Spirulina platensis biomass enhances the proliferation rate of Lactobacillus acidophilus 5 (La-5) and combined with La-5 impact the gut microbiota of medium-age healthy individuals through an in vitro gut microbiome model

Lactobacillus acidophilus extracellular vesicles-coated UiO-66-NH2@siRNA nanoparticles for ulcerative colitis targeted gene therapy and gut microbiota modulation

Ulcerative colitis (UC) is a complex and chronic inflammatory bowel disease whose pathogenesis involves genetic and environmental factors, which poses a challenge for treatment. Here, we have designed an innovative integrated therapeutic strategy using Lactobacillus acidophilus extracellular vesicles (EVs) to encapsulate UiO-66-NH2 nanoparticles bounded with TNF-α siRNA (EVs@UiO-66-NH2@siRNA) for UC treatment. This system shows superior affinity to inflammation-related cells due to the Lactobacillus acidophilus EVs can maintain immune homeostasis by regulating the secretion of cytokines in vitro. siRNA can specifically target the key inflammatory TNF-α in UC and silence its gene expression, thereby regulating the process of inflammatory response. After oral administration, EVs@UiO-66-NH2@siRNA demonstrates an accurate delivery of TNF-α siRNA to colonize the colon site and exerts a siRNA therapeutic effect by inhibiting the expression of TNF-α, which alleviates the intestinal inflammation in DSS-induced UC model. Moreover, this system can modulate the types and compositional structures of gut microbiota and metabolites to achieve an anti-inflammatory phenotype, which is helpful for the repair of intestinal homeostasis. We also have proved that UiO-66-NH2 nanoparticles exhibit a high loading capacity for TNF-α siRNA and good pH responsiveness, improving the potent release of siRNA in colon tissue. Collectively, the EVs@UiO-66-NH2@siRNA nano-delivery system demonstrate a feasible combination therapeutic strategy for UC through gut microecology modulation, immune regulation and TNF-α siRNA silence, which may provide a potential targeted treatment approach for inflammatory bowel disease.

Role of Simulated Nannochloropsis gaditana Digests in Shaping Gut Microbiota and Short-Chain Fatty Acid Levels

The connection between gut microbiota and factors like diet is crucial for maintaining intestinal balance, which in turn impacts the host's overall health. Nannochloropsis gaditana microalgae is a sustainable source of bioactive compounds, mainly known for its used in aquaculture and extraction of bioactive lipids, with potential health benefits whose effects on human gut microbiota are still unknown. Therefore, the goal of this work was to assess the impact of N. gaditana on human gut microbiota composition and derived metabolites by combining the INFOGEST protocol and in vitro colonic fermentation process to evaluate potential effects on human gut microbiota conformation through 16S rRNA gene sequencing and its metabolic functionality. The results have demonstrated the ability of the digests from N. gaditana to significantly modify gut microbiota composition, promoting an increase in beneficial bacterial genera such as Akkermansia, Butyricicoccus, Eisenbergiella, Lachnoclostridium, and Marvinbryantia, in contrast to inulin, after 48 h of colonic fermentation. Additionally, the digests increased the levels of both major and minor short-chain fatty acids (SCFAs), particularly butyric and valeric acids, considered as intestinal biomarkers, and increased ammonium production. This research has demonstrated, for the first time, the potential of N. gaditana microalgae as a sustainable agent for influencing the composition and functionality of human gut microbiota.

