What's normal? Oligosaccharide concentrations and profiles in milk produced by healthy women vary geographically.

Background: Human milk is a complex fluid comprised of myriad substances, with one of the most abundant substances being a group of complex carbohydrates referred to as human milk oligosaccharides (HMOs). There has been some evidence that HMO profiles differ in populations, but few studies have rigorously explored this variability.Objectives: We tested the hypothesis that HMO profiles differ in diverse populations of healthy women. Next, we examined relations between HMO and maternal anthropometric and reproductive indexes and indirectly examined whether differences were likely related to genetic or environmental variations.Design: In this cross-sectional, observational study, milk was collected from a total of 410 healthy, breastfeeding women in 11 international cohorts and analyzed for HMOs by using high-performance liquid chromatography.Results: There was an effect of the cohort (P 4 times higher in milk collected in Sweden than in milk collected in rural Gambia (mean ± SEM: 473 ± 55 compared with 103 ± 16 nmol/mL, respectively; P < 0.05), and disialyllacto-N-tetraose (DSLNT) concentrations ranged from 216 ± 14 nmol/mL (in Sweden) to 870 ± 68 nmol/mL (in rural Gambia) (P < 0.05). Maternal age, time postpartum, weight, and body mass index were all correlated with several HMOs, and multiple differences in HMOs [e.g., lacto-N-neotetrose and DSLNT] were shown between ethnically similar (and likely genetically similar) populations who were living in different locations, which suggests that the environment may play a role in regulating the synthesis of HMOs.Conclusions: The results of this study support our hypothesis that normal HMO concentrations and profiles vary geographically, even in healthy women. Targeted genomic analyses are required to determine whether these differences are due at least in part to genetic variation. A careful examination of sociocultural, behavioral, and environmental factors is needed to determine their roles in this regard. This study was registered at clinicaltrials.gov as NCT02670278

Comparison of Two Approaches for the Metataxonomic Analysis of the Human Milk Microbiome.

Recent work has demonstrated the existence of large inter-individual and inter-population variability in the microbiota of human milk from healthy women living across variable geographical and socio-cultural settings. However, no studies have evaluated the impact that variable sequencing approaches targeting different 16S rRNA variable regions may have on the human milk microbiota profiling results. This hampers our ability to make meaningful comparisons across studies. In this context, the main purpose of the present study was to re-process and re-sequence the microbiome in a large set of human milk samples (n = 412) collected from healthy women living at diverse international sites (Spain, Sweden, Peru, United States, Ethiopia, Gambia, Ghana and Kenya), by targeting a different 16S rRNA variable region and reaching a larger sequencing depth. Despite some differences between the results obtained from both sequencing approaches were notable (especially regarding alpha and beta diversities and Proteobacteria representation), results indicate that both sequencing approaches revealed a relatively consistent microbiota configurations in the studied cohorts. Our data expand upon the milk microbiota results we previously reported from the INSPIRE cohort and provide, for the first time across globally diverse populations, evidence of the impact that different DNA processing and sequencing approaches have on the microbiota profiles obtained for human milk samples. Overall, our results corroborate some similarities regarding the microbial communities previously reported for the INSPIRE cohort, but some differences were also detected. Understanding the impact of different sequencing approaches on human milk microbiota profiles is essential to enable meaningful comparisons across studies. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT02670278

Key genetic variants associated with variation of milk oligosaccharides from diverse human populations

Human milk oligosaccharides (HMO), the third most abundant component of human milk, are thought to be important contributors to infant health. Studies have provided evidence that geography, stage of lactation, and Lewis and secretor blood groups are associated with HMO profile. However, little is known about how variation across the genome may influence HMO composition among women in various populations. In this study, we performed genome-wide association analyses of 395 women from 8 countries to identify genetic regions associated with 19 different HMO. Our data support FUT2 as the most significantly associated (P < 4.23-9 to P < 4.5-70) gene with seven HMO and provide evidence of balancing selection for FUT2. Although polymorphisms in FUT3 were also associated with variation in lacto-N-fucopentaose II and difucosyllacto-N-tetrose, we found little evidence of selection on FUT3. To our knowledge, this is the first report of the use of genome-wide association analyses on HMO

Variation in Human Milk Composition Is Related to Differences in Milk and Infant Fecal Microbial Communities.

