Explore the vast range of titles available.

An expert panel was convened in September 2019 by The International Scientific Association for Probiotics and Prebiotics (ISAPP) to develop a definition for fermented foods and to describe their role in the human diet. Although these foods have been consumed for thousands of years, they are receiving increased attention among biologists, nutritionists, technologists, clinicians and consumers. Despite this interest, inconsistencies related to the use of the term ‘fermented’ led the panel to define fermented foods and beverages as “foods made through desired microbial growth and enzymatic conversions of food components”. This definition, encompassing the many varieties of fermented foods, is intended to clarify what is (and is not) a fermented food. The distinction between fermented foods and probiotics is further clarified. The panel also addressed the current state of knowledge on the safety, risks and health benefits, including an assessment of the nutritional attributes and a mechanistic rationale for how fermented foods could improve gastrointestinal and general health. The latest advancements in our understanding of the microbial ecology and systems biology of these foods were discussed. Finally, the panel reviewed how fermented foods are regulated and discussed efforts to include them as a separate category in national dietary guidelines. Although fermented foods have been consumed for thousands of years, a clear definition has been lacking. This Consensus Statement outlines a definition for the term ‘fermented foods’ as determined by an expert panel convened by the International Scientific Association for Probiotics and Prebiotics in September 2019.

A meeting report on the 7th Wellcome Trust conference on Exploring Human Host-Microbiome Interactions in Health and Disease, held at Hinxton, UK, 5-7 December 2018.A meeting report on the 7th Wellcome Trust conference on Exploring Human Host-Microbiome Interactions in Health and Disease, held at Hinxton, UK, 5-7 December 2018.

Diverse terms have been used in the literature to refer to the health benefits obtained from the administration of non-viable microorganisms or their cell fragments and metabolites. In an effort to provide continuity to this emerging field, the International Scientific Association of Probiotics and Prebiotics (ISAPP) convened a panel of experts to consider this category of substances and adopted the term postbiotic, which they defined as a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host.” This definition does not stipulate any specific health benefit, finished product, target population or regulatory status. In this perspective article, we focused on postbiotics developed for pharmaceutical uses, including medicinal products and medical devices. We address how this field is regulated for products based on inanimate microorganisms, marketing considerations and existing examples of postbiotics products developed as cosmetics for the skin, for vaginal health, and as orally consumed products. We focus on the European Union for regulatory aspects, but also give examples from other geographical areas.

Lactobacilli have been evaluated as probiotics against Candida infections in several clinical trials, but with variable results. Predicting and understanding the clinical efficacy of Lactobacillus strains is hampered by an overall lack of insights into their modes of action. In this study, we aimed to unravel molecular mechanisms underlying the inhibitory effects of lactobacilli on hyphal morphogenesis, which is a crucial step in C. albicans virulence. Based on a screening of different Lactobacillus strains, we found that the closely related taxa L. rhamnosus , L. casei and L. paracasei showed stronger activity against Candida hyphae formation compared to other Lactobacillus species tested. By exploring the activity of purified compounds and mutants of the model strain L. rhamnosus GG, the major peptidoglycan hydrolase Msp1, conserved in the three closely related taxa, was identified as a key effector molecule. We could show that this activity of Msp1 was due to its ability to break down chitin, the main polymer in the hyphal cell wall of C. albicans . This identification of a Lactobacillus- specific protein with chitinase activity having anti-hyphal activity will assist in better strain selection and improved application in future clinical trials for Lactobacillus -based Candida -management strategies.

Summary Several studies have recently pointed towards an increased occurrence and prevalence of several taxa of the lactic acid bacteria (LAB) in the microbiota of the upper respiratory tract (URT) under healthy conditions versus disease. These include several species of the Lactobacillales such as Lacticaseibacillus casei, Lactococcus lactis and Dolosigranulum pigrum. In addition to physiological studies on their potential beneficial functions and their long history of safe use as probiotics in other human body sites, LAB are thus increasingly to be explored as alternative or complementary treatment for URT diseases. This review highlights the importance of lactic acid bacteria in the respiratory tract and their potential as topical probiotics for this body site. We focus on the potential probiotic properties and adaptation factors that are needed for a bacterial strain to optimally exert its beneficial activity in the respiratory tract. Furthermore, we discuss a range of in silico, in vitro and in vivo models needed to obtain better insights into the efficacy and adaptation factors specifically for URT probiotics. Such knowledge will facilitate optimal strain selection in order to conduct rigorous clinical studies with the most suitable probiotic strains. Despite convincing evidence from microbiome association and in vitro studies, the clinical evidence for oral or topical probiotics for common URT diseases such as chronic rhinosinusitis (CRS) needs further substantiation. Several studies have recently pointed towards an increased occurrence and prevalence of several taxa of the lactic acid bacteria (LAB) in the microbiota of the upper respiratory tract (URT) under healthy conditions versus disease. This review highlights the importance of lactic acid bacteria in the respiratory tract, and their potential as topical probiotics for this body site. We focus on the potential probiotic properties and adaptation factors that are needed for a bacterial strain to optimally exert its beneficial activity in the respiratory tract.