Shedding light on the impacts of Spirulina platensis on gut microbiota and related health benefits

Spirulina (S.) platensis is a blue-green algae with reported nutritional and health-promoting properties, such as immunomodulating, antioxidant, cholesterol-lowering properties, and beneficial effects on inflammatory diseases. Spirulina platensis can improve the function and composition of the gut microbiota and exert systemic beneficial effects. Gut dysbiosis is characterized by an imbalance in the composition and function of gut microbiota and is associated with several diseases. Some dietary bioactive compounds can restore the composition, diversity, and function of the gut microbiota and improve health-related parameters. This review proposes to gather relevant information on the effects of S. platensis supplementation on the modulation of the function and composition of gut microbiota and local and systemic measures related to gut health, such as inflammation, oxidative stress, and glucose and lipid metabolism. The body of evidence conducted with animals and clinical studies shows that S. platensis supplementation increased gut microbiota diversity and improved gut microbiota composition, as reported by a decrease in the Firmicutes/Bacteroides ratio, increase in the relative abundance of Prevotella and Lactobacillaceae, increase in short-chain fatty acid production and decrease of gut permeability. Improvements in gut microbiota have been associated with host health benefits such as anti-obesity, anti-diabetic, anti-hypertensive, anti-lipemic, anti-inflammatory, and antioxidant effects.

Revealing the beneficial effects of a dairy infant formula on the gut microbiota of early childhood children with autistic spectrum disorder using static and SHIME® fermentation models

This study evaluated the impact of the Milnutri Profutura® (MNP) dairy infant formula on the gut microbiota of early childhood children (three to five years) with Autistic Spectrum Disorder (ASD) using static fermentation (time zero, 24, and 48 h) and the Simulator of the Human Intestinal Microbiol Ecosystem (SHIME®) (time zero, 72 h, and 7 days). The relative abundance of selected intestinal bacterial groups, pH values, organic acids, and sugars were verified at time zero, 24, and 48 h using flow cytometry and measurements. In addition, the diversity and changes in the gut microbiota, and the amounts of acetic, butyric, and propionic acids and ammonium ions (NH4+) in fermentation using the SHIME® were measured at time zero, 72 h, and 7 days. MNP increased Lactobacillus/Enterococcus and Bifidobacterium populations and decreased Bacteroides/Prevotella, Clostridium histolyticum and Eubacterium rectale/Clostridium coccoides populations (p < 0.05) at 24 and 48 h of static fermentation, showing a positive prebiotic activity score (65.18 ± 0.07). The pH, fructose and glucose decreased, while lactic, butyric, and propionic acids increased (p < 0.05) at 48 h of static fermentation. MNP increased (p < 0.05) the Firmicutes phylum during the fermentation in SHIME®. MNP decreased the diversity at 72 h of fermentation, mostly by the increase (p < 0.05) in the Lactobacillus genus. Microbial groups considered harmful such as Lachnospiraceae, Negativicoccus, and Lachnoclostridium were inhibited after administration with MNP. Propionic and butyric acids increased at 72 h and NH4+ decreased (p < 0.05) at the end of fermentation with MNP. The results indicate MNP as an infant formula which may benefit the gut microbiota of children with ASD.

Microalgae-Sustainable Source for Alternative Proteins and Functional Ingredients Promoting Gut and Liver Health

Dietary proteins derived from animal sources, although containing well-balanced profiles of essential amino acids, have considerable environmental and adverse health effects associated with the intake of some animal protein-based products. Consuming foods based on animal proteins carries a higher risk of developing non-communicable diseases such as cancer, heart disease, non-alcoholic fatty liver disease (NAFLD), and inflammatory bowel disease (IBD). Moreover, dietary protein consumption is increasing due to population growth, posing a supply challenge. There is, therefore, growing interest in discovering novel alternative protein sources. In this context, microalgae have been recognized as strategic crops that can provide a sustainable source of protein. Compared to conventional high-protein crops, using microalgal biomass for protein production presents several advantages in food and feed in terms of productivity, sustainability, and nutritional value. Moreover, microalgae positively impact the environment by not exploiting land or causing water pollution. Many studies have revealed the potential of microalgae as an alternative protein source with the added value of positive effects on human health due to their anti-inflammatory, antioxidant, and anti-cancer properties. The main emphasis of this review is on the potential health-promoting applications of microalgae-based proteins, peptides, and bioactive substances for IBD and NAFLD.

