The Role of Maternal Breast Milk in Preventing Infantile Diarrhea in the Developing World

Seasonal Prevalence and Detection of Enteric and Respiratory Viruses in Wastewater and Hospitalized Children with Acute Gastroenteritis

Human enteric and some respiratory viruses are identified to be involved with acute gastroenteritis that can be shed in feces of infected persons into the environment. Understanding the abundance of these viruses in wastewater is significant when assessing the public health impacts associated with discharge of wastewater into the environment. This study aimed to investigate the prevalence and seasonal variation of human enteric adenovirus (HAdV), Aichi virus (AiV-1), bocavirus (HBoV), and respiratory syndrome coronavirus 2 virus (SARS-CoV-2) in wastewater as well as their prevalence among hospitalized children with acute gastroenteritis. The viruses were detected and quantified with real-time PCR. HAdV was the most detected virus in raw sewage (88.5%), treated sewage (28%), and stool gastroenteritis (74%), followed by HBoV (45.8% for raw sewage, 14.6% for treated sewage, and 55.3% for stool samples). The detection rate of AiV-1 was 59.4%, 19.8%, and 62.6% in raw sewage, treated sewage, and stool samples, respectively. The rate of SARS-CoV-2 detection in raw sewage, treated sewage, and stool samples was 33.3%, 7.3%, and 20.6%, respectively. The viral concentrations ranged between 4.50 × 101 and 8.75 × 107 GC/ml in raw sewage samples, 1.20 × 101 and 5.43 × 106 GC/ml in treated sewage samples, and 4.80 × 101 and 9.88 × 108 GC/gram in stool samples. The overall log means of virus reduction during the wastewater treatment process ranged from 1.68 log10 (HAdV) to 3.31 log10 (AiV-1). The peak prevalence of the four viruses in raw sewage samples occurred during the winter season. This study showed the high detection rates of the four targeted viruses in wastewater and demonstrated that virological surveillance of wastewater in local wastewater treatment plants is a suitable model for epidemiological monitoring of diarrheal and respiratory diseases in middle- and low-resource countries.

Human milk immune factors, maternal nutritional status, and infant sex: The INSPIRE study

OBJECTIVES

Breastfeeding is an energetically costly and intense form of human parental investment, providing sole-source nutrition in early infancy and bioactive components, including immune factors. Given the energetic cost of lactation, milk factors may be subject to tradeoffs, and variation in concentrations have been explored utilizing the Trivers-Willard hypothesis. As human milk immune factors are critical to developing immune system and protect infants against pathogens, we tested whether concentrations of milk immune factors (IgA, IgM, IgG, EGF, TGFβ2, and IL-10) vary in response to infant sex and maternal condition (proxied by maternal diet diversity [DD] and body mass index [BMI]) as posited in the Trivers-Willard hypothesis and consider the application of the hypothesis to milk composition.

METHODS

We analyzed concentrations of immune factors in 358 milk samples collected from women residing in 10 international sites using linear mixed-effects models to test for an interaction between maternal condition, including population as a random effect and infant age and maternal age as fixed effects.

RESULTS

IgG concentrations were significantly lower in milk produced by women consuming diets with low diversity with male infants than those with female infants. No other significant associations were identified.

CONCLUSIONS

IgG concentrations were related to infant sex and maternal diet diversity, providing minimal support for the hypothesis. Given the lack of associations across other select immune factors, results suggest that the Trivers-Willard hypothesis may not be broadly applied to human milk immune factors as a measure of maternal investment, which are likely buffered against perturbations in maternal condition.

Intestinal Parasitic Infections Among Pediatric Patients in a Metropolitan City of Bangladesh With Emphasis on Cryptosporidiosis

Introduction Gastrointestinal parasitic infections are one of the global health concerns in developing countries like Bangladesh. Among them, Cryptosporidium spp. plays an essential role in causing diarrhea, malnutrition, and poor cognitive function, especially in children. This study was conducted to identify the frequency of Cryptosporidium cases and other parasitic agents.  Methods A cross-sectional observational study was conducted among 219 hospitalized children with diarrhea. The conventional microscopic technique was applied for parasitic detection. Particular staining (modified Ziehl-Neelsen) procedure was performed to identify oocysts of Cryptosporidium spp. A polymerase chain reaction (PCR) was performed to determine the SSU rRNA and gp60 gene of Cryptosporidium.  Results Cysts of Giardia duodenalis (2.3%), ova of Ascaris lumbricoides (1.4%,), Trichuris trichiura (0.5%), and both A. lumbricoides and T. trichiura (0.9%) were identified in samples through wet mount preparation. The distribution of Cryptosporidium spp. as detected by the staining method and nested PCR was 1.4% and 4.1%, respectively.  Conclusion Factors independently associated with Cryptosporidium infection are unsafe water, lack of regular hand washing, and insufficiency of exclusive breastfeeding. This study reports, presumably for the first time, the detection of Cryptosporidium oocysts in Chattogram metropolitan city of Bangladesh.

Beneficial role of skim milk against drug-resistant Escherichia coli associated with pediatric diarrhoea

Background

Antibiotic-resistance in E. coli is a global issue affecting humans especially the pediatric population. Antibiotic-resistant E. coli is a pathogen frequently pediatric population as well as healthy adults.

