An Update on Prebiotics and on Their Health Effects.

Prebiotic compounds were originally defined as "a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health"; however, a significant modulation of the definition was carried out in the consensus panel of The International Scientific Association for Probiotics and Prebiotics (ISAPP), and the last definition states that "prebiotics are substrates that are selectively utilized by host microorganisms conferring a health benefit". Health effects of prebiotics compounds attracted the interest of researchers, food companies and Regulatory Agencies, as inferred by the number of articles on Scopus for the keywords "prebiotic" and "health effects", that is ca. 2000, for the period January 2021-January 2024. Therefore, the aim of this paper is to contribute to the debate on these topics by offering an overview of existing knowledge and advances in this field. A literature search was performed for the period 2012-2023 and after the selection of the most relevant items, the attention was focused on seven conditions for which at least 8-10 different studies were found, namely colorectal cancer, neurological or psychiatric conditions, intestinal diseases, obesity, diabetes, metabolic syndrome, and immune system disorders. In addition, the analysis of the most recent articles through the software VosViewer version 1.6.20 pointed out the existence of five clusters or macro-categories, namely: (i) pathologies; (ii) metabolic condvitions; (iii) structure and use in food; (iv) immunomodulation; (v) effect on gut microbiota.

Minimal Inhibitory Concentrations of Thymol and Carvacrol: Toward a Unified Statistical Approach to Find Common Trends.

Thymol and carvacrol are some of the most important and used components of Essential oils (EOs); they are widely studied, and there are much data available in the literature. Their Minimal Inhibitory Concentration (MIC) values found in the literature from 2005 to present were used to assess the bioactivity toward yeasts, molds, Gram-positive bacteria, and Gram-negative bacteria, as well as on some bacterial species/serotypes (Salmonella sp., Escherichia coli, E. coli O157:H7, lactic acid bacteria, Listeria monocytogenes, Staphylococcus aureus, S. epidermidis, etc.) to find possible common trends or differences between the two compounds and among the tested species. The results were quite interesting and pointed out that there is a common range for the MIC of thymol and carvacrol for some bacterial species (150-400 mg/L), with some exceptions to this generalized statement. In addition, the statistics pointed out that bacteria could experience homogeneous (S. epidermidis, E. coli O157:H7) or heterogeneous trends (for example, Salmonella sp.) depending on the existence of possible sub-species or different experimental set-ups. Moreover, this paper suggests that there are some drawbacks and issues that should be solved for the effective use of EOs, which are the strong variability among the microorganisms and the lack of standard protocols and reference strains.

A narrative review on the use of probiotics in several diseases. Evidence and perspectives.

Gut microbiota is a complex ecosystem, strictly linked to health and disease, as a balanced composition (referred as eubiosis) is necessary for several physiological functions, while an unbalanced composition (dysbiosis) is often associated to pathological conditions and/or diseases. An altered microbiota could be positively affected and partially restored through probiotic supplementation, among others. This review addresses the effects of probiotics in several conditions, used as case-studies (colorectal cancer, neuro-psychiatric diseases, intestinal diseases, obesity, diabetes, metabolic syndrome, immune system, and musculoskeletal system disorders) by pointing out the clinical outcomes, the mode of action, mainly related to the production of short chain fatty acids (SCFA), the impact of probiotic dose and mode of supplementation, as well as trying to highlight a hit of the most used genera.

Microbiological Risk Assessment in Foods: Background and Tools, with a Focus on Risk Ranger.

Risk assessment is an important phase of the food production path; it is strictly related to the processing chain as a necessary step for safe foods. This paper represents a contribution to understanding what is and how risk assessment could be conducted; it aims to provide some information on the structure of risk assessment, the tools for its identification and measurement and the importance of risk assessment for correct communication. In this context, after a focus on the background and on some commonly used tools (Risk Ranger, FDA-iRisk, decision tree, among others), the paper describes how to perform risk assessment through three case studies: lettuce (for Listeria monocytogenes), chicken salad (for Escherichia coli), and fresh egg pasta (for Staphylococcus aureus) in the first step, and then a comparison of risk for chicken salad contaminated by different pathogens (E. coli O157:H7, Campylobacter spp. and Salmonella sp.). As a final step, a critical evaluation of Risk Ranger was carried out, pointing out its pros and cons.

