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Published on Leave a comment on Breast Milk Transmits Important Bacteria to the Infant Gut Microbiome
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

It has long been known that breast milk contains hundreds of microbial species (the milk microbiome), which help seed the infant's gut microbiome. Over the weeks and months of breast feeding, the microbial species in the milk change. All this is normal and good.

A recent study of human breast milk examined the species in breast milk and found that that the species could be viewed as a microbial ecosystem - one that is important in helping seed the infant's gut. The milk contained species that are considered beneficial (e.g., Bifidobacterium), but also some that can be viewed as not beneficial (e.g., E.coli). The milk was from healthy mother-infant pairs, so it was clear that this variety was normal.

Researchers analyzed 507 breast milk and infant stool samples from 195 healthy mother-infant pairs at one, three, and six months postpartum. They found characteristic mixes of bacteria dominated by Bifidobacteria (especially B. longum, B. breve, and B. bifidum). More than half of the milk samples contained B. longum, and that same species was abundant in over 98% of the infants' gut microbiomes.

The paper mentioned that numerous times they found the exact same bacterial strain in both the mother and infant pairs - thus evidence that the mothers transmitted that bacteria to the babies in the breast milk (this is referred to as vertical transmission).

From Medical Xpress: Breast milk microbes help shape infants' gut microbiomes, study finds

Most conversations about breast milk tend to focus on topics like nutrients, antibodies and bonding time rather than bacteria. But it turns out that human milk carries its own tiny community of microbes, and those passengers may help shape a baby's developing gut microbiome—which in turn can impact nutrient absorption, metabolic regulation, immune system development, and more. ...continue reading "Breast Milk Transmits Important Bacteria to the Infant Gut Microbiome"

Published on Leave a comment on Breast Milk Can Contain Traces of Pesticides and Other Chemicals
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

Breast milk is considered the best food for infants, but it can be contaminated with chemicals the mother is exposed to in daily life.

A group of scientists analyzed samples of breast milk from nursing mothers in Canada and South Africa for contaminants and found low levels of pesticides, parabens (endocrine disruptors in plastics), and bisphenols, including bisphenol A and S (endocrine disruptor) in many of the samples.

They published several research papers with their findings. They found contaminants, but at different levels, in the 594 breast milk samples of Canadians and South African women. Unfortunately, all breast milk samples showed some contamination - which can occur from personal care products, the packaging used in foods, in medications, household cleaning products, or even as a food additive.

For example, methyl paraben was detected in 96% of the Canadian human milk samples, followed by ethyl paraben (57%) and propyl paraben (37%). The pesticide propanil (an herbicide) was detected exclusively in South African breast milk samples, as was the antiretroviral drug Efavirenz used in HIV treatment.

BOTTOM LINE: The researchers stress that breast milk is the best food (the gold standard) for infants, but women should realize that chemicals they are exposed to do get into breastmilk. Therefore, try to avoid pesticides, read ingredient labels, and try to minimize exposure to harmful chemicals.

From Newsweek: Scientists Discover Pesticide Traces in Breast Milk

Researchers at McGill University have identified several unexpected chemical contaminants in human milk, finding traces of pesticides, antimicrobials and additives used in plastics and personal‑care products.

The team said the data, drawn from Canadian and South African samples, could help strengthen chemical safety regulations and improve protections for infants and parents. ...continue reading "Breast Milk Can Contain Traces of Pesticides and Other Chemicals"

Published on Leave a comment on Large Study Finds That Breastfed Babies Less Likely To Die In Their First Year
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

Breast milk is beneficial a number of ways. For example, it provides some micronutrients to the baby that formula doesn't provide. It also transmits hundreds of microbial species from the mother to the baby - thus important for the baby's microbiome.

Additionally, recent research found that breastfed babies are 33% less likely to die in the first year of life. This is a huge difference! The researchers looked at data for nearly 10 million infants born in 2016 to 2018, and who were then followed for 1 year after birth.

Studies also find that breastfeeding protects against sudden infant death syndrome and necrotizing enterocolitis in preterm infants.

