First introduced in the 1920s, phthalates are commercial chemicals used in a vast array of consumer products: plastic and vinyl, medical supplies, flooring, wall coverings, cosmetics, personal care products and toys. Their usefulness in industry is undeniable but researchers have observed harmful effects on endocrine, metabolic and neurological systems in the human body. Although elimination or substitution of phthalates by governments or voluntary action is underway, the continued ubiquity of phthalates and their concomitant harms remains a serious global public health concern.
The gut microbiota is often the first line of defense against many toxins, which may enter through food and water and may have the potential to disturb the microflora balance. Other exposure routes are through the skin and lungs.
Xenobiotics (Greek, xenos “foreign”; bios “life”) are chemical substances not normally present in or produced by the environment of living organisms. In addition to phthalates, numerous other chemicals of concern exist in the environment due to industrialization; although they will not be discussed here, these include persistent organic pollutants (POPs), and heavy metals, among others. Mounting evidence indicates that chronic xenobiotics exposure negatively affects human health, notably via inflammation, oxidative stress, and disruption of gut microflora composition and metabolite synthesis.
According to a recent review, some probiotic microorganisms may be able to protect against many specific xenobiotics through various mechanisms:
- Binding and/or metabolizing of various chemical pollutants
- Alleviate negative health effects by modulating the composition of the gut microflora
- Reduction of oxidative stress
- Enhancement of the intestinal barrier function
- Modulation of host gene expression
- Increasing the host’s capacity to metabolize xenobiotics
Restoring the functions of the gut microbial population and the integrity of the gut epithelial barrier may be an effective approach to fighting the detrimental effects of environmental pollutants.
However, scientific evidence on phthalates in that regard is scant, relying primarily on animal models or in vitro studies. Yet, the potential for benefit is becoming more promising as research progresses.
Probiotics and phthalates
Di-2-ethylhexyl phthalate (DEHP) is one of the commonly detected phthalate types in the environment. DEHP has a serious disruptive effect on reproductive health. In a 2019 study using DEHP- exposed mice, a strain of Lactobacillus plantarum (currently renamed Lactiplantibacillus plantarum) improved male reproductive system functions by increasing serum testosterone hormone levels, improved the quality of semen, and ameliorated gonad development defects.
Detoxification of another phthalate compound (Di-n-butyl phthalate) by an inactivated strain of Lactobacillus acidophilus was observed in an in vitro cell model as reported in a 2021 publication.
The following two studies combine phthalates and bisphenol A, ostensibly because of their uses in commercial water bottles:
- In a recent study, a multi-strained probiotic mixture (Saccharomyces boulardii, Lacticaseibacillus rhamnosus (formerly known as Lactobacillus rhamnosus), and two different strains of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) reduced the toxicity of phthalates and bisphenol A mixture in Wistar rats. In addition, the probiotic treatment attenuated systemic inflammation as well as almost completely alleviated the changes in biochemical, hematological and hormonal parameters.
- In another study, probiotics were assessed as an intervention in a rat model of asthma induced by a mixture of phthalates and bisphenol A. The multi-strain probiotic could bind the phthalate/bisphenol A mixture in vitro and alleviate its effects on redox status and bioelements in rat lung, thymus and kidney and tissues.
Takeaway on phthalates
In a few animal studies, some probiotics appeared to mitigate the impact of specific phthalates. However, this field of research is still in its infancy.
Yet, given the overarching role of a healthy microbiome on human health, the potential use of probiotics to support microbiome health against phthalates appears to be worth further investigation.
Note: Phthalates are only one class among the many environmental toxins that can be harmful. In the coming months, we will summarize available research exploring the role of probiotics in protecting against other xenobiotics, notably parabens, phenolic compounds, and pesticides.
Abdelsalam, Nehal Adel et al. “Toxicomicrobiomics: The Human Microbiome vs. Pharmaceutical, Dietary, and Environmental Xenobiotics.” Frontiers in pharmacology vol. 11 390. 16 Apr. 2020, doi:10.3389/fphar.2020.00390
Baralić, Katarina et al. “Integrating in silico with in vivo approach to investigate phthalate and bisphenol A mixture-linked asthma development: Positive probiotic intervention.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association vol. 158 (2021): 112671. doi:10.1016/j.fct.2021.112671
Baralić, Katarina et al. “Multi-strain probiotic ameliorated toxic effects of phthalates and bisphenol A mixture in Wistar rats.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association vol. 143 (2020): 111540. doi:10.1016/j.fct.2020.111540
Chen, Lianguo. “Gut Microbiota Manipulation to Mitigate the Detrimental Effects of Environmental Pollutants.” Toxics vol. 9,6 127. 1 Jun. 2021, doi:10.3390/toxics9060127
da Silva Costa, Rouse et al. “Potential risk of BPA and phthalates in commercial water bottles: a minireview.” Journal of water and health vol. 19,3 (2021): 411-435. doi:10.2166/wh.2021.202
Engel, Stephanie M et al. “Neurotoxicity of Ortho-Phthalates: Recommendations for Critical Policy Reforms to Protect Brain Development in Children.” American journal of public health vol. 111,4 (2021): 687-695. doi:10.2105/AJPH.2020.306014
Haverinen, Elsi et al. “Metabolic Syndrome and Endocrine Disrupting Chemicals: An Overview of Exposure and Health Effects.” International journal of environmental research and public health vol. 18,24 13047. 10 Dec. 2021, doi:10.3390/ijerph182413047
Średnicka, Paulina et al. “Probiotics as a biological detoxification tool of food chemical contamination: A review.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association vol. 153 (2021): 112306. doi:10.1016/j.fct.2021.112306
Tian, Xiaozhu et al. “Lactobacillus plantarum TW1-1 Alleviates Diethylhexylphthalate-Induced Testicular Damage in Mice by Modulating Gut Microbiota and Decreasing Inflammation.” Frontiers in cellular and infection microbiology vol. 9 221. 26 Jun. 2019, doi:10.3389/fcimb.2019.00221
Zamkowska, Dorota et al. “Environmental exposure to non-persistent endocrine disrupting chemicals and semen quality: An overview of the current epidemiological evidence.” International journal of occupational medicine and environmental health vol. 31,4 (2018): 377-414. doi:10.13075/ijomeh.1896.01195
Zhao, Lili et al. “Binding and detoxification ability of lactobacillus acidophilus towards di-n-butyl phthalate: Change of MAPK pathway in Caco-2 cell model.” Journal of proteomics vol. 247 (2021): 104333. doi:10.1016/j.jprot.2021.104333