Lactic Acid Bacteria as In Vivo Protective Strategy Against Dietary Methylmercury Exposure

Area of Science:

• Environmental Toxicology
• Microbiology
• Nutritional Science

Background:

• Dietary mercury (Hg) exposure is a significant public health concern.
• Understanding mercury toxicokinetics and identifying mitigation strategies are crucial.

Purpose of the Study:

• To characterize the toxicokinetics of dietary mercury (Hg).
• To identify lactic acid bacteria (LAB) strains that can reduce methylmercury (MeHg) accumulation in organs.
• To evaluate the efficacy of selected LAB strains in reducing Hg accumulation in vivo.

Main Methods:

• BALB/c mice and Wistar rats were exposed to Hg(II) and MeHg via drinking water and feed (swordfish, mushrooms).
• In vitro screening identified two LAB strains (L. intestinalis LE1, L. johnsonii LE2).
• Mice were dosed daily with LE1 or LE2 strains during a 40-day exposure to dietary MeHg.

Main Results:

• The feed matrix did not alter MeHg accumulation but reduced Hg(II) accumulation compared to water exposure.
• Daily administration of LE1 and LE2 strains reduced organ Hg content by 18-64% in mice exposed via drinking water.
• The LE1 strain also decreased Hg content by 13-40% in mice exposed via feed.

Conclusions:

• Lactic acid bacteria show potential for reducing mercury accumulation in organs.
• LAB administration can be a viable dietary strategy for populations with chronic mercury exposure.
• Further research into LAB efficacy against different mercury forms and exposure routes is warranted.