Ultrasound can increase biofilm formation by Lactiplantibacillus plantarum and Bifidobacterium spp.

The main goal of this research was to study the effect of an Ultrasound (US) treatment on biofilm formation of Lactiplantibacillus plantarum (strains c19 and DSM 1055), Bifidobacterium animalis subsp. lactis DSM 10140, Bifidobacterium longum subsp. longum DSM 20219, and Bifidobacterium longum subsp. infantis DSM 20088. From a methodological point of view, each microorganism was treated through six US treatments, different for the power (10, 30, or 50% of the net power, 130 W), the duration (2, 6, or 10 min) and the application of pulses (0 or 10 s). After the treatment, a biofilm of the strains was let to form on glass slides and the concentration of sessile cells was analyzed for 16 days. Biofilms formed by untreated microorganisms were used as controls. As a first result, it was found that US significantly increased the concentration of sessile cells of B. longum subsp. infantis, while for some other strains US treatment could not affect the formation of biofilm while improving its stability, as found for L. plantarum DSM1055 after 16 days. The variable mainly involved in this positive effect of US was the duration of the treatment, as biofilm formation and stability were improved only for 2 min-treatments; on the other hand, the effect of power and pulses were strain-dependent. In conclusion, the results suggest practical implication of a US pre-treatment for various fields (improvement of adhesion of microorganisms useful in food or in the gut, biomedical and environmental industries), although further investigations are required to elucidate the mode of action.

Gut-Microbiota, and Multiple Sclerosis: Background, Evidence, and Perspectives.

Many scientific studies reveal a significant connection between human intestinal microbiota, eating habits, and the development of chronic-degenerative diseases; therefore, alterations in the composition and function of the microbiota may be accompanied by different chronic inflammatory mechanisms. Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), in which autoreactive immune cells attack the myelin sheaths of the neurons. The purpose of this paper was to describe the main changes that occur in the gut microbiota of MS patients, with a focus on both microbiota and its implications for health and disease, as well as the variables that influence it. Another point stressed by this paper is the role of microbiota as a triggering factor to modulate the responses of the innate and adaptive immune systems, both in the intestine and in the brain. In addition, a comprehensive overview of the taxa modified by the disease is presented, with some points on microbiota modulation as a therapeutic approach for MS. Finally, the significance of gastro-intestinal pains (indirectly related to dysbiosis) was assessed using a case study (questionnaire for MS patients), as was the willingness of MS patients to modulate gut microbiota with probiotics.

Using regression and Multifactorial Analysis of Variance to assess the effect of ascorbic, citric, and malic acids on spores and activated spores of Alicyclobacillusacidoterrestris.

The type strain of the species Alicyclobacillus acidoterrestris (DSM 3922) and the strain CB1 (accession number: KP144333) were studied in this research to assess the effects of three weak acids (malic, citric, and ascorbic acids), pH (3 or 4), and spore status (spores, and activated spores). Acids were used to prepare 7 different blends, and the blends used to reduce the pH of Malt Extract broth to 3 and 4; then, media were inoculated with spores or activated spores, stored at 45 °C (optimal temperature for A. acidoterrestris growth), and analyzed immediately and after 2 and 7 days. Data were preliminary standardized as increase/reduction of microbial population, compared to the initial concentration, and modelled through two different statistical approaches (multifactorial ANOVA, and multiple regression). Finally, a binary code (0-no growth or reduction of viable count; 1-growth) was used to perform a multiple regression analysis on the growth probability of A. acidoterrestris. Generally, ascorbic acid was the most effective compound, but other acids (e.g., malic acid) could contribute to increase the inactivation ratio; concerning spore status, the highest sensitivity of activated spores suggests that acids probably act during the outgrowing phase. Finally, the two strains showed different trends at pH 3.0, being the type strain the most resistant one.