Methods

This study aimed to examine the antibiotic resistance of E. coli causing pediatric diarrhea and its drug-resistant rates, its adhering abilities to cell line in vitro, and inhibition efficiency of a few selected chemical compounds. Clinical strains were isolated from both the healthy and infected pediatric population of Mizoram.

Results

Adhesion is a significant pathogenic process during bacterial infections, which has been employed for pathotyping of DEC by comparing adhesion efficiency in both normal (CHO-k1) and cancer (HeLa) cell lines. E. coli adherent pathotypes were identified by both PCR assay and in-vitro cell adhesion assays; the study also evaluated the adhesion inhibition ability of human skimmed milk, gentamicin, and cephalexin in-vitro. Of all isolates, 20.05% of adherent DEC (EPEC, DAEC, and EIEC) and 11.39 % of non-adherent DEC (STEC and ETEC) were found to be associated with pediatric diarrhoea in Mizoram. Human skimmed milk has a high potential adhesion inhibition against EAEC (50.25/90.90 μg/mL), EPEC (53.42/259.70 μg/mL), and EIEC (59.13/30.30 μg/mL) in both cell lines in comparison with gentamicin and cephalexin.

Conclusion

This study concludes that as a dietary supplement-human skimmed milk has high potential to prevent adhesion of DEC pathotypes in cells in-vitro thus in in-vivo.

Revolutionized virome research using systems microbiology approaches

Currently, both pathogenic and commensal viruses are continuously being discovered and acknowledged as ubiquitous components of microbial communities. The advancements of systems microbiological approaches have changed the face of virome research. Here, we focus on viral metagenomic approach to study virus community and their interactions with other microbial members as well as their hosts. This review also summarizes challenges, limitations, and benefits of the current virome approaches. Potentially, the studies of virome can be further applied in various biological and clinical fields.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Knowledge and Practices on the Prevention and Management of Diarrhea in Children Under-2 Years Among Women Dwelling in Urban Slums of Karachi, Pakistan

Background

Diarrhea is the second leading cause of death especially among children. The age-proportionate mortality of diarrheal disease in infants under 2 years is 72%, among children under 5 years of age. Children living in urban slums are more prone to develop diarrhea. Although the disease can be prevented by many simple cost-effective interventions, i.e. proper sanitation and hygiene, appropriate feeding, and timely vaccination, poverty and lack of basic life amenities often potentiate diarrhea mortality. Gadap town is the largest town of Karachi with a deprived health system. This study aims to assess pediatric diarrhea prevalence and related knowledge-practice gaps in the slums of Gadap Town, Karachi, Pakistan.

Method

A community-based cross-sectional study was conducted from November 2016 to May 2017 among mothers of children under 2 years, who were residents of Gadap Town, Karachi, Pakistan. The participants were approached by a multistage sampling method. A validated dichotomous questionnaire, piloted on 40 participants, translated into local language Urdu was used for data collection and the data was analyzed by SPSS® version 20.0.

Results

51.8% (n = 199) of participants were aged between 25 and 34 years. Among all participants, 68% (n = 261) had primary level education or less, compared to 4.7% (n = 18) of women who had graduate-level education. The mean number of children per woman was 2.52 ± 1.62. Self-reported pediatric diarrhea incidence was 72.1% (n = 277). More than half (55.2% n = 149) of participants reported frequent diarrhea episodes during the 2nd year of their child’s life. In this survey, we found the knowledge of women regarding diarrhea management and how to reduce diarrhea morbidity to be inadequate (p > 0.05). However, many women reported appropriate practices which can significantly reduce diarrhea morbidity (p < 0.05).

Conclusion

While the knowledge among women on preventive measures for pediatric diarrhea was insufficient, the translation of the right knowledge into appropriate practices showed promising outcomes for reducing diarrhea morbidity. An integrated approach for improving feeding, sanitation, and hygiene practices along with continuous health education could curtail the burden of diarrhea among infants living in urban slums.

Salmonella Uptake into Gut-Associated Lymphoid Tissues: Implications for Targeted Mucosal Vaccine Design and Delivery

Peyer's patches are organized gut-associated lymphoid tissues (GALT) in the small intestine and the primary route by which particulate antigens, including viruses and bacteria, are sampled by the mucosal immune system. Antigen sampling occurs through M cells, a specialized epithelial cell type located in the follicle-associated epithelium (FAE) that overlie Peyer's patch lymphoid follicles. While Peyer's patches play an integral role in intestinal homeostasis, they are also a gateway by which enteric pathogens, like Salmonella enterica serovar Typhimurium (STm), cross the intestinal barrier. Once pathogens like STm gain access to the underlying network of mucosal dendritic cells and macrophages they can spread systemically. Thus, Peyer's patches are at the crossroads of mucosal immunity and intestinal pathogenesis. In this chapter, we provide detailed methods to assess STm entry into mouse Peyer's patch tissues. We describe Peyer's patch collection methods and provide strategies to enumerate bacterial uptake. We also detail a method for quantifying bacterial shedding from infected animals and provide an immunohistochemistry protocol for the localization of STm along the gastrointestinal tract and insight into pathogen transit in the presence of protective antibodies. While the protocols are written for STm, they are easily tailored to other enteric pathogens.

