoea, Esch. coli, bacteroides, and enterococci tended to occur more frequently, whereas streptococci occurred more frequently in those with acute diarrhoea. Bacilli, staphylococci, micrococci, klebsiellas, pseudomonads, and candidas often occurred in both groups and in large numbers in those with chronic diarrhoea. This confirms previous reports in other parts of the world that some children with malnutrition have considerable bacterial contamination of the jejunum, and that this may be of aetiological significance as a cause of much of the diarrhoea seen in malnourished children. It is possible too that this may be important in the pathogenesis of malnutrition. The presence of intestinal parasites in these malnourished children is also noted. A double-blind trial in the use of antibiotics in this condition is advocated to determine whether it is possible to break the diarrhoea-malabsorption-malnutrition cycle. At the same time the effect of simply removing the child to a more sanitary environment, together with an estimate of the natural clearance of bacteria from the upper intestine, should be evaluated.