Recent developments in essentiality of trivalent chromium and toxicity of hexavalent chromium: Implications on human health and remediation strategies

•Hexavalent forms of chromium are toxic and carcinogenic to living forms.•Trivalent chromium is largely non-toxic.•Trivalent chromium is now known to have roles in lipid and carbohydrate metabolism.•Hexavalent chromium triggers several cellular system responses leading to cell death.•Probiotics have been shown to limit HM absorption in the intestine by enhancing the heavy metal sequestration. Among the many heavy metals, chromium (Cr) is one of the fascinating ones. In its two most prevalent oxidation forms, trivalent (Cr3+) and hexavalent (Cr6+), Cr has completely different toxicity and essentiality in human health, as well as in the soil. In humans, Cr3+ is a necessary micronutrient for metabolism of glucose, lipid, and proteins. In contrast, Cr6+ has no recognized biological functions and is a potent carcinogen. In the search for new and effective ways to protect humans from heavy metals, “gut remediation” using probiotics has been found to be a promising and sustainable approach. Here, we have reviewed the most recent literature on how Cr causes cellular toxicity and DNA damage via cellular oxidation and epigenetic modifications, along with current biological, chemical, and herbal remediation methods, with a focus on sustainable strategies such as gut remediation. [Display omitted]