Fermented foods play a significant role in the diets of many cultures, and fermentation has been recognized for its many health benefits. During fermentation, the physical and biochemical changes due to microorganisms are crucial to the long-term stability of fermented foods. Recently, fermented foods have attracted the attention of scientists all over the world. Some putative mechanisms that explain how fermented foods affect health are the potential probiotic effects of the microorganisms in fermented foods, bioactive peptides and biogenic amines produced as a result of fermentation, phenolic compounds transformed to bioactive substances, and decreased antinutrients. In addition, increased vitamin content, antioxidant, antihypertensive, and antidiabetic activities have associated with fermented products. The purpose of this paper is to present various types of fermented foods and the health-promoting components that emerge during the fermentation of major food matrices, as well as the affect of fermented foods on the gut microbiome once they are ingested.

Heavy metal and pesticide pollution have become an inevitable part of the modern industrialized environment that find their way into all ecosystems. Because of their persistent nature, recalcitrance, high toxicity and biological enrichment, metal and pesticide pollution has threatened the stability of the environment as well as the health of living beings. Due to the environmental persistence of heavy metals and pesticides, they get accumulated in the environs and consequently lead to food chain contamination. Therefore, remediation of heavy metals and pesticide contaminations needs to be addressed as a high priority. Various physico-chemical approaches have been employed for this purpose, but they have significant drawbacks such as high expenses, high labor, alteration in soil properties, disruption of native soil microflora and generation of toxic by-products. Researchers worldwide are focusing on bioremediation strategies to overcome this multifaceted problem, i.e., the removal, immobilization and detoxification of pesticides and heavy metals, in the most efficient and cost-effective ways. For a period of millions of evolutionary years, microorganisms have become resistant to intoxicants and have developed the capability to remediate heavy metal ions and pesticides, and as a result, they have helped in the restoration of the natural state of degraded environs with long term environmental benefits. Keeping in view the environmental and health concerns imposed by heavy metals and pesticides in our society, we aimed to present a generalized picture of the bioremediation capacity of microorganisms. We explore the use of bacteria, fungi, algae and genetically engineered microbes for the remediation of both metals and pesticides. This review summarizes the major detoxification pathways and bioremediation technologies; in addition to that, a brief account is given of molecular approaches such as systemic biology, gene editing and omics that have enhanced the bioremediation process and widened its microbiological techniques toward the remediation of heavy metals and pesticides.