01. Can the product target specific PFAS? Or is it designed to grab a group of PFAS? 

Our research suggests that the product under development will be most effective against long-chain PFAS, which are also most bioaccumulative in the human body. Short-chain PFAS such as PFBA and PFPeA have short half-lives in the human body of only a couple of days and are excreted mainly via urine. On the other hand, long-chain PFAS, such as PFOS, PFNA, and PFDA, have long half-lives of several years in the human body, and their main route of excretion is via feces, despite generally being very slow. Our strategy is most relevant for PFAS compounds that rely on fecal excretion as their main route of reducing PFAS in the body (e.g., PFOA, PFOS, and PFNA). 

02. Do these high-accumulating bacteria exist in the human microbiome? 

While the high-PFAS accumulating bacteria identified in our research are prevalent among the population, meaning that they occur in most healthy people, the levels of these bacteria vary greatly between healthy individuals. 

03. Are any of the high accumulative bacteria currently used as probiotics? 

Typical probiotic strains such as Lactobacillus or Bifidobacteria showed none to low PFAS accumulating capacity in our in vitro screens. At Cambiotics, we are focusing on novel probiotic strains belonging to the Streptococcus and Bacteroides genera that are under study for this purpose.

04. Are there any current alternatives to reduce PFAS from the body? 

For most people, the main routes of PFAS exposure will be through drinking water and food. Exceptions are people with occupational exposure, such as firefighters, chemical manufacturers, or ski waxers. Using appropriately filtered water can help when the main exposure is via the drinking water.  

Currently, there are no efficient and scalable options to actively lower PFAS levels. While donating blood can lower PFAS levels, this is an ethically questionable and non-scalable approach. In addition, research shows that bile sequestrants such as cholestyramine show potential for lowering PFAS levels, but the pharmaceutical nature of this intervention may cause gastrointestinal side effects. Further, recent research suggests that increasing dietary fiber intake may lower PFAS levels to some extent, though evidence remains preliminary. 

05. When you take a group of humans to test the probiotics, what variables would you consider, as these humans are not germ-free? 

Our clinical trial will be conducted as a dietary supplement study in healthy individuals with mid-to-high PFAS levels. We are planning a longitudinal study tracking PFAS levels before and after supplementation. Participants must not have taken antibiotics or other drugs that disrupt the gut microbiota balance. The probiotic under investigation is designed to boost naturally occurring bacteria at the right site in the gut, enhancing the body’s natural PFAS excretion.  

06. Any idea of the minimum quantity of bacteria to be active and have results, as the gut biome is more or less individual? What could be the consequences on the balance with middle or long-term usage? 

Preclinical research suggests the effect is dose-dependent; the more bioaccumulative bacteria, the stronger the PFAS binding and excretion. We are using strains already present in most healthy microbiomes, which we believe will minimize the impact on microbial balance. Microbiome changes are planned to be assessed in the supplement trial. 

07. Is there the ability to measure levels within the body, yet, low, moderate, or high degrees? 

In the US, one can purchase a PFAS blood test from, for example, Quest Diagnostics, which allows quantifying the amount of PFAS levels in the blood. You can get it here.

08. Does the PFAS storage bind to albumin and travel in the blood and through the liver repeatedly, or is it excreted in urine and feces? How much is excreted in feces from highly contaminated people (high fiber diet versus low fiber diet, any studies)? 

PFAS distribution varies by compound, but molecules of most concern, such as PFOS, accumulate in the blood and in the liver. They participate in enterohepatic cycling and only very small amounts are naturally excreted, which makes them difficult to eliminate. Some studies suggest diet, such as higher fiber intake, may influence excretion levels, but the evidence is preliminary at this stage. 

09. Any distribution of the bacterial treatment with different medicines/drugs that people take? 

Some medications, especially antibiotics, can alter gut bacteria composition. It is therefore possible that such medications could influence PFAS kinetics. 

10. Is the species you are using already present in the QPS list from EFSA? 

Currently, we are investigating two probiotic strains for reducing PFAS levels in the human body. Their regulatory status differs; neither strain is currently included on EFSA’s QPS list, so both will require Novel Food approval. One strain is already utilized in the EU for oral health applications, but an application is required to extend its use to dietary supplements. The second strain is a naturally occurring member of the human gut microbiota, yet it is not authorized as a supplement. We are therefore pursuing Novel Food approval to ensure compliance with the regulatory standards.

For the US, we are pursuing GRAS approval to ensure regulatory compliance before launch.