Regulatory Efficacy of Spirulina platensis Protease Hydrolyzate on Lipid Metabolism and Gut Microbiota in High-Fat Diet-Fed Rats

Campylobacter jejuni and casein hydrolysate addition: Impact on poultry in vitro cecal microbiota and metabolome

This study investigates the impact of casein hydrolysates on the poultry ceca inoculated with Campylobacter focusing on microbial molecular preferences for different protein sources in the presence of Campylobacter jejuni. Three casein sources (intact casein (IN), casein enzyme hydrolysate (EH), and casein acid hydrolysate (AH)) were introduced to cecal contents in combination with inoculated C. jejuni in an in vitro model system incubated for 48 h at 42°C under microaerophilic conditions. Samples were collected at 0, 24, and 48 h. Genomic DNA was extracted and amplified using custom dual-indexed primers, followed by sequencing on an Illumina MiSeq platform. The obtained sequencing data were then analyzed via QIIME2-2021.11. Metabolite extracts were analyzed with ultra-high-performance liquid orbitrap chromatography-mass spectrometry (UHPLC-MS). Statistical analysis of metabolites was conducted using MetaboAnalyst 5.0, while functional analysis was performed using Mummichog 2.0 with a significance threshold set at P < 0.00001. DNA sequencing and metabolomic analyses revealed that C. jejuni was most abundant in the EH group. Microbial diversity and richness improved in casein supplemented groups, with core microbial differences observed, compared to non-supplemented groups. Vitamin B-associated metabolites significantly increased in the supplemented groups, displaying distinct patterns in vitamin B6 and B9 metabolism between EH and AH groups (P < 0.05). Faecalibacterium and Phascolarctobacterium were associated with AH and EH groups, respectively. These findings suggest microbial interactions in the presence of C. jejuni and casein supplementation are influenced by microbial community preferences for casein hydrolysates impacting B vitamin production and shaping competitive dynamics within the cecal microbial community. These findings underscore the potential of nutritional interventions to modulate the poultry GIT microbiota for improved health outcomes.

Spirulina versus metformin for controlling some insulin signaling pathway genes in induced polycystic ovary syndrome rat model

Polycystic ovary syndrome (PCOS) is a prevalent endocrinologic and gynecologic disorder that affects women of reproductive age; besides, insulin resistance (IR) occurs in 50-70 % of PCOS cases. Metformin (Met) is commonly prescribed for IR management; however, it does not affect IR with some gastrointestinal symptoms. Spirulina platensis (SP) is a blue-green alga that may increase insulin sensitivity. Therefore, our study aims to evaluate SP as an alternative treatment to Met for improving glucose homeostasis by assessing the expression of 11 crucial genes involved in the insulin signaling pathway. After induction of the PCOS model using dehydroepiandrosterone (DHEA) (60 mg/kg bwt) for 30 consecutive days, rats were allocated into six groups. Relative liver weight, glutamic pyruvic transaminase (GPT) serum levels, glutamic-oxaloacetic transaminase (GOT), and insulin were determined. Furthermore, the gene expression of Ins1, Irs1, Pik3ca, Prkcz, Foxo1, Srebf1, Ppargc1a, Pklr, Gk, G6pc, and Pepck in the rat's liver tissue was determined using qRT-PCR. Treatment of the PCOS control group with Met or SP revealed a decrease in all these parameters compared with the PCOS model. Additionally, we found a statistically significant difference in the expression of both the Gk and Prkcz genes. To summarize our study results, SP or Met supplementation to PCOS rats had almost the same effect on assessed relative liver weight, GOT, GPT, and insulin levels compared with PCOS control rats. If further studies confirm and detect more impact of SP on IR in PCOS, SP could be used instead of Met since the latter causes many side effects.

Beneficial Effects of Spirulina Supplementation in the Management of Cardiovascular Diseases

In recent decades, as a result of rising mortality rates due to cardiovascular diseases (CVDs), there has been a growing urgency to find alternative approaches to conventional pharmaceutical treatment to prevent the onset of chronic diseases. Arthrospira platensis, commonly known as Spirulina, is a blue-green cyanobacterium, classified as a "superfood", used worldwide as a nutraceutical food supplement due to its remarkable nutritional value, lack of toxicity, and therapeutic effects. Several scientific studies have evaluated the cardioprotective role of Spirulina. This article presents a comprehensive review of the therapeutic benefits of Spirulina in improving cardio- and cerebrovascular health. It focuses on the latest experimental and clinical findings to evaluate its antihypertensive, antidiabetic, and antihyperlipidemic properties. The objective is to highlight its potential in preventing and managing risk factors associated with cardiovascular disease (CVD).

