Lacticaseibacillus rhamnosus: A Suitable Candidate for the Construction of Novel Bioengineered Probiotic Strains for Targeted Pathogen Control

Abstract

Probiotics, with their associated beneficial effects, have gained popularity for the control of foodborne pathogens. Various sources are explored with the intent to isolate novel robust probiotic strains with a broad range of health benefits due to, among other mechanisms, the production of an array of antimicrobial compounds. One of the shortcomings of these wild-type probiotics is their non-specificity. A pursuit to circumvent this limitation led to the advent of the field of pathobiotechnology. In this discipline, specific pathogen gene(s) are cloned and expressed into a given probiotic to yield a novel pathogen-specific strain. The resultant recombinant probiotic strain will exhibit enhanced species-specific inhibition of the pathogen and its associated infection. Such probiotics are also used as vehicles to deliver therapeutic agents. As fascinating as this approach is, coupled with the availability of numerous probiotics, it brings a challenge with regard to deciding which of the probiotics to use. Nonetheless, it is indisputable that an ideal candidate must fulfil the probiotic selection criteria. This review aims to show how Lacticaseibacillus rhamnosus, a clinically best-studied probiotic, presents as such a candidate. The objective is to spark researchers' interest to conduct further probiotic-engineering studies using L. rhamnosus, with prospects for the successful development of novel probiotic strains with enhanced beneficial attributes.

Keywords: Lacticaseibacillus rhamnosus; pathobiotechnology; pathogen; probiotics; recombinant probiotics.

Figure 1

Desirable properties of the probiotic microorganisms.

Figure 2

Mechanisms of pathogen inhibition by probiotics.

Figure 3

Health effects of probiotics in the host.

Figure 4

A schematic representation of the steps followed in development of bioengineered probiotics and the mechanism of pathogen inhibition by the bioengineered probiotic strain. (A) Cloning and expression of genes of interest from the pathogen into an expression vector. (B) Transformation of the expression vector carrying the gene of interest from the pathogen into the probiotic and analyses conducted to confirm expression of the foreign gene by the bioengineered probiotic strain. (C) Competitive binding of the bioengineered probiotic strain to the same host receptors to which the target pathogen binds to cause an infection.