Next-Generation Probiotics: Promising Therapeutic Candidates for Metabolic and Gastrointestinal Disorders

Most of the probiotic bacterial candidates currently available in the market consist of various strains belonging to different classes. Nevertheless, the gastrointestinal microbiome is a collection of undefined microbial agents that may contribute some medical benefits to human beings. Hence, currently, researchers from different corners are centered on investigating and identifying gastrointestinal-derived probiotic strains for the advancement of next-generation probiotics. The term next-generation probiotics refers to genetically modified microorganisms created by deleting, adding or modifying specific genes to produce a probiotic strain that modulates the metabolism, gastrointestinal health and delivered directly to the mucosa. Next-generation probiotics generated from different probiotic strains are intended to provide one or more health benefits to a host and for the efficient control and/or treatment of multiple diseases. Even though some next-generation probiotics are auspicious of the control and treatment of several chronic sicknesses, studies on human beings are still sporadic and confirmations from regulatory authorities are thus rare. Furthermore, some problems need to be resolved by releasing their broad application to the public. Probiotic strains such as Faecalibacterium prausnitzii, Prevotella copri, Bacteroides uniformis, Bacteroides thetaiotaomicron, Bacteroides acidifaciens, Clostridium butyricum, Christensenella minuta, Akkermansia muciniphila and Parabacteroides goldsteinii, have been postulated as next-generation probiotic candidates, as a result of their therapeutic or preventive effects on diseases such as colitis, obesity, diabetes and liver diseases. This review highlights the probiotic potential of next-generation probiotics and discusses the potential existing and emerging next-generation probiotics.