Effects of testosterone replacement on lipid profile, hepatotoxicity, oxidative stress, and cognitive performance in castrated wistar rats

OBJECTIVE

Androgen deficiency is associated with multiple biochemical and behavioral disorders. This study investigated the effects of testosterone replacement and Spirulina Platensis association on testosterone deficiency-induced metabolic disorders and memory impairment.

METHODS

Adult male rats were randomly and equally divided into four groups and received the following treatments for 20 consecutive days.

CONTROL GROUP

non-castrated rats received distilled water. Castrated group received distilled water. Testosterone treated group: castrated rats received 0.20 mg of testosterone dissolved in corn oil by subcutaneous injection (i.p.). Spirulina co-treated group: castrated rats received 0.20 mg of testosterone (i.p.) dissolved in corn oil followed by 1000 mg/kg of Spirulina per os.

RESULTS

Data showed that castration induced an increase in plasma ALT, AST, alkaline phosphatase (PAL), cholesterol, and triglycerides level. Castrated rats showed a great elevation in SOD and CAT activities and MDA and H2O2 levels in the prostate, seminal vesicles, and brain. Testosterone deficiency was also associated with alteration of the spatial memory and exploratory behaviour. Testosterone replacement either alone or with Spirulina combination efficiently improved most of these biochemical parameters and ameliorated cognitive abilities in castrated rats.

CONCLUSIONS

Testosterone replacement either alone or in combination with Spirulina improved castration-induced metabolic, oxidative, and cognitive alterations.

Big Things, Small Packages: An Update on Microalgae as Sustainable Sources of Nutraceutical Peptides for Promoting Cardiovascular Health

In 2017, a review of microalgae protein-derived bioactive peptides relevant in cardiovascular disease (CVD) management was published. Given the rapid evolution of the field, an update is needed to illumininate recent developments and proffer future suggestions. In this review, the scientific literature (2018-2022) is mined for that purpose and the relevant properties of the identified peptides related to CVD are discussed. The challenges and prospects for microalgae peptides are similarly discussed. Since 2018, several publications have independently confirmed the potential to produce microalgae protein-derived nutraceutical peptides. Peptides that reduce hypertension (by inhibiting angiotensin converting enzyme and endothelial nitric oxide synthase), modulate dyslipidemia and have antioxidant and anti-inflammatory properties have been reported, and characterized. Taken together, future research and development investments in nutraceutical peptides from microalgae proteins need to focus on the challenges of large-scale biomass production, improvement in techniques for protein extraction, peptide release and processing, and the need for clinical trials to validate the claimed health benefits as well as formulation of various consumer products with the novel bioactive ingredients.

Hypoglycemic effects of different molecular weight konjac glucomannans via intestinal microbiota and SCFAs mediated mechanism

The hypoglycemic effects of konjac glucomannans (KGMs) are well recognized, and our previous study showed KGMs with different molecular weight have different hypoglycemic effects on diabetes rats, but the detailed mechanisms still remain unclear. In this study, KGMs with medium molecular weight (KGM-M, 757.1 kDa) and low molecular weight (KGM-L, 87.3 kDa) were utilized to investigate the possible mechanism on hypoglycemic effects of type 2 diabetic (T2DM) rats. The results revealed that KGM-M had better effects than KGM-L on decreasing fasting blood glucose, mitigating insulin resistance and improving inflammation. Further mechanism analysis showed that KGM-M better enriched gut flora diversity and the abundance of Ruminococcus and Lachnoclostridium, which was accompanied by increased short chain fatty acids (SCFAs) production and expression of G protein-coupled receptors (GPCRs), and improved regulation on bile acid synthesis. Antibiotics treatment eliminated the beneficial effects of KGMs on gut flora, SCFAs, GPCRs and bile acid synthesis. By contrast, fecal microbiota transplantation (FMT) treatment restored the structure of intestinal microbiota. And after FMT treatment, KGM-M displayed higher hypoglycemic activity than KGM-L, probably due to the better effects on intestinal microbiota, SCFAs production, GPCRs expression and bile acid synthesis inhibition.

