Food and drug design for gut microbiota-directed regulation: Current experimental landscape and future innovation

Most diets and medications enhance host health via microbiota-dependent ways, but it is in the present situation of untargeted regulation. Non-targeted regulation may lead to the ineffectiveness of dietary supplements or drug treatment. Microbiota-directed food, aiming to improve diseases by targeting specific microbes without affecting other bacteria, have been proposed to deal with this problem. However, there is currently no universally applicable method to explore such foods or drugs. In this review, thirty studies on recent efforts in microbiota directed diets and medications are summarized from various databases. The methods used to find new foods and medications are primarily divided into four groups depending on the experimental models: in vivo and in vitro, as well as predictions based on bioinformatics. We also discuss their implementation, interpretation, and respective limitations, and describe the present situation. We further put forward a framework for microbiota-directed foods and medicine according to above methods and other microbiome manipulation, which will spur precision medicine.

Protocols to Study Dental Caries In Vitro: Microbial Caries Models

Caries lesions result from the interaction between dental biofilm and sugars. Since the biofilm is an important component in the etiology of the disease, biofilm models have been developed to study the cariogenicity of dietary sugars, as well as the anticaries effect of substances. Two of such models, termed as "static" or "continuous flow," are described in details here together with their advantages, limitations, and applications.

Cyhalothrin biodegradation in Cunninghamella elegans

The insecticide λ-cyhalothrin was incubated with planktonic and biofilm cultures of the fungus Cunninghamella elegans. ¹⁹F nuclear magnetic resonance spectroscopy demonstrated that the compound was initially biosorbed to the biomass and more slowly degraded by the fungus. Furthermore, the presence of trifluoromethyl-containing metabolites was observed. Analysis of culture extracts by gas chromatography-mass spectrometry (GC-MS) identified non-fluorinated metabolites that suggested the likely catabolic pathway. The hydroxylated metabolites were probably generated from the action of cytochromes P450 (CYPs), as the presence of CYP inhibitors resulted in the absence of biodegradation. Planktonic cells were measurably faster at degrading the pesticide compared with biofilm.

Evaluation of fluorinated biphenyl ether pro-drug scaffolds employing the chemical-microbial approach

Incorporation of fluorine in a drug can dramatically affect its metabolism and methods to assess the effect of fluorine substitution on drug metabolism are required for effective drug design. Employing a previously developed chemical-microbial method the metabolism of a series of fluorinated biphenyl ethers was determined. The substrates were synthesized via Ullmann-type condensation reactions between bromotoluene and fluorophenol. The ethers were incubated with the fungus Cunninghamella elegans, which oxidises xenobiotics in an analogous fashion to mammals, generating a number of hydroxylated biphenyl ethers and acids. The propensity of the fluorinated ring to be hydroxylated depended upon the position of the fluorine atom, and the oxidation of the methyl group was observed when it was meta to the oxygen. The experiments demonstrate the applicability of the method to rapidly determine the effect of fluorine substitution on CYP-catalysed biotransformation of pro-drug molecules.