Bottom line: Breastfeeding should be supported and encouraged. As the study researchers point out: "breastfeeding confers a protective benefit during the first year of life".

From Science Daily: Breastfeeding is associated with a 33% reduction in first-year post-perinatal infant mortality

Among nearly 10 million US infants born between 2016 and 2018, breastfed babies were 33% less likely to die during the post-perinatal period (day 7-364) than infants who were not breastfed, reports a new study in the American Journal of Preventive Medicine, published by Elsevier. The findings build on previous US research with smaller datasets, which documented the association between the initiation of breastfeeding and the reduction of post-perinatal infant mortality by a range of 19% to 26%. ...continue reading "Large Study Finds That Breastfed Babies Less Likely To Die In Their First Year"

Published on Leave a comment on Breast Milk Contains Important Micronutrient For Brain Development
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

Another new micronutrient has been discovered in breast milk. This is a sugar molecule called myo-inositol that promotes brain development in infants.

Researchers found that this sugar molecule is most abundant in human breastmilk early after birth when neuronal connections are rapidly forming in the infant brain. Three weeks after birth the levels found in breast milk slowly start to decrease.

This micronutrient was found in breast milk from women at all three study sites (Mexico City, Shanghai, and Cincinnati) - and at similar levels. The researchers stated that this could be one of the reasons why breast milk is so beneficial for a baby's brain development.

Interestingly, adults get myo-inositol from foods, with an adult eating a Western diet getting about 1 gram per day. It is also produced in the brain and other organs. It is especially abundant in fruits (e.g., cantaloupe and oranges), beans, grains, and nuts.

From Medical Xpress: Sugar molecule found in breast milk boosts infant brain development

Breast milk is not simply sustenance. It also is rich in micronutrients that are critical for healthy brain development in infants. ...continue reading "Breast Milk Contains Important Micronutrient For Brain Development"

Published on Leave a comment on Amniotic Fluid is Flavored by the Foods the Pregnant Woman Eats

The possibility of amniotic fluid being flavored by the foods a mother eats is wild! Makes sense, but it is not something normally mentioned anywhere. It turns out that in the last few years a few studies were published that looked at foods flavoring the amniotic fluid and breast milk, and which later influence the flavors and foods a child prefers.

Research finds that at least some of the foods (e.g., alcohol, anise, carrot, garlic) that a mother eats during pregnancy flavors the amniotic fluid and breast milk, and then these foods or flavors are more accepted during infancy and childhood. During the period a mother breastfeeds, there is evidence babies detect the flavors of alcohol, anise/caraway, carrot, eucalyptus, garlic, mint, a variety of vegetables, peaches, and vanilla. Foods with these flavors appear in breastmilk soon after eating them - within 1 hour!

The few studies done all found greater acceptance and willingness to eat foods in infancy and childhood that had flavors the children were exposed to during pregnancy and/or when nursed. The overall thinking of researchers Spahn and others is that the mother's diet during pregnancy and lactation provides "the earliest opportunity to positively influence child food acceptance and preferences."

Of course the studies are limited in that only a few flavors are looked at in each study. But thinking about it - of course that is how a child accepts new flavors. It's the exposure and getting used to them. Formula always tastes the same, but breast milk varies a little every day! Some researchers suggest that there may be a critical period early in life where exposure to sour and bitter tastes (e.g., broccoli) can be made palatable to the baby. [scroll down to study #3]

These results also support not giving bland and unappetizing single flavor foods in baby jars to babies - instead give them the actual foods the parents are eating! Mash it with a fork, or even use a blender or food mill, but give them the real foods, flavored how the parent likes it. After all, they've already been exposed to those tastes.