Exploring the Benefits of Phycocyanin: From Spirulina Cultivation to Its Widespread Applications

Large-scale production of microalgae and their bioactive compounds has steadily increased in response to global demand for natural compounds. Spirulina, in particular, has been used due to its high nutritional value, especially its high protein content. Promising biological functions have been associated with Spirulina extracts, mainly related to its high value added blue pigment, phycocyanin. Phycocyanin is used in several industries such as food, cosmetics, and pharmaceuticals, which increases its market value. Due to the worldwide interest and the need to replace synthetic compounds with natural ones, efforts have been made to optimize large-scale production processes and maintain phycocyanin stability, which is a highly unstable protein. The aim of this review is to update the scientific knowledge on phycocyanin applications and to describe the reported production, extraction, and purification methods, including the main physical and chemical parameters that may affect the purity, recovery, and stability of phycocyanin. By implementing different techniques such as complete cell disruption, extraction at temperatures below 45 °C and a pH of 5.5-6.0, purification through ammonium sulfate, and filtration and chromatography, both the purity and stability of phycocyanin have been significantly improved. Moreover, the use of saccharides, crosslinkers, or natural polymers as preservatives has contributed to the increased market value of phycocyanin.

Recent developments in the production and utilization of photosynthetic microorganisms for food applications

The growing use of photosynthetic microorganisms for food and food-related applications is driving related biotechnology research forward. Increasing consumer acceptance, high sustainability, demand of eco-friendly sources for food, and considerable global economic concern are among the main factors to enhance the focus on the novel foods. In the cases of not toxic strains, photosynthetic microorganisms not only provide a source of sustainable nutrients but are also potentially healthy. Several published studies showed that microalgae are sources of accessible protein and fatty acids. More than 400 manuscripts were published per year in the last 4 years. Furthermore, industrial approaches utilizing these microorganisms are resulting in new jobs and services. This is in line with the global strategy for bioeconomy that aims to support sustainable development of bio-based sectors. Despite the recognized potential of the microalgal biomass value chain, significant knowledge gaps still exist especially regarding their optimized production and utilization. This review highlights the potential of microalgae and cyanobacteria for food and food-related applications as well as their market size. The chosen topics also include advanced production as mixed microbial communities, production of high-value biomolecules, photoproduction of terpenoid flavoring compounds, their utilization for sustainable agriculture, application as source of nutrients in space, and a comparison with heterotrophic microorganisms like yeast to better evaluate their advantages over existing nutrient sources. This comprehensive assessment should stimulate further interest in this highly relevant research topic.

Fish waste to sustainable additives: Fish protein hydrolysates alleviate intestinal dysbiosis and muscle atrophy induced by poultry by-product meal in Lates calcarifer juvenile

Valorising waste from the processing of fishery and aquaculture products into functional additives, and subsequent use in aquafeed as supplements could be a novel approach to promoting sustainability in the aquaculture industry. The present study supplemented 10% of various fish protein hydrolysates (FPHs), obtained from the hydrolysis of kingfish (KH), carp (CH) and tuna (TH) waste, with 90% of poultry by-product meal (PBM) protein to replace fishmeal (FM) completely from the barramundi diet. At the end of the trial, intestinal mucosal barriers damage, quantified by villus area (VA), lamina propria area (LPA), LPA ratio, villus length (VL), villus width (VW), and neutral mucin (NM) in barramundi fed a PBM-based diet was repaired when PBM was supplemented with various FPHs (p &lt; 0.05, 0.01, and 0.001). PBM-TH diet further improved these barrier functions in the intestine of fish (p &lt; 0.05 and 0.001). Similarly, FPHs supplementation suppressed PBM-induced intestinal inflammation by controlling the expression of inflammatory cytokines (tnf-α and il-10; p &lt; 0.05 and 0.001) and a mucin-relevant production gene (i-mucin c; p &lt; 0.001). The 16S rRNA data showed that a PBM-based diet resulted in dysbiosis of intestinal bacteria, supported by a lower abundance of microbial diversity (p &lt; 0.001) aligned with a prevalence of Photobacterium. PBM-FPHs restored intestine homeostasis by enhancing microbial diversity compared to those fed a PBM diet (p &lt; 0.001). PBM-TH improved the diversity (p &lt; 0.001) further by elevating the Firmicutes phylum and the Ruminococcus, Faecalibacterium, and Bacteroides genera. Muscle atrophy, evaluated by fiber density, hyperplasia and hypertrophy and associated genes (igf-1, myf5, and myog), occurred in barramundi fed PBM diet but was repaired after supplementation of FPHs with the PBM (p &lt; 0.05, 0.01, and 0.001). Similarly, creatine kinase, calcium, phosphorous, and haptoglobin were impacted by PBM-based diet (p &lt; 0.05) but were restored in barramundi fed FPHs supplemented diets (p &lt; 0.05 and 0.01). Hence, using circular economy principles, functional FPHs could be recovered from the fish waste applied in aquafeed formulations and could prevent PBM-induced intestinal dysbiosis and muscular atrophy.