Previously published data from our group and others demonstrate that human milk oligosaccharide (HMOs), as well as milk and infant fecal microbial profiles, vary by geography. However, little is known about the geographical variation of other milk-borne factors, such as lactose and protein, as well as the associations among these factors and microbial community structures in milk and infant feces. Here, we characterized and contrasted concentrations of milk-borne lactose, protein, and HMOs, and examined their associations with milk and infant fecal microbiomes in samples collected in 11 geographically diverse sites. Although geographical site was strongly associated with milk and infant fecal microbiomes, both sample types assorted into a smaller number of community state types based on shared microbial profiles. Similar to HMOs, concentrations of lactose and protein also varied by geography. Concentrations of HMOs, lactose, and protein were associated with differences in the microbial community structures of milk and infant feces and in the abundance of specific taxa. Taken together, these data suggest that the composition of human milk, even when produced by relatively healthy women, differs based on geographical boundaries and that concentrations of HMOs, lactose, and protein in milk are related to variation in milk and infant fecal microbial communities

Corrigendum: What's Normal? Microbiomes in Human Milk and Infant Feces Are Related to Each Other but Vary Geographically: The INSPIRE Study

A correction has been made to the Materials and Methods section, subsection Extraction of DNA fromMilk, paragraph 2, The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated

What's Normal? Microbiomes in Human Milk and Infant Feces Are Related to Each Other but Vary Geographically: The INSPIRE Study

Background: Microbial communities in human milk and those in feces from breastfed infants vary within and across populations. However, few researchers have conducted cross-cultural comparisons between populations, and little is known about whether certain “core” taxa occur normally within or between populations and whether variation in milk microbiome is related to variation in infant fecal microbiome. The purpose of this study was to describe microbiomes of milk produced by relatively healthy women living at diverse international sites and compare these to the fecal microbiomes of their relatively healthy infants. Methods: We analyzed milk (n = 394) and infant feces (n = 377) collected from mother/infant dyads living in 11 international sites (2 each in Ethiopia, The Gambia, and the US; 1 each in Ghana, Kenya, Peru, Spain, and Sweden). The V1-V3 region of the bacterial 16S rRNA gene was sequenced to characterize and compare microbial communities within and among cohorts. Results: Core genera in feces were Streptococcus, Escherichia/Shigella, and Veillonella, and in milk were Streptococcus and Staphylococcus, although substantial variability existed within and across cohorts. For instance, relative abundance of Lactobacillus was highest in feces from rural Ethiopia and The Gambia, and lowest in feces from Peru, Spain, Sweden, and the US; Rhizobium was relatively more abundant in milk produced by women in rural Ethiopia than all other cohorts. Bacterial diversity also varied among cohorts. For example, Shannon diversity was higher in feces from Kenya than Ghana and US-California, and higher in rural Ethiopian than Ghana, Peru, Spain, Sweden, and US-California. There were limited associations between individual genera in milk and feces, but community-level analyses suggest strong, positive associations between the complex communities in these sample types. Conclusions: Our data provide additional evidence of within- and among-population differences in milk and infant fecal bacterial community membership and diversity and support for a relationship between the bacterial communities in milk and those of the recipient infant's feces. Additional research is needed to understand environmental, behavioral, and genetic factors driving this variation and association, as well as its significance for acute and chronic maternal and infant health

Comparison Between Fluorescent In Situ Hybridization (FISH) and Culture Method in the Detection of Pasteurella multocida in Organs of Indigenous Birds

A total of forty-eight indigenous birds were intratracheally infected with Pasteurella multocida, paired and sacrificed at specified times. Seven organs from each of the four pairs were swabbed for culture and tissues taken for FISH test to detect the presence of the bacterium in these birds. Oropharyngeal and cloacal swabs were collected, for culture method and bacteria characterized by biochemical tests. While for FISH test, tissues were processed for histology after fixation in formalin for 24 hours and later preserved in 70% alcohol before in situ hybridization test. At any sacrificial time between 1hour and 14 days post inoculation P. multocida FISH signals were observed in 47 to 75% while the bacterium was isolated on culture in 7 to 50% of the organs of the indigenous birds. During the same period four (lung, trachea/oropharynx, liver and spleen) organs on FISH test and one (trachea/oropharynx) on culture were throughout positive for P. multocida. The large intestine/cloaca and pruning gland showed P. multocida FISH signals at various times but were negative for the bacterium on culture. Both tests were positive for P. multocida immediately after inoculation. FISH signals were found in a decreasing manner in the lung, trachea/oropharynx, liver, spleen, caecal tonsils, large intestine/cloaca, and pruning gland. On culture, the bacteria were found in a decreasing manner in the trachea/oropharynx, lung, spleen, liver and caecal tonsils. Most cultured isolates were made between 1 - 24 hours, few and intermittent ones thereafter, and none at all after the 10th day post infection. These results show that FISH test is more sensitive than the culture method for detection of P. multocida in tissues of infected birds. The Kenya Veterinarian Vol. 29 2005: pp. 53-5

