Human milk: a source of more life than we imagine
TL;DR: A better understanding of the link between the milk microbiome and health benefit, the potential factors influencing this relationship and whether or not it can be influenced by nutrition is required to open new avenues in the field of pregnancy and lactation.
Abstract: The presence of bacteria in human milk has been acknowledged since the seventies. For a long time, microbiological analysis of human milk was only performed in case of infections and therefore the presence of non-pathogenic bacteria was yet unknown. During the last decades, the use of more sophisticated culture-dependent and -independent techniques, and the steady development of the -omic approaches are opening up the new concept of the ‘milk microbiome’, a complex ecosystem with a greater diversity than previously anticipated. In this review, possible mechanisms by which bacteria can reach the mammary gland (contamination versus active migration) are discussed. In addition, the potential roles of human milk for both infant and maternal health are summarised. A better understanding of the link between the milk microbiome and health benefit, the potential factors influencing this relationship and whether or not it can be influenced by nutrition is required to open new avenues in the field of pregnancy and ...
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TL;DR: The epidemiological, biological and functional evidence that support the physiological role of the respiratory microbiota in the maintenance of human health are discussed.
Abstract: The respiratory tract is a complex organ system that is responsible for the exchange of oxygen and carbon dioxide. The human respiratory tract spans from the nostrils to the lung alveoli and is inhabited by niche-specific communities of bacteria. The microbiota of the respiratory tract probably acts as a gatekeeper that provides resistance to colonization by respiratory pathogens. The respiratory microbiota might also be involved in the maturation and maintenance of homeostasis of respiratory physiology and immunity. The ecological and environmental factors that direct the development of microbial communities in the respiratory tract and how these communities affect respiratory health are the focus of current research. Concurrently, the functions of the microbiome of the upper and lower respiratory tract in the physiology of the human host are being studied in detail. In this Review, we will discuss the epidemiological, biological and functional evidence that support the physiological role of the respiratory microbiota in the maintenance of human health.
745 citations
TL;DR: Recent knowledge about the impacts on infant microbiome assembly is reviewed, preventive and restorative strategies to ameliorate the effects of these impacts are discussed, and where research is needed to advance this field and improve the health of future generations are highlighted.
703 citations
TL;DR: It is proposed that microbes and microbiomegnosy, or knowledge of the authors' gut microbiome, can become a novel source of future therapies as plants and its related knowledge have been the source for designing drugs over the last century.
Abstract: Metabolic disorders associated with obesity and cardiometabolic disorders are worldwide epidemic Among the different environmental factors, the gut microbiota is now considered as a key player interfering with energy metabolism and host susceptibility to several non-communicable diseases Among the next-generation beneficial microbes that have been identified, Akkermansia muciniphila is a promising candidate Indeed, A muciniphila is inversely associated with obesity, diabetes, cardiometabolic diseases and low-grade inflammation Besides the numerous correlations observed, a large body of evidence has demonstrated the causal beneficial impact of this bacterium in a variety of preclinical models Translating these exciting observations to human would be the next logic step and it now appears that several obstacles that would prevent the use of A muciniphila administration in humans have been overcome Moreover, several lines of evidence indicate that pasteurization of A muciniphila not only increases its stability but more importantly increases its efficacy This strongly positions A muciniphila in the forefront of next-generation candidates for developing novel food or pharma supplements with beneficial effects Finally, a specific protein present on the outer membrane of A muciniphila, termed Amuc_1100, could be strong candidate for future drug development In conclusion, as plants and its related knowledge, known as pharmacognosy, have been the source for designing drugs over the last century, we propose that microbes and microbiomegnosy, or knowledge of our gut microbiome, can become a novel source of future therapies
649 citations
Cites background from "Human milk: a source of more life t..."
...So these have to be consumed at some stage and in this context it is important to note that A. muciniphila is present in early life microbiota and has been detected in mothers’ milk (Collado et al., 2007, 2012; Derrien et al., 2008; Jeurink et al., 2013; Ward et al., 2013)....
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...muciniphila is present in early life microbiota and has been detected in mothers’ milk (Collado et al., 2007, 2012; Derrien et al., 2008; Jeurink et al., 2013; Ward et al., 2013)....
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TL;DR: The main factors shaping the infant microbiome—modes of delivery, feeding, weaning, and exposure to antibiotics are reviewed, starting to build a broader understanding of healthy vs. abnormal microbial alterations throughout major developmental time-points.
