Qing Gu

By Qing Gu and Ping Li

Vitamins are important micronutrients that are often precursors to enzymes, which all living cells require to perform biochemical reactions. However, humans cannot produce many vitamins, so they have to be externally obtained. Using vitamin‐producing microorganisms could be an organic and marketable solution to using pseudo‐vitamins that are chemically produced, and could allow for the production of foods with higher levels of vitamins that could reduce unwanted side effects. Probiotic bacteria, as well as commensal bacteria found in the human gut, such as Lactobacillus and Bifidobacterium, can de novo synthesize and supply vitamins to human body. In humans, members of the gut microbiota are able to synthesize vitamin K, as well as most of the water‐soluble B vitamins, such as cobalamin, folates, pyridoxine, riboflavin, and thiamine.

Part of the book: Probiotics and Prebiotics in Human Nutrition and Health

By Ping Li and Qing Gu

Probiotics are live microorganisms, which confer health benefits on host when administered in adequate amounts. Probiotics exert their beneficial effects by maintenance flora healthy, enhancement of mucosal barrier integrity and modulation of immune responses. Antimicrobial substances including bacteriocins, hydrogen peroxide, organic acids, and short-chain fatty acids (SCFAs) produced by probiotics allow them to inhibit mucosal and epithelial adherence of pathogens and compete for limiting resources, thus suppress the growth of bacterial and fungal pathogens. Probiotics effect the colonization of fungal pathogen Candida to host surfaces, suppress Candida growth and biofilm development in vitro. Clinical results have shown that some probiotics can reduce oral, vaginal, and enteric colonization of Candida, alleviate clinical signs and symptoms, and potentially reduce the incidence of invasive fungal infection. Therefore, probiotics may be potential antifungals for prevention and treatment of candidiasis.

Part of the book: Probiotics

By Ping Li, Han Jiang, Jiayi Xiong, Mengqi Fu, Xianpu Huang, Boxun Huang and Qing Gu

Foodborne pathogens of Enterobacteriaceae including Escherichia coli, Salmonella, Shigella, Yersinia, etc., causes a great number of diseases and has a significant impact on human health. Here, we reviewed the prevalence, virulence, and antimicrobial susceptibility of Enterobacteriaceae belonging to 4 genera: E. coli, Salmonella, Shigella, and Yersinia. The routes of the pathogens’ transmission in the food chain; the antimicrobial resistance, genetic diversity, and molecular epidemiology of the Enterobacteriaceae strains; novel technologies for detection of the bacterial communities (such as the molecular marker-based methods, Immunoaffinity based detection, etc.); and the controlling of the foodborne pathogens using chemical/natural compounds or physical methods (such as UV-C and pulsed-light treatment, etc.), is also summarized.

Part of the book: Enterobacteria