Comparison of the Carrier Status of P. multocida Between Farm and Live Market Indigenous Birds

A total of one hundred and seventy one indigenous birds from smallholder farms and those traded in market centers in Nairobi were examined for the presence of Pasteurella multocida. Of these, 135 were farmed and 36 were market birds. They comprised of 117 indigenous chickens and 54 ducks. Three hundred and forty two oropharyngeal and cloacal swabs were collected from them and cultured onto blood agar and other media. The recovered isolates were characterized using colonial morphology, biochemical and other tests. Twenty three P. multocida isolates were recovered: 11/135 (8%) from farm and 12/36 (33%) from the market birds. Majority of the P. multocida isolates were Pasteurella multocida gallicida 11/23 (48%), followed by Pasteurella multocida multocida 7/23 (30%) and Pasteurella multocida septica 5/23 (22%). Pasteurella multocida gallicida isolates were encountered more in the market birds, while Pasteurella multocida multocida isolates were more in farm birds. Ducks had more isolates than chickens. The concentration of the birds at market areas appeared to favor the maintenance of P. multocida in the cages, crates and pens. Market birds may, therefore, play a major role in the spreading of P. multocida. The Kenya Veterinarian Vol. 29 2005: pp. 45-4

Pasteurella multocida in scavenging family chickens and ducks:Carrier status, age susceptibility and transmission between species

International audience<i>Pasteurella multocida</i> causes fowl cholera, a highly contagious and severe disease in chicken and water fowls. The disease is not well described in less intensive production systems, including scavenging family poultry production in developing countries. <i>P. multocida</i> was isolated from 25.9 % of healthy looking ducks and 6.2 % of chickens from free range family poultry farms and at slaughter slabs at marked. On experimental infection with 1.2 –2.0 x 108 organisms of the <i>P. multocida</i> type strain (NCTC 10322T), 12 week-old chickens expressed fowl cholera clinical signs significantly more times (372) than those of 4, 8 and 16 week chicken (173, 272, 187) and more signs were severe. In family ducks the 8 week-old birds expressed clinical signs significantly more times (188) than those of other age groups (117, 80, and 83) and severe signs were more frequent. <i>P. multocida</i> transmitted from seeder birds (n=12) to sentinel birds (n=30), which developed clinical signs, and in some cases lesions of fowl cholera and allowed bacterial re-isolation, whether infected ducks served as seeder for chicken or chicken served as seeder for ducks. This study has documented the occurrence of <i>P. multocida</i> among healthy-appearing family poultry in tropical setting, and demonstrated that age susceptibility is highest in 12 week old family chicken and 8 week old family ducks when challenged with a low virulent strain of <i>P. multocida</i>. It has further demonstrated that cross transmission of fowl cholera may happen between family ducks and chickens and vice versa

Multipathogen Analysis of IgA and IgG Antigen Specificity for Selected Pathogens in Milk Produced by Women From Diverse Geographical Regions:The INSPIRE Study

Breastfeeding provides defense against infectious disease during early life. The mechanisms underlying this protection are complex but likely include the vast array of immune cells and components, such as immunoglobulins, in milk. Simply characterizing the concentrations of these bioactives, however, provides only limited information regarding their potential relationships with disease risk in the recipient infant. Rather, understanding pathogen and antigen specificity profiles of milk-borne immunoglobulins might lead to a more complete understanding of how maternal immunity impacts infant health and wellbeing. Milk produced by women living in 11 geographically dispersed populations was applied to a protein microarray containing antigens from 16 pathogens, including diarrheagenic E. coli, Shigella spp., Salmonella enterica serovar Typhi, Staphylococcus aureus, Streptococcus pneumoniae, Mycobacterium tuberculosis and other pathogens of global health concern, and specific IgA and IgG binding was measured. Our analysis identified novel disease-specific antigen responses and suggests that some IgA and IgG responses vary substantially within and among populations. Patterns of antibody reactivity analyzed by principal component analysis and differential reactivity analysis were associated with either lower-to-middle-income countries (LMICs) or high-income countries (HICs). Antibody levels were generally higher in LMICs than HICs, particularly for Shigella and diarrheagenic E. coli antigens, although sets of S. aureus, S. pneumoniae, and some M. tuberculosis antigens were more reactive in HICs. Differential responses were typically specific to canonical immunodominant antigens, but a set of nondifferential but highly reactive antibodies were specific to antigens possibly universally recognized by antibodies in human milk. This approach provides a promising means to understand how breastfeeding and human milk protect (or do not protect) infants from environmentally relevant pathogens. Furthermore, this approach might lead to interventions to boost population-specific immunity in at-risk breastfeeding mothers and their infants