An updated review on advantages, disadvantages and uncertainties associated with probiotics

Probiotics, defined as live microorganisms that confer health benefits when administrated in adequate amounts, including genera such as Lactobacillus, Bifidobacterium, Bacillus, Enterococcus, Escherichia, Streptococcus and the fungal strain Saccharomyces boulardii. Extensive research has demonstrated their beneficial effects, including vitamin synthesis, inhibition of pathogenic bacterial colonization, antimicrobial activity through bacteriocins and other bioactive compounds, and modulation of immune responses via secretory IgA antibodies. These attributes render probiotics promising candidates for managing antibiotic-associated colitis, post-surgical recovery and various diarrhoeal conditions. However, concerns regarding the safety of probiotics have emerged, with reports of Bacillus clausii sepsis in immunocompromised individuals and neonates, emphasizing the need for rigorous risk assessment. Similarly, postbiotic bioactive metableelites and components derived from probiotics have gained the attention of the scientific community all over the globe as potential alternatives to live probiotics. The International Scientific Association of Probiotics and Prebiotics defines postbiotics as 'a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host'. Unlike probiotics, postbiotics do not require viability to exert their effects and include bioactive compounds such as short-chain fatty acids, peptides and exopolysaccharides. These molecules exhibit immunomodulatory, anti-inflammatory and antimicrobial properties, making them promising candidates for clinical applications, particularly in immunocompromised patients where live probiotics may pose risks. Despite their recognized benefits, both probiotics and postbiotics require further investigation to optimize their therapeutic potential while mitigating associated risks. This review critically evaluates the advantages, limitations and emerging applications of probiotics and postbiotics, emphasizing the necessity of rigorous scientific validation to ensure their safety and efficacy.

The pros and cons of probiotic microorganisms.