Psycho-Microbiology, a New Frontier for Probiotics: An Exploratory Overview.

Probiotics are gradually gaining importance in the field of psychiatry in the form of psychobiotics. Psychobiotics' studies examine the existing relationship between gut microbiota and mental phenomena; the intake of certain strains of probiotics, such as Bifidobacterium and Lactobacillus, for example, allow the gut microbial system to be modified in order to provide benefits at the psychic, immune, hormonal, and mental levels. Those who suffer from forms of depression, anxiety disorders, chronic stress, low mood, but also people who do not suffer from such disorders, can therefore benefit from the use of psychobiotics. Thanks to probiotics, neurochemicals can in fact be produced within the gut microbiota and interact with receptors of the enteric nervous system that innervate the entire gastrointestinal tract. Once they enter the portal circulation, these substances go on to influence components of the nervous system and ultimately the brain, through what is called the gut-brain axis. This article proposes an exploratory overview of the proven effects of probiotics on brain activity and psycho-related diseases, focusing on clinical studies and measurable outcomes. The search was conducted using two different online tools: ClinicalTrials.gov and PubMed.

A Preliminary Approach to Define the Microbiological Profile of Naturally Fermented Peranzana Alta Daunia Table Olives.

Samples of brines from Peranzana Alta Daunia olives at the end of fermentation were analyzed; samples were taken in two different years from eight different locations (Torremaggiore, San Severo, San Paolo di Civitate, Lucera, Chieuti, Serracapriola, Gargano and Termoli in Southern Italy). Total aerobic count, enterobacteria, pseudomonads, staphylococci, lactic acid bacteria and yeasts (Saccharomyces and non-Saccharomyces) were assessed; moreover, presumptive lactobacilli were characterized in relation to their ability to grow with salt added, and at 10 and 45 °C. Yeasts were generally more abundant than lactic acid bacteria (LAB), but two clusters were found: one including the areas of Torremaggiore, San Severo, Apricena, Lucera and San Paolo di Civitate (area 1, A1), and another comprising Gargano, Termoli and Serracapriola (area 2, A2). Lactobacilli of A1 were more resistant to stress conditions (growth at 10% of salt and at 10 °C); moreover, A1 was characterized by a lower abundance of yeasts. In some areas (Lucera and San Severo), a higher abundance of non-Saccharomyces yeasts was found. This paper offers a first insight into the profile of Peranzana Alta Daunia olives at the end of fermentation, suggesting that some indices (technological traits of lactobacilli, ratio yeasts vs. LAB, abundance of non-Saccharomyces yeasts) could be useful to define a microbiological profile of the variety.

How Diet and Physical Activity Modulate Gut Microbiota: Evidence, and Perspectives.

Gut microbiota plays a significant role in the maintenance of physiological homeostasis, contributing to human health. Nevertheless, some factors (sex, age, lifestyle, physical activity, drug-based therapies, diet, etc.) affect its composition and functionality, linked to pathologies and immunological diseases. Concerning diet, it interacts with microorganisms, leading to beneficial or detrimental outcomes for the health of host. On the other hand, physical activity is known to be useful for preventing and, sometimes, treating several diseases of cardiovascular, neuroendocrine, respiratory, and muscular systems. This paper focuses on diet and physical activity presenting the current knowledge about how different diets (Western, ketogenic, vegan, gluten free, Mediterranean) as well as different types of exercise (intensive, endurance, aerobic) could shape gut microbiota.

Use of Food Spoilage and Safety Predictor for an "A Priori" Modeling of the Growth of Lactic Acid Bacteria in Fermented Smoked Fish Products.