Biodigester Cookstove Interventions and Child Diarrhea in Semirural Nepal: A Causal Analysis of Daily Observations

BACKGROUND

Hundreds of thousands of biodigesters have been constructed in Nepal. These household-level systems use human and animal waste to produce clean-burning biogas used for cooking, which can reduce household air pollution from woodburning cookstoves and prevent respiratory illnesses. The biodigesters, typically operated by female caregivers, require the handling of animal waste, which may increase domestic fecal contamination, exposure to diarrheal pathogens, and the risk of enteric infections, especially among young children.

OBJECTIVE

We estimated the effect of daily reported biogas cookstove use on incident diarrhea among children < 5 y old in the Kavrepalanchok District of Nepal. Secondarily, we assessed effect measure modification and statistical interaction of individual- and household-level covariates (child sex, child age, birth order, exclusive breastfeeding, proof of vaccination, roof type, sanitation, drinking water treatment, food insecurity) as well as recent 14-d acute lower respiratory infection (ALRI) and season.

METHODS

We analyzed 300,133 person-days for 539 children in an observational prospective cohort study to estimate the average effect of biogas stove use on incident diarrhea using cross-validated targeted maximum likelihood estimation (CV-TMLE).

RESULTS

Households reported using biogas cookstoves in the past 3 d for 23% of observed person-days. The adjusted relative risk of diarrhea for children exposed to biogas cookstove use was 1.31 (95% confidence interval (CI): 1.00, 1.71) compared to unexposed children. The estimated effect of biogas stove use on diarrhea was stronger among breastfed children (2.09; 95% CI: 1.35, 3.25) than for nonbreastfed children and stronger during the dry season (2.03; 95% CI: 1.17, 3.53) than in the wet season. Among children exposed to biogas cookstove use, those with a recent ALRI had the highest mean risk of diarrhea, estimated at 4.53 events (95% CI: 1.03, 8.04) per 1,000 person-days.

DISCUSSION

This analysis provides new evidence that child diarrhea may be an unintended health risk of biogas cookstove use. Additional studies are needed to identify exposure pathways of fecal pathogen contamination associated with biodigesters to improve the safety of these widely distributed public health interventions. https://doi.org/10.1289/EHP9468.

Indirect effects of the SARS CoV-2 pandemic on the prevalence of breastfeeding: Modeling its impact

INTRODUCTION

Breastfeeding has a protective effect against acute respiratory and diarrheal infections. There are psychological and social effects due to physical isolation in the population in the mother-child group.

OBJECTIVE

To assess the impact on infant mortality due to a decrease in the prevalence of breastfeeding during 2020 due to the physical isolation against the SARS CoV-2 (COVID-19) pandemic in Colombia.

MATERIALS AND METHODS

We used the population attributable risk approach taking into account the prevalence of breastfeeding and its potential decrease associated with the measures of physical isolation and the relative risk (RR) of the association between exclusive breastfeeding and the occurrence of acute infection consequences in the growth (weight for height) of children under the age of five through a mathematical modeling program.

RESULTS

We found an increase of 11.39% in the number of cases of growth arrest in the age group of 6 to 11 months with a 50% decrease in breastfeeding prevalence, as well as an increase in the number of diarrhea cases in children between 1 and 5 months of age from 5% (5.67%) on, and an increased number of deaths in children under 5 years (9.04%) with a 50% decrease in the prevalence of exclusive breastfeeding.

CONCLUSIONS

A lower prevalence of breastfeeding has an impact on infant morbidity and mortality in the short and medium-term. As a public health policy, current maternal and childcare strategies must be kept in order to reduce risks in the pediatric population.

Climatic Conditions and Infant Care: Implications for Child Nutrition in Rural Ethiopia

We examine the relationships between climatic conditions, breastfeeding behavior, and maternal time use in Ethiopia. Infant feeding practices are important predictors of child nutrition that may be affected by a number of factors including mother's time engaging in agricultural labor, food security, cultural beliefs, and antenatal care. We use panel data from the Living Standards Measurement Study to investigate linkages between climatic conditions during a child's first year of life and year prior to birth and duration of exclusive breastfeeding. We then explore one potential mechanism: women's agricultural labor. Results indicate that rainfall during the primary agricultural season-kiremt-in a child's first year of life plays an important role in duration of exclusive breastfeeding. Experiencing 25 cm of average monthly kiremt rainfall, versus 5 cm, is associated with a 20-percentage-point decrease in the likelihood of being exclusively breastfed for the recommended six months. More kiremt rainfall is associated with a greater number of days that women spend planting and harvesting, and at high levels of rainfall women with infants do not engage in significantly fewer days of agricultural labor than those without infants. Lastly, we find that during the year before birth, greater rainfall during kiremt as well as the dry season is associated with a lower likelihood of six months of exclusive breastfeeding, potentially due to the early introduction of complementary foods. Our findings indicate that agricultural labor demands may in part drive breastfeeding behaviors, leading to "sub-optimal" feeding practices in the short-term, but resulting in improved household food security in the longer-term.

