Background Gut microbiota holds a key-role in numerous biological functions and has emerged as a driving force for the development of diabetes. Diet contributes to gut microbiota diversity and functionality providing a tool for the prevention and management of the disease. The study aimed to investigate the effect of a dietary intervention with pistachio nuts, a rich source of monounsaturated fatty acids, dietary fibers and phytochemicals on gut microbiota composition in the rat model of Type 1 Diabetes. Methods Male Wistar rats were randomly assigned into four groups: healthy animals which received control diet (CD) or pistachio diet (PD), and diabetic animals which received control diet (DCD) or pistachio diet (DPD) for 4 weeks. Plasma biochemical parameters were determined and histological examination of liver and pancreas was performed at the end of the dietary intervention. Adherent intestinal microbiota populations in jejunum, ileum, caecum and colon were analyzed. Fecal microbiota populations at the beginning and the end of the study were determined by microbiological analysis and 16S rRNA sequencing. Results Diabetic animals of both groups exhibited high plasma glucose and low insulin concentrations, as well as characteristic pancreatic lesions. Pistachio supplementation significantly increased lactobacilli and bifidobacteria populations in jejunum, ileum and caecum ( p < 0.05) and normalized microbial flora in all examined intestinal regions of diabetic animals. After 4 weeks of supplementation, populations of bifidobacteria and lactobacilli were increased in feces of both healthy and diabetic animals, while enterococci levels were decreased ( p < 0.05). Next Generation Sequencing of fecal samples revealed increased and decreased counts of Firmicutes and Bacteroidetes , respectively, in healthy animals that received the pistachio diet. Actinobacteria OTUs were higher in diabetic animals and increased over time in the pistachio treated groups, along with increased abundance of Bifidobacterium. Lactobacillus , Turicibacter and Romboutsia populations were elevated in healthy animals administered the pistachio nuts. Of note, relative abundance of Bacteroides was higher in healthy than in diabetic rats ( p < 0.05). Conclusion Dietary pistachio restored normal flora and enhanced the presence of beneficial microbes in the rat model of streptozotocin-induced diabetes.

Over the last decades, the incidence of diabetes has increased in developed countries and beyond the genetic impact, environmental factors, which can trigger the activation of the gut immune system, seem to affect the induction of the disease process. Since the composition of the gut microbiome might disturb the normal interaction with the immune system and contribute to altered immune responses, the restoration of normal microbiota composition constitutes a new target for the prevention and treatment of diabetes. Thus, the interaction of gut microbiome and diabetes, focusing on mechanisms connecting gut microbiota with the occurrence of the disorder, is discussed in the present review. Finally, the challenge of functional food diet on maintaining intestinal health and microbial flora diversity and functionality, as a potential tool for the onset inhibition and management of the disease, is highlighted by reporting key animal studies and clinical trials. Early onset of the disease in the oral cavity is an important factor for the incorporation of a functional food diet in daily routine.

Type 1 Diabetes (T1D) onset has been associated with diet, among other environmental factors. Adipose tissue and the gut have an impact on β-cell biology, influencing their function. Dietary ingredients affect fatty acid profiles of visceral adipose tissue (VAT) and plasma, as well as SCFAs production after microbial fermentation. Pistachios are a rich source of oleic acid, known for their anti-inflammatory actions and favorably affect gut microbiota composition. The purpose of the study was to examine plasma and VAT fatty acids profiles as well as fecal SCFAs after dietary intervention with pistachio nuts in streptozotocin-induced diabetic rats. Plasma and VAT fatty acids were determined by GC-MS and SCFAs by HPLC. After 4 weeks of pistachio consumption, MUFA and especially oleic acid were increased in plasma and VAT of diabetic rats while PUFA, total ω6 and especially 18:2ω6, were decreased. Lactic acid, the major end-product of beneficial intestinal microorganisms, such as lactobacilli, was elevated in healthy groups, while decreased levels of isovaleric acid were recorded in healthy and diabetic groups following the pistachio diet. Our results reveal possible beneficial relationships between pistachio nut consumption, lipid profiles and intestinal health in the disease state of T1D.

Designing stable dried functional food ingredients and foods containing live probiotic cultures maintaining high viable cell loads at the time of consumption is a challenge for the industry. The aim of the present study was the development of stable freeze-dried functional food ingredients with enhanced shelf-life during long storage. Zea flakes, pistachios, and raisins were used as immobilization supports for the wild-type presumptive probiotic strains Pediococcus acidilactici SK and Lactiplantibacillus plantarum F4, while L. plantarum B282 was used as a reference strain. Cell survival was monitored during storage at room and refrigerated temperatures for up to 6 months. Levels of freeze-dried cultures were maintained up to 7.2 logcfu/g after 6 months storage at room temperature and up to 8.5 logcfu/g at refrigerator temperature, in contrast to free cell levels that ranged <7 logcfu/mL, suggesting the positive effects of immobilization and freeze-drying on cell viability. Of note, levels of freeze-dried immobilized P. acidilactici SK cells on zea flakes and pistachios remained stable after 6 months of storage at 4 °C, ranging 8.1–8.5 logcfu/g (survival rates 98.2 and 99.7%, respectively). The technology developed presents important advantages for the maintenance of cell viability during storage, assuring stability of ready-to-use functional food ingredients that could be directly incorporated in food systems.

