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Two new recipes of baker's yeast bread fortified with fermented apple by-products and avocado or walnut were designed resulting in enhanced profiles of total free amino acids, in vitro protein digestibility (IVPD) and predicted glycemic index (pGI). Concurrently, pools of lactic acid bacteria and yeast were screened to select the most promising starters for sourdough preparation. The type II sourdough with Lactiplantibacillus plantarum CR1, Furfurilactobacillus rossiae CR5 and Saccharomyces cerevisiae E10 had the highest acidification and total free amino acids value, while resulting in bread with the highest IVPD and the lowest pGI.Sourdough breads were manufactured with the new recipes. They had improved protein digestibility and starch hydrolysis, and enhanced content of dietary fiber, phenolics and unsaturated free fatty acids. The impact of new fortified sourdough breads on colon microbial ecosystems was investigated by the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). The intake promoted the short-chain fatty acids synthesis and expanded several bacterial taxa with potential to exert beneficial activities. The synergic combination of sourdough fermentation and fortification with fermented plant-based matrices (including by-products) was a suitable strategy to promote better nutritional and digestibility properties in breads, and to promisingly address the modulation of gut microbiota.

ABSTRACT Gluten possesses unique properties that render it only partially digestible. Consequently, it exerts detrimental effects on a part of the worldwide population who are afflicted with celiac disease (1%) or related disorders (5%), particularly due to the potential for cross-contamination even when adhering to a gluten-free diet (GFD). Finding solutions to break down gluten during digestion has a high nutritional and social impact. Here, a randomized double-blind placebo-controlled in vivo challenge investigated the gluten-degrading activity of a novel probiotic preparation comprising lactobacilli and their cytoplasmic extracts, Bacillus sp., and bacterial protease. In our clinical trial, we collected feces from 70 healthy volunteers at specific time intervals. Probiotic/placebo administration lasted 32 days, followed by 10 days of wash-out. After preliminary GFD to eliminate residual gluten from feces, increasing amounts of gluten (50 mg–10 g) were administered, each one for 4 consecutive days. Compared to placebo, the feces of volunteers fed with probiotics showed much lower amounts of residual gluten, mainly with increased intakes. Probiotics also regulate the intestinal microbial communities, improving the abundance of genera pivotal to maintaining homeostasis. Quantitative PCR confirmed that all probiotics persisted during the intervention, some also during wash-out. Probiotics promoted a fecal metabolome with potential immunomodulating activity, mainly related to derivatives of branched-chain amino acids and short-chain fatty acids.IMPORTANCEThe untapped potential of gluten-degrading bacteria and their application in addressing the recognized limitations of gluten-related disorder management and the ongoing risk of cross-contamination even when people follow a gluten-free diet (GFD) emphasizes the significance of the work. Because gluten, a common protein found in many cereals, must be strictly avoided to stop autoimmune reactions and related health problems, celiac disease and gluten sensitivity present difficult hurdles. However, because of the hidden presence of gluten in many food products and the constant danger of cross-contamination during food preparation and processing, total avoidance is frequently challenging. Our study presents a novel probiotic preparation suitable for people suffering from gluten-related disorders during GFD and for healthy individuals because it enhances gluten digestion and promotes gut microbiota functionality.

This study investigated the development of hybrid cheese analogues (HCA) made with fermented brewery side-stream ingredients (spent yeast and malt rootlets) and dairy milk. Different percentages of side-stream flours (3.5%, 5%, and 7.5%) were mixed with pasteurized milk, and the developed HCA were evaluated for their biochemical and textural properties. The addition of a fermentation step improved nutrient availability and led to pH (range 4.79–5.60) and moisture content (range 45.86%–61.29%) similar to traditional animal-based fresh cheeses (control). The inclusion of side-stream flours led to coagulation, even without rennet addition. The higher the concentration of the flour used, the faster the coagulation time, suggesting synergistic effect between the enzymes of the rennet and the enzymes present in the fermented side-stream flours. Nevertheless, textural properties were inferior compared to the control. Selected HCA formulations with added 3.5% flour exhibited increased counts of enterococci and enterobacteria cell densities, ranging from 7.28 ± 0.03 to 7.72 ± 0.09 log CFU/g and 4.90 ± 0.16 to 5.41 ± 0.01 log CFU/g, respectively. Compared to the control sample, HCA formulations exhibited higher concentrations of organic acids, peptides, and free amino acids (FAAs). Lactic acid reached up to 23.78 ± 0.94 g/kg of dry matter (DM), while the peptide area reached up to 22918.50 ± 2370.93 mL⋅AU. Additionally, the total concentration of individual FAAs reached up to 2809.74 ± 104.85 mg/kg of DM, contrasted with the control, which resulted in lower concentrations (847.65 ± 0.02 mg/kg of DM). The overall findings suggested that despite challenges in microbiological quality and textural properties, HCA produced with the inclusion of up to 3.5% brewery side-stream flours could be a sustainable solution to produce nutritious dairy alternatives.