Realities and challenges of breastfeeding policy in the context of HIV: a qualitative study on community perspectives on facilitators and barriers related to breastfeeding among HIV positive mothers in Baringo County, Kenya

Background

Although recent policies have sought to increase the rates of exclusive breastfeeding (EBF) and continued breastfeeding for HIV exposed infants, few programs have considered the multiple social and cultural barriers to the practice. Therefore, to generate evidence for exclusive and continued breastfeeding policies in Kenya, we examined community perspectives on the facilitators and barriers in adherence to EBF for the HIV positive mothers.

Methods

Qualitative research was conducted in Koibatek, a sub-County in Baringo County Kenya, in August 2014 among 205 respondents. A total of 14 focus group discussions (n = 177), 14 In-depth Interviews and 16 key informant interviews were conducted. Transcribed data was analyzed thematically. NVivo version 10.0 computer qualitative software program was used to manage and facilitate the analysis.

Results

Facilitators to exclusive breastfeeding were perceived to include counselling at the health facility, desire to have a healthy baby, use of antiretroviral drugs and health benefits associated with breastmilk. Barriers to EBF included poor dissemination of policies, knowledge gap, misinterpretation of EBF, inadequate counselling, attitude of mother and health workers due to fear of vertical HIV transmission, stigma related to misconception and misinformation that EBF is only compulsory for HIV positive mothers, stigma related to HIV and disclosure, social pressure, lack of male involvement, cultural practices and traditions, employment, food insecurity.

Conclusions

There are multiple facilitators and barriers of optimal breastfeeding that needs a holistic approach to interventions aimed at achieving elimination of mother to child transmission. Extension of infant feeding support in the context of HIV to the community while building on existing interventions such as the Baby Friendly Community Initiative is key to providing confidential support services for the additional needs faced by HIV positive mothers.

Delayed breast feeding initiation increases the odds of colostrum avoidance among mothers in Northwest Ethiopia: a community-based cross-sectional study

BACKGROUND

Colostrum is a yellowish and sticky breast milk produced in late pregnancy. Annually, 60% of 10.9 million under-five deaths globally are due to malnutrition. Of these, over two-thirds of the deaths are accounted by sub-optimal feeding practices in the first year of life, including colostrum discarding. However, evidence on the magnitude of colostrum avoidance and its associated factors at the community level is very limited in Ethiopia, particularly in the study area. Thus, this study aimed to assess the magnitude of colostrum avoidance and associated factors among mothers who gave birth in the last six months in Gozamen district, northwest Ethiopia, 2019.

METHODS

A community-based cross-sectional study was conducted among 741 (741) mothers who gave birth in the last six months in Gozamen district from August 1 to September 12, 2019. A stratified cluster sampling technique was used to select the study participants. Data were collected by face-to-face interviewer-administered, pretested, and semi-structured questionnaire. Binary logistic regressions (bi-variable and multivariable) were fitted to identify statistically significant variables. Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) was used to declare statistically significant variables on the basis of p-value < 0.05 in the multivariable binary logistic regression.

RESULTS

This study indicated that the magnitude of colostrum avoidance was 22.1% (95% CI, 19.0, 25.2%). Mothers who did not get counseling on timely initiation of breast feeding (AOR = 3.91[95% CI, 1.98, 7.72]), not participate in pregnant woman forum (AOR = 2.59[95% CI, 1.30, 5.14]), initiate breast-feeding lately (more than 1 h) (AOR 2.27[95% CI, 1.18, 4.34]), and those having unfavorable attitude towards colostrum feeding (AOR = 7.35[95% CI, 3.89, 13.91]) were factors associated with the increased likelihood of colostrum avoidance. However, institutional delivery (AOR; 0.06[95% CI, 0.02, 0.19]) and prelacteal feeding (AOR; 0.10[95% CI, 0.05, 0.21]) were predictors associated with reduced likelihood of colostrum avoidance.

CONCLUSION

Colostrum avoidance is a common practice in the study area. Therefore, in order to reduce this practice, strengthening infant feeding counseling, promoting institutional delivery, timely initiation of breastfeeding, health education, and community advocating are recommended interventions. In addition, creating awareness on the benefits of colostrum feeding is very instrumental to tackle the practice of colostrum avoidance.

Human Milk Microbiota in an Indigenous Population Is Associated with Maternal Factors, Stage of Lactation, and Breastfeeding Practices

BACKGROUND

Human milk contains a diverse community of bacteria that are modified by maternal factors, but whether these or other factors are similar in developing countries has not been explored. Our objective was to determine whether the milk microbiota was modified by maternal age, BMI, parity, lactation stage, subclinical mastitis (SCM), and breastfeeding practices in the first 6 mo of lactation in an indigenous population from Guatemala.

METHODS

For this cross-sectional study, Mam-Mayan indigenous mothers nursing infants aged <6 mo were recruited. Unilateral human milk samples were collected (n = 86) and processed for 16S rRNA sequencing at the genus level. Microbial diversity and relative abundance were compared with maternal factors [age, BMI, parity, stage of lactation, SCM, and 3 breastfeeding practices (exclusive, predominant, mixed)] obtained through questionnaires.