Annually, the wine industry produces high amounts of waste that can be toxic if disposed of without pretreatment. Vermicomposting is an efficient and low-cost method of decomposing organic matter using earthworms under controlled conditions. The organic substrate used in the vermicomposting process affects microbial populations and reflects the dynamics of enzymatic activity, decomposition of organic matter, and nitrogen transformations. However, the microbiome associations during the whole process are still unexplored. Thus, the aim of the present study was to investigate physicochemical, enzymatic, microbial, and microbiome activities during vermicomposting of winery waste. In this vein, a rectangular vermireactor with Eisenia andrei and Eisenia fetida earthworms, loaded with winery waste, was used. At the end of the process, the carbon/nitrogen (C/N) ratio was decreased, the total nitrogen was increased, the pH was neutralized and excess enzymatic activities were recorded. The bacterial and fungal phyla detected by next-generation sequencing analysis identified Armatimonadetes, Bacteriodetes, Candidatus saccharibacteria, Chloroflexi, Cyanobacteria, Planctomycetes, and Proteobacteria and Ascomycota, Basidiomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, and Mucoromycota, respectively. Physicochemical and microbial changes occurring during vermicomposting of winery waste, along with the microbiome diversity at the beginning and end of the process, may lead to a better understanding of winery-waste biotransformation into effective biofertilizer.

Background: Cheese microbiome plays a key role in determining the organoleptic and physico-chemical properties and may be also used as an authenticity tool for distinguishing probiotic cultures. Due to significant reduction of cell viability often witnessed during food production processes and storage, immobilization is proposed to ascertain high probiotic cell loads required to confer the potential health benefits. Hence, the aim of the present study was to investigate the effect of free or immobilized Lactiplantibacillus plantarum T571 on whey protein on feta cheese microbiome. Methods: Next-Generation Sequencing technology was used to investigate cheese microbiome. Cheese samples containing free or immobilized Lactiplantibacillus plantarum T571 (a wild type strain isolated from Feta cheese brine) on whey protein, along with products containing commercial starter culture, were analyzed. Results: The results showed a great diversity of bacteria and fungi genera among the samples. An increased presence of Lactobacillus OTUs in cheese with immobilized cells on whey protein was witnessed, highlighting the survival of the strain in the final product. The immobilized culture had also a significant impact on other genera, such as Lactococcus, Leuconostoc and Debaryomyces, which are associated with improved technological characteristics and health benefits. Conclusions: Enrichment of feta cheese with immobilized potential probiotics to secure cell viability consists of an industrial challenge and leads to distinct microbiome composition that may be used as a valuable food authenticity tool.

The present study aimed at investigating the possible benefits of a dietary intervention with Corinthian currants, a rich source of phenolic compounds, on type 1 diabetes (T1D) using the animal model of the streptozotocin-(STZ)-induced diabetic rat. Male Wistar rats were randomly assigned into four groups: control animals, which received a control diet (CD) or a diet supplemented with 10% w/w Corinthian currants (CCD), and diabetic animals, which received a control diet (DCD) or a currant diet (DCCD) for 4 weeks. Plasma biochemical parameters, insulin, polar phenolic compounds, and inflammatory factors were determined. Microbiota populations in tissue and intestinal fluid of the caecum, as well as fecal microbiota populations and short-chain fatty acids (SCFAs), were measured. Fecal microbiota was further analyzed by 16S rRNA sequencing. The results of the study showed that a Corinthian currant-supplemented diet restored serum polar phenolic compounds and decreased interleukin-1b (IL-1b) (p < 0.05) both in control and diabetic animals. Increased caecal lactobacilli counts (p < 0.05) and maintenance of enterococci levels within normal range were observed in the intestinal fluid of the DCCD group (p < 0.05 compared to DCD). Higher acetic acid levels were detected in the feces of diabetic rats that received the currant diet compared to the animals that received the control diet (p < 0.05). Corinthian currant could serve as a beneficial dietary component in the condition of T1D based on the results coming from the animal model of the STZ-induced T1D rat.

Nowadays, functional foods supplemented with health-promoting microorganisms have attracted consumer attention due to their health benefits. However, maintaining high cell loads, which consist of an essential requirement for conferring the health effect, is a real bottleneck for the food industry due to viability declines during food processing and storage. Hence, freeze-drying and cell immobilization have been suggested to enhance cell viability. The aim of our study was to assess the effect of freeze-dried immobilized P. acidilactici ORE5 on pistachio nuts on the functional regulation of the Katiki Domokou-type cheese microbiome. Supplementation of Katiki Domokou-type cheese with free or immobilized P. acidilactici ORE5 culture resulted in cell loads > 8.5 logcfu/g up to 7 days of storage. Both free and immobilized P. acidilactici ORE5 cells suppressed the growth of L. monocytogenes after deliberate inoculation, acting as a protecting shield. HS-SPME GC/MS analysis showed that the incorporation of P. acidilactici ORE5 culture in cheese resulted in an improved volatile compounds profile, as verified by the preliminary sensory evaluation. According to Next-Generation Sequencing analysis, a wide range of bacterial diversity was revealed among samples. The most abundant genus was Lactococcus in all samples, while the results showed an increased presence of Pediococcus spp. in cheese fortified with P. acidilactici ORE5 culture, highlighting the ability of the strain to survive in the final product. Furthermore, the incorporation of P. acidilactici ORE5 culture in cheese had a significant impact on cheese microbiome composition, as the presence of spoilage bacteria, such as Chryseobacterium, Acinetobacter and Pseudomonas, was significantly less compared to the control cheese, indicating quality improvement and prolongation of the product’s shelf-life.