Study shows probiotic yogurt reduces toxic risks

Paul Mayne // Western News

Western graduate student Jordan Bisanz recently led a study providing the first clinical evidence that a probiotic yogurt can be used to reduce deadly health risks associated with mercury and arsenic.

New Western-led research showing probiotic yogurt’s ability to reduce the uptake of certain heavy metals and environmental toxins could significantly reduce the risk for developmental issues in children.

Western graduate student Jordan Bisanz said the study provides the first clinical evidence that a probiotic yogurt can be used to reduce deadly health risks associated with mercury and arsenic.

Bisanz, along with fellow graduate student Megan Enos, was first author on the paper, Randomized Open-Label Pilot Study of the Influence of Probiotics and the Gut Microbiome on Toxic Metal Levels in Tanzanian Pregnant Women and School Children, recently published in mBio, the journal of the American Society for Microbiology. Gregor Reid, Western professor and Lawson Health Research Institute scientist, was senior author.

In the study, the group assessed 44 school-aged children and 60 pregnant women living in Mwanza, Tanzania, near Lake Victoria, an area known for having particularly high environmental pollution. The area is also home to a network of community yogurt kitchens set up through the Western Heads East program, providing a locally sourced, low-cost source of nutrition.

The goal of the research was to assess existing metal levels in the environment and participants’ bodies, map their natural bacteria to identify any potential links to metal absorption, and determine whether the probiotic-supplemented yogurt could influence metal absorption.

Thanks to the consumption of silver cyprinids, a small fish found widely in Tanzania’s Lake Victoria region, mercury and lead levels in children are up to seven times higher than what is typically found in Canadian children.

“Seeing the children, you would never think they were walking around with such high levels of toxins,” Bisanz said. “I hate to think of the consequences for them as they age. The children and pregnant women all loved the yogurt. If we could only scale up these yogurt kitchen concepts, the impact on quality of life could be massive.”

After consuming the yogurt, the children showed some positive results, but it was pregnant women who showed the more dramatic outcomes. That group was protected from further uptake of mercury by up to 36 per cent and arsenic by up to 78 per cent.

Research suggests some naturally occurring bacteria in the body can influence toxic metal levels. Bisanz said DNA sequencing identified two bacteria present in children with the highest concentrations of heavy metals, suggesting the presence of these bacteria may be linked to the metal absorption.

He added it’s possible to use the concept of bioremediation – a treatment that uses naturally occurring organisms to break down hazardous substances into less toxic or non-toxic substances – in dealing with the heavy metals, but just apply them in a different setting, which is in the gastrointestinal track.

“We’re not re-inventing the wheel. We’re trying to use the wheel differently – a new application of it,” Bisanz said. “We’ve all evolved with bacteria and they’ve always been there influencing us. It’s about how we can take the good aspect and make them better. It’s doing a good job, but not a good enough job.”

Bisanz said the probiotic yogurt benefits can be easily replicated in our own backyard, where exposure to these toxins occurs daily.

“In Tanzania, on the shore of Lake Victoria, it’s about as bad as Lake Erie. Let’s not kid ourselves; Lake Erie is horrible,” he said. “Depending on where you live in London, your water supply is drawn from Lake Erie. It’s (mercury) out there.

“The fact is a lot of these toxins end up in the food supply, and people are always trying to remove them from the food, which is not always possible, especially with the metals. They are part of the environment and I don’t see any point in the near future how we’re going to magically undo that.”

Even at low levels, chronic exposure to heavy metals has been linked to certain cancers and delayed neurological and cognitive development in children. In Canada, 15 per cent of reproductive-aged women possess mercury levels that pose a high risk for neurodevelopmental abnormalities in their children.