RESULTS

Streptococcus was the most abundant genus (33.8%), followed by Pseudomonas (18.7%) and Sphingobium (10.7%) but relative abundance was associated with maternal factors. First, Lactobacillus and Streptococcus were more abundant in early lactation whereas the common oral (Leptotrichia) and environmental (Comamonas) bacteria were more abundant in established lactation. Second, Streptococcus,Lactobacillus,Lactococcus,Leuconostoc, and Micrococcus had a higher abundance in multiparous mothers compared with primiparous mothers. Third, a more diverse microbiota characterized by a higher abundance of lactic acid bacteria (Lactobacillus,Leuconostoc, and Lactococcus), Leucobacter, and Micrococcus was found in mothers with a healthy BMI. Finally, distinct microbial communities differed by stage of lactation and by exclusive, predominant, or mixed breastfeeding practices.

CONCLUSION

Milk bacterial communities in an indigenous community were associated with maternal factors. Higher microbial diversity was supported by having a healthy BMI, the absence of SCM, and by breastfeeding. Interestingly, breastfeeding practices when assessed by lactation stage were associated with distinct microbiota profiles.

Anti-Infective, Anti-Inflammatory, and Immunomodulatory Properties of Breast Milk Factors for the Protection of Infants in the Pandemic From COVID-19

COVID-19 pandemic since the end of 2019 spreads worldwide, counting millions of victims. The viral invasion, systemic inflammation, and consequent organ failure are the gravest features of coronavirus disease 2019 (COVID-19), and they are associated with a high mortality rate. The aim of this study is to evaluate the role of breast milk in the COVID-19 pandemic, analyzing its antiviral, anti-inflammatory, and immunoregulatory effects due to its bioactive components, so numerous and important for the protection of infants. The study tried to demonstrate that all the components of human milk are capable of performing functions on all the pathogenic events recognized and described in COVID-19 disease. Those human milk factors are well-tolerated and practically free of side effects, so breast milk should become a research topic to discover therapies even in this epidemic. In the first part, the mechanisms of protection and defense of the breast milk elements will be delineated; in the second section, it will describe the human milk effects in viral infections and it will be hypothesized how the known mechanisms could act in COVID infection.

Transient Effect of Infant Formula Supplementation on the Intestinal Microbiota

Breastfeeding is the gold standard for feeding infants because of its long-term benefits to health and development, but most infants in the United States are not exclusively breastfed in the first six months. We enrolled 24 infants who were either exclusively breastfed or supplemented with formula by the age of one month. We collected diet information, stool samples for evaluation of microbiotas by 16S rRNA sequencing, and blood samples for assessment of immune development by flow cytometry from birth to 6 months of age. We further typed the Bifidobacterium strains in stool samples whose 16S rRNA sequencing showed the presence of Bifidobacteriaceae. Supplementation with formula during breastfeeding transiently changed the composition of the gut microbiome, but the impact dissipated by six months of age. For example, Bifidobacterium longum, a bacterial species highly correlated with human milk consumption, was found to be significantly different only at 1 month of age but not at later time points. No immunologic differences were found to be associated with supplementation, including the development of T-cell subsets, B cells, or monocytes. These data suggest that early formula supplementation, given in addition to breast milk, has minimal lasting impact on the gut microbiome or immunity.

Breastfeeding importance and its therapeutic potential against SARS-CoV-2

During postnatal development, colostrum and breastmilk are sequentially the first sources of nutrition with protein components and bioactive molecules that confer protection and immunostimulatory function to the gut. Caseins, whey proteins, secretory immunoglobulin A (sIgA), mucins, tryptophan, and growth factors are among milk-borne elements that are directly important in the control of mucosa development and protection. Consequently, breastfeeding is associated with the low incidence of gastrointestinal inflammation and with the decrease in respiratory diseases during postnatal period. The novel coronavirus (SARS-CoV-2) binds to angiotensin II-converting enzyme (ACE2) on the cell membrane, allowing virus entrance, replication, and host commitment. ACE2 is expressed by different cell types, which include ciliated cells in the lungs and enterocytes in the intestine. Such cells are highly active in metabolism, as they internalize molecules to be processed and used by the organism. The disruption of ACE2 impairs leads to intestinal inflammation and decreased synthesis of serotonin, affecting motility. By reviewing the effects of SARS-CoV-2 in the gastrointestinal and respiratory tracts in infants, and gut responses to breastfeeding interruption, we suggest that it is important to maintain breastfeeding during SARS-CoV-2 infection, as it might be essential to protect newborns from gastrointestinal-associated disorders and relieve disease symptoms.

The human virome: assembly, composition and host interactions

The human body hosts vast microbial communities, termed the microbiome. Less well known is the fact that the human body also hosts vast numbers of different viruses, collectively termed the 'virome'. Viruses are believed to be the most abundant and diverse biological entities on our planet, with an estimated 10³¹ particles on Earth. The human virome is similarly vast and complex, consisting of approximately 10¹³ particles per human individual, with great heterogeneity. In recent years, studies of the human virome using metagenomic sequencing and other methods have clarified aspects of human virome diversity at different body sites, the relationships to disease states and mechanisms of establishment of the human virome during early life. Despite increasing focus, it remains the case that the majority of sequence data in a typical virome study remain unidentified, highlighting the extent of unexplored viral 'dark matter'. Nevertheless, it is now clear that viral community states can be associated with adverse outcomes for the human host, whereas other states are characteristic of health. In this Review, we provide an overview of research on the human virome and highlight outstanding recent studies that explore the assembly, composition and dynamics of the human virome as well as host-virome interactions in health and disease.