GRAPHICAL ABSTRACT

Dietary spirulina supplementation modifies rumen development, fermentation and bacteria composition in Hu sheep when consuming high-fat dietary

Introduction

This study aims to investigate the long-term effects of spirulina supplementation in a high-fat diet (HFD) on rumen morphology, rumen fermentation, and the composition of rumen microbiota in lambs. Spirulina is a blue-green microalgae that has been shown to have high nutritional value for livestock.

Methods

Fifty-four lambs were randomly divided into three groups: a normal chow diet (NCD) group, a high-fat diet (HFD) group, and a high-fat diet supplemented with 3% spirulina (HFD+S) group. Rumen morphology, rumen fermentation, and rumen microbiota were analyzed at the end of the study.

Results

Spirulina supplementation improved the concentration of volatile fatty acids and rumen papilla length. Additionally, there was a tendency for an increase in rumen weight and an upregulation of the genes Claudin-1, Claudin-4, and Occludin in the HFD+S group. Pyrosequencing of the 16S ribosomal RNA gene also showed that spirulina supplementation significantly changed the rumen microbiota composition in the HFD group, with a decrease in richness and diversity. Specifically, the relative abundance of Prevotella 9 and Megasphaera was significantly increased in the HFD group compared to the NCD group, while spirulina supplementation reversed these changes.

Discussion

This study suggests that 3% spirulina supplementation can improve rumen development and fermentation, and effectively relieve rumen microbe disorders in lambs caused by a high-fat diet. However, further research is needed to confirm the findings and to examine the long-term effects of spirulina supplementation in different types of livestock and under different dietary conditions.

Effects of Dietary Supplementation of Spirulina platensis on the Immune System, Intestinal Bacterial Microbiome and Skin Traits of Mink

The impact of dietary inclusion of Spirulina platensis on the immune system, intestinal microbiome and skin of mink was investigated. Forty-eight animals were equally separated into four groups. Groups B and D were control animals, while groups A and C had their feed supplemented daily with 100 mg/kg of body weight Spirulina. Mink in groups A and B were descended from dams supplemented with spirulina during their reproductive period, while those in groups C and D were descended from dams fed the control diets. Fur growth rate and quality were graded semi-quantitatively. Fecal microbiome analysis, skin thickness histomorphometry, immunohistochemical labeling and counts of immune cells in the colon, mesenteric lymph nodes and spleen and quantitative gene expression analysis of cytokines in the colon were performed. Skin thickness, fur growth rate and skin quality were similar among groups (p > 0.05). However, differences were observed among groups concerning the relative and differential abundance of bacterial species. Tgf-β expression was lower in group A, whereas IL-β1 was lower in group C compared to group B (p < 0.05). Group D had significantly lower numbers of inflammatory cells in the colon and mesenteric lymph nodes. The results revealed that Spirulina decreased indices of subclinical inflammation in mink gut, while differences in the bacterial communities among groups were observed.

High fat diet-induced hyperlipidemia and tissue steatosis in rabbits through modulating ileal microbiota

High-fat diet (HFD) and overnutrition are important starting factors that may alter intestinal microbiota, lipid metabolism, and systemic inflammation. However, there were few studies on how intestinal microbiota contributes to tissue steatosis and hyperlipidemia. Here, we investigated the effect of lipid metabolism disorder-induced inflammation via toll-like receptor 2 (TLR-2), toll-like receptor 4 (TLR-4), and nuclear factor-κB (NF-κB) pathways at the intestinal level in response to HFD. Twenty 80-day-old male New Zealand White rabbits were randomly divided into the normal diet group (NDG) and the high-fat diet group (HDG) for 80 days. Growth performance, blood biochemical parameters, lipid metabolism, inflammation, degree of tissue steatosis, and intestinal microbial composition were measured. HFD increased the relative abundance of Christensenellaceae_R_7_group, Marvinbryantia, Akkermansia etc., with a reduced relative abundance of Enterorhabdus and Lactobacillus. Moreover, HFD caused steatosis in the liver and abdominal fat and abnormal expression of some genes related to lipid metabolism and tight junction proteins. The TLR-2, TLR-4, NF-κB, TNF-α, and IL-6 were confirmed by overexpression with downregulation of IL-10. Serum biochemical indices (TG, TCHO, LDL-C, and HDL-C) were also increased, indicating evidence for the development of the hyperlipidemia model. Correlation analysis showed that this microbial dysbiosis was correlated with lipid metabolism and inflammation, which were associated with the intestinal tract's barrier function and hyperlipidemia. These results provide an insight into the relationship between HFD, the intestinal microbiota, intestinal barrier, tissue inflammation, lipid metabolism, and hyperlipidemia. KEY POINTS: • High-fat diet leads to ileal microbiota disorders • Ileal microbiota mediates local and systemic lipid metabolism disorders and inflammation • There is a specific link between ileal microbiota, histopathology, and hyperlipidemia.