Abstract Background In nature, microbial communities undergo changes in composition that threaten their resiliency. Here, we interrogated sourdough, a natural cereal-fermenting metacommunity, as a dynamic ecosystem in which players are subjected to continuous environmental and spatiotemporal stimuli. Results The inspection of spontaneous sourdough metagenomes and transcriptomes revealed dominant, subdominant and satellite players that are engaged in different functional pathways. The highest microbial richness was associated with the highest number of gene copies per pathway. Based on meta-omics data collected from 8 spontaneous sourdoughs and their identified microbiota, we de novo reconstructed a synthetic microbial community SDG. We also reconstructed SMC-SD43 from scratch using the microbial composition of its spontaneous sourdough equivalent for comparison. The KEGG number of dominant players in the SDG was not affected by depletion of a single player, whereas the subdominant and satellite species fluctuated, revealing unique contributions. Compared to SMC-SD43, SDG exhibited broader transcriptome redundancy. The invariant volatilome profile of SDG after in situ long-term back slopping revealed its stability. In contrast, SMC-SD43 lost many taxon members. Dominant, subdominant and satellite players together ensured gene and transcript redundancy. Conclusions Our study demonstrates how, by starting from spontaneous sourdoughs and reconstructing these communities synthetically, it was possible to unravel the metabolic contributions of individual players. For resilience and good performance, the sourdough metacommunity must include dominant, subdominant and satellite players, which together ensure gene and transcript redundancy. Overall, our study changes the paradigm and introduces theoretical foundations for directing food fermentations. Video Abstract

ABSTRACT Raw cow milk is one of the most complex and unpredictable food matrices shaped by the interaction between biotic and abiotic factors. Changes in dairy farming conditions impact the quality and safety of milk, which largely depend on seasonality. Changes in microbiome composition and relative metabolic pathways are derived from microbial interactions, as well as from seasonality, mammary, and extramammary conditions (e.g., farm management and outdoor environment). Breeding data from >600 Apulian farms were examined, and the associated physicochemical parameters were processed by a reductionist approach to obtain a raw cow milk sample subset. We investigated the microbiological variability in cultivable and 16S rRNA sequencing microbiota as affected by seasonal fluctuations at two time points (winter and summer seasons). We identified families (Xanthomonadaceae, Enterobacteriaceae, and Pseudomonadaceae) whose increased abundance during winter may cause a shift toward a pathobiont microbial niche that leads to lower milk quality. Apulian summer season conditions were advantageous to the presence of specific taxa, i.e., Streptococcaceae (i.e., Lactococcus) and Limosilactobacillus fermentum, which in turn may favor better milk preservation. IMPORTANCE The strength of this study lies in the microbiological characterization of a wide range of farm management data to achieve a more comprehensive framework of Apulian milk. Specific regional pedoclimatic and management conditions impact the taxa present and their abundances within this ecological food niche. The obtained results lay the groundwork for comparison with other worldwide extensive farming areas.

Our study proposed date seeds flour (DSF) as an innovative ingredient for sourdough bread production through sustainable bio-recycling. We isolated autochthonous lactic acid bacteria and yeasts from DSF and DSF-derived doughs to build up a reservoir of strains from which to select starters ensuring rapid adaptation and high ecological fitness. The screening based on pro-technological criteria led to the formulation of a mixed starter consisting of Leuconostoc mesenteroides, Lactiplantibacillus plantarum, and Saccharomyces cerevisiae strains, which allowed obtaining a mature type I sourdough after consecutive refreshments, in which an aliquot of the durum wheat flour (DWF) was replaced by DSF. The resulting DSF sourdough and bread underwent an integrated characterization. Sourdough biotechnology was confirmed as a suitable procedure to improve some functional and sensory properties of DWF/DSF mixture formulation. The radical scavenging activity increased due to the consistent release of free phenolics. Perceived bitterness and astringency were considerably diminished, likely because of tannin degradation.

A large subset of fermented foods act as vehicles of live environmental microbes, which often contribute food quality assets to the overall diet, such as health-associated microbial metabolites. Foodborne microorganisms also carry the potential to interact with the human gut microbiome via the food chain. However, scientific results describing the microbial flow connecting such different microbiomes as well as their impact on human health, are still fragmented. The aim of this systematic review is to provide a knowledge-base about the scientific literature addressing the connection between foodborne and gut microbiomes, as well as to identify gaps where more research is needed to clarify and map gut microorganisms originating from fermented foods, either traditional or added with probiotics, their possible impact on human gut microbiota composition and to which extent foodborne microbes might be able to colonize the gut environment. An additional aim was also to highlight experimental approaches and study designs which could be better standardized to improve comparative analysis of published datasets. Overall, the results presented in this systematic review suggest that a complex interplay between food and gut microbiota is indeed occurring, although the possible mechanisms for this interaction, as well as how it can impact human health, still remain a puzzling picture. Further research employing standardized and trans-disciplinary approaches aimed at understanding how fermented foods can be tailored to positively influence human gut microbiota and, in turn, host health, are therefore of pivotal importance.