Fermentation is one of the oldest methods to assure the safety and quality of foods, and to prolong their shelf life. However, a successful fermentation relies on the correct kinetics depending on some factors (i.e., ingredients, preservatives, temperature, inoculum of starter cultures). Predictive microbiology is a precious tool in modern food safety and quality management; based on the product characteristics and the conditions occurring in food processing, the inactivation of or increase in microbial populations could be accurately predicted as a function of the relevant intrinsic or extrinsic variables. The main aim of this study was the optimization of the formula of a smoked fermented fish product using predictive modeling tools (tertiary and secondary models) in order to define the role of each factor involved in the formulation and assure a correct course of fermentation. Product optimization was conducted through the software Food Spoilage and Safety Predictor (FSSP), by modeling the growth of lactic acid bacteria (LAB) as a function of some key parameters such as temperature, pH, salt, liquid smoke, carbon dioxide, and nitrites. The variables were combined through a fractional design of experiments (DoE) (3k-p), and the outputs of the software, i.e., the maximal growth rate (µmax) and the time to attain the critical threshold (tcrit), were modeled through a multiple regression procedure. The simulation, through FSSP and DoE, showed that liquid smoke is the most critical factor affecting fermentation, followed by temperature and salt. Concerning temperature, fermentation at 20-25 °C is advisable, although a low fermentation temperature is also possible. Other parameters are not significant.

Wine Microbiology and Predictive Microbiology: A Short Overview on Application, and Perspectives.

Predictive microbiology (PM) is an essential element in food microbiology; its aims are the determination of the responses of a given microorganism combining mathematical models with experimental data under certain environmental conditions, and the simulation a priori of the growth/inactivation of a population based on the known traits of a food matrix. Today, a great variety of models exist to describe the behaviour of several pathogenic and spoilage microorganisms in foods. In winemaking, many mathematical models have been used for monitoring yeast growth in alcoholic fermentation as well as to predict the risk of contamination of grapes and grape products by mycotoxin producing fungi over the last years, but the potentialities of PM in wine microbiology are underestimated. Thus, the goals of this review are to show some applications and perspectives in the following fields: (1) kinetics of alcoholic and malolactic fermentation; (2) models and approaches for yeasts and bacteria growth/inactivation; (3) toxin production and removal.

Fish Loss/Waste and Low-Value Fish Challenges: State of Art, Advances, and Perspectives.

The sustainability of fishery is a global challenge due to overfishing and reduced stocks all over the world; one of the leading factors of this threat is fish loss/waste. As a contribution to the global efforts towards a sustainable world, this review addresses the topic from different sides and proposes an overview of biorefinery approaches by discussing bioactive compounds that could be produced from fish loss (nitrogen compounds, lipids, minerals and pigments, and fish-based compounds such as chitosan). The second part of this review reports on the possibility of using loss or unwanted fish to design products for human consumption or for animal feeding, with a focus on economic criteria, consumers' segmentation, and some examples of products. The final focus is on Food and Agriculture Organization FAO guidelines as a roadmap for the future with respect to solving this threat by addressing the problem from different sides (technology, skills, market, policy, social and gender equity, and infrastructures).

Innovative Preservation Methods Improving the Quality and Safety of Fish Products: Beneficial Effects and Limits.