Reconfiguration of Gut Microbiota and Reprogramming of Liver Metabolism with Phycobiliproteins Bioactive Peptides to Rehabilitate Obese Rats

Phycobiliproteins (derived from Arthrospira platensis) bioactive peptide extracts (PPE) possess multiple pharmacological effects in the mitigation of human metabolic disorders. The role of PPE in the treatment of diet-induced obesity and the understanding of the underlying mechanism between the gut microbiome and metabolic blood circulation for obese patients remains poorly understood. In this study, we showed that PPE attenuated obesity by reducing body weight, and ameliorated glucose and lipid indexes in serum. In particular, PPE is postulated to mitigate liver steatosis and insulin resistance. On the other hand, dietary treatment with PPE was found to “reconfigure” the gut microbiota in the way that the abundances were elevated for Akkermansia_muciniphila, beneficial Lactobacillus and Romboutsia, SCFA-producing species Faecalibacterium prausnitzii, Lachnospiraceae_bacterium, Clostridiales_bacterium, probiotics Clostridium sp., Enterococcus faecium, and Lactobacillus_johnsonii, while the abundance of Firmicutes was reduced and that of Bacteroidetes was increased to reverse the imbalance of Firmicutes/Bacteroidetes ratio. Finally, the metabolomics of circulating serum using UHPLC-MS/MS illustrated that PPE supplementation indeed promoted lipid metabolism in obese rats. As summary, it was seen that PPE reprogrammed the cell metabolism to prevent the aggravation of obesity. Our findings strongly support that PPE can be regarded as a potential therapeutic dietary supplement for obesity.

Ameliorating Effect on Glycolipid Metabolism of Spirulina Functional Formulation Combination from Traditional Chinese Medicine

Insulin resistance is the major factor involved in the pathogenesis of type 2 diabetes. Although the oral drug metformin (MH) is widely used to reduce hyperglycemia, it is associated with adverse effects. Therefore, there is an urgent need to search for safe and natural foods that do not cause adverse effects as alternatives to commercial drugs. In this study, the active substances from Spirulina platensis, Grifola frondosa, Panax ginseng, and chromium-rich yeast were used to obtain Spirulina functional formulations (SFFs), and its therapeutic effects on mice with glycolipid metabolism disorder (GLD) were investigated. Results showed that SFFs not only improved glycolipid metabolism and reduced inflammation in mice with GLD but also showed good regenerative effects on the liver, jejunum, and cecum tissues. Moreover, SFFs could inhibit the growth of harmful microbes in the intestine and promote the proliferation of beneficial bacteria, thereby promoting the production of short-chain fatty acids and further regulating GLD. Additionally, SFFs significantly increased the expression of INS, INSR, IRS-1, PI3K, AKT-1, and GLUT-4 genes and significantly decreased that of GSK-3β in the INS/PI3K/GLUT-4 signaling pathway. Therefore, the findings of this study suggest that SFFs can be further developed as a new class of therapeutic agents against GLD.

Metabolic Alternations During Gestation in Dezhou Donkeys and the Link to the Gut Microbiota

The maternal intestinal microbial community changes dramatically during pregnancy and plays an important role in animal growth, metabolism, immunity and reproduction. However, our understanding of microbiota compositional dynamics during the whole pregnancy period in donkey is incomplete. This study was carried out to evaluate gut microbiota alterations as well as the correlation with serum biochemical indices, comparing pregnant donkeys to non-pregnant donkeys. A total of 18 pregnant (including EP, early-stage pregnancy; MP, middle-stage pregnancy and LP, late-stage pregnancy) and six non-pregnant (C as a control) donkey blood samples and rectum contents were collected. The results showed that pregnant donkeys had higher microbial richness than non-pregnant donkeys and that the lowest microbial diversity occurred at the EP period. Moreover, the relative abundances of the families Clostridiaceae and Streptococcaceae were significantly higher in the EP group (p < 0.05) than that in the C and MP groups, while the relative abundances of the families Lachnospiraceae and Rikenellaceae were significantly lower in the EP group (p < 0.05) than that in the C group. The predicted microbial gene functions related to the inflammatory response and apoptosis, such as Staphylococcus aureus infection, the RIG-1-like receptor signaling pathway and apoptosis, were mainly enriched in EP. Furthermore, pregnant donkeys had higher glucose levels than non-pregnant donkeys, especially at EP period. EP donkeys had lower triglyceride, total protein and albumin levels but higher malondialdehyde, interleukin 1β, interleukin 6 and tumor necrosis factor-α levels than those in the C and MP groups. Additionally, there were strong correlations between inflammatory cytokine levels and the relative abundances of genera belonging to the Clostridiaceae and Streptococcaceae families. This is the first comparative study performed in donkeys that indicates that pregnancy status (especially in the early pregnancy period) alters the gut microbiota composition, which was correlated with serum biochemical parameters. These results could provide useful information for improving the reproductive management in Dezhou donkeys.