To unravel the biological function of the widely used probiotic bacterium Lactobacillus rhamnosus GG, we compared its 3.0-Mbp genome sequence with the similarly sized genome of L. rhamnosus LC705, an adjunct starter culture exhibiting reduced binding to mucus. Both genomes demonstrated high sequence identity and synteny. However, for both strains, genomic islands, 5 in GG and 4 in LC705, punctuated the colinearity. A significant number of strain-specific genes were predicted in these islands (80 in GG and 72 in LC705). The GG-specific islands included genes coding for bacteriophage components, sugar metabolism and transport, and exopolysaccharide biosynthesis. One island only found in L. rhamnosus GG contained genes for 3 secreted LPXTG-like pilins ( spaCBA ) and a pilin-dedicated sortase. Using anti-SpaC antibodies, the physical presence of cell wall-bound pili was confirmed by immunoblotting. Immunogold electron microscopy showed that the SpaC pilin is located at the pilus tip but also sporadically throughout the structure. Moreover, the adherence of strain GG to human intestinal mucus was blocked by SpaC antiserum and abolished in a mutant carrying an inactivated spaC gene. Similarly, binding to mucus was demonstrated for the purified SpaC protein. We conclude that the presence of SpaC is essential for the mucus interaction of L. rhamnosus GG and likely explains its ability to persist in the human intestinal tract longer than LC705 during an intervention trial. The presence of mucus-binding pili on the surface of a nonpathogenic Gram-positive bacterial strain reveals a previously undescribed mechanism for the interaction of selected probiotic lactobacilli with host tissues.

The lung, and more specifically the airway epithelium, is continuously exposed to a wide range of inhaled environmental agents. Acting as a frontline physical and biochemical barrier, the airway epithelium orchestrates early host defense mechanisms, among which immunoglobulin A (IgA) plays a central role. Long considered sterile, the healthy lung is now recognized as a complex mucosal ecosystem harboring diverse and dynamic microbial communities, including bacteria, fungi, viruses, and archaea. Although the lung microbiome is generally transient and low in biomass, accumulating evidence suggests that it contributes to pulmonary homeostasis by supporting immune system maturation, preserving structural tissue integrity, and limiting pathogen colonization. How immune homeostasis is maintained in this constantly challenged environment remains however a central and largely unanswered question. This review synthesizes current state-of-the-art knowledge on the origin, composition, and functional determinants of the lung microbiome, with a specific focus on its bidirectional interplay with secretory IgA. We discuss microbiota-specific IgA responses, factors influencing IgA–microbiome interactions, and how these processes are disrupted in chronic and inflammatory lung diseases. Finally, we highlight major knowledge gaps and explore emerging therapeutic perspectives targeting IgA–microbiome crosstalk to restore pulmonary immune homeostasis.

The spore-forming capacity of Bacillus spp. enables environmental persistence and stable product formulations, yet the interactions of environmental Bacillus spores and vegetative cells with the human immune system are not fully understood. We investigated the immunostimulatory potential of seven environmental Bacillus isolates ( B. subtilis , B. velezensis , B. licheniformis , B. pumilus ) and optimized their inactivation methods to preserve surface integrity and immunostimulatory activity. Inactivation was evaluated using heat/UV-C and 10–100% formalin, followed by scanning electron microscopy and human reporter cell assays (THP1-Dual monocytes, HEK-Blue hTLR2/6 and hTLR4). Heat/UV-C treatment retained Bacillus morphology and enhanced immune activation compared to 10–100% formalin treatment. Spores and vegetative cells activated key immune transcription factors (nuclear factor kappa B and interferon regulatory factors) in human monocytes, with spores inducing 1.5- to 8-fold lower responses compared to vegetative cells, and strain- and species-dependent effects observed. All tested Bacillus isolates significantly activated Toll-like receptor TLR2/6, but not TLR4. Genome analysis identified Bacillus spore envelope components (SpsAEIK, CotBCGQ) that may influence differences in immune responses. Our findings improve understanding of Bacillus -human immune interactions, revealing strain- and species-specific immunostimulatory activity. These results support further exploration of Bacillus isolates for immune-related and environmental applications.