Fish products are highly perishable, requiring proper processing to maintain their quality and safety during the entire storage. Different from traditional methods used to extend the shelf-life of these products (smoking, salting, marinating, icing, chilling, freezing, drying, boiling, steaming, etc.), in recent years, some alternative methods have been proposed as innovative processing technologies able to guarantee the extension of their shelf-life while minimally affecting their organoleptic properties. The present review aims to describe the primary mechanisms of some of these innovative methods applied to preserve quality and safety of fish products; namely, non-thermal atmospheric plasma (NTAP), pulsed electric fields (PEF), pulsed light (PL), ultrasounds (US) and electrolyzed water (EW) are analysed, focusing on the main results of the studies published over the last 10 years. The limits and the benefits of each method are addressed in order to provide a global overview about these promising emerging technologies and to facilitate their greater use at industrial level. In general, all the innovative methods analysed in this review have shown a good effectiveness to control microbial growth in fish products maintaining their organoleptic, nutritional and sensory characteristics. Most of the technologies have also shown the great advantage to have a lower energy consumption and shorter production times. In contrast, not all the methods are in the same development stage; thus, we suggest further investigations to develop one (or more) hurdle-like non-thermal method able to meet both food production requirements and the modern consumers' demand.

Viability, Sublethal Injury, and Release of Cellular Components From Alicyclobacillus acidoterrestris Spores and Cells After the Application of Physical Treatments, Natural Extracts, or Their Components.

Alicyclobacillus acidoterrestris is a spoiling microorganism regarded as one of the most important causes of spoilage of fruit juices and acidic products. In this paper, four strains of A. acidoterrestris (type strain-DSM 3922; two wild strains isolated from soil-C8 and C24; wild strain isolated from a spoiled pear juice CB1) were treated through natural extracts/active compounds from essential oils (EOs), and physical treatments were used to assess their susceptibility and the presence of sublethal injury. The characterization of damage was also performed. The results suggest that it is possible to control A. acidoterrestris through alternative approaches, although the effect relied upon the age of spores. In addition to the mere antimicrobial effect, some treatments could cause a sublethal injury on spores. Lemon extract was the most effective treatment for both the antimicrobial effect and the sublethal injury, as evidenced by the release of proteins, and calcium dipicolinate [dipicolinic acid (DPA)] by fresh spores and only DPA (with an exception for C8) by old spores. A sublethal injury with protein release was also found for physical treatments [US (ultrasound) or heating]. For the first time, this paper reports on the existence of a sublethal injury for A. acidoterrestris, and this evidence could also be a challenge, because injured microorganisms could restore their metabolism, or an opportunity to design new preserving treatments.

Removal of Phenols in Table Olive Processing Wastewater by Using a Mixed Inoculum of Candida boidinii and Bacillus pumilus: Effects of Inoculation Dynamics, Temperature, pH, and Effluent Age on the Abatement Efficiency.

The main goal of this paper was to assess the ability of a combination of Candida boidinii and Bacillus pumilus to remove phenol in table olive processing water, as a function of some variables, like temperature, pH, a dilution of waste and the order of inoculation of the two microorganisms. At this purpose C. boidinii and B. pumilus were sequentially inoculated in two types of table olive processing water (fresh wastewater, FTOPW and wastewater stored for 3 months-aged wastewater, ATOPW). pH (6 and 9), temperature (10 and 35 °C) and dilution ratio (0, 1:1) were combined through a 2k fractional design. Data were modeled using two different approaches: Multifactorial Analysis of Variance (MANOVA) and multiple regression. A higher removal yield was achieved by inoculating B. pumilus prior to the yeast (192 vs. 127 mg/L); moreover, an increased efficiency was gained at 35 °C (mean removal of 200 mg/L). The use of two statistic approach suggested a different weight of variables; temperature was a global variable, that is a factor able to affect the yield of the process in all conditions. On the other hand, an alkaline pH could increase the removal of phenol at 10 °C (25-43%).

Assessed versus Perceived Risks: Innovative Communications in Agri-Food Supply Chains.

Food preparations, especially those based on animal products, are often accused of being responsible for the increase in food-borne infections, contributing to increased pressure on healthcare systems. The risk assessment in agri-food supply chains is of utmost importance for the food industry and for policymakers. A wrong perception of risks may alter the functioning of supply chains; thus, efforts should be devoted to communicating risks in an efficient way. We adopt a multidisciplinary approach to investigate how consumers perceive different food risks. Our analysis shows that planning effective communication strategies is very much important for efficiently informing consumers on food risks. We also comment on potential innovative ways to better organise the supply chains.