The Functional Interplay between Gut Microbiota, Protein Hydrolysates/Bioactive Peptides, and Obesity: A Critical Review on the Study Advances

Diet is an essential factor determining the ratio of pathogenic and beneficial gut microbiota. Hydrolysates and bioactive peptides have been described as crucial ingredients from food protein that potentially impact human health beyond their roles as nutrients. These compounds can exert benefits in the body, including modulation of the gut microbiota, and thus, they can reduce metabolic disorders. This review summarized studies on the interaction between hydrolysates/peptides, gut microbes, and obesity, focusing on how hydrolysates/peptides influence gut microbiota composition and function that improve body weight. Findings revealed that gut microbes could exert anti-obesity effects by controlling the host’s energy balance and food intake. They also exhibit activity against obesity-induced inflammation by changing the expression of inflammatory-related transcription factors. Protein hydrolysates/peptides can suppress the growth of pro-obesity gut bacteria but facilitate the proliferation of those with anti-obesity effects. The compounds provide growth factors to the beneficial gut bacteria and also improve their resistance against extreme pH. Hydrolysates/peptides are good candidates to target obesity and obesity-related complications. Thus, they can allow the development of novel strategies to fight incidences of obesity. Future studies are needed to understand absorption fate, utilization by gut microbes, and stability of hydrolysates/peptides in the gut under obesity.

Antiaging Potential of Peptides from Underused Marine Bioresources

Aging is a biological process that occurs under normal conditions and in several chronic degenerative diseases. Bioactive natural peptides have been shown to improve the effects of aging in cell and animal models and in clinical trials. However, few reports delve into the enormous diversity of peptides from marine organisms. This review provides recent information on the antiaging potential of bioactive peptides from underused marine resources, including examples that scavenge free radicals in vitro, inhibit cell apoptosis, prolong the lifespan of fruit flies and Caenorhabditis elegans, suppress aging in mice, and exert protective roles in aging humans. The underlying molecular mechanisms involved, such as upregulation of oxidase activity, inhibition of cell apoptosis and MMP-1 expression, restoring mitochondrial function, and regulating intestinal homeostasis, are also summarized. This work will help highlight the antiaging potential of peptides from underused marine organisms which could be used as antiaging foods and cosmetic ingredients in the near future.

Phycocyanin from Arthrospira platensis as Potential Anti-Cancer Drug: Review of In Vitro and In Vivo Studies

The application of cytostatic drugs or natural substances to inhibit cancer growth and progression is an important and evolving subject of cancer research. There has been a surge of interest in marine bioresources, particularly algae, as well as cyanobacteria and their bioactive ingredients. Dried biomass products of Arthrospira and Chlorella have been categorized as “generally recognized as safe” (GRAS) by the US Food and Drug Administration (FDA). Of particular importance is an ingredient of Arthrospira: phycocyanin, a blue-red fluorescent, water-soluble and non-toxic biliprotein pigment. It is reported to be the main active ingredient of Arthrospira and was shown to have therapeutic properties, including anti-oxidant, anti-inflammatory, immune-modulatory and anti-cancer activities. In the present review, in vitro and in vivo data on the effects of phycocyanin on various tumor cells and on cells from healthy tissues are summarized. The existing knowledge of underlying molecular mechanisms, and strategies to improve the efficiency of potential phycocyanin-based anti-cancer therapies are discussed.

Antibiotic affects the gut microbiota composition and expression of genes related to lipid metabolism and myofiber types in skeletal muscle of piglets

BACKGROUND

Early-life antibiotic administration is known to affect gut microbiota and host adiposity, but the effects of antibiotic exposure on skeletal muscle properties remain unknown. The present study evaluated the changes in skeletal muscle properties including myofiber characteristics and composition, as well as intramuscular fat (IMF) content in skeletal muscle of piglets when exposed to a tylosin-containing diet.