In Vitro Characterization of Limosilactobacillus reuteri Lac Ib01 (OL468126.1) Isolated from Traditional Sheep Dry Sausage and Evaluation of the Activity of Arthrospira platensis or Phycocyanin on Its Growth-Promoting Ability

The positive impact of probiotic strains on human health is more evident than ever. To achieve the beneficial health effects and desirable functional properties of probiotics, sufficient numbers of these microorganisms must reach the intestinal tract with high survival rates. The purpose of this study was to identify and characterize a novel strain of Limosilactobacillus reuteri isolated from traditional sheep dry sausage and evaluate its growth-promoting ability with the addition of Arthrospira platensis or phycocyanin extract. In vitro experimental approaches were conducted to determine the physiological features of the candidate probiotic isolate, including biochemical identification, 16S rRNA gene sequencing, tolerance assays to acid and bile salts, antimicrobial activities, adherence ability, and antiproliferative assays. The effects of A. platensis or phycocyanin (0, 1, 5, and 8 mg/mL) on the growth of probiotic cultures were studied after 0, 24, 48, and 72 h. Our results showed that the isolated Limosilactobacillus reuteri (OL468126.1) possesses desirable characteristics as a probiotic candidate and can, therefore, be used as an ingredient in functional foods. Furthermore, A. platensis and phycocyanin extract have great potential for enhancing the growth and prolonging the stationary phase of isolated probiotics. Our findings showed that phycocyanin extract not only plays the role of a natural pigment but also acts as a growth promoter of probiotics.

Arthrospira platensis (Spirulina) fortified functional foods ameliorate iron and protein malnutrition by improving growth and modulating oxidative stress and gut microbiota in rats

The present study was aimed at developing Arthrospira platensis (Spirulina) fortified traditional foods of the Indian subcontinent, namely sattu (multigrain beverage mix) and chikki (peanut bar) and evaluating their ability to promote recovery from protein and iron deficiency anaemia (IDA) using albino Wistar rats. Addition of Spirulina (at 4% w/w Spirulina inclusion levels) enriched the protein content by 20.33% in sattu and 15.65% in chikki while the iron content was enhanced by 45% in sattu and 29.6% in chikki. In addition, the total carotenoid and polyphenol content and antioxidant capacity of the food products improved after Spirulina incorporation. Supplementation of 100 g of Spirulina fortified food products meets more than 50% of recommended dietary allowances (RDA) of protein, dietary fiber, iron and zinc for the age group 3 to 10 years of children. Spirulina contributed between 11% and 22% of RDA for protein and iron, respectively; however it contributed very negligibly to RDA of dietary fibre with respect to the nutrient requirements for the target age group. Supplementation of Spirulina fortified foods individually promoted bodyweight gain in malnourished rats and restored haemoglobin, serum protein, albumin, serum iron, and hepcidin levels and reduced the iron binding capacity indicating recovery from IDA. Spirulina supplementation ameliorated malnutrition induced oxidative stress in the liver, spleen and kidneys by reducing the lipid peroxidation and enhancing superoxide dismutase and glutathione activities. Histopathological analysis revealed that supplementation of Spirulina fortified foods reversed pathological changes such as fatty changes in the liver cells, thinning of cardiac muscle fibers and degeneration of intestinal villi. Fe-protein deficiency significantly altered the gut microflora by reducing the abundance of beneficial microbes. However, supplementation of Spirulina fortified foods improved the levels of beneficial gut microbes such as Lactobacillus reuteri and Akkermansia muciniphila while reducing the abundance of Helicobacteraceae, Enterobacteria and Clostridia. In summary, supplementation of Spirulina fortified foods promoted recovery from protein and iron deficiency indicating the bioavailability of nutrients (iron and protein) from Spirulina at par with casein and ferrous ascorbate.