Norovirus-specific immunoglobulin A in breast milk for protection against norovirus-associated diarrhea among infants

BACKGROUND

Norovirus (NV) causes acute gastroenteritis in infants. Humoral and fecal immunoglobulin A (IgA) responses have been correlated with protection against NV; however, the role of breast milk IgA against NV infection and associated diarrhea is still unknown. This study aimed to evaluate the protective role of NV-specific IgA (NV-IgA) in breast milk.

METHODS

Ninety-five breast milk samples collected from mothers enrolled in a 2016-2017 Peruvian birth cohort study were tested for total IgA and NV-IgA by ELISA using GII·4 variants and non-GII·4 genotype virus-like particles (VLPs). Breast milk samples were grouped according to the NV infection and diarrheal status of infants: NV positive with diarrhea (NV+D+, n=18); NV positive without diarrhea (NV+D-, n=37); and NV negative without diarrhea (NV-D-, n=40). The percent positivity and titer of NV-IgA were compared among groups. The cross-reactivity was estimated based on the correlation of ratio between NV-IgA against GII·4 variants and non-GII·4 genotype VLPs.

FINDINGS

NV-IgA had high positivity rates against different VLPs, especially against GII (89-100%). The NV+D- group had higher percent positivity (89% vs. 61%, p=0·03) and median titer (1:100 vs 1:50, p=0·03) of NV-IgA than the NV+D+ group against GI·1 VLPs. A relatively high correlation between different GII·4 variants (0·87) and low correlation between genogroups (0·23-0·37) were observed.

INTERPRETATION

Mothers with high positivity rates and titers of NV-IgA in breast milk had NV infected infants with reduced diarrheal symptoms. Antigenic relatedness to the genetic diversity of human norovirus was suggested.Funding National Institute of Allergy and Infectious Diseases, National Institute of Health: 1R01AI108695-01A1 and the Japan Society for the Promotion of Science (Fostering Joint International Research B):19KK0241.

Partial Degradation of Recombinant Antibody Functional Activity During Infant Gastrointestinal Digestion: Implications for Oral Antibody Supplementation

Oral administration of engineered immunoglobulins has the potential to prevent enteric pathogen-induced diarrhea in infants. To prevent infection, these antibodies need to survive functionally intact in the proteolytic environment of the gastrointestinal tract. This research examined both ex vivo and in vivo the functional survival across infant digestion of palivizumab, a model FDA-approved recombinant antibody against respiratory syncytial virus (RSV) F protein. Palivizumab-fortified feed (formula or human milk), infant gastric, and intestinal samples were incubated to simulate in vivo digestion (ex vivo digestion). Palivizumab-fortified human milk was also fed to infants, followed by collection of gastric and intestinal samples (in vivo digestion). Palivizumab was purified from the samples of digestate using protein G spin columns followed by filtration through molecular weight cut-off membranes (30 kDa). Palivizumab functional survival across ex vivo and in vivo digestion was determined via an anti-idiotype ELISA and an RSV plaque reduction neutralization test. Palivizumab concentration and RSV neutralization capacity both decreased when incubated in intestinal samples (ex vivo study). The concentration and neutralization activity of orally-supplemented palivizumab also decreased across infant digestion (in vivo study). These results indicate that if recombinant IgGs were selected for oral supplementation to prevent enteric infections, appropriate dosing would need to account for degradation occurring in the digestive system. Other antibody formats, structural changes, or encapsulation could enhance survival in the infant gastrointestinal tract.

Human Bocavirus in Brazil: Molecular Epidemiology, Viral Load and Co-Infections

Human bocavirus (HBoV) is an emerging virus and has been detected worldwide, especially in pediatric patients with respiratory and gastrointestinal infection. In this study, we describe HBoV prevalence, genotypes circulation and DNA shedding, in stool samples from children up to two years of age in Brazil. During 2016 and 2017, 886 acute gastroenteritis (AGE) stool samples from ten Brazilian states were analyzed by TaqMan^®-based qPCR, to detect and quantify HBoV. Positive samples were genotyped by sequencing the VP1/2 overlap region, followed by phylogenetic analysis and co-infections were accessed by screening other gastroenteric viruses. HBoV was detected in 12.4% (n = 110) of samples, with viral load ranging from 1.6 × 10² to 1.2 × 10⁹ genome copies per gram of stool. From these, co-infections were found in 79.1%, and a statistically lower HBoV viral load was found compared to viral loads of rotavirus, norovirus and adenovirus in double infected patients (p < 0.05). No significant differences were found between HBoV viral load in single or co-infections, age groups or genotypes. Phylogenetic analysis identified the circulation of HBoV-1 in 38%, HBoV-2 in 40% and HBoV-3 in 22%. Continuous HBoV monitoring is needed to clarify its role in diarrhea disease, especially in the absence of classic gastroenteric viruses.

