Living close to green space benefits gut bacteria of urban, formula-fed infants

July 9, 2020

Science Daily/University of Alberta Faculty of Medicine & Dentistry

Living close to natural green space can mitigate some of the changes in infant gut bacteria associated with formula feeding, according to new research published in the journal Environment International.

"Not every infant can be breastfed," said Anita Kozyrskyj, pediatrics professor at the University of Alberta. "This is one of the first pieces of evidence for a nature-related intervention that could possibly help promote healthy gut microbial composition in infants who are not breastfed."

"We consider breastfeeding to be the desirable state, and we know that a breastfed infant is at reduced likelihood of many conditions later in life -- for example, developing respiratory infections and becoming overweight," said Kozyrskyj, who is principal investigator for SyMBIOTA, a research team that studies how changes in infant gut microbiota can lead to the development of obesity, allergies and asthma in children.

The researchers examined fecal samples taken during routine home visits from 355 four-month-old infants who are part of the CHILD Cohort Study -- a national study that is following nearly 3,500 Canadian children from before birth to adolescence with the goal of discovering root causes of allergies, asthma and chronic disease.

The babies' postal codes were then cross-referenced with the City of Edmonton's urban Primary Land and Vegetation Inventory (uPLVI), which maps natural green spaces in the city, including natural forest, grasslands, wetlands, lakes, rivers and ravines.

"We found that the infants who lived within 500 metres of a natural environment were less likely to have higher diversity in their gut bacteria," she said. "It may seem counterintuitive, but a young breastfed infant has lower gut microbial diversity than a formula-fed infant because formula feeding increases the number of different gut bacteria."

The results applied only to infants living close to natural spaces, regardless of whether there was a human-made park in the neighbourhood.

The researchers found the greatest association was for formula-fed infants living in a home with a pet. Though the exact mechanism is not understood, they hypothesize that families who walk their dog may use natural areas more often, or that pets may bring healthy bacteria into the home on their fur.

"We know that when you introduce a pet into the home, it does change the types of microbes that are found in household dust," Kozyrskyj pointed out.

The researchers found that 54 per cent of the infants lived close to a natural environment and 18 per cent of the babies were exclusively formula-fed. Nine per cent were both formula-fed and had pets in the home. The results were adjusted for the type of delivery (caesarean section or natural), the season, and the age and education level of the mothers.

They did not distinguish between the type of pets the families owned, but Kozyrskyj said, "We think it's a dog effect."

"Even if you live in a highrise, if you have a dog you go out and use the natural spaces near your home. It's likely that the pet is the conduit."

The researchers reported an increased presence of Proteobacteria -- the type of bacteria more often found in nature -- in the guts of all of the babies.

While numerous studies have examined the impact of living close to natural green spaces on the skin and gut microbiota of adults, this is the first study to cross-reference proximity to natural green spaces with the gut bacteria of infants.

"We had this wonderful opportunity for data linkage between the unique natural assets map, the home locations of infants in the CHILD birth cohort and information on the composition of their gut bacteria," Kozyrskyj said.

Kozyrskyj said the research team included a geographer, a city planner, pediatrics and obstetrics specialists, and international environmental and microbiome scientists.

"It takes an interdisciplinary team to do this kind of research," she said. "That's what made the project so rich in terms of the interpretation of the results and the kinds of questions that could be asked."

Kozyrskyj said the next step for this research will be to follow the formula-fed infants who are exposed to natural areas throughout childhood and track the impact on their health.

She said she often receives emails from new mothers who are unable to breastfeed and are concerned about their children's futures. Based on these results, she will now advise them to take their babies out to natural areas and consider getting a pet.

The research was funded by the Canadian Institutes of Health Research, the Allergy, Genes and Environment (AllerGen) Networks of Centres of Excellence, the Stollery Children's Hospital Foundation through the Women and Children's Health Research Institute and the Spanish Ministry of Science and Innovation.

https://www.sciencedaily.com/releases/2020/07/200709135616.htm

Marijuana found in breast milk up to six days after use

Researchers report 63 percent of breast milk samples from mothers using marijuana contained traces of the drug

August 27, 2018

Science Daily/University of California - San Diego

To better understand how much marijuana or constituent compounds actually get into breast milk and how long it remains, researchers conducted a study.

With the legalization of marijuana in several states, increased use for both medicinal and recreational purposes has been documented in pregnant and breastfeeding women. Although national organizations like the American Academy of Pediatrics recommend that breastfeeding mothers do not use marijuana, there has been a lack of specific data to support health or neurodevelopmental concerns in infants as a result of exposure to tetrahydrocannabinol (THC) or other components of marijuana via breast milk.

To better understand how much marijuana or constituent compounds actually get into breast milk and how long it remains, researchers at University of California San Diego School of Medicine conducted a study, publishing online August 27 in Pediatrics.

Fifty-four samples from 50 women who used marijuana either daily, weekly or sporadically -- with inhalation being the primary method of intake -- were examined. Researchers detected THC, the primary psychoactive component of marijuana, in 63 percent of the breast milk samples for up to six days after the mother's last reported use.

"Pediatricians are often put into a challenging situation when a breastfeeding mother asks about the safety of marijuana use. We don't have strong, published data to support advising against use of marijuana while breastfeeding, and if women feel they have to choose, we run the risk of them deciding to stop breastfeeding -- something we know is hugely beneficial for both mom and baby," said Christina Chambers, PhD, MPH, principal investigator of the study, professor in the Department of Pediatrics at UC San Diego School of Medicine and director of clinical research at Rady Children's Hospital-San Diego.

The World Health Organization recommends exclusive breastfeeding for up to six months. Early breastfeeding is associated with a reduced risk of obesity, asthma and sudden infant death syndrome and with improved immune health and performance on intelligence tests. In mothers, breastfeeding has been associated with lower risks for breast and uterine cancer and type 2 diabetes.

Cannabinoids -- marijuana's active compounds, such as THC -- like to bind to fat molecules, which are abundant in breast milk. This stickiness has suggested that, in women who use marijuana, these compounds can end up in breast milk, raising concerns about their potential effects on nursing babies.

"We found that the amount of THC that the infant could potentially ingest from breast milk was relatively low, but we still don't know enough about the drug to say whether or not there is a concern for the infant at any dose, or if there is a safe dosing level," said Chambers, co-director of the Center for Better Beginnings at UC San Diego. "The ingredients in marijuana products that are available today are thought to be much more potent than products available 20 or 30 years ago."

The samples of breast milk used for the study were obtained from mothers who joined the Mommy's Milk Human Milk Research Biorepository at UC San Diego, a program that focuses on looking at the numerous benefits of breast milk at the molecular level. Chambers and her research team collaborated with Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego to measure the levels of marijuana in the samples.

Chambers said the results are a stepping stone for future research. More studies need to be done, not only to determine the long-term impact of marijuana in breast milk for children, but more specifically: "Are there any differences in effects of marijuana in breast milk for a two-month-old versus a 12-month-old, and is it different if the mother smokes versus eats the cannabis? These are critical areas where we need answers as we continue to promote breast milk as the premium in nutrition for infants."

https://www.sciencedaily.com/releases/2018/08/180827080911.htm