RESULTS

A total of 18 piglets (28 days of age) were randomly allocated into two groups: control basal diet (Control) and Control + 100 mg tylosin phosphate/kg of feed (Antibiotic). The trial lasted for 39 days. High-throughput amplicon sequencing revealed that no significant difference in initial gut microbiota composition was existed between Control and Antibiotic groups. Antibiotic administration increased body weight and growth rate and decreased feed to gain ratio of pigs (P < 0.05). The carcass lean and fat volumes of pigs were increased by the tylosin administration (P < 0.05). Antibiotic treatment increased myofiber density and the expression of genes related to type I and type IIb myofibers in longissimus muscle (P < 0.05). The IMF content in longissimus muscle was increased by antibiotic exposure (P < 0.05). Antibiotic administration increased expression of genes related to fatty acid uptake and de novo synthesis, and decreased expression of genes related to triglyceride hydrolysis (P < 0.05). Tylosin administration affected taxonomic distribution and beta diversity of the caecal and colonic microbiota of piglets.

CONCLUSION

These results confirm that the growth performance, myofiber composition and muscle lipid metabolism are affected by antibiotic administration, which may be associated with an altered gut microbiota, suggesting that the gut microbiota could be served as a potential target for modulating skeletal muscle properties of host.

Spirulina platensis alleviates chronic inflammation with modulation of gut microbiota and intestinal permeability in rats fed a high-fat diet

Recent research suggested that taking a high-fat diet (HFD) may lead to a gut microbiota imbalance and colon tissue damage. This would lead to increased intestinal permeability and consequent constant circulation of low-grade inflammatory cytokines. Spirulina platensis can protect against HFD-induced metabolic inflammation and can stimulate the growth of beneficial bacteria in in vitro stool cultures. However, it is unknown whether this beneficial effect acts on intestinal tissues. In this study, rats were fed a high-fat diet fed with 3% S platensis for 14 weeks. We analysed endotoxin, the composition of the microbiota, inflammation and gut permeability. We found that S platensis decreased the bodyweight and visceral fat pads weight of the HFD-fed rats. In addition, it lowered the levels of lipopolysaccharide and pro-inflammatory cytokines in serum. Our results showed that S platensis could largely reduce the relative amount of Proteobacteria and the Firmicutes/Bacteroidetes ratio in faecal samples from HFD-fed rats. S platensis significantly reduced intestinal inflammation, as shown by decreased expression of myeloid differentiation factor 88 (MyD88), toll-like receptor 4 (TLR4), NF-κB (p65) and inflammatory cytokines. S platensis also ameliorated the increased permeability and decreased expression of tight junction proteins in the intestinal mucosa, such as ZO-1, Occludin and Claudin-1. Therefore, in HFD-induced gut dysbiosis rats, S platensis benefits health by inhibiting chronic inflammation and gut dysbiosis, and modulating gut permeability.

Phocea, Pseudoflavonifractor and Lactobacillus intestinalis: Three Potential Biomarkers of Gut Microbiota That Affect Progression and Complications of Obesity-Induced Type 2 Diabetes Mellitus

PURPOSE

The purpose of this study was to explore the difference and association between intestinal microbiota and plasma metabolomics between type 2 diabetes mellitus (T2DM) and normal group and to identify potential microbiota biomarkers that contribute the most to the difference in metabolites.

METHODS

Six male ZDF model (fa/fa) rats were fed by a Purina #5008 Lab Diet (crude protein 23.5%, crude fat 6.5%) for 3 weeks and their age-matched 6 ZDF control (fa/+) rats were fed by normal rodent diet. Their stool and blood samples were collected at 12 weeks. To analyze the microbial populations in these samples, we used a 16S rRNA gene sequencing approach. Liquid chromatography-mass spectrometry (LC-MS) followed by multivariate statistical analysis was applied to the plasma metabolites profiling. Correlation analysis of them was calculated by Pearson statistical method.

RESULTS

Twelve potential biomarkers of intestinal microbial flora and 357 differential metabolites were found in ZDF fa/fa rats, among which there are three flora that contributed the most to the perturbation of metabolites, including genus Phocea, Pseudoflavonifractor and species Lactobacillus intestinalis.

CONCLUSION

Our study demonstrates the alterations of the abundance and diversity of the intestinal microbiota and the perturbation of metabolites in ZDF rats (fa/fa). We found three potential biomarkers of intestinal microbiota that may lead to perturbation in plasma metabolites. This may prompt new pathogenesis of obesity-related T2DM, but we also need to study further about the causal relationship between intestinal microbe and T2DM, so as to find the target of T2DM treatment or preventive measures.

Recent Advances in Microalgae Peptides: Cardiovascular Health Benefits and Analysis

There is now great interest in food protein hydrolysates and food-derived peptides, because they may provide numerous health benefits. Among other foodstuffs, microalgae appear to be sustainable sources of proteins and bioactive peptides that can be exploited in foods and functional formulations. This review considers protein hydrolysates and individual peptides that may be relevant in cardiovascular disease prevention because they mimic the functions of mediators involved in pathologic processes that represent relevant risk factors for cardiovascular disease development, such as hypercholesterolemia, hypertension, diabetes, inflammation, and oxidative status. Some of these peptides are also multifunctional (i.e., they offer more than one benefit). Moreover, the most efficient techniques for protein extraction and hydrolyzation are commented on, as well as the best methodologies for high-throughput detection and quantification. Finally, current challenges and critical issues are discussed.