Abstract: Several healthy developmental processes such as pregnancy, fetal development and infant development include a multitude of physiological changes: weight gain, hormonal and metabolic changes, as well as immune changes. In this review we present an additional important factor which both influences and is affected by these physiological processes- the microbiome. We summarize the known changes in microbiota composition at a variety of body sites including gut, vagina, oral cavity and placenta, throughout pregnancy, fetal development and early childhood. There is still a lot to be discovered; yet several pieces of research point to the healthy desired microbial changes. Future research is likely to unravel precise roles and mechanisms of the microbiota in gestation; perhaps linking the metabolic, hormonal and immune changes together. Although some research has started to link microbial dysbiosis and specific microbial populations with unhealthy pregnancy complications, it is important to first understand the context of the natural healthy microbial changes occurring. Until recently the placenta and developing fetus were considered to be germ free, containing no apparent microbiome. We present multiple study results showing distinct microbiota compositions in the placenta and meconium, alluding to early microbial colonization. These results may change dogmas and our overall understanding of the importance and roles of microbiota from the beginning of life. We further review the main factors shaping the infant microbiome- modes of delivery, feeding, weaning, and exposure to antibiotics. Taken together, we are starting to build a broader understanding of healthy vs. abnormal microbial alterations throughout major developmental time-points.
389 citations
TL;DR: Recent findings regarding gut microbiota establishment are summarized, including the importance of various factors related to the development of the immune system and allergic diseases later in life are summarized.
377 citations
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TL;DR: The faecal microbial communities of adult female monozygotic and dizygotic twin pairs concordant for leanness or obesity, and their mothers are characterized to address how host genotype, environmental exposure and host adiposity influence the gut microbiome.
Abstract: The human distal gut harbours a vast ensemble of microbes (the microbiota) that provide important metabolic capabilities, including the ability to extract energy from otherwise indigestible dietary polysaccharides. Studies of a few unrelated, healthy adults have revealed substantial diversity in their gut communities, as measured by sequencing 16S rRNA genes, yet how this diversity relates to function and to the rest of the genes in the collective genomes of the microbiota (the gut microbiome) remains obscure. Studies of lean and obese mice suggest that the gut microbiota affects energy balance by influencing the efficiency of calorie harvest from the diet, and how this harvested energy is used and stored. Here we characterize the faecal microbial communities of adult female monozygotic and dizygotic twin pairs concordant for leanness or obesity, and their mothers, to address how host genotype, environmental exposure and host adiposity influence the gut microbiome. Analysis of 154 individuals yielded 9,920 near full-length and 1,937,461 partial bacterial 16S rRNA sequences, plus 2.14 gigabases from their microbiomes. The results reveal that the human gut microbiome is shared among family members, but that each person's gut microbial community varies in the specific bacterial lineages present, with a comparable degree of co-variation between adult monozygotic and dizygotic twin pairs. However, there was a wide array of shared microbial genes among sampled individuals, comprising an extensive, identifiable 'core microbiome' at the gene, rather than at the organismal lineage, level. Obesity is associated with phylum-level changes in the microbiota, reduced bacterial diversity and altered representation of bacterial genes and metabolic pathways. These results demonstrate that a diversity of organismal assemblages can nonetheless yield a core microbiome at a functional level, and that deviations from this core are associated with different physiological states (obese compared with lean).
6,970 citations
"Human milk: a source of more life t..." refers background or result in this paper
...It suggests that human milk contains a greater bacterial diversity than previously assumed and it indicates that a ‘core’ microbiome, as described for other bacterial communities in the human body, may also exist in human milk (Ravel et al., 2011; Turnbaugh et al., 2009)....
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...These findings are in contrast with those of the gut, where only a low set of OTUs is shared among individuals (Turnbaugh et al., 2009) or the vaginal microbiome, which comprises several core groups (Ravel et al., 2011)....
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...These findings are in contrast with those of the gut, where only a low set of OTUs is shared among individuals (Turnbaugh et al., 2009) or the vaginal microbiome, which comprises several core groups (Ravel et al....
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TL;DR: Pediatricians play a critical role in their practices and communities as advocates of breastfeeding and thus should be knowledgeable about the health risks of not breastfeeding, the economic benefits to society of breastfeeding, and the techniques for managing and supporting the breastfeeding dyad.
Abstract: Considerable advances have occurred in recent years in the scientific knowledge of the benefits of breastfeeding, the mechanisms underlying these benefits, and in the clinical management of breastfeeding. This policy statement on breastfeeding replaces the 1997 policy statement of the American Academy of Pediatrics and reflects this newer knowledge and the supporting publications. The benefits of breastfeeding for the infant, the mother, and the community are summarized, and recommendations to guide the pediatrician and other health care professionals in assisting mothers in the initiation and maintenance of breastfeeding for healthy term infants and high-risk infants are presented. The policy statement delineates various ways in which pediatricians can promote, protect, and support breastfeeding not only in their individual practices but also in the hospital, medical school, community, and nation.
5,932 citations
TL;DR: The advances in modeling and analysis of gut microbiota will further the authors' knowledge of their role in health and disease, allowing customization of existing and future therapeutic and prophylactic modalities.
