Gut Microbes Might be the Solution to Forever Chemicals

Concern around per- and polyfluoroalkyl substances (PFAS), often called “forever chemicals”, is growing. Most of us have been unknowingly dosing ourselves with these chemicals on a daily basis, and society is now slowly recognizing the destructive impact they are having on our health.

While avoiding PFAS where possible is still the best strategy, a recent study published in Nature Microbiology provides evidence that the microbes living in our gut may play a role in reducing our PFAS burden. Certain species of microbes were shown to accumulate PFAS within the intestines, preventing them from entering the circulation where it is hard to get rid of them.

We met with Dr. Kiran Patil, an author of the recent study, who said “I think our study is one of the few where that offers a bit of a glimmer of hope.”

What Are Forever Chemicals?

PFAS are a group of over 4,700 compounds widely used in industrial and consumer products such as firefighting foams, waterproof clothing, and nonstick cookware. They are incredibly stable, which is why they are used so frequently, but also why they are called forever chemicals. PFAS persistently contaminate water and agricultural systems, inevitably entering the human body through the food chain.

These chemicals are notoriously hard for our bodies to get rid of, and have been linked to various health issues, including hormonal disruptions, immune dysfunction, and increased cancer risk. A study by NYU Langone Health in 2022 estimated that PFAS exposure costs Americans a minimum of $5.5 billion and potentially up to $63 billion annually. Childhood obesity linked to PFAS exposure was the largest contributor at $2.7 billion, alongside hypothyroidism in women, kidney cancer, testicular cancer, low birth weight, and many more conditions.

Strategies for Reducing Exposure

The best way to reduce our PFAS-related disease burden is by reducing our exposure. We can start by identifying the most significant routes by which they are entering our bodies.

The following list represents only a few of the many potential sources, but these are some impactful places to start.

Contaminated drinking water

Since PFAS stick around nearly forever, they eventually leech into water supplies. Studies have shown that drinking water can account for up to 75% of total PFAS exposure in highly contaminated areas.

Mitigate by:

• Checking local water quality reports for PFAS levels
• Installing certified water filtration systems using granular activated carbon (GAC), reverse osmosis, or ion exchange technology
• Testing private wells regularly for PFAS contamination
• Using bottled water from verified PFAS-free sources in heavily contaminated areas

Seafood

Fish and seafood can account for significant dietary PFAS exposure in adults, particularly in populations with high seafood consumption. Long-chain PFAS bioaccumulate significantly in marine organisms, with highest concentrations in top predators.

Mitigate by:

• Limiting consumption of predatory fish and shellfish from contaminated waters
• Choosing smaller fish species that typically have lower PFAS concentrations
• Avoiding seafood from areas near military bases, airports, or industrial facilities

Food Packaging and Containers

PFAS are widely used in food packaging to provide grease resistance. Studies found high levels of PFAS in food packaging from fast-food chains, takeout containers, and “compostable” bowls.

Mitigate by:

• Avoiding fast-food containers and takeout packaging when possible
• Using glass or stainless steel containers for food storage
• Avoiding microwave popcorn bags and greasy food wrappers
• Choosing fresh foods over packaged alternatives
• Never reheating food in original packaging

Non-stick Cookware and Food Contact Surfaces

PTFE-coated cookware can release PFAS, particularly when overheated or scratched. Studies found 79% of tested non-stick pans contained PTFE coating.

Mitigate by:

• Using stainless steel, cast iron, or ceramic cookware
• Avoiding heating non-stick pans above 400°F (204°C)
• Replacing scratched or damaged non-stick cookware immediately
• Using wooden or silicone utensils instead of metal to prevent scratching
• Choosing cookware specifically labeled as PTFE-free and PFAS-free

Detoxifying with Microbes

Despite doing our best to avoid PFAS, their widespread presence makes complete avoidance nearly impossible. While some methods for clearing them from the body are available, they are limited in number and not as effective as we might like. Researchers have long sought effective and safe ways to reduce PFAS burden within humans.

In the recently published study, researchers discovered that certain human gut bacteria can bioaccumulate PFAS, effectively lowering the chemical burden within the body. When PFAS enter gut microbes instead of the circulation, they never end up travelling to the various human tissues where they might exert toxic effects.  

The study demonstrated significant PFAS accumulation by 38 different gut bacterial strains. Importantly, many of these are common species. “What our study shows is that certain gut bacteria that are present in almost all people, albeit in different amounts, have the capacity to accumulate”, said Dr. Patil. Remarkably, these bacteria were shown to bioaccumulate rapidly without imapired growth or viability.

These insights are significant because they suggest that actively cultivating specific gut microbes or administering them in probiotic form could effectively reduce PFAS levels in humans. Animal trials within the study further supported this hypothesis, showing that mice colonized with high-PFAS-accumulating gut bacteria excreted significantly more PFAS through their feces compared to germ-free mice or those colonized with bacteria that had lower accumulation capacities.

Further studies in humans might shed light on what lifestyle or dietary patterns tend to cultivate the specific bacteria best at accumulating PFAS. However, Dr. Patil and his team are currently focused on developing probiotics which deliver these specific PFAS accumulating bacterial strains. It would be the first of its kind and is incredibly exciting. 

Microbes and Humans as Teammates

This discovery underscores the enormous potential of the microbiome in safeguarding human health. The human gut hosts trillions of microbes that profoundly impact our physiological health, and this study illustrates how nurturing beneficial microbes could provide a natural, effective defense against environmental toxins like PFAS. It highlights a compelling new avenue for probiotic development and personalized health strategies aimed at mitigating chemical exposure.

The power of our microbiome lies in its adaptability and its cooperative relationship with our bodies. By treating our microbial allies well, through diet, lifestyle, and targeted probiotic interventions, we enhance their capacity to protect us from environmental hazards. This research emphasizes not only the pressing need to reduce global PFAS pollution but also the critical importance of cultivating a microbiome that works in harmony with our health.