The following 3 studies discuss this topic in more detail:

1) A group of researchers reviewed studies related to the topic of the mother's diet during pregnancy and lactation (breastfeeding), amniotic fluid flavor, breast milk flavor, and children's food acceptability. From the American Journal of Clinical Nutrition (2019): Influence of maternal diet on flavor transfer to amniotic fluid and breast milk and children's responses: a systematic review

Limited but consistent evidence indicates that flavors (alcohol, anise, carrot, garlic) originating from the maternal diet during pregnancy can transfer to and flavor amniotic fluid, and fetal flavor exposure increases acceptance of similarly flavored foods when re-exposed during infancy and potentially childhood.  ...continue reading "Amniotic Fluid is Flavored by the Foods the Pregnant Woman Eats"

Published on Leave a comment on The Taste of Breast Milk Varies Depending On Foods Eaten
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

A recent small study confirms what many nursing mothers already suspect - that what the mother eats has an effect on the flavor of breast milk. There has been a lot of anecdotal evidence of the taste of breast milk varying depending on foods eaten, but not much evidence. Earlier studies did find a taste effect from some foods (e.g. carrots, garlic), but not others.

Researchers at the Technical Univ. of Munich investigated whether dominant tastes of a curry dish (red chili, pepper, ginger) were transferred to the breast milk of 16 nursing mothers. They found that one hour after eating a curry dish, the breast milk of nursing mothers contained piperine (from pepper), but not substances from red chili and ginger. And it was still there in breast milk produced hours later.

Interestingly, while the researchers thought that even though the piperine could be detected with laboratory instruments, they doubted it could be tasted by infants. Hmm.. don't know if infants would agree. Humans are incredibly sensitive to tastes and odors. It is thought that early exposure to all sorts of different smells and tastes could have an effect on later food preferences.

Because only piperine (from pepper) was detected and not the other chemicals they looked for (curcumin, capsaicin, 6-gingerol, etc.), the researchers hypothesize that there is a barrier between the mother's circulation and the mammary glands - which only some compounds can cross (such as piperine). This would be comparable to the blood-brain barrier (BBB), which regulates and restricts compounds from getting to the brain.

They point out that caffeine and piperine both can cross the blood-brain barrier, and both have been shown to get into breast milk. [By the way, studies show other compounds also appear in breast milk such as lycopene (from tomatoes).] Bottom line: Eat a variety of foods when nursing.

From Science Daily: Spicy breast milk?

Breast milk is the first food that babies consume. Various studies have suggested that the "taste experience" in early childhood influences eating behavior in adults. Unlike standardized infant formula, natural milk does not taste and smell the same every day. The differences are largely due to the maternal diet.  ...continue reading "The Taste of Breast Milk Varies Depending On Foods Eaten"

Published on Leave a comment on The Bacteria In Breast Milk Change Over Time
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

For years it has been known that breast milk transfers hundreds of microbial species to the baby -  which is very important and beneficial for the baby's microbiome (community of fungi, viruses, bacteria, and other microbes) and health. A recent study found that the bacteria in breast milk varies over time, which is a good reason to breastfeed for at least 6 months - the baby ingests all these beneficial species in the breast milk.

Breast milk samples were collected from 76 breastfeeding (lactating) mothers living in 8 villages in the remote Western Highlands of Guatemala during "early lactation" (6–46 days postpartum) or after months of breastfeeding or "late lactation" (109 to184 days postpartum). Modern technologies (genetic sequencing) were used to analyze the breast milk.

The researchers found a bacterial or microbiome shift from Staphylococcus and several Streptococcus species in early lactation to Sphingobium and Pseudomonas species in late lactation, along with other bacterial shifts. The changing bacterial species have different roles in the body. There were even species never before reported in breast milk, such as: Janthinobacterium agaricidamnosum, Novosphingobium clariflavumm, Ottowia beijingensis, and Flavobacterium cucumis.

Of course much is still unknown about the breastmilk microbiome, and even what is a "core" breast milk microbiome - that is, what species are the core species in all breast milk. But it's clear what the baby gets from the breast milk changes over time.  It's still early days in this research!

Note that all these hundreds of species are not those found in probiotic supplements or formula - a baby must breastfeed to get them. Unfortunately, it is estimated that only 26% of North American mothers breastfeed their babies for at least 6 months (Unicef data).