Abstract: Gut microbiota is an assortment of microorganisms inhabiting the length and width of the mammalian gastrointestinal tract. The composition of this microbial community is host specific, evolving throughout an individual's lifetime and susceptible to both exogenous and endogenous modifications. Recent renewed interest in the structure and function of this "organ" has illuminated its central position in health and disease. The microbiota is intimately involved in numerous aspects of normal host physiology, from nutritional status to behavior and stress response. Additionally, they can be a central or a contributing cause of many diseases, affecting both near and far organ systems. The overall balance in the composition of the gut microbial community, as well as the presence or absence of key species capable of effecting specific responses, is important in ensuring homeostasis or lack thereof at the intestinal mucosa and beyond. The mechanisms through which microbiota exerts its beneficial or detrimental influences remain largely undefined, but include elaboration of signaling molecules and recognition of bacterial epitopes by both intestinal epithelial and mucosal immune cells. The advances in modeling and analysis of gut microbiota will further our knowledge of their role in health and disease, allowing customization of existing and future therapeutic and prophylactic modalities.
3,077 citations
TL;DR: The inherent differences within and between women in different ethnic groups strongly argues for a more refined definition of the kinds of bacterial communities normally found in healthy women and the need to appreciate differences between individuals so they can be taken into account in risk assessment and disease diagnosis.
Abstract: The means by which vaginal microbiomes help prevent urogenital diseases in women and maintain health are poorly understood. To gain insight into this, the vaginal bacterial communities of 396 asymptomatic North American women who represented four ethnic groups (white, black, Hispanic, and Asian) were sampled and the species composition characterized by pyrosequencing of barcoded 16S rRNA genes. The communities clustered into five groups: four were dominated by Lactobacillus iners, L. crispatus, L. gasseri, or L. jensenii, whereas the fifth had lower proportions of lactic acid bacteria and higher proportions of strictly anaerobic organisms, indicating that a potential key ecological function, the production of lactic acid, seems to be conserved in all communities. The proportions of each community group varied among the four ethnic groups, and these differences were statistically significant [χ(2)(10) = 36.8, P < 0.0001]. Moreover, the vaginal pH of women in different ethnic groups also differed and was higher in Hispanic (pH 5.0 ± 0.59) and black (pH 4.7 ± 1.04) women as compared with Asian (pH 4.4 ± 0.59) and white (pH 4.2 ± 0.3) women. Phylotypes with correlated relative abundances were found in all communities, and these patterns were associated with either high or low Nugent scores, which are used as a factor for the diagnosis of bacterial vaginosis. The inherent differences within and between women in different ethnic groups strongly argues for a more refined definition of the kinds of bacterial communities normally found in healthy women and the need to appreciate differences between individuals so they can be taken into account in risk assessment and disease diagnosis.
2,848 citations
"Human milk: a source of more life t..." refers background or result in this paper
...It suggests that human milk contains a greater bacterial diversity than previously assumed and it indicates that a ‘core’ microbiome, as described for other bacterial communities in the human body, may also exist in human milk (Ravel et al., 2011; Turnbaugh et al., 2009)....
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..., 2009) or the vaginal microbiome, which comprises several core groups (Ravel et al., 2011)....
[...]
...These findings are in contrast with those of the gut, where only a low set of OTUs is shared among individuals (Turnbaugh et al., 2009) or the vaginal microbiome, which comprises several core groups (Ravel et al., 2011)....
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TL;DR: The results indicate that the microbiota, although personalized, varies systematically across body habitats and time; such trends may ultimately reveal how microbiome changes cause or prevent disease.
Abstract: Elucidating the biogeography of bacterial communities on the human body is critical for establishing healthy baselines from which to detect differences associated with diseases. To obtain an integrated view of the spatial and temporal distribution of the human microbiota, we surveyed bacteria from up to 27 sites in seven to nine healthy adults on four occasions. We found that community composition was determined primarily by body habitat. Within habitats, interpersonal variability was high, whereas individuals exhibited minimal temporal variability. Several skin locations harbored more diverse communities than the gut and mouth, and skin locations differed in their community assembly patterns. These results indicate that our microbiota, although personalized, varies systematically across body habitats and time; such trends may ultimately reveal how microbiome changes cause or prevent disease.
2,839 citations
"Human milk: a source of more life t..." refers background or result in this paper
...Human milk microbiota, as any other ecological niche in the human microbiome, is not thought to be an isolated environment, but rather a network of interrelated communities (Costello et al., 2009)....
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...…microbial community in human milk was stable over time within an individual, which is in line with another study that showed that the microbial communities of various sites of the human microbiome in a particular individual are highly personalised and often stable over time (Costello et al., 2009)....
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...Interestingly, the microbial community in human milk was stable over time within an individual, which is in line with another study that showed that the microbial communities of various sites of the human microbiome in a particular individual are highly personalised and often stable over time (Costello et al., 2009)....
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