The Toxic Effects of Endocrine Disrupting Chemicals (EDCs) on Gut Microbiota: Bisphenol A (BPA) A Review

Background: Bisphenol A (BPA), an important industrial material widely applied in daily products, is considered an endocrine-disrupting chemical that may adversely affect humans. Growing evidence has shown that intestinal bacterial alterations caused by BPA exposure play an important role in several local and systemic diseases. Aims: Finding evidence that BPA-induced alterations in gut microbiota composition and activity may perturb its role on human health. Results: Evidence from several experimental settings shows that both low and high doses of BPA interfere with the hormonal, homeostatic, and reproductive systems in animals and humans. Moreover, it has recently been classified as an environmental obesogenic, with metabolic-disrupting effects on lipid metabolism and pancreatic b-cell functions. Several evidence characterizes PBA as an environmental contributor to type II diabetes, metabolic syndromes, and obesity. However, the highest estimates of the exposure derived from foods alone or in combination with other sources are 3 to 5 times below the new tolerable daily intake (TDI) value, today reduced by the European Food Safety Authority (EFSA) experts from 50 micrograms per kilogramme of bodyweight per day (μg/kg bw/day) to 4 μg/kg bw/day. Conclusion: Considering estimates for the total amount of BPA that can be ingested daily over a lifetime, many International Health Authorities conclude that dietary exposure of adult humans to BPA does not represent a risk to consumers' health, declaring its safety due to very-low established levels in food and water and any appreciable health risk.