Dietary Intake Influences Metabolites in Healthy Infants: A Scoping Review

Metabolites are generated from exogenous sources such as diet. This scoping review will summarize nascent metabolite literature and discriminating metabolites for formula vs. human- milk-fed infants. Using the PICOS framework (P—Patient, Problem or Population; I—Intervention; C—Comparison; O—Outcome; S—Study Design) and PRISMA item-reporting protocols, infants less than 12 months old, full-term, and previously healthy were included. Protocol was registered with Open Science Framework (OSF). Publications from 1 January 2009–2019 were selected, for various biofluids, study designs, and techniques (such as high-performance liquid chromatography (HPLC)). From 711 articles, blinded screening of 214 articles using Abstrackr^® software, resulted in 24 for final review. Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines were adopted, which included a 24-point checklist. Articles were stratified according to biofluid. Of articles reporting discriminating metabolites between formula- and human milk-fed infants, 62.5% (5/8) of plasma/serum/dried blood spot, 88% (7/8) of urine and 100% (6/6) of feces related articles reported such discriminating metabolites. Overall, no differences were found between analytical approach used (targeted (n = 9) vs. un-targeted (n = 10)). Current articles are limited by small sample sizes and differing methodological approaches. Of the metabolites reviewed herein, fecal metabolites provided the greatest distinction between diets, which may be indicative of usefulness for future diet metabolite-focused work.

Rotavirus A shedding and HBGA host genetic susceptibility in a birth community-cohort, Rio de Janeiro, Brazil, 2014-2018

Recent studies have investigated whether the human histo-blood group antigen (HBGAs) could affect the effectiveness of the oral rotavirus vaccines, suggesting secretor positive individuals develop a more robust response. We investigated the Rotavirus A (RVA) shedding in association with the host susceptibility profile in children from a birth community-cohort in Rio de Janeiro, Brazil, from 2014 to 2018. A total of 132 children were followed-up between 0 to 11-month-old, stool samples were collected before/after the 1st/2nd RV1 vaccination doses and saliva samples were collected during the study. RVA shedding was screened by RT-qPCR and G/P genotypes determined by multiplex RT-PCR and/or Sanger nucleotide sequencing. The sequencing indicated an F167L amino acid change in the RV1 VP8* P[8] in 20.5% of shedding follow-ups and these mutant subpopulations were quantified by pyrosequencing. The HBGA/secretor status was determined and 80.3% of the children were secretors. Twenty-one FUT2 gene SNPs were identified and two new mutations were observed. The mutant F167L RV1 VP8* P[8] was detected significantly more in Le (a+b+) secretors (90.5%) compared to non-secretors and even to secretors Le (a-b+) (9.5%). The study highlights the probable association between RV1 shedding and HBGAs as a marker for evaluating vaccine strain host susceptibility.

The stepwise assembly of the neonatal virome is modulated by breastfeeding

The gut of healthy human neonates is usually devoid of viruses at birth, but quickly becomes colonized, in some cases leading to gastrointestinal disorders^1–4. Here we report that viral community assembly in neonates takes place in distinct steps. Fluorescent staining of virus-like particles purified from infant meconium/early stool samples show few or no particles, but by one month of life particle numbers achieve 10⁹ per gram, and these numbers appear to persist through life^5–7. We investigated the origin of these viral populations using shotgun metagenomic sequencing of viral-enriched preparations and whole microbial communities, and followed up with targeted microbiological analyses. Results indicate that, early after birth, pioneer bacteria colonize the infant gut, and by one month prophage induced from these bacteria provide the predominant population of virus-like particles. By four months of life, identifiable viruses that replicate in human cells become more prominent. Multiple human viruses were more abundant in stool samples from babies exclusively fed formula versus those fed partially or fully on breast milk, paralleling reports that breast milk can be protective against viral infections^8–10. Phage populations also differed associated with breastfeeding. Evidently colonization of the infant gut is stepwise, first mainly by temperate bacteriophages induced from pioneer bacteria, and later by viruses that replicate in human cells, with the second phase modulated by breastfeeding.

Therapeutic effect of Saccharomyces boulardii combined with Bifidobacterium and on cellular immune function in children with acute diarrhea

Clinical effect of Saccharomyces boulardii combined with bifidobacterium and its effect on cellular immune function in children with acute diarrhea were studied. In total 116 cases of children with acute diarrhea admitted to Xuzhou Children's Hospital from March 2015 to March 2017 were collected and analyzed retrospectively. There were 59 children treated with Saccharomyces boulardii as control group and 57 children treated with Saccharomyces boulardii combined with bifidobacterium as experimental group. The clinical effect, stool frequency in different time periods, mean antidiarrheal time, mean antipyretic time and length of stay, and immune function of children in the two groups after treatment were analyzed. The cure rate (73.68%) and the total effective rate (87.72%) in the experimental group were significantly higher than those in the control group (47.46 and 71.19%) (P<0.05). The stool frequency in the experimental group was significantly lower than that in the control group 3 days after treatment (P<0.05). The mean antidiarrheal time in the experimental group was significantly shorter than that in the control group (P<0.05). The length of stay in the control group was significantly longer than that in the experimental group (P<0.05). CD3+, CD4+ and CD4+/CD8+ increased significantly in the experimental group after treatment while CD8+ decreased significantly (P<0.05). After treatment, the ratio of Th1 and Th2 in the two groups decreased significantly compared with before treatment (P<0.05), and the experimental group was significantly lower than the control group (P<0.05). After treatment, Th1/Th2 ratio was significantly higher than that before treatment (P<0.05), and the experimental group was significantly higher than the control group (P<0.05). In conclusion, treatment of acute diarrhea in children with Saccharomyces boulardii combined with bifidobacterium can effectively shorten the duration of diarrhea and hospital stay, reduce the number of diarrhea and enhance the cellular immune function.