Increase of acidification of synthetic brines by ultrasound-treated Lactiplantibacillus plantarum strains isolated from olives.

This paper focused on the evaluation of Ultrasound effect on the growth patterns (3-6% of salt and 45 °C), acidification (pH-decrease), interactions with microorganisms, and membrane permeability of nine strains of Lactiplantibacillus plantarum. Ultrasound treatment was applied at 20% of net power by modulating duration (2-10 min) and pulses (2-10 s). Viable count (7.15-8.16 log CFU/mL) was never affected by Ultrasound, while the treatment increased the extent of pH decrease of at least three strains (109, 162 and c19). L. plantarum c19 was the best performer, as a low intensity treatment was able to increase its acidification, without affecting its growth. The effects could be attributed to an increased permeability of the cellular membrane, as suggested by the increase of released intracellular components. Other factors should be further assessed (e.g. possible changes in the metabolism) and the performances of Ultrasound-treated strains in real brines.

Marinated Sea Bream Fillets Enriched with Lactiplantibacillus plantarum and Bifidobacterium animalis subsp. lactis: Brine Optimization and Product Design.

This study aimed to design marinated sea bream fillets, inoculated with either Lactiplantibacillus plantarum (strains 11, 68, 69) or Bifidobacterium animalis subsp. lactis DSM 10140. In the first step, the optimization of brine composition was performed through a centroid; the factors of the design were citric acid, vinegar, and salt. As a result of optimization, the optimal composition of brine was set to 0.75% citric acid, 55% vinegar, and 3% NaCl. In the second step, sea bream fillets were inoculated with L. plantarum strain 69 and B. animalis subsp. lactis, marinated and then packed in a conditioning solution (oil or diluted brine); the samples were stored at 4 °C for 21 days. The viability of the strains and sensory scores were assessed. The bacteria retained a high viability throughout storage (21 days); however, the sensory scores were at their highest level for 4 days. In particular, sensory assessment suggested a preference for a conditioning solution with oil, rather than with a diluted brine. In addition, a slightly higher preference was found for B. animalis subsp. lactis.

Use of Autochthonous Lactiplantibacillus plantarum Strains to Produce Fermented Fish Products.

The present research was aimed to the optimization of the production of a fish fermented salami-like product using autochthonous Lactiplantibacillus plantarum starters. The activity was performed through two phases: (1) Optimization of fermented fish product composition by using a 2k-p Fractional Factorial Design: the variables tested were nitrites (0-150 ppm), salt (2.5-7.5%), sucrose (0-4%), white pepper (0-0.10%), and fermentation temperature (10-30°C); (2) Product realization and evaluation of its microbiological profile [aerobic microbiota (APC), Pseudomonadaceae (PSE), Enterobacteriaceae (E), and lactic acid bacteria (LAB) populations], chemico-physical parameters (pH and aw), and sensorial quality (odor, texture, color, and overall acceptability) during its storage at 4°C for 21 days. In the first step, the fish pulp was mixed with the appropriate amounts of ingredients, according to the experimental design; each batch was individually inoculated with the studied starter (L. plantarum 11, L. plantarum 69, and L. plantarum DSM1055) at 107 cfu/g and incubated at 10, 20, or 30°C for 7 days. The lowest fermentation time (time to reach pH 4.4) was obtained with 4% sucrose, 100 ppm nitrite and a process temperature of 30°C. In the second step, salami-like were produced according to the individuated formulation and inoculated with the studied starters (107 cfu/g); the fish mixture was stuffed into a natural casing and left to ferment at 30°C for 7 days. The use of the selected strains not only assured a correct fermentation but reduced the process time at only 2 days; during refrigerated storage, a good microbiological, chemico-physical and sensorial quality of the final product was recorded for at least 21 days.