In vitro inhibitory activity of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 alone or in combination against bacterial and Candida reference strains and clinical isolates

Abstract

Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 are two strains frequently used as probiotic components in food supplements. The decrease of potentially pathogenic gastrointestinal microorganisms is one of their claimed mechanisms. The aim of this study was to investigate their ability, alone or in combination, to inhibit in vitro the growth of Gram-negative, Gram-positive and Candida reference strains and clinical isolates, using different methods.The cell-free supernatants were obtained by centrifugation and filtration from single or mixed broth cultures and the inhibitory activity was tested using both agar-well diffusion and broth microdilution methods. In order to get some preliminary information about the chemical nature of the active metabolites released in the supernatants, the inhibitory activity was investigated after neutralization, heat and proteolytic treatments.The highest inhibitory activity was shown by the untreated supernatant obtained from broth culture of the two probiotic strains, especially against bacterial reference strains and clinical isolates. This supernatant showed inhibitory activity towards Candida species, too. A decreased inhibitory activity was observed for the supernatants obtained from single cultures and after proteolytic treatment, against bacterial reference strains.The study suggests that the combination of B. longum BB536 and L. rhamnosus HN001 could represent a possible alternative against gastrointestinal and urinary pathogens either as prophylaxis or as treatment.

Corynebacterium accolens Has Antimicrobial Activity against Staphylococcus aureus and Methicillin-Resistant S. aureus Pathogens Isolated from the Sinonasal Niche of Chronic Rhinosinusitis Patients

“…The inhibitory activity of CFCS from C. accolens isolates was tested against representative S. aureus and MRSA isolates following a broth micro-dilution assay protocol as described earlier [ 36 ] with minor modifications. The concentrated CFCS were first diluted in various concentration ranges (30%, 50%, 70% and 90%) using TSB.…”

The Role of Bifidobacteria in Predictive and Preventive Medicine: A Focus on Eczema and Hypercholesterolemia

“…The human gut microbiome contains the largest, densest, and most diverse microbial community (up to 100 billion to one trillion cells per milliliter in the large intestine) [ 1 ]. This acts as a highly efficient bioreactor, helping to extract energy and nutrients from the food we eat, producing short-chain fatty acids (SCFAs) and vitamins; driving functional roles for the host, such as maturation and modulation of the immune system, intestinal epithelial maturation, and regulation of mucosal physiology; and protecting against pathogens, such as Clostridium difficile [ 9 , 10 , 11 , 12 , 13 ].…”

The Possible Role of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 on Locomotor Activity and Oxidative Stress in a Rotenone‐Induced Zebrafish Model of Parkinson’s Disease

“…Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001, in combination and/or individually, possess the ability to inhibit the activity of the major Gramnegative strains, even opportunistic pathogenic entities such as Candida [68,69]. Different teams of researchers have also revealed in several other occasions that rotenone causes a dysfunction of the rat's and mice's gastrointestinal microbiota as well.…”