From Futurity: Breast Milk Offers Different Bacteria Over Time

This bacterial cocktail could act like a daily booster shot for infant immunity and metabolism. ...continue reading "The Bacteria In Breast Milk Change Over Time"

Published on Leave a comment on After COVID-19 During Pregnancy, Breast Milk Has Antibodies Against The Virus
Breastfeeding
Credit: Wikimedia Commons/ Anton Nosik

Finally some good news for pregnant women who develop a COVID-19 infection during pregnancy (a high-risk situation). According to a recent study, it turns out that in women who had a COVID-19 infection during pregnancy and recovered, their breast milk contains antibodies against the virus. Which get transmitted to the baby during nursing.

This means that the mothers are passing "viral immunity" to their babies, and so the babies are protected from COVID-19.  Yay!

Yes, it was a small study of only 15 women, but a second similar study had similar results. As the researchers point out, this discovery has potential benefits to more than the nursing babies. The antibodies in the breastmilk could benefit others.

By the way, so far there is no evidence that a mother can transmit the virus to her baby through breastmilk. The researchers and others have tested breastmilk and have not found any live virus. All these results suggest that donor breastmilk is safe for babies to consume.

Excerpts from The Scientist: Breastmilk Harbors Antibodies to SARS-CoV-2

Milk from lactating moms may hold potent antibodies to counter SARS-CoV-2 infections, according to a new study of 15 women. All of the samples from women who had recovered from COVID-19 and who were breastfeeding babies at the time had antibodies reactive to the virus’s spike protein, researchers report in the November issue of iScience.  ...continue reading "After COVID-19 During Pregnancy, Breast Milk Has Antibodies Against The Virus"

Published on Leave a comment on Beneficial Effect of Breast Milk On the Baby’s Immune System
Breastfeeding
Wikimedia Commons/ Anton Nosik

There are a lot of health reasons why breast milk is better for a baby then formula, and now another reason can be added to the list. A recent study found that specific immune cells (regulatory T cells) expand more in the first three weeks of life in breastfed human babies - nearly twice as abundant as in formula fed babies.

These cells control the baby's immune response against maternal cells transferred with breast milk and help reduce inflammation. In other words, breast milk is good for the baby's immune system development.

The University of Birmingham researchers also found that specific beneficial bacteria, called Veillonella and Gemella, which support the function of regulatory T cells, are more abundant in the gut of breastfed babies.

Breast milk is considered the best food for infants. It contains a range of complex nutrients, antimicrobial proteins, bacteria, human milk oligosaccharides, and hormones from the mother. Thus it isn't surprising that whether the baby receives breast milk or formula influences the gut microbiome (community of microbes in the gut).

From Science Daily: New insight into why breastfed babies have improved immune systems

Research led by the University of Birmingham and Birmingham Women's and Children's NHS Foundation Trust has revealed new insight into the biological mechanisms of the long-term positive health effects of breastfeeding in preventing disorders of the immune system in later life.  ...continue reading "Beneficial Effect of Breast Milk On the Baby’s Immune System"

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Published on 1 Comment on It Is Normal For Fungi To Be In Breast Milk

Researchers have known for a while that human breast milk contains hundreds of species of bacteria that a baby ingests while feeding. This is good! The bacteria is seeding the baby's gut microbiome (microbial community). A recent study of breast milk from different continents found that breast milk from healthy mothers also contains species of fungi - which is the breast milk mycobiome. What was noteworthy was that some  types of fungi in breast milk were found among breast milk samples from all locations (a fungi "core group"), while other types of fungi varied among breast milk from the different locations and even how the baby was delivered (vaginal or C-section birth).

After analyzing the 80 samples of breast milk (20 from each country: Spain, Finland, South Africa, China) it was found that some fungi were the same in breast milk from the different locations: Malassezia, Davidiella, Sistotrema, and Penicillium, while others were different. Fungi from the genus Cryptococcus were higher in breast milk from women who delivered vaginally (as compared to those who had a C-section).  [Note: Genus ranks above species, but below family, and the written name is capitalized.]

This study confirms the importance of breast milk as a source of microbes (along with many nutrients and protective compounds) to the infant and infant gut. From Science Daily:

Breast milk microbiome contains yeast and fungi: Do these benefit the infant?  ...continue reading "It Is Normal For Fungi To Be In Breast Milk"