Impact of Routine Counseling on Breastfeeding Status in Hospitalized Infants Below 6 Months: Observation From a Large Diarrheal Disease Hospital in Bangladesh

Background. Breastfeeding counseling (BFC) plays a crucial role in improving infant and young child feeding practices. To evaluate the impact of activities of BFC unit (BFCU) on breastfeeding practices of infants who were hospitalized for diarrheal illness through their regular counseling, assistance and support, and motivation. Methods. In this retrospective chart analysis conducted at Dhaka Hospital of icddr,b using an electronic database, data were collected from mothers of infants younger than 6 months of age who visited the BFCU from 2011 to 2015. Results. Among a total of 3420 infants enrolled during study period, 429 (12.5%) were predominantly breastfed, 2457 (71.8%) partially breastfed, 531 (15.5%) non-breastfed, and 3 (0.1%) exclusively breastfed (EBF) at home. Through counseling of BFCU (following 24-hour recall technique), 2212 (65%) infants became EBF and 1186 (35%) failed to be EBF during discharge. Logistic regression analysis after adjusting for potential covariates, such as maternal age <18 years and receiving breast milk with other liquid at home, revealed that infants having severe underweight, maternal perception of “baby does not suck,” and “there is not enough milk” were less likely to be associated with EBF during discharge. Among 531 non-breastfed infants, 455 (85.7%) became partial breastfeeding and only 23 (4.3%) became EBF. Conclusion. Counseling of mothers even during acute illness of infants in the hospital can help promote breastfeeding. Therefore, there is great importance of robust counseling on breastfeeding practices and may help establish re-lactation of acutely ill babies.

Diagnosing and tracing the pathogens of infantile infectious diarrhea by amplicon sequencing

Background

Metagenomic methods have been widely applied to study the relationship between gut microbiota and human health. To test whether metagenomic amplicon sequencing could be an effective method to diagnose and trace the pathogens of infantile infectious diarrhea, the fecal samples of 20 diarrheic and 13 healthy infants were collected. After 16S rDNA amplicon sequencing, diversity analyses were carried out. The relationship between the pathogens of the gut microbiota and geography of patients was analyzed.

Results

The diversity of the gut microbiota in diarrheic infants was significantly lower than that of the gut microbiota in healthy ones and that, the composition of gut microbiota in the diarrheic group was significantly different than that of the gut microbiota in the healthy group. The results also indicated that in some of the patients, the amounts of Escherichia coli were significantly increased in the diarrheic infants, which was in agreement with the result of the qPCR analysis. Using a geographical map, we found some patterns between pathogen source and geographical location. This is helpful for an early warning of the disease.

Conclusions

The method of using high-throughput DNA sequencing and a comprehensive and deep data analysis can be a new strategy to detect and trace pathogens in infantile infectious diarrhea.

Trial registration Diagnosing and tracing the pathogens of infantile infectious diarrhea by amplicon sequencing, ChiCTR-DDD-1701088, Registered 16 March 2017-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=18477

Enteric Pathogen Diversity in Infant Foods in Low-Income Neighborhoods of Kisumu, Kenya

Pediatric diarrheal disease remains the second most common cause of preventable illness and death among children under the age of five, especially in low and middle-income countries (LMICs). However, there is limited information regarding the role of food in pathogen transmission in LMICs. For this study, we examined the frequency of enteric pathogen occurrence and co-occurrence in 127 infant weaning foods in Kisumu, Kenya, using a multi-pathogen PCR diagnostic tool, and assessed household food hygiene risk factors for contamination. Bacterial, viral, and protozoan enteric pathogen DNA and RNA were detected in 62% of the infant weaning food samples collected, with 37% of foods containing more than one pathogen type. Multivariable generalized linear mixed model analysis indicated type of infant food best explained the presence and diversity of enteric pathogens in infant food, while most household food hygiene risk factors considered in this study were not significantly associated with pathogen contamination. Specifically, cow’s milk was significantly more likely to contain a pathogen (adjusted risk ratio = 14.4; 95% confidence interval (CI) 1.78–116.1) and more likely to have higher number of enteric pathogen species (adjusted risk ratio = 2.35; 95% CI 1.67–3.29) than porridge. Our study demonstrates that infants in this low-income urban setting are frequently exposed to diarrhoeagenic pathogens in food and suggests that interventions are needed to prevent foodborne transmission of pathogens to infants.