Functional Fermented Milk with Fruit Pulp Modulates the In Vitro Intestinal Microbiota

The effect of putative probiotic fermented milk (FM) with buriti pulp (FMB) or passion fruit pulp (FMPF) or without fruit pulp (FMC) on the microbiota of healthy humans was evaluated. FM formulations were administered into a simulator of the human intestinal microbial ecosystem (SHIME^®) to evaluate the viability of lactic acid bacteria (LAB), microbiota composition, presence of short-chain fatty acids (SCFA), and ammonium ions. The probiotic LAB viability in FM was affected by the addition of the fruit pulp. Phocaeicola was dominant in the FMPF and FMB samples; Bifidobacterium was related to FM formulations, while Alistipes was associated with FMPF and FMB, and Lactobacillus and Lacticaseibacillus were predominant in FMC. Trabulsiella was the central element in the FMC, while Mediterraneibacter was the central one in the FMPF and FMB networks. The FM formulations increased the acetic acid, and a remarkably high amount of propionic and butyric acids were detected in the FMB treatment. All FM formulations decreased the ammonium ions compared to the control; FMPF samples stood out for having lower amounts of ammonia. The probiotic FM with fruit pulp boosted the beneficial effects on the intestinal microbiota of healthy humans in addition to increasing SCFA in SHIME^® and decreasing ammonium ions, which could be related to the presence of bioactive compounds.

Obtaining Bioproducts from the Studies of Signals and Interactions between Microalgae and Bacteria

The applications of microalgae biomass have been widely studied worldwide. The classical processes used in outdoor cultivations of microalgae, in closed or open photobioreactors, occur in the presence of bacteria. Understanding how communication between cells occurs through quorum sensing and evaluating co-cultures allows the production of microalgae and cyanobacteria to be positively impacted by bacteria, in order to guarantee safety and profitability in the production process. In addition, the definition of the effects that occur during an interaction, promotes insights to improve the production of biomolecules, and to develop innovative products. This review presents the interactions between microalgae and bacteria, including compounds exchanges and communication, and addresses the development of new pharmaceutical, cosmetic and food bioproducts from microalgae based on these evaluations, such as prebiotics, vegan skincare products, antimicrobial compounds, and culture media with animal free protein for producing vaccines and other biopharmaceutical products. The use of microalgae as raw biomass or in biotechnological platforms is in line with the fulfillment of the 2030 Agenda related to the Sustainable Development Goals (SDGs).

Cultivation of gastrointestinal microbiota in a new growth system revealed dysbiosis and metabolic disruptions in carcinoma-bearing rats

A challenge in the study of gastrointestinal microbiota (GITm) is the validation of the genomic data with metabolic studies of the microbial communities to understand how the microbial networks work during health and sickness. To gain insights into the metabolism of the GITm, feces from healthy and sick rats with cancer were inoculated in a defined synthetic medium directed for anaerobic prokaryote growth (INC-07 medium). Significant differences between cultures of healthy and sick individuals were found: 1) the consumption of the carbon source and the enzyme activity involved in their catabolism (e.g., sucrase, lactase, lipases, aminotransferases, and dehydrogenases); 2) higher excretion of acetic, propionic, isobutyric, butyric, valeric, and isovaleric acids; 3) methane production; 4) ability to form biofilms; and 5) up to 500 amplicon sequencing variants (ASVs) identified showed different diversity and abundance. Moreover, the bowel inflammation induced by cancer triggered oxidative stress, which correlated with deficient antioxidant machinery (e.g., NADPH-producing enzymes) determined in the GITm cultures from sick individuals in comparison with those from control individuals. Altogether, the data suggested that to preserve the microbial network between bacteria and methanogenic archaea, a complete oxidation of the carbon source may be essential for healthy microbiota. The correlation of 16S rRNA gene metabarcoding between cultures and feces, as well as metabolomic data found in cultures, suggest that INC-07 medium may be a useful tool to understand the metabolism of microbiota under gut conditions.