Effects of Spirulina supplementation on obesity: A systematic review and meta-analysis of randomized clinical trials

OBJECTIVE

Evidence has suggested that Spirulina supplementation may affect anthropometric indices. Therefore, a systematic review and meta-analysis was performed to summarize published randomized clinical trials which assess the effect of Spirulina supplementation on obesity.

SETTING

Pertinent studies were identified using Embase, Scopus, ISI Web of Science, PubMed and Cochrane library databases up to May 2019. Mean Differences (MD) were pooled using a random-effects model. Heterogeneity, sensitivity analysis and publication bias were reported using standard methods.

RESULTS

Results of 5 studies (7 treatment arms) showed a significant reduction in weight (MD: -1.56 Kg, 95% CI: -1.98 to -1.14) after Spirulina supplementation. Subgroup analysis based on health status revealed that weight change in obese subjects (MD: -2.06 Kg, 95% CI: -2.45 to -1.68) was greater than overweight participants (MD: -1.28 Kg, 95% CI: -1.62 to -0.93) following Spirulina supplementation. Also, pooled analysis showed that Spirulina supplementation led to a significant reduction in body fat percent (MD: -1.02, 95% CI: -1.49 to -0.54) and waist circumference (MD: -1.40, 95% CI: -1.40 to -1.39), but not in body mass index and waist to hip ratio.

CONCLUSION

Spirulina supplementation significantly reduces body weight, especially in obese individuals.

High-dose Glycerol Monolaurate Up-Regulated Beneficial Indigenous Microbiota without Inducing Metabolic Dysfunction and Systemic Inflammation: New Insights into Its Antimicrobial Potential

Glycerol monolaurate (GML) has potent antimicrobial and anti-inflammatory activities. The present study aimed to assess the dose-dependent antimicrobial-effects of GML on the gut microbiota, glucose and lipid metabolism and inflammatory response in C57BL/6 mice. Mice were fed on diets supplemented with GML at dose of 400, 800 and 1600 mg kg-1 for 4 months, respectively. Results showed that supplementation of GML, regardless of the dosages, induced modest body weight gain without affecting epididymal/brown fat pad, lipid profiles and glycemic markers. A high dose of GML (1600 mg kg-1) showed positive impacts on the anti-inflammatory TGF-β1 and IL-22. GML modulated the indigenous microbiota in a dose-dependent manner. It was found that 400 and 800 mg kg-1 GML improved the richness of Barnesiella, whereas a high dosage of GML (1600 mg kg-1) significantly increased the relative abundances of Clostridium XIVa, Oscillibacter and Parasutterella. The present work indicated that GML could upregulate the favorable microbial taxa without inducing systemic inflammation and dysfunction of glucose and lipid metabolism.

Effect of Chlorella Pyrenoidosa Protein Hydrolysate-Calcium Chelate on Calcium Absorption Metabolism and Gut Microbiota Composition in Low-Calcium Diet-Fed Rats

In our current investigation, we evaluated the effect of Chlorella pyrenoidosa protein hydrolysate (CPPH) and Chlorella pyrenoidosa protein hydrolysate-calcium chelate (CPPH-Ca) on calcium absorption and gut microbiota composition, as well as their in vivo regulatory mechanism in SD rats fed low-calcium diets. Potent major compounds in CPPH were characterized by HPLC-MS/MS, and the calcium-binding mechanism was investigated through ultraviolet and infrared spectroscopy. Using high-throughput next-generation 16S rRNA gene sequencing, we analyzed the composition of gut microbiota in rats. Our study showed that HCPPH-Ca increased the levels of body weight gain, serum Ca, bone activity, bone mineral density (BMD) and bone mineral content (BMC), while decreased serum alkaline phosphatase (ALP) and inhibited the morphological changes of bone. HCPPH-Ca up-regulated the gene expressions of transient receptor potential cation V5 (TRPV5), TRPV6, calcium-binding protein-D9k (CaBP-D9k) and a calcium pump (plasma membrane Ca-ATPase, PMCA1b). It also improved the abundances of Firmicutes and Lactobacillus. Bifidobacterium and Sutterella were both positively correlated with calcium absorption. Collectively, these findings illustrate the potential of HCPPH-Ca as an effective calcium supplement.