Scientists say probiotic may protect newborns from PBDEs in breastmilk and food

A recent study finds that maternal supplementation with the probiotic L. reuteri mitigates the harmful effects of perinatal exposure to a widely used toxic chemical in mouse offspring. The research team says the mechanism of action likely works by promoting gut microbiome health and diversity.

Nutrition Insight speaks to researchers from the University of California, Riverside (UCR), US, to learn how the damaging effects of polybrominated diphenyl ethers (PBDEs) can be countered while revealing affordable solutions for those socioeconomically disadvantaged.

The fire-retardant chemical is found “everywhere,” including upholstery, carpets, curtains, electronics and infant products. It is known to disrupt hormones and persist in the environment. Research has shown it has been detected in human tissues, breast milk, animals, foods, water and air.

The study’s lead author, Margarita Curras-Collazo, professor of Neuroscience, tells us: “Although information is lacking about this, a healthy gut microbiota has beneficial effects on the activity of the immune system and on thyroid function, two factors that are critical for normal development and that are targeted by PBDEs.” 

“Therefore, the gut microbiome may offset harmful effects of PBDEs on development. There is another way that the gut microbiota may act. Resident microbiota have been shown to reduce absorption and improve degradation of endocrine- and metabolic-disrupting toxicants such as pesticides and bisphenol A, a major component of polycarbonate plastics. However, studies are needed to test whether the same effects of microbiota can occur against PBDE exposure.”

Lactobacillus offers promising solution

The study is published in the Archives of Toxicology and Curras-Collazo suggests that gut bacteria may hold the key to solving neurological issues based on mouse tests.

Curras-Collazo suggests that by learning more about how gut bacteria impact the nervous system, we might be able to find ways to treat neurological and other illnesses and enhance neural and metabolic processes. Her team has previously found that mice exposed to PBDEs during the perinatal period resulted in autistic-like behavior and metabolism syndrome in mice. “Our newest findings indicate that maternal probiotic supplementation can mitigate toxicant-induced reprogramming of development, adult neurobehavior, and glucose metabolism in a sex-dependent manner. These changes were associated with modified gut microbial community structure,” she shares.

“The role of gut microbiota has emerged as a potential target for the treatment of neurodegenerative diseases and neurodevelopmental disorders. Several lactobacillus strains, including L. reuteri have been moderately effective in treating (symptomatic management) children’s neurodevelopmental disorders, such as ASD and ADHD, which have strong links with gastrointestinal disturbances.”

She adds: “These bacteria produce lactic acid that can act on enteric neurons to influence metabolites that stimulate the ‘gut-brain-axis’ to alter neural circuits, brain function and behavior. Abnormal brain lactate levels have been associated with ASD and ADHD neuropathologies. Ingested toxicants such as PBDEs and pesticides can produce an imbalance in the microorganisms that live in the gut that may, then, alter the signaling from the gut to the brain, leading to behavioral and metabolic impairments.”

Socioeconomic risk factors

Medical student and co-author, Maximillian Denys, tells us that low socioeconomic populations are at higher risk for PBDE-related health issues.

PBDE has been detected in human tissues, breast milk, animals, foods, water and air.“Elevated PBDE exposure in low-income populations is linked to housing, diet and environmental factors. People living in older, lower-value homes or renting may face higher exposure due to the presence of older furniture and electronics, which were often treated with PBDEs,” he highlights.

He also notes low-income populations are also more likely to live in food deserts or face food insecurity, making them more reliant on canned and processed foods with higher PBDE levels due to packaging or production.

“Moreover, the risk is compounded by biological and socioeconomic stressors, with children particularly more vulnerable to the neurodevelopmental and hormonal impacts of PBDE exposure. Combined with limited healthcare access and a lack of awareness, these factors place low socioeconomic groups at an increased risk for PBDE-related health issues, exacerbating pre-existing health disparities.”

Affordable nutrition 

Elena Kozlova, PhD Candidate, Neuroscience at UCR, shares affordable food sources of L. reuteri and how they can be incorporated into health initiatives.

“Affordable food sources of L. reuteri include sweet potatoes, beans, artichokes and fermented milk products like kefir, yogurt as well as certain fermented vegetables (kimchi, sauerkraut), sourdough bread, and breast milk for infants,” she suggests. 

“To make these accessible to underserved populations, health initiatives can promote homemade fermentation techniques using low-cost ingredients, providing starter cultures that include L. reuteri to community groups. Public education campaigns can raise awareness about the benefits of probiotics for gut health, inflammation and potential mental health improvements while teaching families how to identify affordable L. reuteri-containing products and incorporate them into their diets.”

She suggests that probiotic-rich foods, like yogurt, be included in supplemental nutrition packages and that community health initiatives and food distribution campaigns collaborate with regional producers to develop reasonably priced options. Kozlova adds schools and clinics could include probiotic foods in meal and wellness plans.

She shares PBDEs are found in foods with high-fat content, such as dairy, meat and oils, with fish containing the highest amount. “Lower amounts are found in fruits, vegetables and tubers. 

The chemical structure of PBDEs makes them lipophilic or ‘fat-loving,’ which means they can accumulate in fatty tissue in humans and animals.”

“Consumers can reduce their exposure by eating a diet that is more plant-based. Also, they can choose low-fat meat and dairy products and discard fat and cooking oils from meats. Manufacturers can avoid using materials treated with PBDEs in food packaging to prevent contamination during storage or transportation and test food products and animal feed for PBDE contamination,” suggests Kozlova.

L. reuteri can be found in affordable food sources such as sweet potatoes, beans, artichokes, fermented milk and vegetables, sourdough bread, and breast milk.Health disparities and PBDE

According to Denys, probiotics are still underutilized despite their growing recognition as a therapeutic agent, especially among lower socioeconomic groups, because of a lack of accessibility and awareness. 

“Higher education and income levels are positively associated with the use of probiotics that are considered over-the-counter dietary supplements. The out-of-pocket expenses hinder accessibility for economically disadvantaged populations. Additionally, these groups often lack access to probiotic-rich foods due to food deserts and limited health education,” he adds. 

“Research indicates that individuals from lower socioeconomic backgrounds tend to have lower gut microbial diversity, a factor linked to chronic health conditions. This is further exacerbated by higher exposure to toxic pollutants in underserved communities, which compounds health risks.”

Denys underscores that chronic stress associated with economic disadvantage and food security unpredictability also compounds the negative impacts of ingested toxicants on gut health, creating a “cycle of vulnerability.”

Maternal nutrition guidelines on horizon

According to Kozlova, probiotic supplementation is not specifically recommended as a standard practice by any universally recognized maternal nutrition guidelines. 

“Probiotic use is being integrated into some personalized care plans, especially in research-focused clinical practices, and health initiatives are increasingly incorporating probiotics into public health conversations. Recent preclinical and clinical studies have explored how probiotics administered during the preconception period and pregnancy can support offspring health. This research is still in its infancy,” she shares.

Kozlova says that promising findings, including epigenetic modifications as a potential mechanism, the optimal dose timing, specific bacterial strains and individual responses to probiotics require further investigation to fully realize long-term beneficial health outcomes. 

“To our knowledge, our study is the first to examine the use of maternal probiotics to combat the developmental effects of PBDEs. Further research and larger-scale trials could pave the way for their inclusion in standardized maternal nutrition guidelines in the future.”