Probiotics are live microorganisms that confer health benefits on the host. However, in recent years, several concerns on their use have been raised. In particular, industrial processing and storage of probiotic products are still technological challenges as these could severely impair cell viability. On the other hand, safety of live microorganisms should be taken into account, especially when administered to vulnerable people, such as the elderly and immunodeficient individuals. These drawbacks have enhanced the interest toward new products based on non-viable probiotics such as paraprobiotics and postbiotics. In particular, paraprobiotics, defined as “inactivated microbial cells (non-viable) that confer a health benefit to the consumer,” hold the ability to regulate the adaptive and innate immune systems, exhibit anti-inflammatory, antiproliferative and antioxidant properties and exert antagonistic effect against pathogens. Moreover, paraprobiotics can exhibit enhanced safety, assure technological and practical benefits and can also be used in products suitable for people with weak immunity and the elderly. These features offer an important opportunity to prompt the market with novel functional foods or nutraceuticals that are safer and more stable. This review provides an overview of central issues on paraprobiotics and highlights the urgent need for further studies aimed at assessing safety and efficacy of these products and their mechanisms of action in order to support decisions of regulatory authorities. Finally, a definition is proposed that unambiguously distinguishes paraprobiotics from postbiotics.

This study aimed to compare phenotypic and genetic characteristics of Lactobacillus rhamnosus strains isolated at the end of the ripening of Parmigiano Reggiano cheese and to investigate an important prerequisite of probiotic interest, such as the capability to survive at low pH and in presence of bile salts. The use of API 50 CH, RAPD-PCR analysis and species-specific PCR allowed to ascertain the identity of 63 L. rhamnosus strains. Three L. rhamnosus strains isolated from Parmigiano Reggiano cheese, L. rhamnosus ATCC 7469T and the commercial strain L. GG were assayed to estimate the resistance to various stress factors reproducing in vitro some conditions of the gastro-intestinal environment such as low pH and different amounts of bile salts and acids. The behaviour of almost all the tested strains isolated from Parmigiano Reggiano cheese resulted analogous to that showed by L. GG.

Lactic acid fermentation is one of the oldest methods used worldwide to preserve cereals and vegetables. Europe and Asia have long and huge traditions in the manufacturing of lactic acid bacteria (LAB)-fermented foods. They have different cultures, religions and ethnicities with the available resources that strongly influence their food habits. Many differences and similarities exist with respect to raw substrates, products and microbes involved in the manufacture of fermented products. Many of them are produced on industrial scale with starter cultures, while others rely on spontaneous fermentation, produced homemade or in traditional events. In Europe, common LAB-fermented products made from cereals include traditional breads, leavened sweet doughs, and low and non-alcoholic cereal-based beverages, whereas among vegetable ones prevail sauerkraut, cucumber pickles and olives. In Asia, the prevailing LAB-fermented cereals include acid-leavened steamed breads or pancakes from rice and wheat, whereas LAB-fermented vegetables are more multifarious, such as kimchi, sinki, khalpi, dakguadong, jiang-gua, soidon and sauerkraut. Here, an overview of the main Euro-Asiatic LAB-fermented cereals and vegetables was proposed, underlining the relevance of fermentation as a tool for improving cereals and vegetables, and highlighting some differences and similarities among the Euro-Asiatic products. The study culminated in “omics”-based and future-oriented studies of the fermented products.

This work aimed to evaluate the antibiotic susceptibility of 63 Lactobacillus rhamnosus\ud strains isolated from Parmigiano Reggiano cheese, of Lactobacillus GG and of the type strain\ud L. rhamnosus DSM 20021. Antimicrobial susceptibility was determined by the disc diffusion\ud method on 41 antibiotics. Inhibition zone diameter was carefully measured and the results (the mean\ud of four determinations) were expressed in terms of resistance or susceptibility. All the strains isolated\ud from cheese showed resistance to six antibiotics (cefixime, vancomycin, neomycin, enoxacin,\ud pefloxacin and sulphamethoxazole plus trimethoprim). The strain DSM 20021T was resistant to\ud nine antibiotics (the previous six plus cephalexin, bacitracin and lincomycin), while the commercial\ud strain L. GG showed resistance to eighteen antibiotics. A high strain-specific resistance to different\ud antibiotics was ascertained in Lactobacillus rhamnosus isolated from cheese. The results obtained\ud in this study confirm that antibiotic resistance is a very important feature in the selection of potentially\ud probiotic lactic acid bacteria

This study was aimed at selecting novel strains of Lactobacillus paracasei, Lactobacillus casei and Lactobacillus\ud rhamnosus for their capability to withstand different stress factors encountered in food processing\ud and in the gastrointestinal tract. In spite of the extensive use of Lactobacillus strains in food\ud applications and as commercial probiotics, there is little information on the diversity in the stress\ud tolerance within these species. In this work 108 L. paracasei, 68 L. rhamnosus and 8 L. casei strains,\ud isolated from different sources (dairy and meat products, sourdoughs, wine, beverages, vegetables and\ud human body) and geographical regions were screened for tolerance to acid, bile salts, high osmolarity\ud and capability to grow at different non-optimal temperatures and survival after exposure to refrigeration\ud or freezing.\ud The study highlighted a noticeable heterogeneity in the ability of the strains to withstand harsh\ud growth conditions suggesting that different stress factors should be applied to identify the most\ud promising candidates for technological uses. In this investigation thirteen strains, isolated from wine,\ud human faeces and sourdough niches, that showed better tolerance to high acidity, bile salts and NaCl,\ud thus more interesting for being industrially exploited, were selected